xi. CETEOSAURUS FORE-LIMB. 271 



scapular margin (incomplete), 18 inches; if complete, probably 

 20; breadth between scapular and sternal margins, 18-5 inches; 

 greatest thickness, 5-0. 



The two bones are not quite alike ; one is much thicker toward 

 the anterior margin, and seems to have had a deeper and narrower 

 sinuosity behind the glenoid surface, but it is much crushed in 

 that part. 



Scapula. A pair of these fine bones, belonging to the great 

 ceteosaurus of Enslow Rocks, was carefully dug up ; and, as well 

 as the thinness and feebleness of parts of the bone allowed, both 

 have been restored. The length is 54 inches ; the breadth where 

 greatest, near the coracoid, 26 ; where least, at about half the length, 

 10 inches in one, and 9 inches in the other \ near the upper edge, 

 now broken away in each case on the anterior side, when complete, 

 20 inches. The upper part of the bone, for a space of 3 inches, has 

 a peculiar structure, which seems to have been cartilage incompletely 

 ossified. The outline is very concave on the anterior edge for two- 

 thirds of the length; then it becomes convex in a semicircular 

 curve; the posterior edge is undulated, but on the whole almost 

 straight to near the glenoid cavity, which has a prominent upper 

 border. The upper edge is truncate, the lower projects in the 

 middle. 



The surfaces, nearly plane in the upper part, become undulated 

 below ; on one side the middle is convex for half the length (see left- 

 hand figure in Diagram XCIX.) ; from this point the convexity 

 subsides, and is replaced by a diverging depression, which presently 

 is followed by a broad, even concave sweep, reaching to the lower 

 edge. This is supposed to be the outer surface. 



The other side is ridged parallel to the posterior edge, the 

 ridge continuing to the border of the glenoid cavity ; towards 

 the anterior edge the bone is rounded in the middle, and undulated 

 and broadly depressed in the lower part (see right-hand figure, 

 Diagram XCIX.). 



It is somewhat difficult to determine the external and internal 

 sides of this bone, for it differs materially from other known scapulae. 

 There is a delusive resemblance to the corresponding bone in the 

 crocodile. 



Humerus. A fine pair of these bones belonging to the larger 

 animal, quite complete, shews as great a difference in proportion 



