hollow places.

but insects, worms, The various species

They are rather mixed feeders; roots, and bulbs constitute their ordinary diet. are widely distributed over Australia, Tasmania, New Guinea, and several of the adjacent islands, as Aru, Kei, and New Ireland. The best known are—P. gunni (Fig. 42), bougainvillei, nasuta, obesula, and macrura from Australia, and P. doreyana, raffrayana, and longicaudata from New Guinea.

Remains apparently referable to existing species are found in the cave-deposits of New South Wales.

Peragale.-Molar teeth curved, typically with longer crowns and shorter roots than in the last. Hinder extremities proportionally longer, and hallux without claw. Muzzle much elongated and narrow. Fur soft and silky. Ears very large, long, and pointed. Tail long, its apical half clothed on the dorsal surface with long hairs which form a crest. Vertebræ: C 7, D 13, L 6, S 2, C 23. Skull distinguished from that of Perameles by the large size and double structure of the auditory bulla, of which the mastoid portion is inflated. There is also an abrupt contraction of the muzzle at the third premolar.

The type species of Rabbit - Bandicoot (P. lagotis), as these animals are called, is found in Western Australia, and also occurs fossil in the cave-deposits of New South Wales. It is the largest member of the family, being about the size of the common Rabbit, to which animal it bears sufficient superficial resemblance to have acquired the name of "Native Rabbit" from the colonists. It burrows in the ground, but in other respects resembles the true Bandicoots in its habits.

The smaller P. leucura has short-crowned molars, with distinct cusps, which are almost obsolete in the type species.

Charopus.2-Dentition generally resembling that of Perameles, but the canines are less developed, and in the upper jaw two-rooted. Limbs very slender; posterior nearly twice the length of the anterior. Fore feet with the functional toes reduced to two, the second and third, of equal length, with closely united metacarpals and short, sharp, slightly curved, compressed claws. First toe represented by a minute rudiment of a metacarpal bone; the fourth by a metacarpal and two small phalanges without a claw, and not reaching the middle of the metacarpal of the third; fifth entirely absent. Hind foot (Fig. 43) long and narrow, mainly composed of the strongly developed fourth toe, terminating in a conical pointed nail, with a strong pad behind it; the hallux absent or represented by a rudimentary metatarsal; the remaining toes completely developed, and with claws, but exceedingly slender; the united second and third reaching a little way beyond the metatarso-phalangeal articulation of

1 Gray, in Grey's Australia, vol. ii. p. 401 (1841).

2 Ogilby, Proc. Zool. Soc. 1838, p. 25.

the fourth; the fifth somewhat shorter.

Tail not quite so long as

the body, and covered with short hairs forming a slight crest. Ears large and pointed, and folded down when the animal is at rest. Fur soft and loose. Vertebræ: C 7, D 13, L 6, S 1, C 20. Skull short and wide, with a small and single bulla, and a contraction of the e muzzle at the third premolar.

cb.

FIG. 43.-Skele

ton of right hind foot of Charopus castanotis. c, Cal

caneum ; a, astragalus; cb, cuboid; n, navicular; c3,

ectocuneiform ; II

and III, the conjoined second and third digits; IV, the large and only functional digit

V, the rudimentary fifth digit.

The only known species of this genus (Fig. 44), chiefly remarkable for the singular construction of its limbs, is an animal about the size of a small Rat, found in the interior of the Australian continent. Its general habits and food appear to resemble those of the other Peramelida. It was first described as C. ecaudatus by Ogilby from a mutilated specimen, but the specific name was afterwards changed, as being inappropriate, by Gray to castanotis.

Suborder DIPROTODONTIA.

For the leading characters of this group, see page 132.

Family PHASCOLOMYIDÆ

Dentition c, i 8, p }, m 4 = 24. All the teeth with persistent pulps. The incisors large, scalpriform, with enamel only on the front surface, as in the Rodentia. The molars strongly curved, forming from the base to the summit about a quarter of a circle, the concavity being directed outwards in the upper and inwards in the lower teeth. The first of the series, or premolar, appears to have no milk-predecessor, and is single-lobed; the other four composed of two lobes, each subtriangular in section. Limbs equal, stout, and short. Fore feet with five distinct toes, each furnished with a long, strong, and slightly curved nail, the first and fifth considerably shorter than the other three. Hind feet with a very short nailless hallux, the second, third, and fourth toes partially united by integument, of nearly equal length, the fifth distinct and rather shorter; all four provided with long and curved nails. In the skeleton of the foot, the second and third toes are distinctly more slender than the fourth, showing a slight tendency towards the peculiar character so marked in the next two families. rudimentary. Stomach simple, provided with a special gland situated near the cardiac orifice. Cæcum very short, wide, and with a peculiar vermiform appendage. Pouch present. The auditory bullæ of the skull are imperfect, open behind, with their anterior

Tail

wall formed by a descending process of the squamosal, instead of the

FIG. 44.-Choropus castanotis. From Gould. alisphenoid. Masseteric fossa of mandible with a perforation and a deep pit.

FIG. 45.-Common Wombat (Phascolomys ursinus).

Phascolomys.-The existing Wombats (Fig. 45) comprise three

1 Geoffroy, Ann. du Muséum, vol. ii. p. 365 (1803).

species, all of which are included in the one genus Phascolomys, and all of which date from the Pleistocene.

In the typical group we find the following characters. Fur rough and coarse. Ears short and rounded. Muffle naked. Postorbital process of the frontal bone obsolete. Ribs fifteen pairs. Vertebræ C 7, D 15, L 4, S 4, C 10-12. The Wombat of Tasmania and the islands of Bass's Straits (P. ursinus) and the closely similar but larger animal of the southern portion of the mainland of Australia (P. mitchelli) belong to this group.

In the second group the characters are as follows. Fur smooth and silky. Ears large and more pointed. Muffle hairy. Frontal region of skull broader than in the other group, with wellmarked postorbital processes. Ribs thirteen. Vertebræ: C 7, D 13, L 6, S 4, C 15-16. One species, P. latifrons, the Hairy-nosed Wombat of Southern Australia.

In their general form and actions the Wombats resemble small bears, having a somewhat similar shuffling manner of walking, but they are still shorter in the legs, and have broader, flatter backs than bears. They live entirely on the ground, or in burrows or holes among rocks, never climbing trees, and feed entirely on grass, roots, and other vegetable substances. They sleep during the day, and wander forth at night in search of food, and are shy and gentle in their habits generally, though they can bite strongly when provoked. The only noise the common Wombat makes is a low kind of hissing, but the Hairy-nosed Wombat is said to emit a short quick grunt when annoyed. The prevailing colour of the lastnamed species, as well as of P. ursinus of Tasmania, is a brownish gray. The large wombat of the mainland is very variable in colour, some individuals being found of a pale yellowish brown, others dark gray, and some quite black. The length of head and body is about three feet.

It is noteworthy that P. mitchelli was first described from the evidence of fossil remains, the living form subsequently described as P. platyrhinus being found to be indistinguishable. Other extinct species occur in the Pleistocene of Australia.

Phascolonus.-Remains of a large extinct Wombat, which must have nearly equalled the dimensions of a Tapir, occur in the Pleistocene of Queensland, and have been described as Phascolonus. It is probable that the expanded and flattened upper incisors from the same deposits upon the evidence of which the presumed genus Sceparnodon was founded, are likewise referable to the same form. The characters of both the upper and lower incisors distinguish Phascolonus from Phascolomys.

1 Owen, Phil. Trans. 1872, p. 257.

Family PHALANGERIDE.

Dentition extremely variable, owing to the presence of minute rudimental teeth not constant in the same species, or even in the two sides of the jaws of the same individual; exclusive, however, of 3 1 (2-3) (3-4)

Tarsipes, the formula i, c, P (0-2) m (3-4) represents fairly the general condition of the functional teeth. First incisors long and stout; the lower pair very large and pointed, but without the scissorlike action found in the existing Macropodida; second and third lower incisors minute and probably functionless. Fourth premolar generally secant; milk-molar generally minute and deciduous at an early period. Molars either with sharp cutting-crests or bluntly tuberculate; fourth sometimes absent. Mandible without pit, and at most a very minute perforation in the masseteric fossa. Limbs subequal. Fore feet with five distinct, subequal toes, furnished with. claws. Hind feet short and broad, with five 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. Tail generally long, and frequently more or less prehensile. Stomach simple. Cæcum present (except in Tarsipes), and usually large. Pouch complete. Animals of small or moderate size and arboreal habits, usually feeding on a vegetable or mixed diet, inhabiting Australia and the Papuan Islands.

The homologies of the lower functionless teeth between the first incisor and fourth premolar are very difficult to determine, but it is probable that one represents a canine only when the largest known number is present; this tooth, according to Mr. Thomas, being the first to disappear.

Phalangers are small woolly-coated animals, with long, powerful, and often prehensile tails, large claws, and, as in the American opossums, with opposable nailless great toes. Their expression seems in the day to be dull and sleepy, but by night they appear to decidedly greater advantage. They live mostly upon fruit, leaves, and blossoms, although some few feed habitually upon insects, and all relish, when in confinement, an occasional bird or other small animal. Several of the Phalangers possess flying membranes stretched between their fore and hind limbs (Fig. 48), by the help of which they can make long and sustained leaps through the air, like the Flying Squirrels, but it is interesting to notice that the possession of these flying membranes does not seem to be any indication of special affinity, the characters of the skull and teeth sharply dividing the flying forms, and uniting them with other species of the non-flying groups. Their skulls (Fig. 47) are as a rule broad and flattened, with the posterior part swollen