. ^ '20 



Peocamelus angustidens, Sp. IIOV. 



Eepresented by the nearly entire mandibles, with most of the teeth of 

 two individuals, and two superior molars referred, with probability, to 

 the same. 



This camel is the size of the P. rohustns Leidy, but differs from it in 

 the much narrower teeth, especially the last molar and last premolar, 

 the much smaller first molar, and totally different form of the second 

 premolar. Thus, while the last molar has the same length, it supports 

 an anterior expansion, whose angles are the summits of ridges on the 

 inner and outer sides of the crown, which are wanting in P. rohustus. 

 Behind the outer rib in P. angustidens there is a considerable groove. 

 While the M. 3 is as large as that of P. rohustus, the M. 1 is 

 strikingly smaller ; while the P. M. 3 is about as long, is onh' half as 

 ■wide when worn to the same degree. The second premolar, instead of 

 presenting a contracted subconic crown, is longitudinally extended and 

 compressed, resembling closely the third premolar. The molars are 

 remarkably flat on the outer side, each lobe being devoid of a median 

 ridge, and the first and second even wanting that between the lobes. 

 The diastemata are long, and the first premolar is compressed and 

 equi-distant between the canine and the second premolar. The dias- 

 tema in front of the canine is not wider than one tooth. The lower 

 incisors are broad and oblique. The lower posterior boundary of the 

 symphysis is almost immediately below the first premolar. 



Measurejnents. 



Total length of dental series to 1. i 0.240 



Length from first to third incisor on crowns 035 



Length from first incisor to canine 040 



Length from first incisor to first premolar 073 



Length from first incisor to second premolar 103 



Length of molar series 134 



Length of pre-molars 2, 3, 4 039 



Length of second premolar 010 



Length of fourth premolar , 016 



"Width of fourth premolar, (half worn) 005 



Length of first molar, (half worn) 019 



Width of first molar, (half worn) 014 



Length of third molar 047 



Width of third molar, anterior column 013 



In the second specimen the molars are a little narrower. 



Peocamelus heteeodontus sp. nov. 



Eepresented by the right distal portion of a mandibular ramus, with 

 incisor, canine, and premolar teeth, and by the greater part of the den- 

 tition of the premaxillary and maxillary bones. These indicate an an- 

 imal of the size of the species last described. 



An interesting fact in the strncture of the genus is indicated by these 

 specimens, namely, that the premaxillary bones support a full series 

 of incisor teeth, a fact not heretofore known, as the pieces in question 

 have not been previously identified by authors. The median incisors 

 were inserted into rather small sockets and were separated by diaste- 

 mata from the third or caniniform incisor, from each ol her, and from the 

 anterior extremity of the bone. 



A second result of the investigation is that the genus Homocamelus 

 Leidy is probably the same as Procamelus, and that H. caninus should 

 be regarded as the P. rohustus, unless new evidence exists to the con- 

 trary. The former was established on dentition of the upper series 



