IGO Prof. II. G. Sceley on 



the distal end. It is about H inch lon^;. Beyond this 

 articular surface the unusually expanded radial crest is 

 exposed, so that it is reflected downward, forming an open 

 angle with the head. The measurement from the inferior 

 border of the radial crest to the proximal articular surface is 

 3^ inches, and the extreme width of the proximal end, as 

 preserved, 3| inches. This expanded proximal surface is 

 concave from side to side, with a median depression pro- 

 longed distally till it passes into the ridge which divides the 

 distal end into a narrow oblique internal area, and a wide 

 flattened external area, inclined to the inner surface at a great 

 angle. The proximal articular surface, compressed from 

 above downward, becomes narrower from within outward, and 

 appears to have much the same relation to the radial crest 

 as the corresponding parts of the humerus in Crocodiles. The 

 radial crest at its outer inferior border is fully yu ii^ch thick, 

 and the length of its inferior border, as preserved, is about 

 2y''o inches. At the distal fracture the bone is about lyV inch 

 wide and j% inch thick, and thickest on the inner border. 



Fiff. 9. 



Distal articnlation 



Plight humerus of Palaosanrun. showing part of the distal articulation ; 

 the proximal end is imperfect. Brist. Mus. no. .37. -^ nat. size. 



No. 37 (fig. 9) appears to indicate the length of the bone 

 as being 6;^ inches, w ith the articular ends less perfectly ossified 

 than in Thecodontosaurus ; the large radial crest is prolonged 

 for about halfway down the length of the humerus. There 

 a]jpear to be two condyles at the distal end, which measure 

 about 1 ,% inch from side to side as preserved. There is a 



