_Dorcopsis_ and the next genus to be described, _Dendrolagus_, differ from _Macropus_ and its immediate allies, _Petrogale_ and _Lagorchestes_, in a number of anatomical points. In the first place, the premolars are twice the size of those of _Macropus_, and they have a characteristic pattern not observable in the Kangaroos. This consists of a median ridge (the whole tooth being rather prismatic in shape), with lateral ridges at right angles to it. The upper canines are developed, but are minute. The stomach is not quite like that of _Macropus_, though built upon a similar plan. The blind cardiac extremity is a single, not a double cul-de-sac; in this it is like that of _Petrogale_. The distribution of the squamous, white, oesophageal epithelium is very much like that of _Dendrolagus_. In both genera the orifice of the oesophagus into the stomach is guarded by two strong longitudinal folds, which run for some distance towards the pylorus. In _Dendrolagus_, at any rate, this tract is bordered on each side by glandular patches. In _Dendrolagus_, moreover, the squamous epithelium does not extend into the cardiac cul-de-sac. This latter is separated from the rest of the stomach by two slightly diverging folds, which are faintly represented in _Petrogale_ and in _Halmaturus_. In the last two genera the folds surrounding the oesophageal orifice are but slightly represented; better in _Halmaturus_ than in _Petrogale_. But there are not the patches of glands already referred to. The small intestine of _Dorcopsis_ is 97 inches in length, the large being 32, _i.e._ proportionately long, as in Marsupials generally. The small caecum (2-1/2 inches) is not sacculated. The spleen is Macropodine, being [81]-shaped or [82]-shaped. The differences between _Dorcopsis_ and the evidently closely allied _Dendrolagus_ will be further considered under the description of {136} the latter. _Dorcopsis_ is confined to New Guinea, and contains three species, viz. _D. muelleri_, _D. luctuosa_, and _D. macleani_. _D. muelleri_ has a striking resemblance to _Macropus brunii_, with which it has been confounded. Though intermediate between _Macropus_ and _Dendrolagus_, these Kangaroos are not arboreal. The genus _Dendrolagus_ is remarkable for its un-kangaroo-like habit of living in trees. In accordance with this change of habit is a relative shortening of the hind-limbs, a feature which begins to be observable in _Dorcopsis_. "The general build," writes Mr. Thomas, "is of the ordinary mammalian proportions, not macropodiform at all." The muffle is not naked for the greater part, though the shortness of the hairs gives that effect. As in _Dorcopsis_, but not as in _Macropus_, the bulla tympani is not swollen. There are altogether five species, the fifth, _D. bennetti_, having been lately described from specimens living in the Zoological Society's Gardens. [Illustration] FIG. 67.--Tree-Kangaroo. _Dendrolagus bennetti._ x 1/12.