﻿40 



FOSSIL REPTILIA OF THE 



probably, of marine habits, on the evidence of the coarse cancellous tissue of the long 

 bones which show no trace of medullary cavity." 1 

 In reference to their affinities ; 



" In the great expanse of the coracoid [fig. 8] and pubic bones, as compared with the 

 Teleosaur and Crocodiles, the gigantic Saurians in question manifested their closer affinity 

 to the Enaliosauria" 2 — closer, that is, than the Teleosaurs or Crocodiles show ; but 

 " their essential adherence to the Crocodilian type is marked by the form of the long 

 bones of the extremities, especially of the metatarsals : and, above all, by the toes being 

 terminated by strong claws." Here, in 1842, the clawless character of the limbs of 

 Plesio- and Ichthyo-sauri was the dominant idea, to the exclusion of the then novel 

 group of Dinosauria, " characterised by a large sacrum composed of five anchylosed 

 vertebras of unusual construction," &c. 3 



The question to be determined in respect to Cetiosaurus is the admissibility of the 

 genus by the sacral character to the Dinosaurian order. This character, in 1842, I put 

 in the van, relating as it does, physiologically, to terrestrial progression more after the 

 manner of Mammalian quadrupeds than of existing four-footed Saurians, whether 

 Crocodiles or Lizards ; an extent of the trunk being thereby transmitted, through a 

 co-extensive ilium, upon hind limbs, the chief bones of which are ' medullary ' in 

 Dinosauria. 



Fig. 9. 



Ilium, Cetiosaurus longus, y^th nat. size. (Phps., cv, p. 278.) 



The ilium (fig. 9) of the Cetiosaurus longus, from the Kirtlington quarry, is estimated 

 by Phillips as probably equal to six vertebras. He writes: 



"The extreme length of one (ilium) is 42, of the other 45 inches, probably equal to 

 six vertebrae," 4 such sacral vertebras being estimated each at a little over 7 inches in 

 length. 



These vertebras are briefly noticed as follows : — " Several bones of this portion are in 

 the collection, but there is great difficulty in so placing them as to acquire a just notion of 

 the structure or to present a satisfactory drawing. In some degree it (the sacrum) must 



1 ' Kepoft,' id supra, p. 102. 2 lb., ib. ' lb., p. 102. 4 Op. cit., p. 2/8. 



