454 AXNALS OF THE CaRNEGIE MuSEUiM. 



and extends in a curved line nearly to the suj^erior border, dividing 

 the blade into a greater post- and lesser pre-scapula. Superiorly the 

 scapula is comparatively much broader than that of the camel, which 

 has a long'and slender scapula with the pre- and post-scapulae more 

 nearly equal. The acromion is broad. 



The Humerus. — (PI. VIl, Figs. 2 and 3.) With the exception 

 of the tuberosity, the humerus of the cotype (No. 886) of this 

 genus is well preserved. Other material in the museum collec- 

 tions supplement this and the humerus agrees in its chief characters 

 with Cope's description of that in Procainehis occidentalism^ Of the 

 latter Cope says, " The humerus is rather slender, and is characterized 

 by the large size of the tuberosi.ties. They are connected at their 

 bases, the connecting mass enclosing a deep fossa with the head, or 

 condyle. The greater tuberosity is produced much beyond the head 

 proximally, but not much beyond the line of the anterior border of 

 the shaft." In the cotype the head is comparatively as large as that 

 of the llama, and fully as convex. From material at hand it appears 

 that the bicipital groove is so situated that in a direct front view it 

 appears on one side while that of the camel and the llama is exactly 

 .in front. The deltoid ridge and hook, as well as the supinator ridge, 

 is fully as well developed as in the recent forms. The distal end of 

 the humerus is proportionally narrow, and as in PoehrotJieriuui the 

 trochlea is more oblique to the long axis of the shaft and extends 

 higher up on the bone posteriorly than it does in the llama. In 

 Camelus this character is more nearly like that in O. loiigipcs. The 

 internal epicondyle has a greater development in O. loiigipcs than in 

 the recent forms. The external epicondyle is less developed and is 

 more like that of the recent camels. The anconeal fossa is narrow 

 and high. There is no evidence of a supratrochlear foramen. The 

 appearance of the humerus aside from the greater development of the 

 tuberosities, compares closely with that of the llama. The deltoid 

 crest is turned backward. The bone is light, in harmony with the 

 slender proportions of the limb. 



Tlie Ulna and Radius. — (PI. VIII, Fig. i.) There is preserved in 

 the type only the proximal end of the ulna and radius. The cotype 

 (No. 886) has both bones present. The two bones are as com- 

 pletely coussified as in the recent forms. The shaft is as straight as 

 that of the camel and- less curved than that of the llama. The head 



'1 " U. S. Geogr. S.," Part II, Vol. IV, p. 533, 1877. 



