CONDYLAETHRA. 421 



extends much in front of the internal tubercle. There is no anterior 



inner tubercle, nor are there any cinguki. The enamel of the sides of the 



croATO presents a few vertical ridges. The last inferior molar only differs 



from the second in the greater size of the median posterior lobe, which is 



nevertheless smaller than in the two other species of Haploconus. 



There is a mental foramen below the posterior edge of the alveolus of 



the second inferior premolar. 



Measurements. 



M. 



Length of last five inferior molars 0250 



Length of third premolar 0050 



Length of fourth premolar 0066 



Length of second true molar 0050 



Width of second true molar 0032 



Length of third true molar 0050 



Depth of ramus at Pm. iii 0095 



Depth of ramus at M. iii 0130 



The two rami witli the temporary premolars exhibit the last true molar, 

 inclosed in the jaw. The third and fourth premolars are much like the 

 fourth premolar of the specimen above described, but the foui-th is a little 

 more robust than that of the latter, which is very much like the third of the 

 deciduous series. The space occupied by the supposed first premolar of 

 the type specimen is too short for the fourth premolar of the deciduous 

 series, otherwise it might l)e supposed to have occupied that position. The 

 two true molars resemble those of the type, excepting that the last one does 

 not extend so far into the base of the coronoid process, and its posterior 

 lobe is smaller, in accordance with its position as No. two in the series. 



The specimens were procured by Mr. D. Baldwin in the Puerco beds 

 of New Mexico. 



Haploconus entoconus Cope. 



American Naturalist, 1882, p. 686. 

 Piute XXV/,- figs. 4-5. 



This is the largest species of Hcq)Joco)ms, and repi'esents a group in it 

 slightly different from that which is typical. Mr. Baldwin has sent me frag- 

 ments of the skulls and jaws of seven individuals, so that its molar dentition 

 is entirely known. 



The premolars are more robust than the molars in this species. The 

 third of the superior series has a subti'iangular base, with broadly rounded 

 angles. The crown is absolutely simple, the apex having a nearly round sec- 



