"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_. [Illustration: THYLACYNUS CYNOCEPHALUS.] "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.