In some respects intermediate between the preceding and the next genus is _Dasyuroides byrnei_, of Central Australia, an animal of the size of a rat, with one lower premolar less than in _Phascologale_, without the first hind toe, and with a somewhat thickened tail. The pouch is incomplete, with two lateral folds, and the number of teats six.
_Sminthopsis_ includes several very small species, with the same dental formula as _Phascologale_, but distinguished from that genus by the narrowness of the hind foot, in which the first toe is present, and the granulated or hairy (in place of broad, smooth and naked) soles. A pouch is present, and there are eight or ten teats. Nearly allied is the jumping _Antechinomys laniger_, of East Central Australia, an elegant mouse-like creature, with large oval ears, elongated limbs, a long and tufted tail and no first hind toe. In connexion with the large size of the ears is the excessive inflation of the auditory bulla of the skull.
From all other members of the family the marsupial, or banded, ant-eater (_Myrmecobius fasciatus_) differs by the presence of more than seven pairs of cheek-teeth in each jaw, as well as by the exceedingly long and protrusile tongue. Hence it is made the type of a distinct sub-family, the _Myrmecobiinae_, as distinct from the _Dasyurinae_, which includes all the other members of the family. From the number of its cheek-teeth, the banded ant-eater has been regarded as related to some of the primitive Jurassic mammals; but this view is disputed by Mr Bensley, who regards this multiplicity of teeth as a degenerate feature. On the other hand, it is noteworthy that this marsupial retains in its lower jaw the so-called mylo-hyoid groove, which is found in the aforesaid Jurassic mammals. _Myrmecobius_ has a total of 52 or 54 teeth, which may be classed as i. 4/3, c. 1/1, p. + m. (8 or 9)/(8 or 9). 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 first toe externally, but the metatarsal bone is present. Tail long, clothed with long hairs. Fur rather harsh and bristly. Female without pouch, the young when attached to the nipples being concealed by the long hair of the abdomen. Vertebrae: C. 7, D. 13, L. 6, S. 3, Ca. 23. The single species, which is a native of western and southern Australia, is about the size of an English squirrel, to which 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 marked with broad, white, transverse bands on a dark ground.