902 ROBERT COLLETT, 



The teeth. The dentition was in neither of the 2 mature spe- 

 cimens quite normal. The type specimen (F) exhibited the individual 

 irregularity, that in the left lower jaw p^ and the milk premolar 

 were still present , without having been replaced hy p ^ , as in the 

 other jaws ; and no trace can be seen that a p 2 will ever be formed 

 under the functional premolars. 



In the other mature specimen (E) the left upper i^ was unde- 

 veloped. 



Of the incisors in the upper jaw, the central pair are twice as 

 long, as each of the others, and considerably broader. The two outer 

 incisors are about equal in size, and on the whole small. In younger 

 specimens i^ appears to have a trace of a central groove, which 

 disappears in the older ones. The grinding surface of *2 is almost 

 quite triangulär, 



The canine is long, but slender, cylindrical and rather curved. 



The premolar (p^ ) is very long and large, with the usual cutting 

 edge; its anterior portion, divided from the posterior by a shallow 

 incision, is almost as broad as this, but somewhat less, and has a 

 cusp in the centre. The base of the premolar is almost double as 

 large, as the base of m 1 . 



Each of the molars has two transverse ridges; the inner ridge 

 on m* is only half as large, as the anterior. 



The whole row of teeth is almost straight, and only diverges 

 slightly in the middle. 



In the lower jaw the incisors are normal, and, in the mature in- 

 dividuals, extend beyond the margin of the socket about 13,5 mm. 

 The distance between the incisor and the premolar is less than the 

 length of the incisor. 



The premolar (p'^) is as long as, but narrower than the upper 

 one, and its anterior pointed cusp rather shai^ and prominent, and 

 the incision deeper. 



The molars are constructed as in the upper jaw. 



The teeth of the young. The canine had not y et quite risen 

 above the alveolar margin ; p^ and the milk premolar are still in use ; 

 p 2, barely half developed, lies hidden in the jaw above the^r roots. 

 Only the 2 first molars were developed; m^ hidden in the jaw. The 

 outer incisors are very broad. p^ is short and thick, its base about 

 the same , as the base of m 1 . It has a longitudinal cutting edge, 

 which, however, is short, and forms two pointed tubercles. The milk 



