312 TAPIBOIDA. 



Pachyderms by reason of their vastly superior size, the 

 latter also having the two ridges of the grinding surface 

 relatively thinner and higher ; and limiting the present 

 comparison to those molar teeth of the animals more 

 nearly equal in size to the species indicated by the fossils ; 

 we find that the molars of the Kangaroos, both recent 

 and extinct, differ in the longitudinal ridge which unites 

 together the two transverse ridges, by crossing the middle 

 of the valley ; while those of the Manatee have the two 

 principal transverse ridges lower and thicker, their angles 

 are not bent forward, the posterior transverse basal ridge, 

 or " talon," is relatively larger and higher, the anterior 

 talon is wanting, and the fangs descend in parallel lines, 

 or slightly converge near their extremities. 



The fossil tooth in question, on the other hand, com- 

 bines the more obvious and common character of the 

 double-ridged grinding surface with those minor modifica- 

 tions, which distinguish the molars of the Tapir from those 

 of the Kangaroo and Manatee. Both angles of the ridges 

 are slightly bent forwards, making the fore-part of each 

 ridge concave ; a secondary ridge is continued from the 

 outer angle of each of the primary ones, from the posterior 

 one to the intermediate valley, from the anterior one to 

 the anterior basal ridge, or talon. From this talon a 

 ridge extends along the outside of the base of the anterior 

 primary ridge, and swells into a small tubercle at the 

 outer angle of the middle valley : this little character is 

 repeated, also, in the molar teeth of the Tapir ; but not 

 in those of the Kangaroo or Manatee. Compared with the 

 corresponding tooth, viz. the third or fourth molar, right 

 side, lower jaw, in the American or Indian Tapirs, the 

 following differences are noticeable : the anterior principal 

 transverse eminence is relatively smaller in the fossil, and 



