An Almost Perfect Shell of a New Primitive Theriodont. 205 



festly due to crushing. From Seeley's figure of the specimen 

 (Fig. 31) one would be led to believe that the depression was 

 bordered in front by a crescent of bone, but in the specimen this 

 is seen to be a crescent of remaining matrix. As Cynognathus 

 crateronotus and other species of the same genus have only one 

 canine present it is manifest that the presence of two canines in the 

 snout of Cynognathus platyceps is a temporary condition. 



In the skull which forms the type of Trirachodon Kannemeyeri, 

 Seeley, there is seen in front of the canine on one side the point of a 

 second canine which resembles the anterior canine of both Cyno- 

 gnathus and Lycosuchus in being serrated in front. 



We may therefore assume that the anterior canine is morphologi- 

 cally equivalent to the permanent mammalian canine and that the 

 posterior corresponds to the deciduous canine of the mammal. It is 

 quite probable, however, that both teeth are retained as functional 

 for a considerable time in Lycosuchus and possibly also in the higher 

 Theriodonts. This is rendered the more probable from the fact that 

 the posterior canine which is the first to be developed is a much 

 more powerful tooth than the other and also from the fact that the 

 anterior canine is peculiarly specialised, as if developed for some 

 function slightly different from that of the large canine. 



