DAKOTA AND NEBRASKA. 157 



or the South Fork of the Makisi-ta-Wakpa. These were found together with nume. 

 reus remains of solipeds and other animals in loose sand belonging to a formation 

 like that of the Niobrara River, which has yielded so many fossils. The fragments 

 alluded to are apparently intermediate in proportions with those referred to Proca. 

 melus rohusiiis and P. occidentalis, leading me to suspect that these are really of the 

 same species, the more robust remains probably pertaining to the male, the other to 

 the female. 



The specimens consist of the following : 



1. A small fragment of the lower jaw, containing the second premolar, or the first 

 of the continuous series. The tooth is like that of Pvcamelus robustvs, represented 

 in figure 1, h, plate XV, but is smaller, the crown measuring 4| lines long and 5i 

 lines broad. 



2. A small fragment of the right side of a lower jaw, containing the third pre- 

 molar. The tooth has the same form as that in P. rohustus and P. occidentalis, rep- 

 resented in figure 1, 6, c, plate XV. Its breadth is 8 lines, its thickness posteriorly 

 3i lines. 



3. The symphysial portion of a lower jaw, containing the canines on both sides, 

 the median pair of incisors and one lateral incisor. This specimen, represented in 

 figure 5, plate IX, is interesting, as it proves that the anterior extremity of the 

 lower jaw, and the form, number and relation of incisor and canine teeth of Proca- 

 melus are the same as in the existing Camel. The canines are proportionately not 

 quite so well developed as in the latter. In the specimen, the teeth are all consider- 

 ably worn, including the apices of the canines. The breadth of the latter at the base 

 of the crown is 7 lines, the thickness 4 J lines. The distance between the outer part 

 of the bases of the crowns of the canines is 23 lines. 



Accompanying the jaw fragments from Little White River, there are several speci- 

 mens of first phalanges, resembling in form those of the Camel, but longer in pro- 

 portion with their breadth, which probably belong to Procamelus. Two specimens 

 of the same form present the following measurements : 



Length through the axis, ..... 

 Breadth of upper articulating surface, 

 Width of do. from before backward at the middle, 

 Breadth of distal articular surface behind, 



Lines. 



Lines. 



45 



40 



16 



13 



12 



10 



13 



12 



