Page:Scientific results HMS Challenger vol 18 part 1.djvu/417

VI. Subfamily Spongiommida. (Spherical shell whole or partly spongy, with or without enclosed latticed medullary shells in the centre.)	$\scriptstyle {\left\{{\begin{matrix}\ \\\\\ \\\ \\\ \\\ \\\ \\\ \\\ \\\ \\\ \\\ \\\ \\\ \\\ \\\ \\\ \\\ \\\ \\\ \\\ \\\ \\\ \ \end{matrix}}\right.}$	I. Tribe Spongodrymida, without latticed medullary shell.	$\scriptstyle {\left\{{\begin{matrix}\ \\\\\ \\\ \\\ \ \end{matrix}}\right.}$	Spongy sphere solid.	$\scriptstyle {\left\{{\begin{matrix}\ \\\ \end{matrix}}\right.}$	Spines simple,			111. Spongiomma.
						Spines branched,			112. Spongodrymus.
				Spongy sphere hollow.	$\scriptstyle {\left\{{\begin{matrix}\ \\\ \end{matrix}}\right.}$	Spines simple,			113. Spongechinus.
						Spines branched,			114. Spongothammus.
		II. Tribe Rhizoplegmida, with one single latticed medullary shell.	$\scriptstyle {\left\{{\begin{matrix}\ \\\\\ \\\ \\\ \\\ \\\ \\\ \\\ \\\ \\\ \\\ \ \end{matrix}}\right.}$	Medullary shell spherical.	$\scriptstyle {\left\{{\begin{matrix}\ \\\\\ \\\ \\\ \\\ \\\ \ \end{matrix}}\right.}$	Framework arising from the medullary shell,			115. Spongopila.
						Framework separate from the medullary shell.	$\scriptstyle {\left\{{\begin{matrix}\ \\\\\ \\\ \\\ \ \end{matrix}}\right.}$	No medullary by-spines,	116. Rhizoplegma.
								Medullary by-spines,	117. Lychnosphæra.
				Medullary shell a simple cube.	$\scriptstyle {\left\{{\begin{matrix}\ \\\\\ \\\ \\\ \ \end{matrix}}\right.}$	Framework arising immediately from the medullary shell,			118. Centrocubus.
						Framework separate from the medullary shell,			119. Octodendron.
		III. Tribe Rhizosphærida, with two concentric latticed medullary shells.			$\scriptstyle {\left\{{\begin{matrix}\ \\\\\ \\\ \\\ \ \end{matrix}}\right.}$	Framework arising from the medullary shell,			120. Spongosphæra.
						Framework separate from the medullary shell,			121. Rhizosphæra.

Subfamily Coscinommida, Haeckel.

Heliosphærida, Haeckel, 1881, Prodromus, pp. 449, 450.

Definition.—Astrosphærida with one single spherical lattice-shell.

Genus 88. Acanthosphæra,^[1] Ehrenberg, 1858, Monatsber. d. k. preuss. Akad. d.

Wiss. Berlin, p. 12.

Definition.—Astrosphærida with one simple lattice-sphere, covered with simple radial spines of the same kind.

The genus Acanthosphæra exhibits the most simple form of all Astrosphærida; a simple spherical lattice-shell, the surface of which is covered by radial spines of one and the same kind. The number of the latter is very variable, often twelve to twenty, regularly disposed; in other cases forty to sixty or more; and sometimes at each nodal-point of the network a spine is developed.

1. Acanthosphæra = Spiny sphere; ἄκανθα, σφαῖρα.