40 DESCRIPTION OF THE SKELETON. 



for the second and third metacarpals, in which it differs, as all these bones 

 do in some slight degree, from the carpals of the elephant. In the latter, 

 this articulating surface is single, and connected with the middle metacarpal 

 only. The external face corresponds exactly with that of the unciforme, 

 having a superior and inferior articulating surface, and a large median 

 excavation for the attachment of a veiy strong connecting ligament. The 

 internal face articulates with the trapezoides. 

 unciforme. Unciforme (Plate XL G). — This is the largest bone in the carpus, though 

 the cuneiforme will bear comparison with it. It approaches to a cuboidal 

 form, but is flattened from above downwards. Its anterior face forms a 

 part of the carpal surface ; the superior is smooth, to form an articulating 

 surface, which connects it with the cuneiforme. The posterior rough face, 

 of a triangular form, makes part of the carpal hollow. The inferior face is 

 divided into two articulating surfaces ; one for a part of the third, and the 

 other for the fourth metacarpal. By its internal face, it is connected with 

 the os magnum, and by its external with the fifth metacarpal. There does 

 not appear to be any process analogous to the hook-like process of the 

 human unciforme. 



Metacarpus. — The metacarpal bones are five in number (Plates XL 

 and XII. L). The first metacarpal, or that which supports the thumb, is the 

 smallest and shortest of the bones of this range. It has two-thirds 

 the length of the corresponding bone of the next finger. Its superior face, 

 articulating with the trapezium, is a little excavated, but not so much as 

 in the human bone. Its infero-anterior face has an extensive articulating 

 surface for the movement of the phalanx beyond. Its upper and lower 

 extremities are decidedly enlarged, and its body contracted. Its length is 

 more than four inches. 



pus. 



