Report on the Radiolaria/Phaeosphaeria
Order II. PHÆOSPHÆRIA, Haeckel, 1879.
Definition.—Phæodaria with a simple or double, usually spherical lattice-shell, which is not bivalved and has no peculiar mouth or peristome. Central capsule placed in the centre of the shell.
Definition.—Phæodaria with a big spherical (sometimes polyhedral or ellipsoidal), very coarse shell, which is composed of thick bars containing an axial canal. Nodal points of the coarse network without astral septa. Meshes of moderate size, irregularly polygonal. Surface of the shell usually with radial spines and pyramidal elevations. No peculiar mouth in the shell. Central capsule tripylean, in the centre of the shell.
The family Orosphærida comprises those Phæodaria which possess a simple spherical or polyhedral lattice-shell, composed of hollow, very thick, non-articulate rods, without a peculiar shell-mouth. They agree in the considerable size of the spherical lattice-shell and the absence of a peculiar shell-mouth with the other Phæosphæria, but differ from them in the coarse and irregular shape of the massive network, which is composed of irregular polygonal meshes, separated by very thick concentrically stratified rods, containing a fine axial canal. The closely allied Sagosphærida differ from them in the delicate shape of the solid and very thin, filiform rods of the network, and its subregular triangular meshes. The Aulosphærida differ in the development of the peculiar nodal cavities and astral septa, by which the thin-walled cylindrical tubes of the articulated network are separated in the stellate nodal points. The Cannosphærida, closely allied to these latter, also differ in the articulated network, and further in the possession of an internal concentric shell. The Castanellida are sometimes similar to the Orosphærida, but distinguished by a peculiar large shell-mouth and a network of different shape.
The Orosphærida belong to the biggest Radiolaria, and the lattice-work of their spherical shell is of a ruder and coarser shape than in any of the other families of this class. Nevertheless they have been hitherto perfectly unknown, and were first discovered by the Challenger. We have been able to distinguish in the collection four genera and twenty-seven species. This strange fact may be explained by the circumstance, that they are in general rare, and restricted to a few localities, and that probably all the species are inhabitants of great depths. Complete shells also are rarely found, whilst broken fragments of their big shells, easily recognisable by the coarse irregular meshes and the thick stratified bars, are met with frequently in the Radiolarian ooze of some Pacific Stations, especially at Stations 265 and 268, at a depth of 2900 fathoms.
The lattice-shell of the Orosphærida is usually spherical, or an endospherical polyhedron (Pl. 106, fig. 4); rarely one axis is somewhat prolonged, so that the shell becomes slightly ellipsoidal (Pl. 106, fig. 1). Its diameter is usually between 2 and 3, often also between 2 and 1 mm., rarely more than 3, or less than 1 mm. The largest shells observed attained 5 to 6, the smallest 0.5 to 0.6 mm. Their general habit is very characteristic, so that they may be easily distinguished from all other spherical lattice-shells, especially from the Castanellida and from the simple Monosphærida (Cenosphæra, Acanthosphæra), with which I confounded them in the beginning (hence the first shell observed, figured in 1878, was placed among the Monosphærida in Pl. 12). A closer examination of the coarse network and of the peculiar structure of its thick bars always enables one to recognise even small isolated fragments of broken shells.
The meshes of the coarse network exhibit in all observed Orosphærida a very irregular form and unequal size; the majority are usually more or less quadrangular, more rarely they are triangular, pentagonal or hexagonal, very rarely rounded. They are often arranged in parallel rows, which seem to be determined by prominent crests, connecting the bases of the radial spines (Pl. 12, fig. 1; Pl. 106, fig. 4, &c.). The diameter of the meshes is usually between 0.05 and 0.1, often 0.1 to 0.2, rarely more than 0.25, or less than 0.025 mm. In Oroplegma, which develops an outer loose, spongy shell around the inner primary shell, the big meshes of the former become much larger and very irregular (Pl. 107, fig. 1).
The coarse bars which separate the large meshes of the irregular network are very thick and massive, cylindrical, usually of unequal thickness, straight or slightly curved, never angular or prismatic. Their diameter is usually between 0.01 and 0.02, rarely more than 0.03 or less than 0.005 mm. Their surface is either smooth or slightly spinulate. Examined in the dry state and by strong lenses, they constantly exhibit a fine, but distinct longitudinal striation, as the expression of concentric stratification. A fine axial canal or central tubule is usually visible in the axis of each rod, and often this axial canal is studded with numerous short lateral branches (Pl. 107, figs. 2, 4, 8). But very often the axial canals become rudimentary or lost, or are developed only in a part of the bars (Pl. 12, fig. 1). When they are completely developed, the entire network of the shell is drained by a reticulate system of communicating axial canals; they are probably filled by jelly in the living body. This tubular system never attains that regularity and high development which is constantly found in the Aulosphærida; and the characteristic stellate nodal points of the latter, with their astral septa, are never found in any of the Orosphærida. Moreover the wall of the tubular bars is very thin and structureless in the Aulosphærida, very thick and stratified in the Orosphærida, the enclosed canal very wide in the former, very narrow in the latter. The stratification of the concentric cylindrical lamellæ, which surround the narrow axial canal, is effected by the gradual deposition of the concentric layers, and is very similar to that which is found in the thick spicula of many sponges. The peculiar structure of the bars in the Orosphærida becomes very distinct if the skeleton be burned, or acted upon by fire for some time; it then assumes a brown colour and its surface often appears dimpled. Sometimes the concave dimples on the surface of the bars are rather deep and separated by prominent crests (Pl. 107, figs. 4, 7). The few genera of Orosphærida which are here distinguished have all the same structure, are closely allied, and differ mainly in the shape of the outer surface of the lattice-sphere. The latter is quite simple and smooth only in Orona. In the common Orosphæra (Pl. 106, figs. 1-3) it is studded with radial spines. In the most frequent form, Oroscena, the shell has a pyramidal or tent-shaped elevation on the base of each radial spine, and usually the bases of the neighbouring spines are connected by strong prominent crests, the edges of the three-sided or four-sided pyramids (Pl. 12, fig. 1; Pl. 106, fig. 4). This remarkable form is more or less polyhedral, with concave sides, and is similar to the characteristic shells which are represented by Auloscena among the Aulosphærida, by Sagoscena and Sagoplegma among the Sagosphærida (compare Pls. 108 and 110). The pyramids or tents, however, are in these latter more regularly and distinctly developed than in the Orosphærida. The radial spines which arise form the top of the pyramids are often branched, and the branches become connected to form an outer enveloping secondary shell or a loose spongy framework in Oroplegma (Pl. 107, fig. 1).
The radial spines of the Orosphærida never exhibit a constant number or disposition in the individual species; their usual number is from twenty to sixty. Their form exhibits two different types, which, however, are not sharply separated; robust club-shaped and slender rod-shaped spines. The robust club-shaped spines are usually about as long as the diameter of the shell; they are longitudinally striped in the basal part, spinulate or reticulately dimpled in the distal part; sometimes they are straight, at other times curved or undulate (Pl. 106, figs. 1-4; Pl. 107, figs. 4-6). The slender rod-shaped spines are usually longer than the diameter of the shell, cylindrical, more or less curved or even undulate, smooth or thorny, sometimes irregularly branched, and often the branches are all or partly connected (Pl. 106, fig. 3; Pl. 107, fig. 1). In the majority of the shells observed the radial spines were found to be partly broken off. Their structure is the same as that of the bars of the network; but the central axial canal and the surrounding concentric lamellæ are usually more distinct than in the latter.
The central capsule of the Orosphærida lies in the centre of the spherical lattice-shell, surrounded by the voluminous calymma, which fills up its cavity. The form, structure, and size of the central capsule are the same as in the closely allied Aulosphærida (Pl. 111, fig. 2). Its diameter is usually about 0.2, or between 0.15 and 0.25, rarely more than 0.3 or less than 0.12. The dark phæodium is of about the same volume as the central capsule, and envelops its oral half with the radiate operculum and the proboscis of the astropyle. The two opposite parapylæ are small.
Synopsis of the Genera of Orosphærida.
| I. Subfamily Oronida. Surface of the shell without pyramidal or tent-shaped elevations. | Surface smooth, without radial spines, | 671. Orona. | |
| Surface studded with simple or branched radial spines, | 672. Orosphæra. | ||
| II. Subfamily Oroscenida. Surface of the shell with numerous pyramidal or tent-shaped elevations. | Pyramids of the surface free, without spongy envelope, | 673. Oroscena. | |
| Pyramids of the surface connected by a spongy envelope or an external lattice-shell, | 674. Oroplegma. |
Genus 671. Orona,[1] n. gen.
Definition.—Orosphærida with a simple spherical or slightly ellipsoidal shell, without pyramidal elevations and radial spines.
The genus Orona is the simplest of the Orosphærida, and probably the common ancestral form of this family. The lattice-shell is a simple fenestrated sphere, sometimes slightly ellipsoidal, with prolonged main axis, and bears on its surface neither tent-shaped elevations nor radial spines. It may be confounded with some big forms of Cenosphæra; it differs, however, in the possession of hollow central canals in the thick bars of the very coarse lattice-plate.
1. Orona maxima, n. sp. (Pl. 107, fig. 5).
Shell spherical, with very irregular polygonal meshes. Bars of the loose network smooth or slightly spinulate, very thick, with a pinnulate axial canal.
Dimensions.—Diameter of the sphere 5.0 to 5.5, of the meshes 0.2 to 0.4, of the bars 0.01.
Habitat.—Central Pacific, Station 265, depth 2900.
2. Orona robusta, n. sp.
Shell spherical, with irregular quadrangular meshes (intermingled with single triangular, pentagonal, and hexagonal meshes). Bars of the coarse network very thick, spinulate.
Dimensions.—Diameter of the sphere 3.0 to 3.6, of the meshes 0.05, of the bars 0.012.
Habitat.—Central Pacific, Station 268, depth 2900 fathoms.
3. Orona crassissima, n. sp. (Pl. 107, fig. 7).
Shell ellipsoidal, slightly prolonged in the main axis, with irregular polygonal meshes of very different sizes and unequal forms. Bars of the coarse network very thick, thorny and dimpled, their surface being covered with a network of prominent polygonal crests.
Dimensions.—Diameter of the sphere 3.0 to 4.0, of the meshes 0.2 to 0.5, of the bars 0.02 to 0.06.
Habitat.—South Pacific, Station 289, depth 2550 fathoms.
Genus 672. Orosphæra,[2] n. gen.
Definition.—Orosphærida with a simple, spherical (sometimes slightly ellipsoidal or polyhedral) lattice-shell without pyramidal elevations, but with numerous radial spines.
The genus Orosphæra differs from the preceding Orona, its ancestral form, in the development of simple or branched radial spines. It bears, therefore, the same relation to the latter that Acanthosphæra has to Cenosphæra. In the two latter genera, however, the bars of the network are solid, in the two former hollow. The species referred to Orosphæra are closely allied and require a further accurate examination.
Subgenus 1. Oronium, Haeckel.
Definition.—Radial spines simple, smooth or spiny, but neither branched nor arborescent.
1. Orosphæra hastigera, n. sp.
Radial spines cylindrical, straight, smooth, simple, about as long as the diameter of the spherical shell, and as broad as its smooth bars. Meshes of the network irregularly polygonal, the majority quadrangular, of different sizes.
Dimensions.—Diameter of the sphere 1.0 to 1.2, length of the radial spines 1.1 to 1.5, middle breadth 0.004.
Habitat.—Central Pacific, Station 272, depth 2600 fathoms.
2. Orosphæra spinigera, n. sp.
Radial spines cylindrical, irregularly curved, thorny, simple, two to three times as long as the diameter of the spherical shell, and as broad as its spiny bars. Meshes of the network irregularly polygonal, the majority pentagonal.
Dimensions.—Diameter of the sphere 1.5 to 1.8, length of the spines 3.0 to 5.0, breadth 0.006.
Habitat.—North Atlantic, Station 353, depth 2965 fathoms.
3. Orosphæra fusigera, n. sp.
Radial spines slender, spindle-shaped, straight, smooth, about as long as the diameter of the spherical or slightly ellipsoidal shell, in the thicker middle part five times as broad as the bars, and tapering equally towards both ends. Meshes of the network irregularly polygonal, the majority quadrangular, separated by smooth bars.
Dimensions.—Diameter of the shell 1.0 to 1.2, length of the spines 1.2 to 1.6, basal breadth 0.02, middle breadth 0.1.
Habitat.—North Pacific, Station 253, depth 3125 fathoms.
4. Orosphæra foveolata, n. sp.
Radial spines spindle-shaped, straight, dimpled, half as long as the radius of the spherical shell and three to five times as thick as the bars. Meshes irregular, polygonal, of very different shapes, separated by dimpled bars. (Similar to Oroscena gegenbauri, Pl. 106, fig. 4, but with spherical dimpled shell, without pyramidal elevations.)
Dimensions.—Diameter of the shell 2.0 to 2.4, length of the spines 0.5, breadth 0.15.
Habitat.—Central Pacific, Station 267, depth 2700 fathoms.
5. Orosphæra serpentina, n. sp. (Pl. 106, fig. 1).
Radial spines cylindrical, dimpled, undulate or curved in a snake-like manner, about as long as the diameter of the ellipsoidal or spherical shell and four to six times as broad as its smooth bars. Meshes very irregular, polygonal.
Dimensions.—Diameter of the shell 1.0 to 1.2, length of the spines 0.12 to 0.15, breadth 0.12.
Habitat.—South Pacific, Station 289, depth 2550 fathoms.
6. Orosphæra horrida, n. sp. (Pl. 106, fig. 2).
Radial spines club-shaped, very strong, straight, about as long as the diameter of the polyhedral shell, ovate and smooth in the distal half, slenderly conical, and armed with recurved spines in the proximal half; their outer third is the thickest, and five times as broad as the smooth bars of the coarse network. Meshes of the latter irregularly quadrangular.
Dimensions.—Diameter of the shell 1.2 to 1.6, length of the spines 1.2 to 2.0, breadth 0.2.
Habitat.—South Pacific, Station 291, depth 2250 fathoms.
7. Orosphæra clavigera, n. sp.
Radial spines club-shaped, thickened towards the distal end, more or less curved, spinulate, about as long as the diameter of the spherical shell; in the distal third four to six times as broad as the spinulate bars. Meshes irregularly polygonal, the majority pentagonal.
Dimensions.—Diameter of the shell 2.0 to 2.5, length of the spines 1.8 to 2.2, breadth 0.16.
Habitat.—Central Pacific, Station 263, depth 2650 fathoms.
Subgenus 2. Orothamnus, Haeckel.
Definition.—Radial spines branched or arborescent.
8. Orosphæra ramigera, n. sp.
Radial spines cylindrical, spinulate, straight, about twice as long as the diameter of the spherical shell and as thick as its spinulate bars. Numerous simple spinulate branches, straight or slightly curved, and two to four times as long as the meshes, are irregularly scattered, and arise nearly perpendicularly from the bars.
Dimensions.—Diameter of the shell 2.0 to 2.2, length of the spines 4 to 5, breadth 0.05.
Habitat.—South Atlantic, Station 332, depth 2200 fathoms.
9. Orosphæra furcata, n. sp.
Radial spines cylindrical, smooth, irregularly curved, about as long as the radius of the spherical shell and as thick as its smooth bars, forked at the distal end, with two or three terminal branches of various lengths. Meshes irregularly polygonal (the majority hexagonal).
Dimensions.—Diameter of the shell 1.2, length of the spines 0.7, breadth 0.03.
Habitat.—Indian Ocean, Madagascar (Rabbe), surface (?).
10. Orosphæra confluens, n. sp.
Radial spines cylindrical, smooth, irregularly curved, two to three times as long as the diameter of the polyhedral shell, twice as broad as its smooth bars, bearing numerous irregular, lateral branches, which are partly confluent and fenestrated (similarly as in Pl. 107, fig. 1), but not forming an outer lattice-shell. Meshes irregularly polygonal.
Dimensions.—Diameter of the shell 3.3, length of the spines 6 to 9, breadth 0.03.
Habitat.—Tropical Atlantic, Station 347, depth 2250 fathoms.
11. Orosphæra arborescens, n. sp. (Pl. 106, fig. 3).
Radial spines cylindrical, rough, more or less curved, somewhat longer than the diameter of the subspherical or slightly ellipsoidal shell, and at the thicker base three times as broad as its smooth bars, bearing numerous irregularly branched and curved, sometimes confluent, lateral branches. Meshes irregularly quadrangular.
Dimensions.—Diameter of the shell 1.2 to 1.6, length of the spines 1.5 to 2.2, breadth 0.06.
Habitat.—South Atlantic, Station 335, depth 1425 fathoms.
Genus 673. Oroscena,[3] n. gen.
Definition.—Orosphærida with a simple, polyhedral or subspherical lattice-shell, and with numerous pyramidal elevations on its surface, the top of which bears a radial spine.
The genus Oroscena differs from the preceding Orosphæra in the possession of numerous pyramidal or tent-shaped elevations, each of which bears on its top a radial spine. It exhibits therefore the same relation to the latter that Sagoscena does to Sagosphæra and Auloscena to Aulosphæra. The bases of the radial spines are usually connected by prominent concave crests, the edges of the pyramids. The species described of Oroscena seem to be very variable and transformistic.
Subgenus 1. Oroscenium, Haeckel.
Definition.—Radial spines simple, smooth or spiny, but neither branched nor forked.
1. Oroscena gegenbauri, n. sp. (Pl. 106, fig. 4).
Radial spines club-shaped, about half as long as the radius of the shell, cylindrical and finely sulcate in the basal third, ovate and elegantly dimpled in the distal two-thirds. The bases of the radial spines are connected by prominent concave crests, which form the edges of the polyhedral shell. Meshes irregularly polygonal, the majority quadrangular, separated by denticulate bars.
Dimensions.—Diameter of the shell (without spines) 1.2 to 1.8, of the meshes 0.04 to 0.1; length of the spines 0.3 to 0.5.
Habitat.—Central Pacific, Station 268, depth 2900 fathoms.
2. Oroscena mülleri, n. sp. (Pl. 107, fig. 8).[4]
Radial spines club-shaped, very similar to that of the preceding species, but much larger, about as long as the radius of the shell. Meshes irregularly polygonal, the majority pentagonal, separated by smooth bars.
Dimensions.—Diameter of the shell 2.0 to 2.4, length of the spines 1.0 to 1.2.
Habitat.—Central Pacific, Station 265, depth 2900 fathoms.
3. Oroscena cuvieri, n. sp. (Pl. 107, fig. 6).
Radial spines club-shaped, compressed and smooth in the proximal half, spindle-shaped and dimpled in the distal half, about as long as the radius of the shell. Meshes irregularly polygonal, the majority hexagonal, separated by denticulate bars.
Dimensions.—Diameter of the shell 1.5, length of the spines 0.8.
Habitat.—South Pacific, Station 289, depth 2550 fathoms.
4. Oroscena bærii, n. sp. (Pl. 107, fig. 4).
Radial spines nearly spindle-shaped, undulate, tapering from the thicker middle towards both ends, coarsely dimpled, about one-third as long as the radius of the shell. Meshes irregularly polygonal, the majority pentagonal, separated by spinulate bars.
Dimensions.—Diameter of the shell 3.2, length of the spines 1.0 to 1.2, breadth 0.1.
Habitat.—North Pacific, Station 244, depth 2900 fathoms.
5. Oroscena wolffii, n. sp.
Radial spines cylindrical, spinulate, more or less curved, longer than the diameter of the shell and about twice as broad as its bars. Meshes irregularly polygonal, of very variable form and unequal size, separated by smooth bars.
Dimensions.—Diameter of the shell 2.5, length of the spines 3.0 to 3.5, breadth 0.02.
Habitat.—Indian Ocean, Zanzibar (Pullen), depth 2200 fathoms.
Subgenus 2. Orodendrum, Haeckel.
Definition.—Radial spines branched or arborescent.
6. Oroscena huxleyi, n. sp. (Pl. 12, figs. 1, 1a).
Radial spines cylindrical, obliquely ascending and irregularly curved, about as long as the diameter of the shell and somewhat thicker than its thorny bars. A variable number of short, irregular, partly simple, partly forked, lateral branches arises from the spines. Meshes of the network very irregular, partly solid, partly hollow (fig. 1a*), the majority quadrangular. This species, the first observed form of Orosphærida (captured the 21st February 1873 at Station 5), was at the beginning of my observations, in 1876, and when I had no knowledge of the central capsule, erroneously regarded by me as a gigantic Sphæroid (of the Monosphærida) and therefore placed in Pl. 12. The long branched spines, afterwards observed complete in another specimen, were broken off in the specimen first figured.
Dimensions.—Diameter of the shell 2.0 to 2.5, length of the spines 2 to 3 mm., breadth 0.03.
Habitat.—North Atlantic (west of Canary Islands), Station 5, depth 2740 fathoms.
7. Oroscena darwinii, n. sp.
Radial spines cylindrical, irregularly curved and branched, about twice as long as the diameter of the shell; the branches are all again ramified and partly confluent (as in Pl. 107, fig. 1). The branches and the bars of the network are of equal breadth, smooth (not thorny as in the similar preceding species). Meshes rather subregular, quadrangular.
Dimensions.—Diameter of the shell 2.4 to 2.8, length of the spines 4 to 5 mm., breadth 0.015.
Habitat.—Tropical Atlantic, Station 348, depth 2450 fathoms.
8. Oroscena duncanii, n. sp.
Radial spines cylindrical, thorny, arborescent, somewhat shorter than the diameter of the shell, with irregular ramified branches (similar to Orosphæra arborescens, Pl. 106, fig. 3). The size and ramification of the arborescent spinulate branches decrease towards the apex. The thicker branches are from two to three times as broad as the spinulate bars of the network. Meshes of the latter irregular, the majority quadrangular.
Dimensions.—Diameter of the shell 3.2, length of the spines 3.5 to 4.5, breadth 0.02 to 0.3.
Habitat.—South Atlantic, Station 318, depth 2040 fathoms; coast of Portugal, 1095 fathoms.
Genus 674. Oroplegma,[5] n. gen.
Definition.—Orosphærida with a spongy, spherical or slightly polyhedral lattice-shell, which is enveloped by a loose spongy framework and bears numerous radial spines.
The genus Oroplegma differs from the other Orosphærida in the development of an external lattice-work enveloping the internal primary shell, and produced by the union of the branches of the radial spines. This outer shell is either a simple lattice-plate (comparable to the cortical shell of Diplosphæra), or a spongy framework (as in Rhizoplegma).
Subgenus 1. Oroplegmium, Haeckel.
Definition.—External shell a simple fenestrated lamella, forming an outer concentric lattice-sphere around the inner primary shell.
1. Oroplegma diplosphæra, n. sp. (Pl. 107, fig. 1).
Radial spines slender, cylindrical, smooth, more or less curved, about twice as broad as the smooth bars of the network. External shell a simple irregular lattice-sphere, with loose polygonal meshes, which are on an average three to four times as broad as the irregular meshes of the internal shell. The free prominent parts of the radial spines are irregularly branched, very long, with partly confluent branches.
Dimensions.—Diameter of the inner sphere 1.5 to 2.0, of the outer 2.5 to 3.0; length of the free spines 1.2, breadth 0.04.
Habitat.—Central Pacific, Station 265, depth 2900 fathoms.
2. Oroplegma spinulosum, n. sp.
Radial spines slender, cylindrical, thorny, more or less curved, very similar to those of the preceding species; the shell also much resembles that of Oroplegma perplexum. It differs from the latter in the more regular fenestration of both shells, and mainly in the shape of the bars and the spine-branches, which are all spinulate and densely studded with small conical thorns.
Dimensions.—Diameter of the inner sphere 1.5 to 2.0, of the outer 2.5 to 3.0; length of the spines 1.2, breadth 0.03.
Habitat.—Central Pacific, Station 268, depth 2900 fathoms.
3. Oroplegma velatum, n. sp.
Radial spines stout, cylindrical, somewhat club-shaped, spiny, slightly curved, about three to four times as broad as the thorny bars of the network. External shell a simple lattice-sphere with irregular polygonal meshes, which are for the most part pentagonal and about four times as broad as the polygonal meshes of the inner shell. The free prominent parts of the radial spines are thickened, club-shaped, and about as long as the radius.
Dimensions.—Diameter of the inner sphere 2.0 to 2.4, of the outer 2.8 to 3.6; length of the free spines 0.5 to 0.7, breadth 0.12 to 0.15.
Habitat.—Tropical Atlantic, Station 338, depth 1990 fathoms.
Subgenus 2. Orodictyum, Haeckel.
Definition.—External shell a complex framework, forming an outer spongy envelope around the inner primary shell.
4. Oroplegma spongiosum, n. sp. (Pl. 107, fig. 3).
Radial spines stout, cylindrical, spinulate, slightly curved, three to five times as broad as the inner rough bars. External shell with pyramidal elevations, forming a loose spongy framework, the irregular polygonal meshes of which are two to five times as broad as those of the enclosed internal shell; the thickness of the spongy envelope equals about half the radius of the inner shell. External free prolongations of the radial spines about equal to the radius.
Dimensions.—Diameter of the inner sphere 2 to 2.5, of the outer 3 to 3.5; length of the free radial spines 0.5 to 2.0, breadth 0.1.
Habitat.—North Pacific, Station 241, depth 2300 fathoms.
5. Oroplegma giganteum, n. sp. (Pl. 107, fig. 2).
Radial spines slender, cylindrical, spinulate, irregularly curved, about twice as broad as the spinulate tubular bars of the network (fig. 2). External shell an irregular, loose, spongy framework, the polygonal meshes of which are three to six times as broad as the rounded irregular meshes of the inner shell; the thickness of the spongy envelope about equals the radius of the inner shell. External free prolongation of the radial spines irregularly branched.
Dimensions.—Diameter of the inner sphere 3.2 to 3.5, of the outer 5.4 to 6.6; length of the free spines 1.4 to 1.5, breadth 0.03.
Habitat.—Tropical Atlantic, Station 347, depth 2250 fathoms.
Family LXXV. Sagosphærida, n. fam. (Pl. 108).
Definition.—Phæodaria with a large spherical (or sometimes polyhedral), very delicate shell, which is composed of solid, very thin and long threads. Nodal points of the arachnoidal network without astral septa. Meshes large, triangular. Surface of the shell usually armed with radial spines and often studded with pyramidal elevations. No peculiar mouth in the shell. Central capsule tripylean, in the centre of the shell.
The family Sagosphærida comprises a rather large number of common and widely distributed Phæodaria, which in respect of the special form and differentiation of the shell exhibit the greatest similarity to the common Aulosphærida, but differ essentially from them in the peculiar structure of the network. This is not composed of stout hollow cylindrical tubes, but of solid, very thin threads; and these fine arachnoidal threads are simply united or confluent at the nodal points, and are not connected by a radial or stellate septal junction, as in the Aulosphærida. There are, therefore, neither astral septa nor a nodal cavity in each nodal point. The delicate shape of the thin and fragile threads separates the Sagosphærida from the closely allied Orosphærida, the thick bars of which contain a central axial canal and exhibit a concentric structure. Another difference between these two similar families is indicated by the form of the meshes of the network, which are constantly triangular in the Sagosphærida, but irregularly polygonal or quadrangular in the Orosphærida. The general habit of these two families, however, is very different, since the big and stout spheres of the Orosphærida are the coarsest and rudest spherical shells of all Radiolaria, whilst the fragile and delicate spheres of the Sagosphærida represent the finest and most tender in the whole class.
The spherical lattice-shell of the Sagosphærida has a considerable size, its diameter being usually between one and three millimetres, rarely less or more. Some species are very common and widely distributed, usually accompanying the common Aulosphærida; very frequently the similar shells of the two are found interwoven. But in spite of this frequency and visible size, the Sagosphærida have hitherto almost completely escaped the attention of observers. The main cause of this strange fact may be their extreme delicacy and fragibility, so that complete and intact shells occur very rarely, the majority being more or less broken and incomplete. It seems that only two species of Sagosphærida have been hitherto observed.
The first form described is Sagmarium trigonizon, observed by me in 1859 living at Messina, and figured in 1862 in my Monograph as Dictyosoma trigonizon (Taf. xxvi. figs. 4-6), but afterwards called Spongodictyum trigonizon (loc. cit., p. 459). I supposed at that time (now twenty-five years ago), that this remarkable and in many respects distinct form might belong to the Spongosphærida, and that an internal, triple, spherical lattice-shell, found entangled in its spongy framework, might be its central "medullary shell." But at present, having found many shells of different Radiolaria accidentally entangled in the arachnoidal framework of various Sagosphærida, I think it much more probable, that that "triple medullary shell," composed of three simple concentric lattice-spheres, was really a species of Plegmosphæra or Actinomma, accidentally entangled in the arachnoidal spongy framework of Sagmarium. This is the more probable, as I had observed very frequently at Messina, in 1859, fragments of that framework, but only once the triple lattice-shell which I supposed to be the "triple medullary shell" of the former. The peculiar structure of the loose framework, its very large triangular meshes and thin arachnoidal bars, partly provided with cruciate verticils (loc. cit., Taf. xxvi. figs. 4, 5) have been very frequently observed by me during the last ten years in various Sagosphærida (Phæodaria), but never in any true Sphæroidea (Spumellaria).
The second species of Sagosphærida hitherto observed, is Sagoscena gracilis, described and figured in 1879 by Richard Hertwig as Aulosphæra gracilis (Organism. d. Radiol., p. 91, Taf. ix. fig. 4). He too observed only fragments of destroyed and incomplete shells, and was led by their striking similarity to fragments of Aulosphæra elegantissima to unite it with the genus Aulosphæra. But the accurate description and the figure given by him of the fragments observed leaves no doubt that it was a true Sagoscena.
In the collection of the Challenger the Sagosphærida are so common and so richly represented, that we may describe here not less than seven genera and thirty-three species, but this may be a small part only of the numerous species of this family, which seems to be widely distributed over all oceans, in the Arctic and Antarctic as well as in temperate and tropical zones. The majority are inhabitants of the surface, but a few species have been found only in deep-sea soundings. A striking fact is their usual association with the similar Aulosphærida. The majority of shells of both families were found entangled in one another.
The shell of all Sagosphærida seems to be spherical or nearly spherical in the complete state; but complete spheres can be observed only very rarely, and it is not impossible that deviations from the spherical form exist just as in some Aulosphærida (e.g., the lenticular Aulophacus and the spindle-shaped Aulatractus). The diameter of the spheres usually seems to be between 1 and 2, often also 3 millimetres; very rarely shells occur which are less than 1 or more than 3 (4 or 5) millimetres.
The siliceous network or lattice-work of the Sagosphærida exhibits a very characteristic shape, and this enables one to distinguish it at first sight from all the other Radiolaria. It is constantly composed of triangular, very large meshes, which are separated by very thin and delicate, flexible and elastic bars. With respect to the arrangement of these meshes we distinguish two different subfamilies; in the Sagenida the wall of the spherical shell is very thin and composed only of a simple lattice-plate; in the Sagmarida the wall is thickened and spongy, with a complete wicker-work of threads, interwoven in different directions.
The typical triangular form of the large meshes is usually regular or subregular in the fenestrated Sagenida, more or less irregular in the spongy Sagmarida. In many cases, however, irregular triangles also occur in the former, and regular triangles in the latter subfamily. Very rarely irregular polygonal meshes are found in a part of the network, small connecting bars being developed accidentally between two neighbouring sides of the triangles. The diameter of the meshes is usually between 0.1 and 0.2 mm., often also greater, between 0.2 and 0.3, rarely smaller, 0.05 to 0.09 mm. The triangular meshes of the Sagosphærida are therefore on an average ten times as large as the usual meshes in the network of the common Sphæroidea.
The filiform bars, or the thread-shaped, very long and thin rods between the triangular meshes, are scarcely less characteristic of the Sagosphærida than the form and size of the meshes. Their length is usually between 0.1 and 0.2 mm., often also from 0.2 to 0.3 mm., whilst their thickness is only 0.002 to 0.004 mm., often it is less than 0.001, rarely more than 0.005 mm. The nodal points of the network, in which six threads are usually united, are more or less thickened, often stellate (Pl. 108, figs. 9, 12, &c.). Sometimes they are pierced by a central pore. The thin threads are constantly cylindrical, never edged or prismatic, very elastic and flexible; usually they are perfectly smooth, rarely spiny or thorny, sometimes provided with scattered cruciate verticils of lateral branches, as in Sagena crucifera and in the first described form of this family, Sagmarium trigonizon (compare my Monograph, 1862, Taf. xxvi. fig. 5).
The surface of the spherical shell is smooth only in two genera of Sagosphærida, in Sagena and Sagmarium (Pl. 108, figs. 2, 8). In the five other genera it is covered either with radial spines, arising from the nodal points of the network, or with peculiar cortical pyramids or tent-shaped elevations (Pl. 108, figs. 1, 3-6, &c.). These pyramids are of the same characteristic shape as in the similar Auloscena among the Aulosphærida (Pl. 110, fig. 1); usually, however, they are less regular than in the latter. The pyramids or tents are usually six-sided, often, however, they are also four-sided or three-sided, more rarely five, seven or more sided. The edges of the pyramids are formed by filiform bars similar to those which compose the original lattice-work of the Sagosphærida. The cavity of the pyramids is quite simple in Sagoscena (figs. 1, 5, 6), whilst in Sagenoscena and Sagoplegma a radial column arises in its axis, the thickened axial rod (figs. 3, 4, 10).
The radial spines, which arise either from the tops of the pyramids or from the nodal points of the network, exhibit in the Sagosphærida a variety and elegance similar to the closely allied Aulosphærida. Sometimes a single radial spine arises in each nodal point or at the top of each pyramid (figs. 3, 4, 10); at other times two, three, or four (rarely more) divergent spines (figs. 6-9, 12, 13). These are rarely quite simple, usually provided with lateral and terminal branches. The lateral branches are either scattered irregularly, or regularly disposed in elegant verticils, each of which is usually composed of three or four short branches (Pl. 108, figs. 9, 13). The terminal branches form either a similar verticil, or a bunch or corona, composed of numerous radial secondary spines. The distal ends of the terminal as well as of the lateral branches are rarely simple, usually they are provided with a spinulate knob or with an elegant spathilla (Pl. 108, figs. 3, 9, 13).
The central capsule of the Sagosphærida is comparatively small, as it also is in the Aulosphærida and Orosphærida. Its diameter is usually about one-third or one-fourth that of the enveloping shell, between 0.2 and 0.3, often only 0.12 to 0.18, rarely more than 0.3 mm. It is surrounded on the oral half by a red or dark phæodium and separated from the inner surface of the shell by the voluminous calymma. The subspherical nucleus is usually about half as broad as the capsule. The three openings of the latter, the large tubular astropyle and the two opposite lateral parapylæ, exhibit the same shape as in the closely allied Aulosphærida (Pl. 111, fig. 3). The pseudopodia arising from the central capsule form a loose network in the calymma, and proceed over its surface as numerous delicate radial filaments, often supported by the radial spines.
Synopsis of the Genera of Sagosphærida.
| I. Subfamily Sagenida.
Wall of the spherical shell composed of a simple lattice-plate with or without pyramidal elevations. |
Surface of the spherical shell smooth or spiny, without pyramidal elevations. | No radial spines, surface smooth, | 675. Sagena. | ||
| Radial spines in the nodal points, | 676. Sagosphæra. | ||||
| Surface of the spherical shell covered with pyramidal or tent-shaped elevations. | Pyramids without internal axial rod, | 677. Sagoscena. | |||
| Pyramids with an internal radial axial rod, | 678. Sagenoscena. | ||||
| II. Subfamily Sagmarida.
Wall of the spherical shell spongy, composed of an irregular complicated wicker-work. |
Surface of the spherical shell smooth or spiny, without pyramidal elevations. | Surface smooth, without radial spines, | 679. Sagmarium. | ||
| Surface studded with radial spines, | 680. Sagmidium. | ||||
| Surface of the spherical shell covered with pyramidal elevations. | Pyramids on the top with a radial spine or a bunch of divergent spines, | 681. Sagoplegma. |
Subfamily 1. Sagenida, Haeckel.
Definition.—Sagosphærida with a delicate spherical shell, the thin wall of which is composed of a simple lattice-plate, not spongy.
Genus 675. Sagena,[6] n. gen.
Definition..—Sagosphærida with a delicate shell, the thin wall of which is composed of a simple smooth lattice-plate, without radial spines.
The genus Sagena is the simplest of the Sagosphærida and may be regarded as the common ancestral form of this family. The delicate wall of the simple spherical lattice-shell is composed of large, regular, or subregular, triangular meshes, the nodal points of which bear no radial spines. It agrees therefore perfectly with Aularia, and differs from this simplest form of Aulosphærida only in the structure of the skeleton, which is composed not of hollow articulated tubes, but of very thin solid threads. The skeleton may therefore also be confounded with Cenosphæra, but the central capsule of this latter is "peripylean," with numerous fine pores in the entire wall, whilst that of Sagena is "tripylean," having the proboscis of all Phæodaria.
1. Sagena ternaria, n. sp. (Pl. 108, fig. 8).
Network subregular, with equilateral triangular meshes, intermingled with single irregular meshes (fig. 8). Bars of the network smooth, its nodal points solid, not pierced.
Dimensions.—Diameter of the spherical shell 1.5 to 2.5, length of the bars 0.1 to 0.2, breadth 0.002 to 0.005.
Habitat.—Cosmopolitan; Mediterranean, Atlantic, Indian, Pacific, surface.
2. Sagena pertusa, n. sp.
Network subregular, with nearly equal triangular meshes. Bars of the network smooth, its nodal points pierced by a circular hole.
Dimensions.—Diameter of the shell 1.2 to 1.8, length of the bars 0.2 to 0.25, breadth 0.003.
Habitat.—Central Pacific, Stations 270 to 274, surface.
3. Sagena triangula, n. sp.
Network very regular, with equilateral triangular meshes. Bars of the network spinulate, like those of Sagoplegma spinulosa. (Pl. 108, fig. 14), its nodal points solid, not pierced.
Dimensions.—Diameter of the shell 2.2, length of the bars 0.25, breadth 0.004.
Habitat.—South Atlantic, Station 325, surface.
4. Sagena crucifera, n. sp.
Network more or less irregular, with unequal triangular meshes. Bars of the network studded with scattered, rectangular, minute crosses, arising perpendicularly, each cross composed of four small equal bars. Nodal points partly solid, partly pierced by a hole. Network very similar to that of Dictyosoma trigonizon, figured in my Monograph, Taf. xxvi. figs. 4, 5.
Dimensions.—Diameter of the shell 1.5, length of the bars 0.1 to 0.2, breadth 0.003.
Habitat.—Mediterranean, Atlantic, Canary Islands, Station 353, surface.
Genus 676. Sagosphæra,[7] n. gen.
Definition.—Sagosphærida with a delicate spherical shell, the thin wall of which is composed of a simple lattice-plate, and bears on its nodal points radial spines.
The genus Sagosphæra differs from the preceding Sagena, its ancestral form, in the development of radial spines on the nodal points of the simple delicate lattice-sphere. It exhibits therefore the same relation to the latter as Aulosphæra bears to Aularia. The regular or subregular triangular meshes of the lattice-sphere are separated in Sagosphæra by solid, very thin threads, in the similar Aulosphæra, however, by thicker hollow tubes. The genus Sagosphæra may be divided into two subgenera:—Sagosphærella with a single radial spine at each nodal point of the network, and Sagosphæroma with a bunch of two to four or more divergent radial spines.
1. Sagosphæra trigonilla, n. sp.
Radial spines simple, straight, smooth, about as long as the smooth bars of the network, a single one at each nodal point. Meshes very regular, of equal size, equilateral triangular. (Similar to the common Aulosphæra trigonopa.)
Dimensions.—Diameter of the sphere 1.2 to 1.8, length of the bars 0.1 to 0.2, breadth 0.002 to 0.006.
Habitat.—Cosmopolitan; Mediterranean, Atlantic, Pacific, surface.
2. Sagosphæra penicilla, n. sp. (Pl. 108, fig. 10).
Radial spines straight, stout, a single one at each nodal point, twice as thick, but of the same length as the smooth bars of the network, armed at the distal end with a brush of numerous thin radial bristles. (Very similar to Sagenoscena penicillata, but without pyramidal elevations on the surface of the sphere.)
Dimensions.—Diameter of the sphere 1.0 to 1.5, length of the bars 0.1 to 0.15, breadth 0.002 to 0.004.
Habitat.—Antarctic Ocean, Station 154, surface.
3. Sagosphæra verticilla, n. sp.
Radial spines slender, slightly curved, a single one at each nodal point, armed with three to five cruciate verticils, each of which is composed of four crossed lateral branches with spinulate terminal knobs (similar to Sagmidium crucicorne, Pl. 108, fig. 9), but with a spherical shell, having a simply latticed, and not a spongy wall.
Dimensions.—Diameter of the sphere 2.0 to 2.5, length of the bars 0.1 to 0.2, breadth 0.002.
Habitat.—North Pacific, Station 256, surface
4. Sagosphæra furcilla, n. sp. (Pl. 108, figs. 11, 11a).
Radial spines short, spinulate, with a spiny terminal knob (fig. 11a), two or three arising from each nodal point of the network in divergent directions, only one-third or one-fourth as long as its smooth bars. Meshes more or less irregular, triangular.
Dimensions.—Diameter of the sphere 2.2, length of the bars 0.2 to 0.3, breadth 0.004.
Habitat.—South Pacific, Station 293, depth 2025 fathoms.
5. Sagosphæra coronilla, n. sp.
Radial spines slender, smooth, three to six arising from each nodal point of the network in divergent directions, about as long as its smooth bars, crowned at the distal end with a bunch of twenty to thirty radial terminal branches, and provided with a spinulate knob at the distal end (similar to Sagenoscena stellata, Pl. 108, fig. 3).
Dimensions.—Diameter of the sphere 3.0, length of the bars 0.1 to 0.2, breadth 0.002.
Habitat.—Central Pacific, Station 271, depth 2425 fathoms.
Genus 677. Sagoscena,[8] n. gen.
Definition.—Sagosphærida with a delicate spherical shell, the thin wall of which is composed of a simple lattice-plate and covered with numerous pyramidal elevations; each pyramid bears on its top one or more radial spines, but has no axial rod in its radial axis.
The genus Sagoscena, and the following closely allied Sagenoscena (both very common and widely distributed), exhibit a peculiar and very remarkable structure of the delicate lattice-shell, similar to that which Auloscena represents among the Aulosphærida. The surface of the simple spherical lattice-shell is covered with numerous pyramidal or tent-shaped elevations. These elegant and delicate pyramids are, however, in Sagoscena usually not so regular as in the similar Auloscena; the edges of the pyramids are in the latter hollow cylindrical tubes, in the former thin solid threads. The top of each pyramid usually bears a bunch of apical spines.
1. Sagoscena castra, n. sp. (Pl. 108, fig. 1).
Pyramids subregular, of equal size and similar form, usually three-sided, crowned at the top with three divergent apical spines, which alternate with the three edges of the pyramids and bear a small spinulate terminal knob. (Some four-sided and single five-sided pyramids are often intermingled with the three-sided.)
Dimensions.—Diameter of the sphere 1.7 to 2.3, length of the bars 0.2 to 0.25, breadth 0.008.
Habitat.—South-Eastern Pacific, Stations 295, 296, surface.
2. Sagoscena tentorium, n. sp. (Pl. 108, fig. 6).
Pyramids subregular, of equal size and similar form, usually four-sided, crowned at the top with three divergent apical spines, which are trifurcate at the distal end. (Some three-sided and five-sided pyramids are often intermingled with the four-sided.)
Dimensions.—Diameter of the sphere 2.2, length of the bars 0.2 to 0.25, breadth 0.005.
Habitat.—South Pacific, Station 291, surface.
3. Sagoscena prætorium, n. sp. (Pl. 108, fig. 7).
Pyramids subregular, of equal size and similar form, usually four-sided, crowned at the distal top with three or four divergent apical spines, which bear some irregular verticils of lateral and terminal branches. (Some five-sided and some six-sided pyramids are often intermingled with the four-sided.)
Dimensions.—Diameter of the sphere 2.6, length of the bars 0.3, breadth 0.006.
Habitat.—Central Pacific, Stations 271 to 274, surface.
4. Sagoscena pellorium, n. sp. (Pl. 108, fig. 5).
Pyramids subregular, of equal size and similar form, usually five-sided or six-sided, crowned at the distal end with three to six divergent apical spines, which bear an irregularly spinulate terminal knob. (The size and form of the apical spines is here very variable, as well as the number of the edges of the pyramids, which varies between three and six.)
Dimensions.—Diameter of the sphere 3.2, length of the bars 0.15 to 0.25, breadth 0.008.
Habitat.—Antarctic Ocean, Station 156, surface.
5. Sagoscena cruciarium, n. sp.
Pyramids subregular, usually six-sided (intermingled with single five-sided and seven-sided or eight-sided forms), crowned at the distal top with three divergent, slender, apical spines, each of which bears three to six regular cruciate verticils; the four crossed lateral branches of each verticil bearing a spinulate terminal knob. (Similar to Sagoplegma scenophora, Pl. 108, fig. 13.)
Dimensions.—Diameter of the shell 2.5, length of the bars 0.2 to 0.3, breadth 0.004.
Habitat.—North Pacific, Stations 240 to 244, surface.
6. Sagoscena debilis, n. sp.
Pyramids more or less irregular, with four, five, or six sides, of somewhat different form and unequal size; crowned at the top with one, two, or three slender apical spines, of variable length. These spines as well as the bars of the network bear scattered cruciate verticils, each usually composed of four crossed, small, lateral branches.
Dimensions.—Diameter of the shell 2 to 3.0, length of the bars 0.1 to 0.15, breadth 0.003.
Habitat.—Central Pacific, Stations 263 to 274, surface.
7. Sagoscena gracilis, Haeckel.
Pyramids more or less irregular, with five, six, or seven sides, often of somewhat different form and unequal size; crowned at the top with a single radial spine, which has the same size as the bars of the network, and bears in its distal half four cruciate verticils, each composed of four crossed and curved horizontal branches.
Dimensions.—Diameter of the sphere 1 to 2, length of the bars 0.08 to 0.09, breadth 0.002.
Habitat.—Mediterranean (Messina), surface.
8. Sagoscena fragilis, n. sp.
Pyramids very irregular, with four to eight sides, of different form and unequal size; crowned at the top with a single, slender, radial spine, of the same thickness as the slender bars of the network; the latter as well as the former are smooth, without lateral branches.
Dimensions.—Diameter of the sphere 1.0 to 2.0, length of the bars 0.1 to 0.2, breadth 0.001 to 0.002.
Habitat.—Cosmopolitan; Atlantic, Pacific, surface.
Genus 678. Sagenoscena,[9] n. gen.
Definition.—Sagosphærida with a delicate spherical shell, the thin wall of which is composed of a simple lattice-plate and covered with numerous pyramidal elevations; each pyramid bears on its top one or more radial spines, and has an internal axial rod in its radial axis.
The genus Sagenoscena differs from the preceding closely allied Sagoscena in the possession of an internal radial axial rod, which arises in the centre of the base of each pyramid, and is prolonged usually over its apex into a free, radial, apical spine. The distal end of the latter is usually armed with a bunch of terminal teeth or bristles. In the similar Sagoscena the internal cavity of the pyramids is simple, without axial rod.
1. Sagenoscena stellata, n. sp. (Pl. 108, fig. 3).
Pyramids rather regular, usually six-sided (intermingled with single five-sided and four-sided forms); their axial rod and its prolongation, the radial apical spine, three to four times as thick as the slender edges of the pyramid. The distal end of the apical spine bears an elegant star of numerous radially divergent terminal branches, each of which is armed with a spinulate terminal knob.
Dimensions.—Diameter of the sphere 3.5 to 4.0, length of the net bars 0.3, breadth 0.003; length of the radial spines 0.2, breadth 0.012.
Habitat.—South Atlantic, Station 318, depth 2040 fathoms.
2. Sagenoscena ornata, n. sp. (Pl. 108, fig. 4).
Pyramids rather regular, usually six-sided (intermingled with single five-sided and seven-sided forms); their axial rod and apical spine spindle-shaped, two to four times as thick as the smooth bars of the network. The distal end of the radial spines bears an elegant, foliate, terminal knob, composed of four to six vertical pinnate leaves, lying in crossed meridional planes.
Dimensions.—Diameter of the sphere 2 to 3, length of the rods 0.1 to 0.2, breadth 0.003 to 0.01.
Habitat.—Antarctic Ocean, Station 156, depth 1975 fathoms.
3. Sagenoscena penicillata, n. sp. (Pl. 108, fig. 10).
Pyramids rather regular, usually six-sided (intermingled with single five-sided, seven-sided, and eight-sided forms); their axial rod and apical spine spindle-shaped, thicker than the smooth bars of the network. The distal end of the radial spines is penicillate and bears a brush of bristle-shaped, radial, terminal spinules (compare Sagosphæra penicilla, p. 1607).
Dimensions.—Diameter of the sphere 1 to 1.5, length of the bars 0.1 to 0.15, breadth 0.004 to 0.005.
Habitat.—Antarctic Ocean, Station 157, depth 1950 fathoms.
4. Sagenoscena coronata, n. sp.
Pyramids rather regular, usually four-sided (intermingled with single five-sided and six-sided forms); their axial rod and apical spines cylindrical, scarcely thicker than the smooth bars of the network. The distal end of the radial spines bears a corona of twenty to thirty curved terminal branches, which form a regular circle, and are armed with a spinulate terminal knob.
Dimensions.—Diameter of the sphere 2 to 3, length of the bars 0.12 to 0.18, breadth 0.004 to 0.008.
Habitat.—North Pacific, Station 256, surface.
5. Sagenoscena spathillata, n. sp.
Pyramids more or less irregular, of different sizes and various forms, each composed of four to eight convergent rods and a central axial rod. The latter is prolonged into a free apical spine, which bears at the distal end a spathilla of eight to twelve recurved teeth, and often beyond it a second similar verticil.
Dimensions.—Diameter of the sphere 4.0, length of the bars 0.1 to 0.2, breadth 0.002.
Habitat.—Arctic Ocean, Greenland (Olrik).
6. Sagenoscena cruciata, n. sp.
Pyramids very irregular, of different sizes and various forms, each composed of six to nine convergent rods and a central axial rod. The latter is prolonged into a free apical spine, which bears three to five cruciate verticils, each composed of four perpendicularly crossed lateral branches which bear at the distal end a spinulate knob (similar to Sagmidium crucicorne, Pl. 108, fig. 9).
Dimensions.—Diameter of the sphere 1.0 to 1.2, length of the bars 0.06 to 0.09, breadth 0.001.
Habitat.—Central Pacific, Station 266, depth 2750 fathoms.
Subfamily 2. Sagmarida, Haeckel.
Definition.—Sagosphærida with a spongy spherical shell, the thickened wall of which is composed of a loose spongy framework.
Genus 679. Sagmarium,[10] n. gen.
Definition.—Sagosphærida with a spongy spherical shell, the thickened wall of which is composed of a loose spongy framework, and exhibits a smooth surface, without radial spines and pyramidal elevations.
The genus Sagmarium, and the following two genera of Sagosphærida, represent together the subfamily Sagmarida, differing from the preceding Sagenida in the spongy structure of the shell-wall. Whilst in the latter the thin wall of the delicate spherical shell is composed of a simple lattice-plate with triangular meshes, in the former numerous branches diverge from the nodal points of these meshes, and produce by union an irregular and loose spongy framework. The surface of this spongy hollow sphere (similar to Plegmosphæra) is in Sagmarium smooth.
1. Sagmarium spongodictyum, n. sp. (Pl. 108, fig. 2).
Spongy wall of the hollow sphere about half as thick as the radius of its cavity. Bars of the spongy framework very thin and fragile, smooth, without thorns.
Dimensions.—Diameter of the sphere 2.0 to 2.4; length of the bars 0.1 to 0.2, breadth 0.001.
Habitat.—South Atlantic, Station 333, surface.
2. Sagmarium plegmosphærium, n. sp. (Pl. 108, fig. 14).
Spongy wall of the hollow sphere about one-fourth as thick as the radius of its cavity. Bars of the spongy framework rather stout, studded with numerous small spines, which arise perpendicularly from their surface.
Dimensions.—Diameter of the sphere 1.2 to 1.5, length of the bars 0.1 to 0.16, breadth 0.004.
Habitat.—Tropical Atlantic, Station 347, surface.
3. Sagmarium trigonizon, Haeckel.
Bars of the spongy framework thin, irregularly curved, bearing scattered small crosses, which are composed of four small rods arising perpendicularly from the bars. Nodal points of the framework partly pierced by a hole. The peculiar network of a complete specimen, observed by me at Portofino in 1880, was so similar to that of Spongodictyon trigonizon, described above (p. 91), and figured in 1862 in my Monograph, that I am doubtful if the two forms are not identical, the two medullary shells of the latter being accidentally entangled in the framework. (Compare p. 1602.)
Dimensions.—Diameter of the sphere 1.1 to 1.5, length of the bars 0.1 to 0.2, breadth 0.002.
Habitat.—Mediterranean (Messina, Portofino), surface.
Genus 680. Sagmidium,[11] n. gen.
Definition.—Sagosphærida with a spongy spherical shell, the thickened wall of which is composed of a loose spongy framework, and bears on the nodal points of its surface radial spines.
The genus Sagmidium differs from the preceding Sagmarium in the development of radial spines on the surface of the spongy hollow sphere. It bears therefore the same relation to the latter as Sagosphæra does to Sagena, and may be derived either from Sagmarium by the formation of radial spines, or from Sagosphæra by development of the spongy envelope.
1. Sagmidium unicorne, n. sp.
Radial spines simple, straight, smooth, a single one at each nodal point of the surface of the spongy sphere, bearing on its distal end a spinulate knob, or a bunch of numerous radial bristles. (Similar to Sagenoscena penicillata, Pl. 108, fig. 10.) Bars of the spongy framework smooth.
Dimensions.—Diameter of the sphere 3.0 to 3.5, length of the bars 0.15 to 0.2, breadth 0.003 to 0.006.
Habitat.—Antarctic Ocean, Station 256, surface.
2. Sagmidium tricorne, n. sp.
Radial spines simple, smooth, usually three divergent united at each nodal point of the surface (sometimes two or four instead of three). Each spine bears on its distal end three short divergent conical teeth. (Similar to the terminal teeth of Sagoscena tentorium, Pl. 108, fig. 6.) Bars of the spongy framework smooth.
Dimensions.—Diameter of the sphere 1.6 to 2.4, length of the bars 0.06 to 0.09, breadth 0.001 to 0.002.
Habitat.—Central Pacific, Stations 263 to 268, surface.
3. Sagmidium crucicorne, n. sp. (Pl. 108, fig. 9).
Radial spines slender, verticillate, three or four divergent arising from each nodal point of the surface. Each spine bears three to six cruciate verticils of lateral branches; each verticil being composed of four crossed small branches with a spinulate terminal knob. Bars of the spongy framework partly covered with similar verticils.
Dimensions.—Diameter of the sphere 2.0 to 3.0, length of the bars 0.2 to 0.3, breadth 0.002 to 0.003.
Habitat.—North Pacific, Stations 240 to 244, surface.
4. Sagmidium quadricorne, n. sp. (Pl. 108, fig. 12).
Radial spines stout, smooth, cylindrical, usually four divergent arising from each nodal point of the surface (sometimes three, five, or six, instead of four). Each spine bears on its distal end a club-shaped stellate knob. Bars of the spongy framework smooth.
Dimensions.—Diameter of the sphere 4.5, length of the bars 0.2 to 0.3, breadth 0.003 to 0.005.
Habitat.—South Pacific, Station 293, depth 2025 fathoms.
5. Sagmidium multicorne, n. sp.
Radial spines slender, more or less curved, verticillate, in variable number (three to six) divergent, arising from the nodal points of the surface. The spines as well as the bars of the spongy framework are partly simple, partly covered with irregularly scattered cruciate verticils, very similar to those of Sagmarium trigonizon (or Dictyosoma trigonizon), figured in my Monograph, pl. xxvi. figs. 4, 5.
Dimensions.—Diameter of the sphere 5.0, length of the bars 0.2 to 0.3, breadth 0.003.
Habitat.—Indian Ocean, Cocos Islands (Rabbe), surface.
Genus 681. Sagoplegma,[12] n. gen.
Definition.—Sagosphærida with a spongy spherical shell, the thickened wall of which is composed of a loose spongy framework, and bears on its surface numerous pyramidal elevations.
The genus Sagoplegma differs from Sagmarium, its ancestral form, in the development of pyramidal or tent-shaped elevations on the surface of the spongy hollow sphere. It exhibits, therefore, the same relation to the latter as the similar Sagoscena bears to Sagena. The wall of the spherical shell is in the two latter genera a thin simple lattice-plate, in the former a thickened spongy framework.
1. Sagoplegma pyramidophora, n. sp.
Pyramids on the surface of the spongy sphere subregular, mostly tetrahedral, of nearly equal size and similar form. The three edges of each pyramid are prolonged over its top into three short, divergent, apical spines which are forked at the distal end. (Very similar to Sagoscena castra and Sagoscena tentorium, Pl. 108, figs. 1, 6, probably derived from them, but differing in the spongy structure of the thickened shell-wall, which is half as thick as the radius of its cavity.)
Dimensions.—Diameter of the sphere 2.0 to 2.5, length of the bars 0.15 to 0.2, breadth 0.002.
Habitat.—North Pacific, Stations 231 to 239, surface.
2. Sagoplegma scenophora n. sp. (Pl. 108, fig. 13).
Pyramids on the surface of the spongy sphere irregular, with three to six sides, unequal in size and different in form. The edges of each pyramid are prolonged over its top into three to six divergent apical spines, which bear three to six cruciate verticils, each composed of four small, crossed, lateral branches, armed with a spinulate knob at the distal end.
Dimensions.—Diameter of the sphere 3.0 to 3.5, length of the bars 0.25 to 0.35, breadth 0.003.
Habitat.—North Pacific, Stations 252, 253, surface.
Aulosphærida, Haeckel, 1862, Monogr. d. Radiol., p. 357.
Definition.—Phæodaria with a large spherical or subspherical (rarely spindle-shaped) articulated shell, which is composed of hollow tangential tubes. Nodal points of the loose network stellate, with a nodal cavity and astral septa. Meshes either triangular or polygonal. Hollow radial spines arise usually at the nodal points of the surface. No peculiar mouth in the shell. Central capsule tripylean, placed in the centre of the shell.
The family Aulosphærida comprises a great number of splendid and widely distributed Phæodaria, which have a special interest on account of the peculiarly complicated structure of their large lattice-shell, of the extraordinary beauty of their form and of their remarkable relations to the other Phæodaria. They differ from all the other Radiolaria in the peculiar articulate composition of the spherical skeleton of hollow tangential tubes, which are connected (and at the same time separated) by sutural or astral septa and filled up by jelly. The same peculiar structure recurs only in the closely allied Cannosphærida, which, however, differ in the possession of a second internal concentric shell, connected with the outer by radial beams. The similar Sagosphærida, which exhibit corresponding forms in various genera, differ from the Aulosphærida in the simpler structure of the delicate lattice-sphere, which is composed of very thin solid threads of silica, without astral septa. The Orosphærida, finally, also nearly related to the preceding families, differ from them in the coarse structure of the lattice-sphere, which is composed of very thick tangential, concentrically stratified rods, with an internal axial canal, but without astral septa at the nodal points.
One genus only, and two species, of Aulosphærida have been hitherto known, having been discovered by me in 1859 at Messina, and described in my Monograph in 1862 as Aulosphæra trigonopa and Aulosphæra elegantissima (loc. cit., p. 357, Taf. x. figs. 4, 5; Taf. ix. figs. 5, 6). The characteristic structure of their central capsule, as true Tripylea, was afterwards, in 1879, described more accurately by Richard Hertwig (Organism. d. Radiol., p. 90, Taf. x. figs. 2, 8, 14). The rich collection of the Challenger has demonstrated that the Aulosphærida belong to the most common and most widely distributed Phæodaria; many of them are distinguished by the admirable elegance and astonishing regularity of their large and delicate shell. Nine genera and fifty-six species of this great family are described in the following pages, which, however, may represent only a small part of the numerous forms which are found on the surface as well as in different depths of all oceans and in all zones.
The shell is in the great majority of Aulosphærida a regular sphere or an endospherical polyhedron. Two genera only, both rather rare, exhibit a different monaxonial form, one vertical main axis being developed either more or less than all the other ones of the sphere:—Aulatractus is spindle-shaped or ellipsoidal, with prolonged main axis; Aulophacus is lenticular or discoidal, with shortened main axis. The former may be compared to the Prunoidea, the latter to the Discoidea, in opposition to the common regular Sphæroidea. The size of the lattice-shell is very considerable in all Aulosphærida, its diameter varying usually between 1 and 3 mm., often it amounts to 4 or 5 mm.; very rarely the diameter is more than 5 or less than 1 mm. The largest form observed is the spindle-shaped Aulatractus, in which the vertical prolonged main axis attains 6 to 10 mm., the horizontal equatorial axis 3 to 5 mm.
The network of the lattice-shell exhibits in the Aulosphærida two different types, according to which we distinguish two different subfamilies: Aularida and Aulonida; the former are much more common and richer in remarkable forms than the latter. The meshes of the network are in the Aularida constantly triangular, regular or subregular, and very similar to those of the Sagosphærida; at each nodal point six tangential tubes are usually united, so that the network may be regarded also as composed of regular hexagonal meshes, each of which is divided into six smaller triangular meshes (Pl. 109, figs. 1, 3, 5). The second subfamily, the Aulonida, are much rarer than the former, and are distinguished by the polygonal meshes of the network; these are usually more or less irregular, pentagonal and hexagonal intermingled, more rarely tetragonal, heptagonal, or octagonal; usually three or four, rarely five or more tangential tubes are united at each nodal point (Pl. 111, figs. 1, 3). The size of the meshes is very considerable, and agrees with that of the Sagosphærida; their diameter being usually between 0.1 and 0.3, rarely less or more.
The hollow tubes which compose the loose network are usually cylindrical, straight or slightly curved, smooth (Pl. 111, fig. 2), more rarely somewhat spinulate (Pl. 109, fig. 5). Their length is usually between 0.1 and 0.2 mm., rarely less than 0.08, or more than 0.24 mm.; their diameter usually between 0.003 to 0.005, sometimes only 0.002 or less, at other times 0.006 or more. In several species the tangential tubes are thinner in the middle part, and thickened towards the two ends (Pl. 109, figs. 3, 4). Each tube consists of a thin cylindrical wall of silex, and of a jelly-mass filling up its cavity; in its axis runs a very thin, straight or slightly curved thread of silica, the axial filament.
The arrangement of the tangential tubes, which originally, in the simplest Aulosphærida, lie tangentially in the spherical face of a simple lattice-sphere, exhibits various secondary modifications, leading to various interesting generic forms. Two genera only, Aularia (with triangular meshes, Pl. 111, fig. 2) and Aulonia (with polygonal meshes, Pl. 111, fig. 1) possess a smooth, perfectly simple lattice-sphere, and may therefore be regarded as the ancestral genera of the two subfamilies. Two other corresponding genera, the common Aulosphæra (Pl. 109) and the rarer Aulastrum (Pl. 111, fig. 3), differ from the former in the development of radial spines at the nodal points of the simple lattice-sphere. Aulophacus may be developed from Aulosphæra by shortening, Aulatractus, however, by prolongation of the vertical main axis (Pl. 111, figs. 6, 7). In two genera, Auloplegma and Aulodictyum, the latticed wall of the spherical shell becomes thickened and spongy, an irregular framework being formed by tubes connected in different directions (Pl. 111, fig. 8). The most remarkable and the most elegant form, however, of the whole family is represented by Auloscena (Pl. 110). The entire surface of the spherical lattice-shell is here covered with numerous regular or subregular pyramids, or tent-shaped elevations. Usually each pyramid is six-sided, and surrounded by six other six-sided pyramids, their bases being separated by six triangular meshes, which lie in the spherical face. A similar elegant form is developed among the Sagosphærida in the genera Sagoscena, Sagenoscena and Sagoplegma (Pl. 108, fig. 1). The structure of Auloscena, however, is usually more regular, and in the top of each pyramid a radial tube arises.
The junction of the cylindrical tubes at the nodal points of the network is very remarkable. Aularia, the simplest form of the family, exhibits at each nodal point the union of six tangential tubes (Pl. 111, fig. 2); their ends are so pointed and truncated that they are connected in the form of a regular six-radiate star; the conical end of each tube is separated from, and at the same time closely connected with, the adjacent conical ends of the two neighbouring tubes by a thin septum, the astral or sutural septum. The six astral septa compose together a six-radiate star, and in the centre of this star the six axial filaments of the tubes are united. Their central union is surrounded by a small, double-contoured circle, and this circle seems to be the perimeter of a small and flat cavity on the inside of the star, which we call shortly the "nodal cavity" ("die kleine Vertiefung" according to Hertwig, loc. cit., p. 90). The nodal cavity of Aularia probably possesses a central opening on its inside and six small surrounding pores, which lead into the six connected tangential tubes. In Aulosphæra and Auloscena, where a radial spine arises at each nodal point, its axial filament arises from the centre of the star, and is usually prolonged on the inside into a free centripetal beam (Pl. 109, figs. 6, 7; Pl. 110, figs. 4, 6). This centripetal beam is a slender, very thin, conical tube (often with a six-sided pyramidal base) and perhaps of great morphological interest as a rudiment, being homologous to the hollow radial beams which connect the two concentric spheres of the Cannosphærida. Possibly the Aulosphærida have been derived from the latter by loss of the inner shell and reduction of the radial beams; the centripetal beams which are found in many (but not in all) Aulosphærida, may be the last remnant of those radial beams. They contain also an axial filament, as a direct internal prolongation of that of the external radial spine. The axial filaments of the radial spines are usually connected with their thin wall by a variable number of scattered transverse threads, or sometimes even by thin transverse septa (Pl. 110, figs. 4-7, &c.). This structure corresponds to the similar axial filaments and their thin filiform transverse branches which we have found in other Phæodaria, e.g., in the Tuscarorida and Circoporida.
The Aulonida (with polygonal meshes) exhibit in general the same structure as the Aularida (with triangular meshes). But whilst in the latter usually six tangential tubes are united at each nodal point, in the former only three or four tubes become united. Therefore also the number of the small sutural partitions or astral septa, which radiate from the central openings of the nodal cavity, is six in the latter, three or four in the former. Correspondingly three or four small pores lead from the nodal cavity into the surrounding tangential tubes.
The true nature of the nodal points, and the intimate structure of the different parts here united, is a matter which it is very difficult to explain. It is a certain fact, well established by hundreds of observations, that in the complete and well-preserved skeletons which are perfectly purified by fire, or by hot mineral acids, and afterwards dried, all the tubes of the skeleton, the tangential as well as the radial cylinders, become filled up by air. Each tube contains usually one large cylindrical air-bubble, with two hemispherical ends. But the air-bubbles of the neighbouring tubes are completely separated one from another by the thin astral or sutural septa, and the air-bubble of the radial tubes is also separated from the former. The central cavity of each nodal point is therefore surrounded in the Aularida by six, in the Aulonida by three or four separate cylinders of air. This fact seems to be explained only on the supposition that each single tube has two terminal pores or fissures, which open into the two nodal cavities on its two ends. The radial tubes must also possess at least one small opening, probably on their base, and probably they have another on their distal apex. In no other way can it be explained, that in all complete, well-preserved and purified skeletons, each single tube constantly becomes easily filled by an air-bubble after drying.
In the living Aulosphærida the cavities of all tubes are filled up by a jelly-substance, which may be stained by carmine and is probably identical with the jelly of the calymma. The latter is probably in direct connection with the former by the central pore of the nodal cavity, which is placed on its inside and surrounded by the astral septa; these separate the tangential tubes, radiating from one nodal point, completely, and are thin and simple, but very solid lamellæ of silica. Therefore the nodal stars of broken shells usually remain united, whilst the single radiating tubes composing them are broken off (Pl. 110, figs. 3, 8, 10). But it happens only rarely (and only in certain individual species) that complete single tubes separate; usually the fragments of the connected neighbouring tubes remain on their ends. The two small terminal openings of each tangential tube, which lead from its cavity into the nodal cavity, and are surrounded on each end by the truncated ends of two neighbouring astral septa, are very difficult to observe (Pl. 110, figs. 8-10).
The wonderful elegance and the high complication of these regular skeletons of the Aulosphærida, produced by a single cell, becomes increased by the graceful and manifold appendages and apophyses which are usually developed on the radial tubes. In only a few species these are simple, as in the common and cosmopolitan Aulosphæra trigonopa. Usually lateral or terminal appendages are developed in great variety, a selection of which is figured in Pls. 109-111. The lateral branches are either irregularly scattered spines (Pl. 110, figs. 3-7) or regular verticils of cruciate or radiate spines; each verticil is usually composed of four perpendicularly crossed horizontal branches (Pl. 109, figs. 3, 4, 7, 10, &c.), more rarely of a greater number of radiating transverse branches.
The terminal appendages of the radial spines exhibit a striking similarity with those of the Aulacanthida (Pls. 102-105). They are either forks with two or three divergent branches (Pl. 111, figs. 3, 4), or regular crosses with four branches opposite in pairs (Pl. 109, figs. 2, 6, 7, 10), or elegant crowns or verticils, composed of numerous radiating branches (Pl. 110, figs. 1-6). The distal ends of the terminal as well as of the lateral branches are either simple, pointed, or armed with a spinulate knob, or with a terminal spathilla. The variety and elegance of these terminal ornaments, the function of which is that of capturing tentacles, is in the Aulosphærida not less admirable than in the Aulacanthida and Cœlodendrida.
The central capsule of the Aulosphærida (Pl. 111, fig. 2) was first figured in my Monograph (1862, Taf. xi. fig. 5) of Aulosphæra elegantissima, as a sphere of 0.2 to 0.3 mm. in diameter. I described there the large nucleus (of half that size) as a spherical "Binnenblase," and the numerous pseudopodia which arise from the capsule and radiate through the meshes of the lattice-shell. But I had not observed at that time the three typical openings of the capsule, which were first discovered and accurately described by R. Hertwig (1879, loc. cit., p. 94, Taf. x. figs. 2, 4, 5, 8, 14). The large astropyle with its radiate operculum and proboscis, and the two smaller lateral parapylæ, provided with a smaller tubule, have in general the same shape as in the closely allied Sagosphærida and Orosphærida, and agree in their strong development with that of the Aulacanthida. The collection of the Challenger contains numerous well-preserved preparations of Aulosphærida, which were stained by carmine immediately after being captured, and in which the central capsule and its nucleus exhibit the same intimate structure already accurately described by R. Hertwig. The diameter of the capsule is usually between 0.2 and 0.3, rarely less than 0.15 or more than 0.35 mm., the nucleus has half that size. The phæodium has usually about the same volume (Pl. 109, fig. 1), but seems to be in many Aulosphærida less developed than in the other Phæodaria.
Synopsis of the Genera of Aulosphærida.
| I. Subfamily Aularida.
Meshes of the network triangular, regular or subregular. Six tangential tubes united at each nodal point of the net. |
Shell spherical, with a simple network. | Without radial tubes, | 682. Aularia. | ||
| With radial tubes in the nodes of the net, | 683. Aulosphæra. | ||||
| Shell spherical, with pyramidal elevations or with spongy framework. | Shell covered with pyramidal elevations, the top of which bears a radial tube, | 684. Auloscena. | |||
| Shell with spongy framework, the surface of which bears radial tubes, | 685. Auloplegma. | ||||
| Shell not spherical, either lenticular or spindle-shaped, with simple network. | Shell lenticular, with shortened main axis and radial tubes, | 686. Aulophacus. | |||
| Shell spindle-shaped, with prolonged main axis and radial tubes, | 687. Aulatractus. | ||||
| II. Subfamily Aulonida.
Meshes of the network polygonal, usually irregular. Three or four (rarely more) tangential tubes united at each nodal point. |
Shell spherical, with a simple network. | Without radial tubes, | 688. Aulonia. | ||
| With radial tubes in the nodes of the net, | 689. Aulastrum. | ||||
| Shell spherical, with a spongy framework. | Without radial tubes, | 690. Aulodictyum. |
Subfamily 1. Aularida, Haeckel.
Definition.—Network of the shell with triangular, regular or subregular meshes; six tangential tubes being united at each nodal point.
Genus 682. Aularia,[13] n. gen.
Definition.—Aulosphærida with triangular meshes in the network, the tangential tubes of which form a simple smooth lattice-sphere. No radial tubes at the nodal points.
The genus Aularia is the simplest form of the subfamily Aularida, or of those Aulosphærida in which the network of the shell is composed of regular or subregular triangular meshes; they are the main group of the family, much more common and far richer in distinct forms than the Aulonida (or the Aulosphærida with polygonal meshes). The shell of Aularia, the probable ancestral form of the family, is a simple lattice-sphere with smooth surface, and differs from the common Aulosphæra in the absence of radial tubes, arising at the nodal points.
1. Aularia ternaria, n. sp. (Pl. 111, fig. 2).
Tangential tubes of the network cylindrical, straight, smooth, of equal breadth. Triangular meshes of the reticular sphere very regular, equilateral triangular. This species is the simplest of all Aulosphærida and similar to the common Aulosphæra trigonopa, but has no radial tubes.
Dimensions.—Diameter of the sphere 1.0 to 2.0; tubes 0.1 to 0.15 long, 0.007 to 0.01 broad.
Habitat.—Central Pacific, Stations 270 to 274, surface.
2. Aularia tubularia, n. sp.
Tangential tubes of the network cylindrical, straight, of equal breadth, thorny, covered with numerous short bristle-shaped thorns, which are all of the same length and perpendicular to the tube.
Dimensions.—Diameter of the sphere 3.0; tubes 0.15 long, 0.005 broad.
Habitat.—South Pacific, Station 291, depth 2250 fathoms.
3. Aularia trigonaria, n. sp.
Tangential tubes of the network smooth, very thin in the middle part, gradually dilated towards both ends, so that the nodal points of the network are inflated. (Similar to Aulosphæra sceptrophora, Pl. 109, fig. 3, but without radial tubes.)
Dimensions.—Diameter of the sphere 2.2; tubes 0.1 long, 0.002 broad in the middle part, 0.01 on both sides.
Habitat.—North Pacific, Station 253, depth 3125 fathoms.
Genus 683. Aulosphæra,[14] Haeckel, 1860, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, p. 802.
Definition.—Aulosphærida with triangular meshes in the network, the tangential tubes of which form a simple lattice-sphere. Radial tubes arise at its nodal points.
The genus Aulosphæra, the first observed form of all Aulosphærida, is also the most common form of the whole family, the richest in distinct species, and widely distributed over all oceans, in the tropical as well as in the temperate and Arctic zones.
The twenty-one species here enumerated may be only a small part of the numerous forms, which may be distinguished according to the different forms of the tubes. One of the two Mediterranean species, which I first described in my Monograph, is cosmopolitan. The shell is in all species a simple regular lattice-sphere with triangular meshes; it differs from the preceding Aularia in the development of radial tubes at the nodal points of the lattice-work.
Subgenus 1. Aulosphærantha, Haeckel.
Definition.—Radial tubes simple, smooth, without terminal teeth and without lateral branches.
1. Aulosphæra trigonopa, Haeckel.
Radial tubes of the spherical shell cylindro-conical, straight, smooth, of the same length as the tangential tubes of the network, which are also smooth, straight, cylindrical.
Dimensions.—Diameter of the sphere 1.0 to 2.0; tangential tubes 0.1 to 0.2 long, 0.002 to 0.004 broad.
Habitat.—Cosmopolitan; Mediterranean, Atlantic, Indian, Pacific, surface.
2. Aulosphæra flexuosa, n. sp.
Radial tubes slenderly conical, smooth, gradually tapering towards the distal end, more or less irregularly curved, two to three times as long as the tangential tubes, which are cylindrical, straight and smooth.
Dimensions.—Diameter of the sphere 2.2; tangential tubes 0.15 long, 0.006 broad.
Habitat.—North Atlantic, Færöe Channel (Gulf Stream), John Murray, surface.
Subgenus 2. Aulosphærella, Haeckel.
Definition.—Radial tubes smooth, without lateral branches or spines, but armed with a verticil of teeth at the distal end.
3. Aulosphæra diodon, n. sp.
Radial tubes cylindro-conical, straight, smooth, of the same length as the smooth, cylindrical, tangential tubes; armed at the distal end with two divergent terminal teeth, which are slightly curved, pincer-shaped, and about one-fourth as long as the tube.
Dimensions.—Diameter of the sphere 2.5; tangential tubes 0.16 long, 0.003 broad.
Habitat.—South Atlantic, Station 332, depth 2200 fathoms.
4. Aulosphæra triodon, n. sp. (Pl. 109, fig. 8).
Radial tubes cylindrical, straight, smooth, two to three times as long as the smooth, cylindrical, tangential tubes; armed at the distal end with three divergent terminal teeth, which are straight or slightly curved and about one-third as long as the tube.
Dimensions.—Diameter of the sphere 1.2; tangential tubes 0.1 long, 0.01 broad.
Habitat.—North-Eastern Pacific (off Japan), Station 231, surface.
5. Aulosphæra tetrodon, n. sp.
Radial tubes slender, cylindrical, straight, smooth, about three times as long as the smooth, cylindrical, tangential tubes; armed at the distal end with a regular cross of four terminal teeth, which are directed almost horizontally, and are slightly recurved (just as in Aulosphæra spathillata, Pl. 109, fig. 7, but longer and without lateral verticils).
Dimensions.—Diameter of the sphere 1.6; tangential tubes 0.15 long, 0.005 broad.
Habitat.—South Pacific, Station 289, depth 2550 fathoms.
6. Aulosphæra polyodon, n. sp.
Radial tubes slender, spindle-shaped, gradually tapering towards the two ends, smooth, about twice as long as the cylindrical, smooth, tangential tubes; armed at the distal end with a verticil of twelve to twenty or more divergent, conical, slightly curved teeth.
Dimensions.—Diameter of the sphere 3.3; tangential tubes 0.2 long, 0.01 broad.
Habitat.—Central Pacific, Station 272, depth 2600 fathoms.
Subgenus 3. Aulosphærissa, Haeckel.
Definition.—Radial tubes verticillate, armed with a variable number of regular verticils of lateral branches.
7. Aulosphæra verticillata, n. sp.
Radial tubes slender, cylindro-conical, straight, tapering towards the distal end, about as long as the smooth, cylindrical, tangential tubes; armed with eight to twelve verticils of three curved, simple, lateral branches. (Very similar to the tubes of Aulastrum trichoceros, Pl. 111, fig. 5a.)
Dimensions.—Diameter of the sphere 1.6; tangential tubes 0.15 long, 0.008 broad.
Habitat.—South Pacific, Station 300, surface.
8. Aulosphæra spathillata, n. sp. (Pl. 109, figs. 7, 7a).
Radial tubes slender, cylindro-conical, straight, tapering towards the distal end, two to three times as long as the smooth, cylindrical, tangential tubes; armed with two or three distal alternate verticils, each of which forms a horizontal cross of four (sometimes three or five) equidistant branches; their distal ends are on the terminal cross simple hooks, on the proximal cross spathillæ.
Dimensions.—Diameter of the sphere 3.2; tangential tubes 0.12 to 0.16 long, 0.01 broad.
Habitat.—South-Eastern Pacific (off Valparaiso), Station 298, depth 2225 fathoms.
9. Aulosphæra cruciata, Haeckel (Pl. 109, fig. 10).
Radial tubes slender, cylindro-conical, straight, tapering towards the distal end, twice as long as the smooth, cylindrical, tangential tubes; armed with four to eight cruciate equidistant verticils, each of which forms a regular cross of four equal, horizontal, lateral branches, bearing at the end a small knob or spathilla.
Dimensions.—Diameter of the sphere 1.2 to 1.8; tangential tubes 0.1 to 0.15 long, 0.003 broad.
Habitat.—Mediterranean (Messina), North Atlantic (Canary Islands), Caribbean Sea.
10. Aulosphæra elegantissima, Haeckel.
Radial tubes cylindrical, straight, twice as long as the smooth, cylindrical, tangential tubes; armed with four to eight equidistant verticils, each of which is composed of eight to twelve simple, horizontal, lateral branches.
Dimensions.—Diameter of the sphere 1.5 to 2; tangential tubes 0.12 to 0.16 long, 0.004 broad.
Habitat.—Mediterranean (Messina), surface.
11. Aulosphæra bisternaria, n. sp. (Pl. 109, figs. 11, 12).
Radial tubes cylindrical, straight, about as long as the cylindrical tangential tubes, smooth or somewhat thorny, armed at the distal end with two alternate verticils of three branches, which bear a terminal spathilla; the proximal branches are twice as long as the distal, and alternate with them regularly, so that the six branches lie in six different meridional planes.
Dimensions.—Diameter of the sphere 2.5; tangential tubes 0.2 long, 0.01 broad.
Habitat.—Antarctic Ocean, Station 156, surface.
12. Aulosphæra dendrophora, n. sp. (Pl. 109, figs. 1, 2).
Radial tubes cylindrical, straight, about as long as the cylindrical, smooth, tangential tubes, armed in the distal half with three verticils of four crossed branches; the four proximal branches are three times as long as the four distal, and twice as long as the four intermediate branches. All twelve branches bear a terminal spinulate knob, and lie in two perpendicularly crossed meridian planes.
Dimensions.—Diameter of the sphere 2.2 to 2.8; tangential tubes 0.2 long, 0.01 broad.
Habitat.—Central Pacific, Station 271, depth 2425 fathoms.
13. Aulosphæra sceptrophora, n. sp. (Pl. 109, figs. 3, 4).
Radial tubes straight, in the proximal half conical, with inflated base; in the distal half cylindrical, with five or six cruciate verticils, each of which has four perpendicularly crossed teeth. Tangential tubes half as long as the radial tubes, in the middle part very thin, thickened towards both ends.
Dimensions.—Diameter of the sphere 1.2; tangential tubes 0.1 long, 0.002 broad in the middle part, 0.012 on both ends.
Habitat.—Central Pacific, Station 266, depth 2750 fathoms.
14. Aulosphæra spathophora, n. sp.
Radial tubes slender, cylindrical, more or less curved, about three times as long as the tangential tubes, in the distal half with eight to twelve verticils of six to eight lateral branches, which are forked, decrease in length towards the distal end, and bear on each ramule a terminal spathilla. Tangential tubes slightly curved and thorny. (Similar to Auloplegma perplexum, Pl. 111, fig. 8a, but with a simple lattice-sphere.)
Dimensions.—Diameter of the sphere 2.2; tangential tubes 0.2 long. 0.006 broad.
Habitat.—North Pacific, Station 244, depth 2900 fathoms.
Subgenus 4. Aulosphæromma, Haeckel.
Definition.—Radial tubes spiny or thorny, with irregular lateral branches, often with forked distal ends.
15. Aulosphæra bifurca, n. sp.
Radial tubes cylindrical, straight, thorny, twice as long as the smooth, cylindrical, tangential tubes, forked at the distal end, with two curved, convergent, thorny, terminal branches. (Similar to Aulastrum dendroceros, Pl. 111, figs. 4a-4c, but with longer and more spinulate branches.)
Dimensions.—Diameter of the sphere 3.2; tangential tubes 0.25 long, 0.01 broad.
Habitat.—North Pacific, Station 239, surface.
16. Aulosphæra trifurca, n. sp. (Pl. 109, fig. 9).
Radial tubes cylindrical, straight, thorny, about as long as the smooth, cylindrical, tangential tubes, forked at the distal end, with three curved, convergent, terminal branches.
Dimensions.—Diameter of the sphere 2.5 to 3.0; tangential tubes 0.2 long, 0.01 broad.
Habitat.—North Pacific, Station 240, surface.
17. Aulosphæra quadrifurca, n. sp.
Radial tubes cylindro-conical, straight, about as long as the smooth, cylindrical, tangential tubes; studded with numerous irregular lateral branches in the distal half, and armed at the distal end with a cross of four divergent, forked, terminal branches.
Dimensions.—Diameter of the sphere 4.2; tangential tubes 0.2 long, 0.01 broad.
Habitat.—Indian Ocean, Madagascar (Rabbe), surface.
18. Aulosphæra multifurca, n. sp.
Radial tubes cylindrical, more or less curved, three to four times as long as the smooth, often curved, tangential tubes; studded with numerous forked, irregular, lateral branches, and armed at the distal end with a verticil of twelve to sixteen divergent, forked, terminal branches.
Dimensions.—Diameter of the sphere 1.2; tangential tubes 0.06 long, 0.003 broad.
Habitat.—Arctic Ocean, Greenland (Olrik), surface.
19. Aulosphæra coronata, n. sp.
Radial tubes spindle-shaped, tapering from the thicker middle part towards both ends, twice as long as the thorny tangential tubes, studded with numerous irregular, curved, lateral spines, and bearing at the distal end a corona of twenty to twenty-five divergent, curved, terminal branches. (Similar to Auloscena flammabunda, Pl. 110, fig. 4.)
Dimensions.—Diameter of the sphere 3.0; tangential tubes 0.2 long, 0.08 broad.
Habitat.—Tropical Atlantic, Station 347, surface.
20. Aulosphæra undulata, n. sp. (Pl. 109, fig. 6).
Radial tubes slender, cylindro-conical, undulate, about twice as long as the spinulate and undulate tangential tubes; studded with numerous short, perpendicular, lateral branches which are partly simple, partly forked, and bear small terminal spathillæ. The distal end of each radial tube bears usually a verticil of four to eight similar pediculate spathillæ.
Dimensions.—Diameter of the sphere 2.4; tangential tubes 0.2 long, 0.005 broad.
Habitat.—North Pacific, Station 252, surface.
21. Aulosphæra spinosa, n. sp. (Pl. 109, fig. 5).
Radial tubes and tangential tubes equal in size and similar in form, more or less curved, slender, cylindrical, densely studded with numerous irregular spines.
Dimensions.—Diameter of the sphere 1.6; tangential tubes 0.1 long, 0.004 broad.
Habitat.—Central Pacific, Station 271, depth 2425 fathoms.
Genus 684. Auloscena,[15] n. gen.
Definition.—Aulosphærida with triangular meshes in the network, the tangential tubes of which arise in pyramidal groups of six over the surface of the spherical shell. Radial tubes arise at the tops of the six-sided pyramids, which cover the whole surface.
The genus Auloscena differs from the preceding Aulosphæra, its ancestral form, in a very remarkable and elegant character. The tangential tubes of the network here lie not on a spherical face (as in the latter), but arise over the surface of the spherical calymma in the form of numerous, regular, hexagonal pyramids; each pyramid being composed of six convergent ascending tubes, which are united in a common nodal point; at the latter arises a radial tube, which usually bears an elegant corona of radially divergent terminal branches. Therefore the base of each hexagonal pyramid is in contact at its six corners with the basal corners of six similar neighbouring pyramids, whilst the neighbouring sides of the bases are separated by six regular triangular meshes, which lie on the spherical face. In some species this remarkable and elegant structure is quite regular, whilst in others it becomes more or less irregular.
Subgenus 1. Auloscenium, Haeckel.
Definition.—Radial tubes smooth, without lateral branches or spines, bearing a terminal verticil at the distal end.
1. Auloscena mirabilis, n. sp. (Pl. 110, figs. 1, 2).
Radial tubes cylindrical, straight, smooth, about as long as the smooth pyramidal tubes (or the convergent tubes which form the edges of the six-sided pyramids of the network). The distal end of each radial tube bears an elegant spathillate terminal corona (fig. 2), or a verticil of fifteen to twenty curved radial branches, the distal end of which is armed with a spinulate knob.
Dimensions.—Diameter of the sphere 2.0 to 3.0; pyramidal tubes 0.16 to 0.24 long, 0.008 broad.
Habitat.—Central Pacific, Stations 271 to 274, depth 2350 to 2750 fathoms.
2. Auloscena spectabilis, n. sp. (Pl. 110, figs. 8, 9).
Radial tubes cylindro-conical, straight, smooth, twice as long as the smooth pyramidal tubes, armed at the distal end with a conical terminal corona, or a verticil of twelve to sixteen divergent, straight, pointed, terminal branches.
Dimensions.—Diameter of the sphere 4.0 to 5.0; pyramidal tubes 0.25 to 0.3 long, 0.012 broad.
Habitat.—Antarctic Ocean, Station 154, surface.
3. Auloscena pyramidalis, n. sp.
Radial tubes slender, conical, straight, smooth, of the same length as the smooth pyramidal tubes, armed at the distal end with a hexagonal terminal corona, or a verticil of six divergent, straight, pointed, terminal branches, which correspond to the six sides of a pyramid; the proximal apex of this terminal pyramid is opposed to the distal apex of the similar basal pyramid.
Dimensions.—Diameter of the sphere 3.0 to 4.0; pyramidal tubes 0.2 to 0.3 long, 0.01 broad.
Habitat.—Tropical Atlantic, Stations 347 to 349, surface.
Subgenus 2. Auloscenidium, Haeckel.
Definition.—Radial tubes thorny, with lateral branches or spines, usually with a terminal verticil at the distal end.
4. Auloscena tentorium, n. sp. (Pl. 110, fig. 6).
Radial tubes spindle-shaped, tapering towards both ends, nearly smooth, of the same length as the smooth pyramidal tubes. The distal part of the radial tubes is thorny, and bears a verticil or a corona of twenty to thirty slender terminal branches, which are about one-third as long as the tube, sabre-shaped, with concave outer edge and pointed distal end.
Dimensions.—Diameter of the sphere 4.0; radial tubes 0.3 to 0.4 long, 0.02 to 0.03 broad.
Habitat.—North-Western Pacific (off Japan), Station 231, surface.
5. Auloscena verticillus, n. sp. (Pl. 110, figs. 10, 11).
Radial tubes slender, cylindrical, twice as long as the smooth or somewhat thorny pyramidal tubes, armed in the distal part with two or three irregular verticils of three to six perpendicular spines, and on the distal end with a corona of twelve to eighteen straight, divergent, pointed, terminal branches, which often arise in pairs.
Dimensions.—Diameter of the sphere 3.2; pyramidal tubes 0.15 long, 0.01 broad.
Habitat.—South Atlantic, Station 318, depth 2040 fathoms.
6. Auloscena penicillus, n. sp. (Pl. 110, fig. 3).
Radial tubes slender, cylindrical, thorny, one and a half times as long as the thin and smooth pyramidal tubes, armed in the distal half with densely crowded perpendicular spines and a terminal corona of numerous (twenty to thirty or more) bristle-shaped branches, like a brush.
Dimensions.—Diameter of the sphere 2.0 to 2.5; radial tubes 0.15 to 0.2 long, 0.005 to 0.01 broad.
Habitat.—Antarctic Ocean, Stations 156, 157, surface.
7. Auloscena flammabunda, n. sp. (Pl. 110, fig. 4).
Radial tubes cylindro-conical, twice as long as the thorny pyramidal tubes, studded with numerous curved spines, and armed with a verticil or corona of numerous (twenty to thirty or more) undulate, divergent, pointed, terminal branches.
Dimensions.—Diameter of the sphere 3.0; radial tubes 0.3 to 0.4 long, 0.02 to 0.03 broad.
Habitat.—North Pacific, Station 252, surface.
8. Auloscena gigantea, n. sp. (Pl. 110, fig. 7).
Radial tubes cylindrical, thorny, about as long as the thorny pyramidal tubes, armed in the distal half with four to eight verticils of short curved ciliæ, and at the distal end with a similar small terminal verticil.
Dimensions.—Diameter of the sphere 5.2; pyramidal tubes 0.2 to 0.3 long, 0.01 broad.
Habitat.—Central Pacific, Stations 265 to 268, surface.
9. Auloscena arboretum, n. sp.
Radial tubes cylindrical, straight or slightly curved, about the same length as the smooth pyramidal tubes; armed in the distal half with three or four verticils, tapering in size towards the distal end; each verticil is composed of four crossed and curved branches, which bear a terminal spinulate knob. (This species is very similar to Aulosphæra dendrophora, Pl. 109, fig. 1, and may be derived from it by elevation of the hexagonal pyramids, which in the latter lie in the spherical plane).
Dimensions.—Diameter of the sphere 4.4; pyramidal tubes 0.25 long, 0.01 broad.
Habitat.—Indian Ocean, Cocos Islands (Rabbe), surface.
10. Auloscena serrata, n. sp. (Pl. 110, fig. 5).
Radial tubes spindle-shaped, tapering towards both ends, thorny, twice as long as the thorny pyramidal tubes; armed at the distal end with an elegant corona which is composed of twelve to sixteen curved terminal branches. Each branch bears two opposite series of small recurved teeth and a terminal spathilla of six to eight larger recurved teeth.
Dimensions.—Diameter of the sphere 3.0; pyramidal tubes 0.3 long, 0.012 broad.
Habitat.—South Pacific, Station 298, depth 2225 fathoms.
Genus 685. Auloplegma,[16] Haeckel, 1879, Sitzungsb. med.-nat. Gesellsch. Jena, Dec. 12, p. 6.
Definition.—Aulosphærida with triangular meshes in the network, the tubes of which are connected in different directions, and form the spongy wall of a spherical shell. Radial tubes arise on the surface at the nodal points.
The genus Auloplegma, one of the rarest forms of Aulosphærida, differs from the preceding genera in the spongy structure of the lattice-sphere, the thickened wall of which is composed of a loose framework. Numerous tubes, irregularly disposed in different directions, are connected at the nodal points of this loose spongy framework, whilst radial tubes arise on the surface of the latter. Auloplegma exhibits therefore a relation to Aulosphæra, its probable ancestral form, similar to that which Plegmosphæra does to Acanthosphæra among the Sphæroidea.
1. Auloplegma perplexum, n. sp. (Pl. 111, figs. 8, 8a).
Radial tubes straight, cylindro-conical, armed with six to eight verticils of lateral branches, which increase in size towards the base; each verticil is a cross of four dichotomous delicate ramules, ending with a spinulate knob. The length of the radial tube is about equal to the radial diameter of the spongy framework, which forms the thick wall of the spherical shell, and is composed of smooth and straight cylindrical tubes.
Dimensions.—Diameter of the shell 1.5 to 2.0, of its wall 0.3 to 0.4; length of the radial tubes 0.2 to 0.3, basal breadth 0.015.
Habitat.—North Pacific, Station 237, surface.
2. Auloplegma spongiosum, n. sp. (Pl. 111, fig. 9).
Radial tubes slender, straight, cylindro-conical, studded irregularly with lateral branches, which are short, simple, slightly curved, partly verticillate in the distal third, and ending with a small spinulate knob. The length of the radial tubes is about twice as great as the radial diameter of the spongy framework, which forms the wall of the spherical shell, and is composed of thorny or verticillate cylindrical tubes.
Dimensions.—Diameter of the shell 3.2, of its wall 0.1; length of the radial tubes 0.24, breadth 0.01.
Habitat.—North Pacific, Station 231, surface.
Genus 686. Aulophacus,[17] n. gen.
Definition.—Aulosphærida with triangular meshes in the network, the tangential tubes of which form a simple, lenticular, biconvex lattice-shell, with shortened vertical main axis. Radial tubes arise at its nodal points.
The genus Aulophacus differs from the common Aulosphæra, its ancestral form, only in the lenticular compression of the spherical lattice-shell, the vertical axis of which is considerably shortened. It exhibits therefore to the latter the same relation as Cenodiscus does to Cenosphæra among the Sphæroidea. The contrary condition is shown in the following genus Aulatractus, in which the vertical axis is prolonged. In the two species of Aulophacus observed the radial spines exhibit a remarkable peculiarity, being longer on the circular periphery of the lens, shorter on both its faces, and shortest in the vertical main axis.
1. Aulophacus lenticularis, n. sp. (Pl. 111, fig. 5a).
Shell biconvex, lenticular, with rounded circular margin; its horizontal diameter three times as great as its thickness (or its vertical main axis). Radial tubes cylindro-conical, straight, with six to nine triradiate verticils, those of the margin of the lens twice as long as the smooth tangential tubes, the others shorter.
Dimensions.—Horizontal diameter of the lens 5.5 mm., vertical main axis 0.2; length of the radial tubes 0.2, breadth 0.01.
Habitat.—Indian Ocean, Belligemma, Ceylon (Haeckel), surface.
2. Aulophacus amphidiscus, n. sp. (Pl. 111, fig. 5b).
Shell discoidal, slightly biconvex, with rounded circular margin; its horizontal diameter five times as great as its thickness. Radial tubes cylindrical, covered with numerous short thorns, those of the margin of the lens three times as long as the smooth tangential tubes, the others shorter.
Dimensions.—Horizontal diameter of the lens 6.0, vertical main axis 1.2; length of the radial tubes 0.2, breadth 0.005.
Habitat.—Indian Ocean, Madagascar (Rabbe), surface.
Genus 687. Aulatractus,[18] n. gen.
Definition.—Aulosphærida with triangular meshes in the network, the tangential tubes of which form an ellipsoidal or spindle-shaped, simple lattice-shell, with prolonged vertical main axis. Radial tubes arise at its nodal points.
The genus Aulatractus differs from all the other Aulosphærida in the peculiar prolongation of the vertical axis of the lattice-sphere, by which the latter becomes ellipsoidal or spindle-shaped. The triangular meshes of the regular lattice-work become usually more or less irregular and polygonal at the two poles of the elongated main axis. Aulatractus seems to be developed from Aulosphæra in the opposite way from Aulophacus, the former by elongating, the latter by shortening of the vertical main-axis.
1. Aulatractus fusiformis, n. sp. (Pl. 111, figs. 6, 6a, 6b).
Shell spindle-shaped, about twice as long as broad, rounded at both poles of the main axis. Tangential tubes smooth, cylindrical. Radial tubes of the same length as the tangential tubes, but much thinner, slender cylindrical, studded with perpendicularly arising, short, lateral branches, which are scattered in the proximal part, verticillate in the distal part, and bear a spinulate terminal knob.
Dimensions.—Length of the shell 7.5 to 10.0, breadth 3.5; length of the radial tubes 0.15 to 0.18, breadth 0.004.
Habitat.—Tropical Atlantic, Stations 348, 349; surface, and in various depths.
2. Aulatractus diploconus, n. sp. (Pl. 111, fig. 7).
Shell diploconical or nearly spindle-shaped, about three times as long as broad, equally pointed at the two poles of the main axis, not inflated in the middle part. Radial tubes slenderly conical, thorny, only half as long as the smooth tangential tubes.
Dimensions.—Length of the shell 6.0 to 8.0, breadth 2.2 to 4.5; length of the radial tubes 0.1 to 0.15, breadth 0.007.
Habitat.—North Atlantic, Canary Islands, Station 353, surface.
3. Aulatractus fusulus, n. sp.
Shell spindle-shaped, about twice as long as broad, pointed at the two equal poles of the main axis. Radial tubes cylindro-conical, smooth, about as long as the smooth tangential tubes. This species resembles in its simple structure the common cosmopolitan Aulosphæra trigonopa, and differs from it only in the constant spindle-form of the shell.
Dimensions.—Length of the shell 6 to 8, breadth 3 to 4; length of the radial tubes 0.16 to 0.2, breadth 0.008.
Habitat.—North Atlantic, Færöe Channel, Gulf Stream (John Murray); Hebrides (Mœbius).
4. Aulatractus ellipsoides, n. sp.
Shell ellipsoidal, about twice as long as broad, with equally rounded poles on the main axis. Radial tubes straight, cylindrical, verticillate, about twice as long as the smooth tangential bars; each verticil is cruciate, composed of four rectangularly crossed, short, lateral branches which bear a small spathilla at the distal end.
Dimensions.—Length of the shell 6.6, breadth 3.6; length of the radial tubes 0.2, breadth 0.01.
Habitat.—South Atlantic, Station 332, surface.
Subfamily 2. Aulonida, Haeckel.
Definition.—Network of the shell with polygonal, usually irregular meshes; three or four tangential tubes usually being united at each nodal point.
Genus 688. Aulonia,[19] n. gen.
Definition.—Aulosphærida with polygonal meshes in the network, the tangential tubes of which form a simple smooth lattice-sphere. No radial tubes at the nodal points.
The genus Aulonia is the simplest form of the subfamily Aulonida, or of those Aulosphærida in which the lattice-work of the shell is composed not of triangular but of polygonal meshes; all these Aulonida are much rarer and much less differentiated than the Aularida or the common Aulosphærida with triangular meshes. Aulonia has the same simple, smooth, spherical lattice-shell as Aularia, and differs from it only in the polygonal form of the meshes, which, however, is very constant.
1. Aulonia tetragonia, n. sp.
Meshes regular or subregular, square, sometimes intermingled with a variable number of irregular, triangular, and pentagonal meshes. Bars cylindrical, of equal breadth.
Dimensions.—Diameter of the spherical shell 2.0 to 3.2, of the meshes 0.12 to 0.18; breadth of the bars 0.008.
Habitat.—Antarctic Ocean, Station 154, depth 1800 fathoms.
2. Aulonia pentagonia, n. sp.
Meshes subregular, pentagonal, intermingled with a smaller number of quadrangular and triangular irregular meshes. Bars cylindrical, of equal breadth.
Dimensions.—Diameter of the spherical shell 2.8 to 3.2, of the meshes 0.15 to 0.2; breadth of the bars 0.01.
Habitat.—South Pacific, Stations 293 to 302, depth 1375 to 2270 fathoms.
3. Aulonia hexagonia, n. sp. (Pl. 111, fig. 1).
Meshes regular or subregular, hexagonal, often intermingled with a variable number of pentagonal and heptagonal meshes. Bars cylindrical, of equal breadth.
Dimensions.—Diameter of the spherical shell 2.5 to 3.3, of the meshes 0.15 to 0.25; breadth of the bars 0.012.
Habitat.—Tropical Atlantic, Stations 347 to 349, surface.
4. Aulonia metagonia, n. sp.
Meshes subregularly alternating, larger octagonal and smaller tetragonal. The network of this remarkable species has a striking similarity to the arrangement of the radial tubes in some species of Sycon, figured in my Monograph of the Calcispongiæ (1872, Bd. iii., Taf. ix. fig. 12).
Dimensions.—Diameter of the sphere 4.4, of the greater octagonal meshes 0.24 to 0.3, smaller tetragonal 0.1 to 0.12; breadth of the bars 0.007.
Habitat.—Indian Ocean, Cocos Islands (Rabbe), surface.
5. Aulonia polygonia, n. sp.
Meshes irregular, polygonal, variable in form and unequal in size; the majority usually pentagonal or hexagonal, but numerous intermingled meshes with three, four, seven, or eight sides. Very variable in the size of the bars and the form of the meshes.
Dimensions.—Diameter of the sphere 2.5 to 5.5, of the meshes 0.1 to 0.2; breadth of the bars 0.008 to 0.12.
Habitat.—Cosmopolitan; Atlantic, Indian, Pacific, surface.
Genus 689. Aulastrum,[20] n. gen.
Definition.—Aulosphærida with polygonal meshes in the network, the tangential tubes of which form a simple lattice-sphere. Radial tubes arise at its nodal points.
The genus Aulastrum differs from the preceding Aulonia, its ancestral form, only in the development of radial spines at the nodal points of the simple lattice-sphere. It exhibits therefore to the latter the same relation as Aulosphæra does to Aularia. But the meshes of the spherical network are constantly triangular in the two latter genera, polygonal in the two former. The different species of Aulastrum are much rarer, and are not so differentiated as those of the common Aulosphæra.
1. Aulastrum monoceros, n. sp.
Radial tubes simple, smooth, straight, cylindro-conical, about as long as the smooth tangential tubes or somewhat longer. Meshes of the network irregularly polygonal, the majority usually pentagonal or hexagonal.
Dimensions.—Diameter of the sphere 3.0 to 4.0, of the meshes 0.15; breadth of the tubes 0.012.
Habitat.—Tropical Atlantic, Stations 347, 348, depth 2250 to 2450 fathoms.
2. Aulastrum dichoceros, n. sp.
Radial tubes cylindrical, more or less curved, undulate, smooth, twice as long as the smooth tangential tubes, forked at the distal end, with two divergent curved branches. Meshes of the network subregular, hexagonal (as in Aulonia hexagonia, Pl. 111, fig. 1), intermingled with single pentagonal and square meshes.
Dimensions.—Diameter of the sphere 2.0 to 2.5, of the meshes 0.12 to 0.18; breadth of the tubes 0.01.
Habitat.—Antarctic Ocean, Station 157, depth 1950 fathoms.
3. Aulastrum dendroceros, n. sp. (Pl. 111, figs. 4a, b, c).
Radial tubes cylindrical, straight or slightly curved, thorny, forked at the distal end, two to three times as long as the thorny tangential tubes; the thorns are short and thin, partly simple, partly irregularly branched and scattered, arborescent. Meshes of the network irregularly polygonal, the majority pentagonal or tetragonal.
Dimensions.—Diameter of the sphere 2.4; radial tubes 0.2 to 0.3 long, 0.02 broad.
Habitat.—North Pacific, Station 241 to 244, surface.
4. Aulastrum triceros, n. sp. (Pl. 111, figs. 3, 3a).
Radial tubes cylindrical, straight, smooth, about twice as long as the smooth tangential tubes, armed with three divergent curved teeth at the distal end. Meshes subregular, pentagonal, intermingled with a small number of tetragonal and hexagonal meshes.
Dimensions.—Diameter of the sphere 1.2 to 1.8; radial tubes 0.15 long, 0.01 broad.
Habitat.—Tropical Atlantic, Station 349, depth 2450 fathoms.
5. Aulastrum trichoceros, n. sp.
Radial tubes slender, straight, cylindro-conical, about twice as long as the smooth tangential tubes, armed with six to eight verticils of lateral branches, each of which is composed of three short curved branches (similar to those of Aulophacus lenticularis, Pl. 111, fig. 5a). Meshes irregularly polygonal, the majority tetragonal, intermingled with pentagonal and triangular meshes.
Dimensions.—Diameter of the sphere 2.2; tangential tubes 0.12 long, 0.007 broad.
Habitat.—South Pacific, Station 289, depth 2550 fathoms.
6. Aulastrum tetraceros, n. sp.
Radial tubes straight, cylindrical, about three times as long as the smooth tangential meshes, armed with three to six subregular cruciate verticils of branches, each of which is composed of four short, regularly crossed branches, bearing at the end a spinulate knob (similar to those of Aulatractus fusiformis, Pl. 111, fig, 6b). Meshes subregular, square, intermingled with single pentagonal and hexagonal meshes.
Dimensions.—Diameter of the sphere 1.5, of the meshes 0.12 to 0.16; breadth of the bars 0.008.
Habitat.—South Atlantic, Station 318, depth 2040 fathoms.
7. Aulastrum pentaceros, n. sp.
Radial tubes straight, cylindrical, smooth, about as long as the smooth tangential tubes, armed at the distal end with a corona of five curved teeth (of the same shape as in Cannosphæra atlantica, Pl. 112, fig. 6). Meshes subregular pentagonal (intermingled with single tetragonal, hexagonal, and heptagonal meshes).
Dimensions.—Diameter of the sphere 5.0, of the meshes 0.2; breadth of the bars 0.015.
Habitat.—Indian Ocean, Madagascar (Rabbe), surface.
8. Aulastrum polyceros, n. sp.
Radial tubes spindle-shaped, tapering from the broader middle towards both ends, spiny, twice as long as the spiny tangential tubes, armed at the distal end with a corona of twelve to twenty divergent curved teeth (similar to the radial tubes of Auloscena tentorium, Pl. 110, fig. 6). Meshes irregular, polygonal, very variable in size and form. All tubes of this species are armed with scattered, short, conical spines.
Dimensions.—Diameter of the sphere 4.5, of the meshes 0.1 to 0.2; breadth of the bars 0.006.
Habitat.—Central Pacific, Station 271, depth 2425 fathoms.
Genus 690. Aulodictyum,[21] Haeckel, 1879, Sitzungsb. med.-nat. Gesellsch. Jena, Dec. 12, p. 6.
Definition.—Aulosphærida with polygonal meshes in the network, the tubes of which are connected in different directions and form the spongy wall of a spherical shell. No radial tubes prominent over the surface.
The genus Aulodictyum differs from Aulonia, its ancestral form, in the development of a spongy framework in the thickened wall of the spherical lattice-shell. It bears therefore to the latter the same relation as Auloplegma does to Aularia. But the outer surface of the hollow sphere is in Aulodictyum completely smooth, as well as the inner, and bears no radial tubes. Only one species of this genus has been observed.
1. Aulodictyum hydrodictyum, n. sp.
Shell spherical, smooth on the outer and inner surfaces, composed of an irregular framework of straight and smooth cylindrical tubes; its meshes very irregular, of unequal size and various forms. The diameter of the sphere is about six or eight times as great as the thickness of its reticular wall.
Dimensions.—Diameter of the sphere 2 to 3, of its meshes 0.1 to 0.2; breadth of the bars 0.01.
Habitat.—Antarctic Ocean, Station 157, depth 1950 fathoms.
Family LXXVII. Cannosphærida, Haeckel (Pl. 112).
Cannosphærida, Haeckel, 1879, Sitzungsb. med.-nat. Gesellsch. Jena, Dec. 12, p. 6.
Definition.—Phæodaria with two concentric spherical or subspherical shells, which are connected by numerous thin, tubular, radial beams. Inner shell simple, spherical or ovate, solid or latticed, with a peculiar mouth. Outer shell spherical or polyhedral, articulate, composed of hollow tangential tubes, which are separated by astral septa at the stellate nodal points. From the latter arise hollow radial tubes, whilst the inner radial beams, connecting the two shells, are inserted in the middle of the tangential tubes. No peculiar mouth in the outer shell. Central capsule enclosed by the inner shell.
The family Cannosphærida comprises a small number of remarkable Phæodaria which are rare and found only in a few localities. They differ from all the other Phæodaria in the possession of two concentric spherical shells, which are connected by radial beams, and the inner of which is quite simple, like that of the Medusettida, whilst the outer is articulated and composed of hollow tangential tubes, like that of the Aulosphærida. This latter family seems to be most nearly allied to the Cannosphærida, and is perhaps derived from them by loss of the inner shell. The possession of a peculiar mouth in this inner shell brings the Cannosphærida nearer to the Phæogromia. The similar Cœlodrymida, in which also two concentric spherical shells are connected by hollow radial beams, differ essentially in the bivalved shape of the inner shell and the simple, non-articulated, network of the outer shell.
Only a single species of Cannosphærida has been hitherto known, described and figured in 1879 by R. Hertwig as Cœlacantha anchorata (loc. cit., p. 92, Taf. ix. fig. 2). The rich collection of the Challenger has added to it only four other species, one of which is most nearly allied to the former, whilst the others belong to a separate genus, Cannosphæra (Pl. 112). The inner shell is in this latter genus a solid lamella of silica, whilst in the former it is fenestrated. In all other essential points of structure both genera are scarcely different.
The inner shell is either spherical or ovate and has a diameter of 0.1 to 0.4 (usually 0.2 to 0.3 mm.). A distinct main axis is always marked by the large open mouth on its oral pole. The aboral part of the shell-cavity contains the spherical central capsule, the oral part the dark phæodium, a part of which is often prominent through the mouth (figs. 1, 2, 4). The wall of the inner shell is a very thin and transparent lamella of silica, which is structureless and solid in Cannosphæra, distinctly fenestrated in Cœlacantha; the pores of the latter are irregularly rounded and seem to possess a thickened margin.
From the surface of the inner shell arise numerous thin tubular, radial beams (twenty to eighty or more) and connect it with the outer shell. These beams are always very thin and straight cylindrical tubules, about twice to four times as long as the diameter of the inner shell, and usually 0.001 mm. broad, or even less. Their basal end at the surface of the latter appears mammillated (figs. 2, 4). The cavity of the inner shell seems to pass over immediately into the tubular cavities of the radial beams. These latter are sometimes simple, at other times articulated or jointed by a number of transverse septa. The radial beams are covered in all the species observed either with scattered spines (fig. 5) or with verticils of anchor-threads, very thin, filiform, lateral branches which bear a spathilla with three or four recurved teeth on the distal end (figs. 2, 4).
The outer shell is either spherical or an endospherical polyhedron, the prominent nodal points of which fall into a spherical face. Its diameter is usually from 2 to 3 mm., rarely more than 3 or less than 1 mm. Its structure is the same as described for the Aulosphærida, being composed of hollow cylindrical tubes, which form a loose network and are separated at its nodal points by astral septa. The meshes of the network are very large, usually twice to three times as broad as the inner shell, and irregularly polygonal; the usual and prevailing form is pentagonal, but hexagonal meshes are also often intermingled, more rarely meshes with five, seven, or eight sides.
The cylindrical tangential tubes possess in general the same shape as in the similar Aulosphærida, have a thin wall, are filled with jelly, and contain a delicate axial filament in their axis; they differ, however, in a peculiar constant character; in the middle of each tube is inserted an inner radial beam coming from the inner shell, so that both together have the form of a T. The central point of insertion has a somewhat shorter radial distance from the centre of the body than the two nodal points on both ends of the tangential tube, so that the latter is somewhat geniculate (figs. 1-5). The two halves of each tangential tube are usually somewhat thinner on the central end (where the inner radial beam is inserted), thicker on the distal end (where the outer radial tube arises); at both ends they are closed by a thin transverse septum. Often also some other septa are developed, so that each tangential tube seems to be composed of four to six joints or segments. Usually the tangential tubes are armed with spines or anchor threads, similar to those of the inner radial beams. The length of the single tangential tubes is usually between 0.1 and 0.3, their diameter from 0.01 to 0.02.
The nodal points of the outer lattice-sphere, in which the outer radial spines arise, seem to possess the same structure as in the similar Aulosphærida. Since three tangential tubes are connected to each nodal point, in its centre is the union of three small astral septa or sutural partitions. The small nodal cavity on the inside of the nodal point has probably three small pores, which lead into the three tangential tubes between the three astral septa. A fourth pore probably leads from the nodal cavity into the cavity of the hollow radial tube. This structure is difficult to observe, but seems to be demonstrated by the fact, that in the complete and carefully purified skeletons which are treated with hot mineral acids and afterwards dried, all cylinders, the tangential as well as the radial tubes, become easily filled by air (compare the description of the similar structure in the Aulosphærida).
The external radial tubes which arise in the nodal points of the outer shell are either cylindrical or cylindro-conical, straight, and usually about as long as the diameter of the inner shell. Their structure and armature is the same as in the similar Aulosphærida. In the axis of each radial tube runs a delicate axial filament, which is connected with its thin and fragile wall either by filiform transverse branches or by delicate transverse septa. The outside of the radial tubes is either smooth (figs. 3-5) or armed with scattered spines (fig. 4) or with verticils of lateral branches; each verticil is usually composed of three or four branches. The distal end of the radial tubes is rarely simple, pointed; it is usually armed with a spathilla of three or four curved terminal branches (figs. 3, 5) sometimes with an elegant corona composed of twenty to thirty thin radially divergent branches (fig. 4).
The central capsule of the Cannosphærida is small (of 0.1 to 0.15 in diameter) and hidden in the aboral half of the enclosing inner shell, whilst the oral half of the latter is filled up by the phæodium (figs. 2, 4). The structure of the capsule and of its three openings seems to be the same as in the closely allied Aulosphærida. I have, however, not been able to recognise the two parapylæ or secondary openings, and have only observed the astropyle or the main-opening with its radiate operculum surrounded by the phæodium, and directed with its tubular proboscis towards the mouth of the inner shell. As R. Hertwig also could not recognise the two parapylæ, it is not impossible that they are wanting, and that the Cannosphærida possess only one opening, the astropyle, like the Medusettida and Challengerida. The nucleus, enclosed in the central capsule, is spherical, half or one-third as broad as the latter, and contains numerous nucleoli.
Synopsis of the Genera of Cannosphærida.
| Internal shell solid, without open pores, | 691. Cannosphæra. |
| Internal shell latticed, with open pores, | 692. Cœlacantha. |
Genus 691. Cannosphæra,[22] Haeckel, 1879, Sitzungsb. med.-nat. Gesellsch. Jena, Dec. 12, p. 6.
Definition.—Cannosphærida with a solid, not latticed internal shell.
The genus Cannosphæra comprises those Cannosphærida in which the inner shell is formed by a thin solid siliceous-plate and exhibits no pores between the prominent bases of the radial beams.
1. Cannosphæra atlantica, n. sp. (Pl. 112, figs. 5, 6).
Internal shell not mammillate, with fifteen to twenty radial rods, which are loosely studded with single, scattered, simple, lateral spines. External shell with irregular, mostly hexagonal meshes, armed with numerous scattered forks of paired divergent spines, and with twenty to thirty larger simple radial spines, which are about half as long as the internal rods, and bear at the distal end a verticil of three to five curved, simple, terminal branches.
Dimensions.—Diameter of the inner shell 0.1, of the outer 0.5.
Habitat.—Tropical Atlantic, Stations 347 to 349, depth 2250 to 2450 fathoms.
2. Cannosphæra antarctica, n. sp. (Pl. 112, figs. 1-3).
Internal shell mammillate, with sixty to ninety radial rods, which are studded with cruciate verticils of tridentate anchor-threads. External shell with irregular, mostly pentagonal meshes, the bars of which bear on the outside bunches of similar tridentate anchor-threads. At each nodal point arises a simple, smooth, radial spine, which bears at the distal end a verticil of three or four small, curved, terminal branches.
Dimensions.—Diameter of the inner shell 0.2 to 0.3, of the outer 1.5 to 2.0.
Habitat.—Antarctic Ocean, Stations 154 to 157, depth 1300 to 1975 fathoms.
3. Cannosphæra pacifica, n. sp. (Pl. 112, fig. 4).
Internal shell mammillate, with one hundred to one hundred and twenty radial rods, which are studded with cruciate verticils of tridentate anchor-threads. External shell with irregular, mostly hexagonal meshes, the bars of which bear on the outside and on the inside bunches of similar tridentate anchor-threads. At each nodal point arises a simple, thorny, radial spine, which bears at the distal end an elegant verticil of fifteen to twenty flatly expanded, thin, terminal branches.
Dimensions.—Diameter of the inner shell 0.25 to 0.35, of the outer 2.0 to 2.5.
Habitat.—Central Pacific, Stations 270 to 274, depth 2350 to 2925 fathoms.
Genus 692. Cœlacantha,[23] R. Hertwig, 1879, Organism. d. Radiol., p. 91.
Definition.—Cannosphærida with a latticed internal shell.
The genus Cœlacantha comprises those Cannosphærida in which the inner shell is formed by a fenestrated flint-plate, and exhibits numerous pores between the prominent bases of the radial beams.
1. Cœlacantha anchorata, R. Hertwig.
Internal shell slightly mammillate, with thirty to forty radial rods, which are densely studded with verticils of tridentate anchor-threads. External shell with irregular, mostly pentagonal meshes, the bars of which bear the same verticils, each composed of three thin, tridentate anchor-threads. At each nodal point arises a slender radial spine, which bears six verticils, each composed of three to five lateral branches.
Dimensions.—Diameter of the inner shell 0.5, of the outer 3.0.
Habitat.—Mediterranean, Messina (R. Hertwig), surface.
2. Cœlacantha mammillata, n. sp.
Internal shell strongly mammillate, with sixty to eighty radial rods, which are densely studded with cruciate verticils of quadridentate anchor-threads. External shell with irregular, mostly hexagonal meshes, the bars of which bear the same verticils, each composed of four thin quadridentate anchor-threads. At each nodal point arises a slender, smooth, radial spine, which bears at its distal end a verticil of four large, curved, terminal branches.
Dimensions.—Diameter of the inner shell 0.4, of the outer 3.2.
Habitat.—South Atlantic, Station 332, depth 2200 fathoms.
- ↑ Orona = Hilly or tuberculate shell; ὄρος, ὠνή.
- ↑ Orosphæra = Sphere with hilly elevation; ὄρος, σφαῖρα.
- ↑ Oroscena = Shell with tent-shaped elevations; ὄρος, σκηνή.
- ↑ In the plate the number is omitted by mistake. The figure is above in the middle.
- ↑ Oroplegma = Hilly shell of framework; ὄρος, πλέγμα.
- ↑ Sagena = Drag-net; σαγήνη.
- ↑ Sagosphæra = Spherical armour; σάγη, σφαῖρα.
- ↑ Sagoscena = Armour with tents; σάγη, σκηνή.
- ↑ Sagenoscena = Net with tents; σαγήνη, σκηνή.
- ↑ Sagmarium = Covering of a shield, armour; σαγμάριον.
- ↑ Sagmidium = Small armour, military clock; σαγμίδιον.
- ↑ Sagoplegma = Armour of framework; σάγη, πλέγμα.
- ↑ Aularia = Tubular shell; ἀυλάρια.
- ↑ Aulosphæra = Tubular sphere; ἀυλός, σφαῖρα.
- ↑ Auloscena = Tubular tent; ἀυλός, σκηνή.
- ↑ Auloplegma = Tubular framework; ἀυλός, πλέγμα.
- ↑ Aulophacus = Tubular lens; ἀυλός, φακός.
- ↑ Aulatractus = Spindle composed of tubes; ἀυλός, ἄτρακτος.
- ↑ Aulonia = Tubular object; ἀυλός, ὠνίον.
- ↑ Aulastrum = Tubular star; ἀυλός, ἄστρον.
- ↑ Aulodictyum = Tubular net; ἀυλός, δίκτυον.
- ↑ Cannosphæra = Sphere with tubules; κάννα, σφαῖρα.
- ↑ Cœlacantha = Hollow spine; κοιλός, ἄκανθα.