[Illustration: FIG. 55.—Skull and Teeth of the Red-necked Wallaby (_Macropus ruficollis_). _i¹_, _i²_, _i³_, First, second, and third upper incisors; _pm_, fourth or posterior premolar (the penultimate or third having been already shed); _m¹_, _m²_, _m³_, _m⁴_, the four true molars. The last, not fully developed, is nearly concealed by the ascending ramus of the jaw.] _Æpyprymnus._[73]—Head short and broad. Auditory bullæ not inflated. No palatine foramina. Tarsus long. Muffle partially hairy. Tail evenly hairy, not crested above. Molars oblong, less distinctly quadritubercular, and not decreasing so much in size posteriorly as in the other genera. Represented only by _Æ. rufescens_. Remains of _Æ. rufescens_ occur in the Pleistocene cave-deposits of New South Wales. Subfamily =Macropodinæ=.—This subfamily includes the largest forms. The cutting edges of the upper incisors are nearly level, or the first pair but slightly longer than the others (Fig. 55). The canines are rudimentary and often wanting. The premolars are usually not longer (from before backwards) than the true molars and less compressed than in the last subfamily; they are placed in precisely the same line with the molars. The crowns of the molars always have two prominent transverse ridges; and these teeth increase in size from before backwards, the fourth molar appearing very late. The fore limbs are small, with subequal toes armed with strong, moderately long, curved claws. Hind limbs very long and strongly made. Head small, with more or less elongated muzzle. Ears generally rather long and ovate. Upwards of forty-four existing species of this group have been described, and many attempts have been made to subdivide them into smaller groups or genera for the convenience of arrangement and description, but these have generally been based upon such trivial characters that it is preferable to speak of many of them as sections of the genus _Macropus_, reserving generic rank only to forms somewhat aberrant in structure. According to this arrangement the genera will be as follows: _Lagostrophus._[74]—Represented only by the Banded Wallaby (_L. fasciatus_) of Western Australia, which presents the following distinctive features. Size small. Muffle naked. Hind feet covered with long bristly hairs, concealing the claws. Lower part of back marked by dark cross-bands. Skull with a narrow pointed muzzle and inflated auditory bullæ; symphysis of mandible firmly united. No canine. Upper incisive series meeting at a sharp angle, and diverging but slightly behind. First incisor smaller in section than either of the others and scarcely longer, bluntly pointed; second with a flattened oral surface; third smaller, similarly flattened, but with a groove on oral surface forming a notch at its postero-external angle. Fourth premolar short, with a distinct inner ledge. Molars as in _Macropus_.