Vol. 4] Sinclair. — Mammalia from Quaternary Caves. 



157 



lower, the posterior molars are of the same size as in that 

 species. 



The scapula (PI. 22, fig'. 1) is broken anteriorly, and lacks 

 the supraspinous fossa, the scapular spine, and the coracoid 

 process. These parts had disappeared before the specimen was 

 discovered. At the anterior border of the glenoid fossa there is 

 a rough surface for the attachment of a glenoid epiphysis like 

 that found in young individuals of Megalonyx jeffersonii. 



The glenoid fossa as preserved in the cave specimen is much 

 longer and wider than in jeffersonii. 



The anterior extremity of the superior border of that part 

 of the scapula preserved is greatly thickened; the posterior 

 extremity much less so. The posterior scapular border is 

 strongly concave antero-posteriorly, differing in this respect 

 from jeffersonii .* 



The subscapular fossa, so far as preserved, is smooth and 

 basin shaped, without the alternation of ridges and sloping 

 surfaces described by Leidy for jeffersonii:* 



The supraspinous fossa is not shown, and the thickening 

 of the anterior border mentioned above represents the base of 

 the scapular spine. The infraspinous fossa is convex in all 

 directions, with a low median ridge. In jeffersonii both fossae 

 on the lateral surface of the scapula are deeply concave. t 



No foramina are indicated beneath the thin layer of stalag- 

 mite which preserves the specimen. 



The scapho-trapezius (PL 20, figs. 7-8, s-t) is irregularly 

 tetrahedral in shape, with a broad convex proximal facet for 

 the radius. Distally, the most prominent facet is that for the 

 trapezoid, which extends from the dorsal almost to the palmar 

 margin of the bone, while in jeffersonii it is broadly separated 

 from the latter. The facets for the magnum and lunar are not 

 well preserved, as the specimen has suffered considerably from 

 decay which has reduced its dimensions at several places. A 

 similar though slightly larger and somewhat less complete bone 

 was obtained from the Potter Creek Cave (No. 8201) . 



* J. Leidy, op. cit. PL VIII, fig. 3. 

 t Ibid. pp. 24 and 25. 

 t Ibid. p. 25. 



