70 GEOLOGICAL SURVEY OP TEXAS. 



The molar tooth is about the size of that of. the P. compressus, Lee, 

 while the canine is more robust than any specimen of that species which 

 I have seen. The corresponding parts of the P. vetus, Leidy, are un- 

 known. The P. aleinanii* Duges, from Mexico, is apparently about as 

 large as the P. vetus, Leidy, and exceeds somewhat the present species in 

 dimensions. Casts of the first and second inferior molars of the P. 

 aleinanii were kindly sent me by Dr. Duges, and these display a basal 

 cingulum, which is not present in the last molar of the P. bicaharatus. 

 The posterior faces of the cusps are not keeled. 



PLIAUCHENIA, Cope. 



Proceedings Academy Philadelphia, 1875, p. 278. 



Report U. S. G. Surveys W. of 100th Meridian, IV, p. 340, 1875; 

 American Naturalist, 1886, p. 621. 



Camel bones are abvmdant in the Blanco beds, and their dimensions 

 indicate the presence of two species. But one of these is represented in 

 the collections by specimens sufficiently perfect for determination, and 

 this is a large species of the genus Pliauchenia. This genus has hitherto 

 obtained only in the Loup Fork beds of Santa Fe, New Mexico, where it 

 is represented by species of considerably smaller dimensions than the one 

 now under consideration. 



PLIAUCHENIA SPATULA, CopC. 



Sp. nov. Plate XXI, Figures 1, 2. 



This camel is represented by a mandible which lacks all posterior to the 

 coronoid process of the left ramus and all posterior to the second true 

 molar of the right ramus. Well preserved representatives of all the 

 teeth are preserved. 



The dental formula is that of the P. hv/mp7iresiana, Cope, viz.: I. -^; 

 C. y; P. M. -^; M. ^. The canines are large and distinct in character 

 from the incisors; the fourth premolar is separated from the canine and 

 from the second premolar by long diastemata, and is caniniform. The 

 second and first premolars are without internal valley. The last true 

 molar has a well developed third column. 



The mandibular rami are compressed and of moderate depth, and the 

 symphysis is a little longer than the series of true molar teeth, and its 

 posterior extremity marks the anterior third the distance between the 

 fourth and second premolars. The incisive portion of the mandible is 

 more expanded than in the cameloids generally, to accommodate the 

 large canine and incisor teeth. The region of the masseteric fossa is 

 concave outward, and is thin; the anterior base of the coronoid process 



*La Naturaleza Mexico, 1887, 1, p. 16, plates I, II. 



