u 7 3 



CLASS REPTILIA. 



would agree better with a dorsal vertebra from the. same deposits 

 subsequently described as Bothriospondylus robustus. This vertebra 

 is somewhat longer than the dorsals of C. oxoniensis, but need not 

 be generically distinct. In Cetiosaurus the caudal vertebrae have 

 no distinct postzygapophyses, and articulate by two facets with the 

 chevrons, of which the upper extremities are not united, as in Cro- 

 codiles. The scapula is much expanded at its distal extremity, and 

 the humerus, though long, is wider and shorter than in the Euro- 

 pean forms mentioned among the AtlantosauridcE. The ischium 

 appears to be of the same general type as that of Morosanrus (fig. 



Fig. 1077. — The left side of the pelvis of Morosaurus grandis ; from the Upper Jurassic of 

 North America. One-sixteenth natural size. «, Acetabulum; il, Ilium; is, Ischium; p, p' ', 

 Pubis. (After Marsh.) 



1077), in which the shaft is bent backwards and has no distal 

 expansion, while the symphysis does not extend to the extremity ; 

 thus causing the middle of the acetabular part to be far above the 

 axis of the shaft. 



The typical species of Cetiosanrits is comparatively well known through 

 the labours of the late Professor Phillips. This huge reptile was perhaps 

 somewhat smaller than Pelorosaurus ; and it was inferred from the well- 

 ossified extremities of the limb-bones, the free projection of the head of 

 the femur into the acetabulum, and the large terminal claws, that this 

 creature was of terrestrial or subaquatic habits, and that it probably 

 dwelt on the banks of lakes or rivers among brakes of ferns, cycads, and 

 conifers. From the structure of a tooth (Cardiodon) found in the same 



