1NSECTIVORA. 



997 



F/-. 4-12 



abnormal deviation from the usual construc- 

 tion. It is extremely short and broad, forming 

 in fact nearly a square ; about the middle of its 

 anterior margin a strong process rises, which 

 gives origin to the subclavian muscle, which in 

 this animal is greatly developed. It is articu- 

 lated, as usual, with the sternum by its interior 

 extremity, which may here be more properly 

 called its interior margin ; but by its external 

 margin it is connected moveably with the head 

 of the humerus, which connection is rendered 

 more solid towards the anterior part by a strong 

 ligament. Its connexion with the acromion of 

 the scapula is by a ligament merely, which 

 extends from the acromion to the posterior and 

 outer angle of the clavicles. In Condytura and 

 even in Scalops the construction of this bone is 

 on a similar type; but in Chrysochloris it is 

 long and slender as in the other Insectivora. 



The scapula (a) in the mole is no less singu- 

 larly formed than the bone just described. It is 

 elongated to an extraordinary degree, being not 

 less than six times as long as it is broad at the 

 broadest part, which is at the superior extremity. 

 Towards the middle it is contracted and almost 

 cylindrical; and the spine, which runs nearly 

 the whole length of the bone, is at this part 

 almost effaced. The acromion, as before ob- 

 served, has only a ligamentous connexion with 

 the clavicle. In Condytura and Scalops the 

 construction of this bone is somewhat similar, 

 and in Chrysochloris it is also of considerable 

 length. 



The humerus in the mole (fgs. 442, c, 443) 

 is of so extraordinary a form, that were it 

 examined alone, isolated from its natural con- 

 nexions, it would be impossible to detect 



Fig. 443. 



its true character. It is of a square form, 

 extremely broad at the superior part, where 

 it presents two articular surfaces; the an- 

 terior is very broad, slightly convex; the 

 posterior and internal is narrow, but more 

 convex than the former ; by the first it is 

 articulated to the clavicle, and by the latter 

 to the scapula. Between the former, which 

 may be considered as appertaining to the 

 greater tuberosity of the bone, and the head, is 

 a deep fossa. The body of the bone is short, 

 thick, and very broad, and is curved upwards, 

 so that its articulation with the forearm is 

 placed actually higher than the shoulder, and 

 the palm of the hand is consequently turned 

 outwards. In Chrysochloris the form of this 

 bone is not less remarkable. It is somewhat 

 longer than that of the mole ; its articulation 

 with the forearm constitutes half a sphere ; and 

 the inner condyle is so elongated and inclined 

 downwards, that the whole bone forms an arch 

 of which the convexity is turned outwards. 

 This condyle is articulated with a bone, which 

 must be considered as a most extraordinary 

 modification of the ospisiforme, which is as long 

 as the radius, so that in fact the forearm may be 

 said to be composed of three bones. 



The bones of the forearm (JtgA42, d,e) in the 

 extraordinary animal which otters so many de- 

 viations from typical structure, the mole, are 

 no less remarkable than those of the shoulder. 

 The ulna is very broad and much flattened ; its 

 superior extremity is enlarged transversely, the 

 anterior surface concave, the posterior convex. 

 The radius is separated by a considerable in- 

 terval from the ulna throughout their length, 

 and the two bones are only united at the upper 

 extremity by a capsular ligament. But the 

 articular surfaces of the two bones are flat, and 

 the head of the radius is prolonged into a hook- 

 like process, forming a sort of radial olecranon, 

 so that rotation is impossible. The carpal bones 

 C/g.444) consist of two series of five in each, and 

 an additional bone of a very peculiar construc- 

 tion. This is a large sickle-shaped or falciform 

 bone, having the convex margin outwards ; it 

 extends from the carpal extremity of the radius 

 to the first metacarpal bone. It is this bone 

 which gives the great breadth to the hand, 

 which is so important to this animal in its 

 peculiar mode of life. 



The phalanges of the fingers are very short, 

 and covered by the integument in such a 

 manner as to appear to belong to the meta- 



Fig. 444. 



