﻿34 



FOSSIL REPTILIA OF THE 



Fig. 5 



of an original cartilaginous superscapula, the proportions of which element would thus be 

 more crocodilian than lacertian. The resemblance of the blade-bone of Cetiosaurus to 

 that of Scelidosaurus has already been noted. But the production of the anterior or 

 humeral angle of the articular end is somewhat greater, approaching that in Hylaosaurus. 

 The length of the scapula of Cetiosaurus longus is 4 feet 6 inches, the breadth of the 

 articular end is 2 feet 2 inches, the least breadth of the body of the bone 10 

 inches. 



The humerus of Cetiosaurus is far from exhibiting the outstanding plates and 

 ridges for muscular attachments, such as we see in the larger existing lizards {Hydro- 

 saurus, Monitor), which run swiftly on land ; they are even more feebly indicated than 

 in the Crocodiles, but how much of this inferiority may be due to posthumous injury and 

 abrasion in the present huge fossils is questionable. 



The head of the humerus, fig. 3, a, a, is an elongate, semi-oval, narrow convexity, 

 broadest at the middle, which projects toward the hinder or anconal surface of the bone, 

 as in Lizards and Crocodiles ; l the degree of the projection is shown in the outline of the 

 proximal end of the bone, at c , fig. 3, a. 



The ridge from the radial side of the proximal third 

 of the shaft (fig. 4, b), answering to the ' pectoral ' or 

 ' deltoidal ' one in the Mammals, commences, as in the 

 Monitors, near the head, not, as in the Crocodiles, abruptly 

 at some distance below ; it has suffered abrasion in the Kirt- 

 lington specimen, yet seems not to have stood out in the 

 same relative degree as in the Monitor, in which, as in the 

 Crocodile, it is bent toward the fore or palmar side of the 

 bone. 



The shaft of the humerus in Cetiosaurus is subcompressed, 

 subtrihedral, through an obtusely angular longitudinal low 

 ridge or prominence, on the anconal side (fig. 3), continued 

 from below the head to near the distal end, inclining toward 

 the radial side. There is no trace of the distal ridge from 

 that border of the shaft which, in Monitors, answers to the 

 * supinator ' ridge in Mammals (PI. XVII, fig. 6,*). The 

 more prominent of the two distal articular convexities, that, 

 viz., for the head of the radius, is feebly indicated ; the back 

 part of the convexity for the ulna is traceable at the worn 

 distal end of the bone (fig. 4, «')• 

 uina, cetiosaurus longus, T yh nat. p ec |- ora ] an( j supinator ridges are still more feebly in- 



size. (Phps., diagr. cm, p. 275.) r r a j 



1 ' Supplement (No. Ill) to Monograph of the Fossil Reptilia of the Cretaceous Formations,' Paleeon- 

 tographical Society's vol. for 1858 (issued 18G1), p. 15, tab. iii, fig. 10. 



