122 BitUetin American Museum of Natural History. [Vol. XII, 



lacking. The only important character in which it differs from 

 Vulpavus is seen in the nearly equal size of the two external cusps 

 of the first superior molar, whereas in Vulpavus the anterior 

 greatly exceeds the posterior in size. This at first sight would 

 seem to be of little significance, but the primitive condition was 

 undoubtedly the one displayed by Vulpavus., and the more ad- 

 vanced one that of Procynodictis and Cynodictis. It therefore 

 represents a distinct advance. The other teeth are very similar 

 in their structure to those of Vulpavus and need no special 

 mention. 



The hind foot contains five toes ; the metapodials are shorter 

 and somewhat heavier than in Cynodictis., in which the hind foot 

 had already begun to assume the elongated form so characteristic 

 of the modern Canidae. The tarsal bones are very like those of 

 Cynodictis, as are also the remainder of the podial elements. The 

 claws are much compressed laterally, with heavy subungual pro- 

 cesses, and the middle phalanges are unsymmetrical, indicating 

 some degree of retractility of the claw. 



The fore foot also contains five toes, but, as in Cytwdictis, it is 

 ^ much shorter than in any of the modern 



Canidae. The scaphoid, lunar, and cen- 

 trale are completely co-ossified as in the 

 modern Dogs, without any trace of suture, 

 into a scapholunar, which differs from that 

 of Cynodictis, according to Scott's figure, 

 in the greater vertical depth anteriorly, 

 which is again a more primitive condition. 

 The other carpals have practically the 

 same proportions as in Cynodictis. The 

 fore foot of Vulpavus is unknown, but it is 

 more than probable that the scaphoid and 

 lunar were separate in that genus, which if 

 true will constitute an important difference 

 between it and the present genus. 



sc/ 



Fig. 8. Procynodictis vul- 

 piceps W. & M. Fore foot, 

 three halves natural size. No. 

 2506. 



IV. — Notes on a Skeleton of Cynodictis 



GREGARIUS. 



In the American Museum Collection, Expedition of 1898, is a 

 nearly complete and very well-preserved skeleton of Cynodictis 



