EXTINCT ORDERS OF REPTILES. 233 



researches of Professor Phillips have shown that it belongs 

 really to the Deinosauria. Having obtained a magnificent 

 series of remains of this reptile, Professor Phillips has been 

 able to determine many very interesting points as to the 

 anatomy and habits of this colossal animal, the total length 

 of which he estimates as being probably not less than sixty 

 or seventy feet. As to its mode of Kfe, this accomplished 

 writer remarks : — 



" Probably when ' standing at ease ' not less than ten feet 

 in height, and of a, bulk in proportion, this creature was un- 

 matched in magnitude and physical strength by any of the 

 largest inhabitants of the Mesozoic land or sea. Did it live 

 in the sea, in fresh waters, or on the land ? This question 

 cannot be answered, as in the case of Ichthyosaurus, by 

 appeal to the accompanying organic remains; for some of the 

 bones lie in marine deposits, others in situations marked by 

 estuarine conditions, and, out of the Oxfordshire district, in 

 Sussex, in fluviatile accumulations. Was it fitted to live 

 exclusively in water ? Such an idea was at one time enter- 

 tained, in consequence of the biconcave character of the 

 caudal vertebrae, and it is often suggested by the mere magni- 

 tude of the creature, which would seem to have an easier life 

 while floating in water, than when painfully lifting its huge 

 bulk, and moving with slow steps along the ground. But 

 neither of these arguments is valid. The ancient earth was 

 trodden by larger quadrupeds than our elephant ; and the 

 biconcave character of vertebrae, which is not uniform along 

 the column in Cetiosaurus, is perhaps as much a character 

 of a geological period as of a mechanical function of life. 

 Good evidence of continual life in water is yielded in the 

 case of Ichthyosaurus, and other Enaliosaurs, by the articu- 

 lating surfaces of their limb-bones, for these, all of them, to 

 the last phalanx, have that slight and indefinite adjustment 

 of the bones, with much intervening cartilage, which fits the 

 leg to be both a flexible and forcible instrument of natation, 

 much superior to the ordinary oar-blade of the boatman. 

 On the contrary, in Cetiosaur, as well as in Megalosaur and 

 Iguanodon, all the articulations are definite, and made so as 

 to correspond to determinate movements in particular direc- 



