TREE-KANGAROOS I 3 5 



blance to the English hare," and L. leporoides was so called by 

 Gould on account of general appearance as well as face. 



Borcopsis has shorter hind-legs than Macropus, and a naked 

 mufile. The ears are small. The structure of B. luctuosa has 

 been studied by Garrod/ who pointed out the existence of four 

 enlarged hair follicles on the neck near the mandibular sym- 

 physis. These are, however, represented in the next genus 

 Dendrolagus, and occur also in Petrogale. The limbs are not so 

 disproportionate as in Macropus, and the tail is naked at the tip. 



Dorcopsis and the next genus to be described, Dendrolagus, 

 differ from Macropus and its immediate allies, Petrogale and Lagor- 

 chestes, in a number of anatomical points. In the first place, the 

 premolars are twice the size of those of Macrop'us, 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 dis- 

 tribution 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 longi- 

 tudinal 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 Halma- 

 turus 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|- inches) is not 

 sacculated. 



The spleen is Macropodine, being T-shaped or Y-shaped. The 

 differences between Dorcopisis and the evidently closely allied 

 Dendrolagus will be further considered under the description of 



^ rroc. Zool. Soc. 1875, p. 48. 



