BETTONGIA. 41 



Genus tV. BETTONGIA, Gray (1837). 



Rhinariuru wholly naked. Ear very short and rounded. Fore 

 claws long and strong. Hind feet longer than the head, the soles 

 naked and coarsely granulated. Tail more or less prehensile, 

 thickly hairy, with a more or less distinct crest. 



n .-, T 1.2.3 /-i 1 -D 0.0.3.4 I.. 1.2.3.4 o Q) 



Dentition. i. ^ C. , P. ^^, M. ^^ x 2 = 34. 

 Habits. Terrestrial ; herbivorous. 



Note. It occasionally happens that a fifth molar is present 

 either in one or both rami of the upper jaw, or even in both rami 

 of both jaws, so that, as Mr. Oldfield Thomas remarks, while 

 having the comparatively highly specialized characters of the 

 other members of the family, this genus presents the remarkable 

 condition of retaining such an ancient and generalized character 

 as the possession of more than four molars. On the other hand 

 the fourth molar is often aborted. The members of this genus 

 alone among terrestrial mammals possess prehensile tails, which 

 they use for carrying grass, sticks, <fcc., these being firmly held by 

 the tail being twisted downwards upon them. The four species 

 are very similar to each other externally, so much so that no 

 reliance can be placed on any determination which does not rest 

 upon an examination of the cranial and dental characters. 



1. BETTONGIA LESUEURI, Quoy & Gaimard, sp. (1824). 

 Lesueur's Rat -Kangaroo. 



Fur soft, close, and thick. General color above grizzled gray ; 

 below white ; sometimes an indistinct white hip-mark. Arms 

 and legs white ; hands and feet white or pale brown ; hairs of the 

 latter long and bristly, nearly covering the claws. Tail colored 

 above like the back, the upper hairs not forming a distinct crest ; 

 below pale brown or white ; the tip white. 



Dimensions. Head and body about eighteen inches; tail about 

 twelve inches. 



Habitat. South and West Australia. 



References. Thomas, B.M. Catal. p. 112, pis. xiii. figs. 6 and 7 

 (teeth), xiv. fig. 7 (nasals), 8 (bulla); Gould, Manim. Austr. ii. 

 pi. Ixiv. 



2. BETTONGIA CUNICULUS, W. Ogilby, sp. (1838). 



Tasmanian Bat-Kangaroo. 



Fur and general color as in B. lesueuri, but without trace of 

 hip- mark. Arms, legs, hands, and feet white ; hairs of latter as 

 in B. lesueuri. Tail above as in B. lesueuri, except that towards 

 the end it occasionally becomes dark brown or black ; below dirty 

 white ; tip sometimes white all round. 



