AMERICAN JURASSIC PLESIOSAURS 351 
similar. A comparison with the description of the following salient 
features of T. seeleyi Andrews will show the similarity of these two 
forms. 
The fore limb is peculiar in several respects and differs considerably from 
that of Cryptocleidus and Muraenosaurus; its most striking characteristic 
ve a a 
Se 
- 3d 
Fic. 3.—Muraenosaurus reedii. 3a, coracoids, 3b, lateral ventral ribs, 3c and 3d, 
median ventral ribs, all xt. 
is that the humerus articulates distally with four bones—three, the radius, 
ulna, and pisoform, being large, the fourth a small postaxial accessory ossicle. 
The humerus is short and stout; the head is round in outline and convex; at 
its upper anterior border it is continuous with the surface of the strongly 
developed tuberosity. This is bounded both in front and behind by strong 
- ridges, which extend down a little on the shaft; its upper surface is flattened, 
and a little below its upper border there is a well-marked rugosity for the 
