54 
POPULAR SCIENCE REVIEW. 
The coracoid is always pierced with a foramen near to its union 
w r ith the scapula. The scapula always widens at its union with 
the coracoid, and sometimes, as in the cretaceous genera, deve- 
lopes a not inconsiderable acromial process, which is absent in 
examples from the older rocks. In Megalosaurus the scapula 
and coracoid are often blended together. In many genera 
the scapula has a slight backward curve, and is also convex 
in length, so as to adapt itself to the form of the ribs. This 
form of scapular arch finds no parallel in the form of the bones 
among existing Reptilia except in the Chamseleon and Hatteria. 
Yet the resemblance of these bones to some in the Triassic 
Crocodilia is remarkably close, and the absence of clavicles 
rather points to a Crocodilian than a Lacertilian affinity. 
The fore-limb presents nothing bird-like (Fig. 9). The 
humerus, as already remarked, differs from that bone in the 
Crocodile rather in detail than in plan, and the expansion of 
the head of the bone and of the distal condyles, probably has 
more relation to the weight of the animal to be supported 
than to the characters of the type from which the group 
was modified. The head of the bone, however, is not parallel 
to its distal end, and there are characteristics that would as 
well admit of a Lacertilian as of a Crocodilian interpretation ; 
yet the form of the bone in most cases permits no doubt as to the 
ordinal group to which it belongs. The ulna and radius were 
placed one behind the other, more after the manner of the 
Lizard, perhaps, than of the Crocodile. Specimens in the 
British Museum show that the radius was received in a groove 
or depression of the ulna at its proximal end. The olecranon 
process at the humeral end is large (Fig. 9). The carpus has 
hitherto been imperfectly figured. It is represented by Professor 
Owen in Iguanodon in union with the ulna and radius, and 
appears to consist of two bones. In this genus Professor Owen 
has figured a remarkable spur on the inner side of the foot, thus 
identifying a bone which M ant ell formerly regarded as a nasal 
horn, and which Professor Owen had subsequently interpreted 
as a claw phalange. The specimen is obscure, but from 
evidence that many Dinosaurs have five digits in the fore- 
limb it may not perhaps be impossible that this supposed 
anomalous spur may be an abnormally modified digit. The 
number of phalanges in the fore-limbs appears to be variable. 
Altogether the fore-limb is but little specialized, and might 
have been modified from any generalized reptilian type. Its 
characters have been but little discussed. Taken as a whole, 
it must be regarded as furnishing important evidence of rep- 
tilian affinities, which, unlike the parts of the skeleton already 
mentioned, change their type but little in the various genera 
which conserve this grade of animal organization. 
