No. 2391. DESCRIPTIONS OF PLEISTOCENE VERTEBRATA—HAY. 625 



the fossil bone would be about 130 mm. That part present, from 

 the front of the odontoid process to the rear of the neural arch, is 

 125 mm. long; and there is still no indication of the ridges that must 

 have run forward from the postzygapophyses. The width of the 

 bone, across the front end is 50 mm. The width, 80 mm. behind 

 the front end, is 26 mm.; the height, 39 mm. On the part of the 

 bone preserved there are no, or very obscure, indications of the 

 wing-like transverse processes that are present on the axis of 

 the llama and that of the dromedary; nor is there any beginning 

 of the posterior enlargement of the median ridge on the lower face; 

 likewise none of the posterior enlargement of the crest of the 

 neural arch. 



The fragment of cannon bone (pi. 124, fig. 4) is 288 mm. long. It 

 is complete above, but does not quite reach the split at the lower end. 

 The hinder face is occupied by a broad groove. At the upper artic- 

 ular surface the side-to-side diameter is 44 mm.; the greatest fore- 

 and-aft diameter, 40 mm. At a point 125 mm. below the upper 

 articular surface the fore-and-aft diameter is 32 mm. on the outer 

 face; 25 mm. in the median plane. Figure 8 of plate 120 presents a 

 section at this point. The lateral faces are convex and nearly 

 parallel; the front face is rounded. At the lower end the fore-and- 

 aft diameter is 22 mm.; the side-to-side diameter, 28 mm. This 

 bone is to be compared with the corresponding one of P. minimus. 16 

 Similar parts of the two bones are preserved. The two agree in 

 having a strong ridge running down in front of the process at the 

 rear of the upper articular surface. In this they differ from both 

 the dromedary and the llama. A comparison of figure 8 of plate 120 

 and figure 9 of plate 120 will show that the cross sections, taken 125 

 mm. below the upper ends, are very different. In section the bone 

 of P. major resembles that of the dromedary, while that of 

 P. longurio is not greatly different from the corresponding bone of 

 the llama. Two first phalangeals (Cat. No. 101 6S) are present and 

 are taken to be the anterior. One has lost the epiphysis. The 

 other is here illustrated (pi. 123, fig. 3). 



The following comparative measurements are given: 



Measurements of anterior first phalangeals. 



Length of bone in itsmodian plane 



Fore and aft diameter of upper articular surface 



Side-to-side diameter of articular surface 



Width of distal articular surface 



Fore-and-aft diameter at middle of bone 



Side-to-side diameter at middle of bone 



18 Leidy and Lucas, p. 60, pi. 16, fig. 1. 



27177— 21— Proc.N.M.vol.59 40 



