XI. 



CETEOSA UR US TIBIA . 



283 



cartilage a constant fact in all the long bones which gives the 

 appearance of deficient epiphyses. 



The lower part of the bone, on the front, is marked by a tri- 

 angular depression, much as in megalosaurus, but not so sharply 

 denned. The corresponding part in a crocodile is convex, and gives 

 the idea of the ascending process of the astragalus being separated 

 from its base and anchylosed to the tibia ; while in megalosaurus 

 the connection remains, and the ascending process is not joined by 

 synostosis to the tibia. In this way of regarding the bone, ceteo- 

 saurus would be allied to megalosaurus, and not to crocodile. 



Diagram CX. Tibia of young Ceteosaurus. Scale, one-tenth of nature. 

 i. The view from behind, right side. 2. The view from the front. 



One specimen of tibia has also been obtained from a young 

 animal, corresponding with the humerus already noticed. It 

 agrees in all essential points with the larger bone, but has yielded 

 more to pressure, and is less complete at the lower end. Length, 

 21-35 inches; breadth, upper 9-5, lower 6-35; greatest depth 

 (crushed), 3-3,5 (Diagram CX.). 



Small Fibula Length, 2675 inches ; breadth at the wider end, 

 6-5 ; in the narrowest part of the shank, 3-0 ; at the smaller ex- 

 tremity, 4-9. This bone is of a nearly symmetrical form, rather 

 slender, and compressed. It shews no protuberances or asperities ; 

 the two terminal faces are nearly parallel, and the smaller is of 

 a flat oval figure; the other curved, to fit the hollow surface of 

 the bone. 



