98 SINCLAIR— A NEW HOPLOPHONEUS. 



From the table of measurements it will readily be seen that 

 Hoplophoneus mentcdis is considerably smaller than the large H. 

 occidentalis, approximating in size individuals of the insolens and 

 robustus groups. A comparison with the specimens in the Prince- 

 ton collection used by Adams in defining these two forms shows that, 

 although the jaw depth back of the flange is the same in H. robustus 

 and H. insolens as in the new form, the flange is absolutely larger in 

 the latter and tapers less rapidly in width distally ; both premolars 

 are smaller, and in p4 the paraconid is disproportionately smaller, 

 than in H. insolens (Princeton Univ. Geol. Mus. No. 11372) and is 

 out of line with the other two cusps, toward the inner side of the 

 jaw as in Eusmilus and hoplophonids in general, and has sharper 

 cutting edges than in //. insolens; also the alveolus for mi is very 

 much wider transversely, in front, than in the latter species. Be- 

 tween H. robustus and H. mentalis there is the same striking differ- 

 ence in the shape of the jaw flange, which is decidedly V-shaped in 

 robustus, while in the new species it is U-shaped and of the Eusmilus 

 type. The third premolar is as small as in robustus, but rakes back- 

 ward a bit stronger and has a larger posterior cuspule. To the 

 paraconid of p4 the same remarks are applicable as in the compari- 

 son with H. insolens. 



