_Phascologale._[45]—This genus comprises a considerable number of small Marsupials, none of them exceeding a common Rat in size, differing from the Dasyures in possessing an additional premolar—the dentition being _i_ ⁴⁄₃, _c_ ¹⁄₁, _p_ ³⁄₃, _m_ ⁴⁄₄; total 46,—and having the teeth generally developed upon an insectivorous rather than a carnivorous pattern, the upper middle incisors being larger and inclined forwards, the canines relatively smaller, and the molars with broad crowns, armed with prickly tubercles. The muzzle is pointed. Ears moderately rounded and nearly naked. Feet broad and short. Fore feet with five subequal toes, having compressed, slightly curved, pointed claws. Hind feet with the four outer toes subequal, having claws similar to those in the fore feet; the hallux always distinct and partially opposable, though small and nailless. Tail long, very variable in its covering, being either bushy, crested, or nearly naked. Pouch represented merely by a few folds of skin. Mammæ varying from four to ten in number. The food of these animals is almost entirely insects; some species pursuing their prey among the branches of trees, while others are purely terrestrial. They are found throughout Australia, and also in New Guinea and the Aru and some of the adjacent islands. _P. cristicaudata_, a species with a thick compressed tail ornamented upon its apical half with a crest of black hair, differs from the others by the very reduced size of the fourth premolar in the upper, and its complete absence in the lower jaw, thus forming an interesting transition in dentition towards _Dasyurus_. It constitutes the genus _Chætocercus_ of Krefft, but is included by Mr. O. Thomas in _Phascologale_, the frequent absence of the fourth lower premolar in _P. thorbeckiana_ indicating that the total absence of this tooth in the known specimens of this species cannot be regarded as of generic importance. All the members of this and the two following genera can be at once distinguished from _Dasyurus_ by the absence of white spots on the fur. _Sminthopsis._[46]—The genus _Sminthopsis_ includes several small species allied to _Phascologale_ but characterised by the narrowness of the hind foot, and by the soles of the feet being either granulated or hairy, instead of naked. _Antechinomys._[47]—The last genus of the _Dasyurinæ_ is _Antechinomys_, represented only by _A. laniger_ of Queensland and New South Wales. This elegant little mouse-like creature, which has large oval ears and a long tail with the terminal part bushy, is distinguished from _Sminthopsis_ by the absence of the hallux and the great elongation of the limbs. The tympanic bullæ of the skull are also unusually large, with the mastoid portion much swollen. A full account of the habits and anatomy of this animal, which appears to be of very rare occurrence, is given in the _Proc. Zool. Soc._ 1880, p. 454.