THOOPTERrs. 



663 



Dentition (tigs. 56, 57). — Dental formula as in C'l/nojiterus : — 



i' i-cp'p p'ni' 



X 2=30 *. 



Upper and lower incisors subterete, i'^ slightly shorter than i'. 

 Upper canine with a broad and deep vertical groove on antero- 

 rucdial surface, extending to base but not quite to tip of crown ; 

 no secondary (cingulum) cusp ; cingulum of lower canine forming 

 a thickened cusp-like lobule at inner base of tooth ending abruptly 

 at level of tips of incisors, p' small, slightly heavier in section 



Pf 



Fig. 57. — A, B, 0. Thoopferus nigrescens (type of species). 



A', B', C. Di/acoptcrus spadiceux (type of species). 



A, A', upper right, B, B', lower left tooth-rows. 



C, C, right p^, p^, aud left pj, p^, viewed from behind. 



■J (linear). 



than an upper incisor ; p, unmodified, p^-m' and Pj-m^ short and 

 very broad, the increased breadth particularly conspicuous in ])^ 

 and mj, which are even much broader than ramus of mandible at 



" Tiie type skull of Tk. nigrcsccns has three lower incisors, without any 

 space left "for the missing one, which is apparently the left i^ (see fig. 5(3 

 front view). 



