Peterson: The Osteology of Promerycochcerus. 



181 



I)()silion of the spine, so that the supra- and infraspinous fossa^ are 

 subcqual, more as in Sks and Ilippopotanms than in the ruminants. 

 The acromion process, however, is very strongly developed, unlike 

 that in Sits and even more prominent than in the most of the recent 

 selenodont Artiodactyls, but it has not attained the great development 

 seen in the hippopotamus. The spine is prominent, quite heavy, and 

 greatly overhangs the inlraspinous fossa. The metacromion process 

 is as well developed and points downward and backward fully as 

 much as in Mesoreodon chc- 

 lonyx Scott and Merycoidodon 

 ciilbertsoni Leidy, here used 

 for comparison.^" The acro- 

 mion process points in the 

 opposite direction at least 

 equally as much as in the 

 latter species, i.e., the meta- 

 cromion process points down- 

 wards and backwards, while 

 the acromion process is re- 

 curved from the main axis of 

 the spine and points down- 

 wards and forwards (see Fig. 

 26). The glenoid cavity is 

 comparatively large, the co- 

 racoid is heavy, quite rugose, 

 and has a somewhat large 

 coracoid process, which, how- 

 ever, is not relatively as ro- 

 bust as in the hippopotamus. 

 The neck is also longer than 



that in the latter, and is more nearly as in .S'/rv. The glenoid border is 

 heavy and the upper half of its length is curved outward, thus forming 

 togetherwith the curved posterior face of the spine, a very concave, deep, 

 and subtriangular infraspinous fossa somewhat as in Siis. Superiorly 



'0 The metacromion process of Merycoidodon perhaps varies in its development. 

 Scott state? ("The Mammalia of the Deep River Beds," Trans. Amer. Philos. Soc, 

 Vol. XVII, 1893, p. 135): "No other genus of the family [besides Mesoreodon] 

 has j-et been found in which a metacromion occurs. ... In Oreodon there is no 

 metacromion." Wortman speaks of a metacromion in Merycoidodon. BidLAiner. 

 Mus. Nat. Hist., Vol. VII, 1895. p. 152. 



Fig. 26. External view of left scapula 

 of Promerycochcerus carrik*^ri. No. 1047; § 

 nat. size. 



