1871.] MR. ST. GEORGE MIVART ON HEMICENTETKS. C3 



premolar in front of it, it is much antero-posteriorly extended, i, e. 

 less canine-like. 



The third premolar is nearly contiguous to the second ; it is 

 much simpler than is the homologous tooth in Centetes. The prin- 

 cipal cusp predominates less over the talon ; and sometimes there is 

 a minute cusp in front of the principal one. The tooth is as it were 

 formed entirely of the cingulum, there seeming to be nothing an- 

 swering to the normal principal cusps, still less to any internal cin- 

 gulum. Nevertheless it is probable that the actual principal cusp is 

 really made up of the normal external cusps, plus the cingulum, 

 fused together. 



The first and second upper molars are similar to the last pre- 

 molar, except that the part answering to the normal cusps is more 

 developed, and extending inwards, most so in the more posterior 

 tooth, and showing that the principal cusp of the third premolar 

 is (as before stated) probably of similar nature. The external 

 cingulum develops two low subequal cusps. There is no internal 

 cingulum. 



The third and last upper molar is less in antero-posterior and 

 very much less in vertical extent than is the tooth in front of it. 

 Also the cingulum bears a smaller proportion to the rest of the 

 tooth, which thus comes to consist of two subequal parts, one ex- 

 terior, the other internal. All the molars are contiguous to each 

 other and to the third premolar. 



In the lower jaw the six incisors are much closer together than 

 are those of the upper jaw. This is less due to their implantation 

 than to the lateral expansion of their crowns. They are less ver- 

 tinally extended than are the upper ones, and each expands upwards 

 from the root to the cutting-edge. 



Fig. 5. 



^£S 



Teeth of lower jaw, four times the size of nature. 



The canine is very much smaller, relatively as well as absolutely, 

 than in Centetes. It is not received into any fossa in the upper jaw. 

 It is a much curved conical tooth, with a considerable posterior cusp 

 at its base. The first premolar, in size and shape, is quite like the 

 canine in front of it. It is separated from the latter by a consider- 

 able interval. 



The second premolar is quite like the first lower premolar of 

 Centetes. In consists of three unequal cusps, without any internal 

 production. The middle cusp is much the largest, and curved and 

 pointed like the principal cusp of the first premolar. 



The third premolar projects inwardly hardly, if at all, more than 



