XIII. 



LIMB BONES. 



363 



a large trochanterial prominence. The distal extremity is defined 

 by a simply convex curve, or has two broad emarginations, or two 

 broad and one narrow emargination. The shank is laterally com- 

 pressed in some, but has nearly a circular section in others. 



The largest, from Swindon, is represented in Diagram CLIX., 

 and is referred to as P. macromerus, p. 357. 



The dimensions have been given on p. 357* There is a rough 

 wrinkled surface below the head, on the outside. There is a 

 fragment of a larger specimen. The small depth of this bone at 

 the proximal end is remarkable. 



Diagram CLX. Humerus of Pleiosaurus brachydeirus. Scale one-tenth of nature. 



The dimensions have been given on p. 354. 



Diagram CLXI. 



Femur of Pleiosaurus grandis. Owen. 1838. 

 of nature. 



Scale one-tenth 



