PTEEODON ArEICANUS. 



223 



The following specimens are referred provisionally to this species : — 

 C. 8898. Left humerus, somewhat imperfect at proximal end (text-fig. 70). The head (A.) is 

 very strongly convex from before backwards, and less so transversely ; its surface looks 

 nearly as much backwards as upwards. The outer tuberosity (o.t.) is massive and 

 roughened, but it is broken away above, so that its height cannot be observed. The 

 shaft is to some extent laterally compressed till just above the distal expansion. The 



Left humerus of (?) Pterodon africanus : A, from front ; B, from outer side. 



o!., deltoid crest ; «n./., entepieondylar foramen ; A., head ; i.e., inner condyle ; o.c, outer condyle ; o.i., outer 

 (greater) tuberosity ; s.p., supratrochlear perforation ; s.r., supinator ridge, j nat. size. 



deltoid crest [d.) is only moderately prominent, and extends down about two-thirds of 

 the shaft. The supinator ridge (s.r.) is very slightly marked. The inner condyle (i.e.) 

 is moderately prominent, and there is a large entepicondylar foramen (em./.). Both 

 the coronoid and olecranon fossse are large and communicate by a very large supra- 

 trochlear foramen [s.p.). The trochlear surface consists of an inner portion produced 

 considerably downwards, a broadly rounded intercondylar ridge, and a narrower outer 

 portion. The whole bone seems to resemble the humerus of the American species of 



