292 THE BATH OOLITE PERIOD. CHAP. 



which were contemporary with, ceteosaurus, or stand to it, though 

 obscurely, in the relation of precursors or successors. 



To speculate on the habits of life of the huge creature we have 

 been considering in fragments, may seem a hopeless waste of time, 

 in the absence of almost all trace of a head, and in total ignorance 

 of the special organs of sense and apparatus for obtaining food. Yet 

 some general inferences appear to be justified, and to be worthy of 

 attention. First, in regard to the size of a full-grown animal we 

 have some ground for a reasonable opinion : 



When the great femur came to the Museum accompanied by other 

 bones, its obvious analogy to the corresponding bone in the crocodile 

 suggested and seemed to justify a simple mode of calculation of 

 the size of the animal which had possessed and employed it. 



An adult crocodile, 9 feet long, has a femur less than 9 inches 

 long; if like proportions hold, the eeteosaur, which had a femur 

 of 64 inches, must have had a body at least 64 feet long. 



Later disinterments made us acquainted with tibia, humerus, and 

 scapula; and if the computation were made for these also, we 

 should have the length of the body as under : 



Twelve or fourteen times the femur . . . = 64 to 74 feet 



Twenty times the tibia . . -.''-* "' . -. . = 63 



Twenty-four times the scapula , , '. v . = 100 ,, 



Fifteen or sixteen times the humerus . . . = 64 



No small analogy is observed between the deinosaurian reptiles 

 and the living monitors. If we employ the same method, and take 

 the proportions in the same way, the length of the ceteosaur 

 would appear to have been 100 feet. 



There are reasons for not being satisfied with these results. The 

 length of limb-bones as compared to the body is too variable to 

 be trusted beyond the limits of a natural family having similar 

 habits of life, and we cannot assume this to be the case on com- 

 paring the fossil and recent tribes in question. 



The same difficulty occurred in respect of iguanodon and megalo- 

 saurus, and it was met by Professor Owen in the same manner, 

 viz. by taking for standard of comparison the vertebral column. 



Thus in crocodile, we have usually 7 cervical, 12 dorsal, 5 lumbar, 

 2 sacral, and 34 to 42 caudal vertebrae. If ceteosaurus were in this 

 respect like crocodile, its length will be thus estimated, allowing 

 for cartilage : 



