R. S. Lull — Fauna of the Dallas Sand Pits. 175 



Equus cf. fraternus Leidy. 



Cat. No. 1.61, S. M. U., a cannon-bone (mcp III), and 

 No. 1.56, the distal halves of two right humeri, are all 

 the horse material in the present collection. They repre- 

 sent a small horse or horses near to if not identical with 

 Equus fraternus Leidy. I have compared them with the 

 skeleton of a recent pony in the museum of the Yale Zoo- 

 logical Laboratory, with the following results : 



No. 1.61 



B. cabdllus Ratio S. M. U. 



mm. mm. 



Molar 1, fore and aft diameter. . 22 1.07 28.5* 



Cannon-bone, length 207 1.06 220 



Breadth, prox. end 46 0.91 42 



Breadth, mid-shaft 44 0.88 40 



Breadth, dist. end 29 1.09 31 



Humerus, breadth, mid-shaft ... 30 1.23 37 



Breadth, dist. end 70 1.10 77 



Ant.-post. diameter, dist. end. . 66 1.21 80 



Average ratio 1.07 



* Taken from IE. fraternus, No. 9217, U. S. N. M. See Gidley, Bull. 

 Amer. Mus. Hist., vol. 14, 113, 1901. 



The ratios of teeth and cannon-bone are very close, 

 the apparent discrepancies being due in part to erosion 

 of the present fossil. The humeri, on the other hand, 

 seem to pertain to slightly heavier horses, but the range 

 of individual variation within the species might account 

 for the difference in size. 



Elephas columhi Falconer. 



The proboscidean material from the Lagow sand pit 

 now in my hands includes a tooth. No. 1.54, S. M. U., and 

 a cervical vertebra, No. 1.55, S. M. U. The tooth is 

 unquestionably from the upper level, having all the char- 

 acters, color, preservation, etc., of the Camelops skull 

 already described. The matrix on the cervical differs, 

 however, resembling that of the camel ulno-radius. 



The tooth appears to be a left upper second deciduous 

 molar, and has four and a half elliptical enamel ridges, 

 having a single plate intercalated between the two for- 



