The Phascolarctos, or Koala (Phascolarctos cinereus), is closely allied to the wombat. He is strongly but clumsily made, with robust limbs and powerful claws, which he employs in clinging to the branches of the trees where he chiefly makes his home. However, he frequently visits terra firma, and burrows with great ease; concealing himself in a torpid state in his subterranean retreat during the cold season. His fore-feet have each five toes, of which two are opposed to the other three—a circumstance noted in no other mammal. He has no tail, like the wombat. His coat is a bluish-gray fur, very thick and extremely soft, darkest on the back, and very pale under the throat and belly. An elongated nose looks as if it were tipped with black leather. The eyes are round and dark; the ears almost hidden in the plenitude of fur. By day he is a drowsy and, sooth to say, a stupid animal; but at night he wakes up into a more active state. He feeds upon the fresh young tops of trees, selecting their blossoms and young shoots; and though in appearance resembling the Phalanga, in habits seems closely allied to the Sloth.
The Phalangas form the typical genus of the tribe of Phalangistins, which comprehends, in addition, the genera Trichosura, Pseudochira, and Dromicia. Several species are met with in Malaysia, but they chiefly belong to the Australian Fauna. They live chiefly in trees, feeding on various kinds of small animals, insects, eggs, and fruits, which they grasp between their fore-paws, and so bring to their mouth. Their appearance may be imagined by putting together a rather short head with short ears and short woolly fur; a squirrel-like body and long prehensile tail, sometimes completely covered with hair: the body measures about twenty-six inches, and the tail about fifteen inches. The two principal species are the Sooty Phalanga (Phalangista fuliginosa), found in Van Diemen’s Land, and named in reference to its smoky black fur; and the Vulpine Phalanga, or Vulpine Opossum (P. vulpina), widely distributed over Australia, and having a fox-like character about his head. The Flying Phalangas are also allied to this genus.
The Thylacyni are distinguished from the Opossums by the hind-feet having no thumb, by a hairy and non-prehensile tail, and by having two incisors less to each jaw. Only one species is known to exist in Australia,[142] where it is called the “Tasmanian Wolf,” and sometimes “Tiger” and “Hyæna.” It resembles a wolf in many respects, but its hinder parts are sensibly higher than its fore; its elongated muzzle is almost cylindrical in shape, and very thick; and his tail, broad at the base, tapers away to a fine point. The colour is gray, striped with black across the hinder limbs.
Of the Thylacynus cynocephalus M. Paul Gervais furnishes the following description:[143]—
“There exists in Tasmania an animal of carnivorous habits almost as large as a wolf, and whose external forms at the first glance do not differ sufficiently from those of the latter to prevent one from including him in the family Canidæ; but this member of the Carnivora, though he has also the wolf’s appetite, and commits havoc in the same manner among the flocks of the colonists, belongs, like most of the Australian Mammals, to the sub-class of Marsupials. There is also much analogy, in many of its osteological characteristics, with the extinct genera of the Hyenodons and Ptérodons; but the latter are in reality Monodelphia, and should be ranged among the Carnivora properly so called. The English settlers in Van Diemen’s Land give the thylacynus the name of Zebra Wolf, because it has, in effect, the greater portion of the dorsal region and the base of the tail marked with transversal brown lines, like zebra stripes. This carnivorous animal is also their Dog-headed Opossum.
“Allied to other Marsupials by the totality of its anatomical characteristics, it is nevertheless easy to distinguish generically; in the first place, it is of great size, and its exterior recalls that of the Wolf, though it has a longer head and a tail garnished with very short hair; the latter is, at the same time, a little depressed. Moreover, it numbers forty-six teeth, with wide intervals between each. It is digitigrade: it has five toes on the fore, and four toes on its hinder feet; its marsupial bones are simply rudimental.”
If there be one group of animals more than another whose unforeseen discovery has succeeded in astonishing and embarrassing zoologists, it is assuredly that which has been designated by the name of Monotremata. It is the lowest order of vertebrated animals, the very bottom of the scale, approximating in many characteristic points to the family of Birds. The pelvis, it is true, is furnished with marsupial bones, but these animals possess no pouch. The skull is smooth, the brain-case proportionately very small, the snout much prolonged, while the jaws have neither teeth nor soft movable lips. The shoulder-bones do not resemble those of a mammal, but in some respects the scapular joint of the bird; in other respects, that of the reptiles. The feet have five toes, each armed with a long nail; and, in addition, the hind-feet are provided with a perforated spur-like weapon, which is connected with a gland. The genus derives its distinctive name from the circumstance that the orifices of the urinary canals, the intestinal and the generative canals, open, as in birds, into a common vent. The mammary glands, of which only one exists on each side, are not furnished with nipples, but open by simple slits on each side of the abdomen.
This order includes two families: the Ornithorhynchidæ and the Echidnidæ, both belonging to Australia and Tasmania. The former are aquatic in their habits, the latter terrestrial.