Page:Encyclopædia Britannica, Ninth Edition, v. 15.djvu/403

Rh MAESUPIALIA.] MAMMALIA 381 Subfamily Myrmecobiinae. Molars and premolars exceeding the normal number of seven on each side. Tongue long and extensile. Myrmccobius. Dentition : i |, c y, p J, m or ; total 52 or 54, being the largest number of teeth in any existing Marsupial. The distinction between the molars and premolars is not certain, as it is not founded on a knowledge of the succession of the teeth, but on their form. The teeth are all small and (except the four posterior inferior molars) separated from each other by an interval. Head elongated, but broad behind. Muzzle long and pointed. Ears of moderate size, ovate, and rather pointed. Fore feet with five toes, all having strong, pointed, compressed claws, the second, third, and fourth nearly equal, the fifth somewhat and the first considerably shorter. Hind feet with no trace of hallux externally, but the metatarsal bone is present. Tail long, clothed with long hairs. Fur rather harsh and bristly. Female without any trace of a pouch, the young when attached to the nipples being concealed only by the long hair of the abdomen. Vertebrae : C 7, D 13, L 6, S 3,&quot; C 23. FIG. 27. Myrmecobivt fasciatut. From Gould. Of this singular genus but one species is known, M. fasdatus, found in western and southern Australia. It is about the size of an English squirrel, to which animal its long bushy tail gives it some resemblance ; but it lives entirely on the ground, especially in sterile, sandy districts, feeding on ants. Its prevailing colour is chestnut-red, but the hinder part of the back is elegantly marked with broad, white, transverse bands on a dark ground. Family PERAMELID^E. Dentition : i -|, c {-, p, m % ; total 48. Upper incisors small, with short, broad crowns. Lower incisors moderate, narrow, pro- clivous. Canines well developed. Premolars compressed, pointed. Molars with quadrate tuberculated crowns. Third premolar pre ceded by a very minute molariform tooth, which remains in place until the animal is nearly full grown. Fore feet with two or three of the middle toes of nearly equal size, and provided with strong, sharp, slightly curved claws ; the other toes rudi mentary. Hind feet long and narrow ; the hallux rudimentary or absent ; the second and third toes very slender, and united in a common integument ; the fourth very large, with a stout elongated conical claw; the fifth smaller than the fourth (see fig. 29). The ungual phalanges of the large toes of both feet cleft at their ex tremities (as in Manis among the Edentata, but in no other Marsupials). Head elongated. Muzzle long, narrow, and pointed. Stomach simple. Crecum of moderate size. Pouch complete, generally opening backwards. Alone among Marsupials they have no clavicles. The Peramelidze form a very distinct family, in some respects intermediate between the sarcophagous Dasyuridse and the phytophagous Macropodidae,. In dentition they resemble the former, but they agree with the latter in the peculiar structure of the hind feet. In the construction of the fore feet they differ from all other Marsupials. They may be divided into three genera. Perameles. Anterior and posterior extremities not differing greatly in development. Fore feet with three middle toes well developed, the third slightly larger than the second, the fourth somewhat shorter, provided with long, strong, slightly curved pointed claws. First and fifth toes very short and without claws Him! feet with hallux of one or two phalanges, forming a distinct tubercle visible externally ; the second and third toes very slender ii. From Gould. of equal length, joined as far as the ungual phalanx, but with distinct claws ; the fifth intermediate in length between these and the largely developed fourth toe. Ears of moderate or small size, ovate, pointed. Tail rather short, clothed with short adpressed hairs. Fur short and harsh. Pouch opening backwards. Verte bra: C7, D13, L6, SI, 017. The animals of this genus, commonly called &quot; Bandicoots&quot; in Australia, are all small, and live entirely on the ground, mak ing nests composed of dried leaves, grass, and sticks in hollow places. They are rather mixed feeders : but insects, worms, roots, and bulbs constitute their ordinary diet. The various species are widely distributed over Australia, Tasmania, New Guinea, and several of the adjacent islands, as Am, Kei, and New Ireland. The best known are P.fasciata, gunnii(fg. 28), myosurus, nasuta, obesula, and macrura from Australia, and P. dorcyana, saffrayana and longicauda from New Guinea. Macrotis. Molar teeth curved&quot;, and with longer crowns and shorter roots than in the last. Hinder extremities proportionally longer, and hallux represented only by a small metatarsal bone. Muzzle much elon gated and narrow. Fur soft and silky. Ears very large, long, and pointed. Tail long, its apical half c& clothed on the dorsal surface with long hairs. Pouch opening forwards. Vertebra: 07, D 13, L 6, S 2, C23. But one species is known, M. lagolis, from western Australia. It is the largest member of the family, being about the size of the common Rabbit, to which animal it bears sufficient super ficial resemblance to have acquired the name of &quot; Native Rabbit &quot; from the colonists. It burrows in the ground, but in other respects resembles the Bandicoots in its habits. Chczropus. 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 renching the middle of the metacarpal of the third ; fifth entirely absent. Hind foot long and narrow, mainly composed of the strongly devel oped fourth toe, terminating in a conical pointed nail, with a strong pad behind it ; the hallux repre sented by a rudimentary metatarsal ; the remaining toes completely developed, and with claws, but ex ceedingly slender; the united second and third reach ing a little way beyond the metatarso-phalangeal articulation of the fourth; the fifth somewhat shorter. Tail not quite so long as the body, and covered with short hairs. Ears large and pointed, and folded down when the animal is at rest. Fur soft and loose. Pouch opening backwards. Ver tebra: 07, D13, L6, SI, 020. The only known species of this genus, chiefly remarkable for the singular construction of its limbs, is an animal about the size of a m 10. 29. Skeleton of Hind Foot of Cliceropus casta- notis. c, oscalcis; a, astragalus ; c6, cuboid ; it, nuicular; tf, ec- tocunciform; If, and III, the conjoined second and third digits; IV, the large and only func tional digit; V, the rudimen tary fifth digit. Compare this foot with that of the Kangaroo, vol. xiii. P. 839.