Page:Encyclopædia Britannica, Ninth Edition, v. 15.djvu/404

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382 MAMMALIA [MARSUPIALIA. small Rat, found in the interior of the Australian continent. Its general habits and food appear to resemble those of the other blossoms of Mel ileucae, &c. One kept in confinement by Mr Gould was also observed to eat fli. S. FIG. 30. Chceropus castanotis. From Gould. Fcramcliclee. It was first described as C. ccaudatus by Ogilby from a mutilated specimen, but the specific name was afterwards changed by Gray to castanotis. Family MACROPODIDA:. The general characters of this family, and an account of the animals composing it, will be found in the article KANGAROO, vol. xiii. p. 838 sq. Family PHALANGISTID.<E. Dentition (except in the aberrant genus Tarsipcs}: i , the first above strong, curved, and cutting, the other two gene rally somewhat smaller ; the single lower incisor large, more or less proclivous; Cj- ^-5, upper small or moderate, conical and harp-pointed; lower absent or quite rudimentary ; 2 fr|> variable; m $ or f, with four obtuse tubercles. Limbs subequal. Fore feet with five distinct, subequal toes with claws. Hind feet, short and broad, with live well-developed toes ; the hallux large, nailless and opposable ; the second and third slender and united by a common integument as far as the claws. Stomach simple. Caecum present (except in Tarsipcs}, and usually large. Pouch complete. Animals of small or moderate size and arboreal habits, feeding on vegetable or mixed diet, inhabiting Australia and the Papuan Islands. Excluding Pkascolarctjs and especially Tarsipes, they form a very natural family. The latter is, however, evidently a modified form of the same general type, chiefly aberrant in the characters of its alimentary organs, which are adapted for a peculiar mode of subsistence. It may constitute a distinct subfamily. Subfamily Tarsipedinee. Teeth almost rudimentary and vari able in number. Tongue long, slender, pointed, and very extensile. Cpecum absent. Tarsipcs. This is named from some supposed resemblance of its foot to that of the Lemurine genus Tarsius ; but it must be remarked that it has none of the peculiar elongation of the calcaneum and scaphoid so characteristic of that genus. Head with elongated and slender muzzle. Mouth opening small. The two lower incisors are long, very slender, sharp-pointed, and horizontally placed. All the other teeth are simple, conical, minute, and placed at considerable and irregular intervals apart in the jaws, the number appearing to vary in different individuals and even on different sides of the two individuals. The formula in a specimen in the Museum of the Royal College of Surgeons is ifrf, Cj^, p and m|f|; total 20. Rami of the mandible extremely slender, nearly straight, and without coronoid process or inflected angle. Fore feet with five well- developed toes, with small, flat, scale-like nails, not reaching to the extremity of the digits. Hind feet rather long and slender com pared with that of the Phalangistiiiie, with well-developed opposable and nailless hallux ; second and third digits syndactylous, with sharp compressed curved claws; the fourth and fifth free, and with small flat nails. Ears of moderate size and rounded. Tail longer than the body and head, scantily clothed with short hairs, pre hensile. Vertebra: C 7, 1)13, L 5, S3, 024. Of this singular genus but one species, T. restrains (fig. 31), is known, about the size of a common Mouse. It inhabits western Aus tralia, lives in trees and bushes, uses its tail in climbing, and feeds on honey, which it procures by inserting its long tongue into the FIG. 31. Tarsipes rostratus. FI-OTI Gould. Subfamily Phalangistinsc. Teeth normal. Rudimentary lower canines present. Tongue of ordinary structure. No cheek pouches. Stomach and ascending colon simple. Caecum long, simple. Tail well-developed. A numerous group, varying in size from that of a Mouse to a large Cat, arboreal in their habits, and abundantly distributed through out the Australian region. One section is distinguished by the possession of a flying membrane, or fold of skin, extending on each side of the body between the fore and hind legs, forming when the limbs are extended a kind of parachute, as in the Flying Squirrels, and also by a non-prehensile tail. This includes the genera Pctaurus, Bclidcus, and Acrobata. The remainder have no snch membrane, ami have the tail more or less prehensile, the under sur face at least of the apical portion being bare. These are the typical Phalangcrs, or "Opossums" as they are commonly called in Australia (genus Phalangista), and their various modifications, as discus, Pseudochirus, and Dactyl opsila. These will be more fully described in the article PHALANGER. Subfamily Phascolarctinae. Teeth normal ; no rudimentary lower canines. Tongue of ordinary structure. Distinct cheek pouches. Stomach with a special gland near the cardiac orifice. Caecum very long, and (with the upper portion of the colon) dilated and provided with numer ous longitudinal folds of mucous membrane. In many anatomical cha racters, especially the possession of a special gastric gland, this group resembles the Phasco- lomyidse, to which it obviously forms a transi tion. 1 Phascolarctos. Denti tion : i , c J, p , m % ; total 30. Upper incisors crowded together, cylin- droidal, the first much larger than the others, with a bevelled cutting edge (fig. 25). Caninevery small ; a considerable in terval between it and the premolar which is as long FlG 32 ._ skelcton of nind F()0t of Konla (Phnffnt . from before backwards arctos cinereus), showing the stout opposablc but not SO broad as the hallux, followed by two slender toes, which in true molars and has a tlie livi "K animal are enclosed as far us the nai.s ... .,, in a common integument, cutting edge, with a smaller parallel inner ridge. The molars slightly diminishing in size fr m the first to the fourth, with square crowns, each bearing four pyramidal cusps. The lower incisors are semiproclivous, com-

1 Cf. V. A Forbes, " Anatomy of the Koala," Proe. Zoo!. Soc,, 1881, p. 18 ).