^34 Bulletin American Museum of Natural History. [Vol. X, 



the first premolar, a moderately well developed tooth, with a 

 compressed, internally grooved, pointed, recurved crown, very 

 similar to the lower canine of Aiichenia. After a relatively long 

 interval follows the fourth premolar, which with the molars makes 

 a continuous series. The fourth premolar is relatively more robust 

 than that of the Llama or Dromedary, and gives evidence by this 

 fact of a less reduced condition. Its form is the same as in these 

 two genera. The molars display the same structure as those of 

 the later Cameloids in general, except the second and especially 

 the. third show the first indication of the external buttress so 

 characteristic of Aucheuia. The two rami are firmly coossified at 

 the symphysis. I distinguish the species from Camelus drome- 

 darius by the relatively small incisiform canine, as well as by the 

 less reduced fourth premolar and much smaller size. A compari- 

 son of the measurements of this species with C. dromedarius and 

 A. lama are herewith given : 



Length from incisive border to end of 

 last molar 



Length of molars and fourth premo- 

 lar 



Length from incisive border to fourth 

 premolar 



Eschatius conidens Cope. 



The last of the American Cameloids to be considered is this 

 species which, so far as we are now aware, was the most special- 

 ized of the C'amelidie. As already noted, the characters which 



Fig. 22. Crown view of lower teeth of .4 iicketn'a lama. 



distinguish this group from all others is found in the extreme 

 reduction of the fourth superior i)remolar to a simple cone, as 

 originally pointed out by Cope ; this is associated with a marked 

 reduction in size of the lower canine. The specimens from which 



