280 THE BATH OOLITE PERIOD. CHAP. xi. 



same, it being compressed, about 36 inches ; diameter of the 

 smallest part of the bone, 8| inches ; circumference at the same 

 part, much compressed, 21 inches ; extreme breadth over the con- 

 dyles, 14-5 inches ; circumference at the same part, 37 inches. 



The bone belonged to the left leg ; its hinder surface is presented 

 for observation. The bone is nearly straight, in this respect differ- 

 ing much from the crocodilian, and approaching toward the demo- 

 saurian type. The expansion which corresponds to the great 

 trochanter does not rise to the level of the head ; there is hardly 

 a distinct neck, but yet a marked interspace between the head and 

 the trochanter, and a great inward flexure of the outline below 

 the head (left-hand figure in Diagram CVIIL). 



The shaft of the crocodilian femur may be described as twisted 

 through about 60, so that the plane of compression of the head 

 makes this angle with the plane passing through both condyles. 

 This does not appear to have been the case with ceteosaurus ; all 

 the specimens in our Museum have these planes nearly parallel, 

 and this can hardly be attributed to the pressure which they have 

 sustained. 



The head of these bones is formed on a continuous sweep into the 

 trochanterial surface in the crocodile ; not so in ceteosaurus, which 

 in this respect more resembles the ordinary deinosaurian type. The 

 condyles are like those of crocodile and megalosaurus. 



The pair of large femora have a length of 64 inches ; breadth 

 of the upper part, taken obliquely, so '75 inches ; circumference 

 of the same, 46*0 inches; diameter of the smallest part of the 

 bone, 11*125 inches; circumference at the same part, 27-5 inches ; 

 extreme breadth over the condyles, 17-5 inches; circumference 

 at ihe same part, 44-35 inches. (Diagram CVIIL, right-hand 

 figure.) 



These are by much the largest limb-bones of any known saurian, 

 the nearest approach being the humerus of pelorosaurus, in the 

 British Museum, from the Wealden, almost 54 inches long; the 

 largest femur of megalosaurus being 42 inches. 



Placed near to the corresponding femur of ceteosaurus, this large 

 megalosaurian bone is like a child by the side of a giant ; yet it 

 is three times as long and as large as the femur of the largest 

 crocodile. 



The specimen is from the left side, and is mounted to shew the 



