46 



and sharp pyramidal crowns, with strong basal ridges sepa- 

 rated from the acute blades by deep clefts. Between the 

 incisors and the canine there is a long diastema. 



The canine is of great size ; it has a swollen fang, and a 

 long recurved crown which is much compressed, and has 

 sharp serrated cutting-edges. The external face is the more 

 convex, the internal has a well-marked basal ridge, and both 

 are longitudinally striated. The canine is separated from 

 the premolars by a short diastema. 



Premolars. — The first premolar stands by itself, separated 

 by a short interval from the second. It is implanted by two 

 fangs, and has a compressed crown with sharp cutting-edges. 

 It is nearly twice the size of the corresponding tooth in 

 Palceosyops, which is simple and conical. In the specimen 

 under description there is, besides the principal lobe of the 

 tooth, a rudimentary anterior lobe which gives the crown an 

 elongate shape. The basal ridge is shown on the inner side 

 only. The second premolar has a crown which is oval in 

 section. The external part consists of two shai'p-pointed 

 cusps, separated by a valley, but confluent at base ; while the 

 internal division is a low ridge (not a pointed cone as in 

 PalcEosyops) with a tubercle developed behind it. The basal 

 ridge is marked all around, and sends up a buttress along the 

 antero-external lobe ; as is also the case in the third and 

 fourth premolars. These are enlarged copies of the second ; 

 but have the internal lobe elevated into a sharp cone, and 

 showing a much stronger basal ridge and deeper median val- 

 ley. These teeth differ in several respects from the premolars 

 of PaliEosyops. The crowns are higher and the lobes sharper ; 

 the basal ridge is more distinct, and is not interrupted at the 

 mternal cusp; the external ascending buttress is stronger; 

 and there is no fold between the external lobes of the fourth. 



The molars are constructed in a manner which resembles 

 that of P. pahidosiis rather than of P. major, but its resem- 

 blance to the form shown in Titanotheriiim is stronger than 

 to either. They have broad, square crowns, which increase 

 progressively in size from first to last. There is a convexity 

 running up the median line of the external lobes, and the two 

 posterior lobes are connected together at their bases. The 

 first molar does not exhibit such a decided increase in size 



