52 PROFESSOR OWEN ON THE AYE-AYE. 



the trapezium (t), and the trapezial sesamoid (o) : the cuneiform (c) offers a cup for 

 the hemispheric end of the styloid process of the ulna (fig. 17, "), and a flatter surface 

 for the pisiform (ib. p) ; this wrist-bone is long, and its articular surface is divided 

 between the ulnar process and the cuneiform. The intermedium and cuneiform com- 

 bine to form the cup for the ball common to the magnum (m) and unciform [u), of 

 which the latter bone contributes the largest share. The intermedium (z) articulates 

 with the trapezoid (z). The distal series of carpal bones have the usual relations to the 

 metacarpals. 



The metacarpal of the pollex (Pis. XIX. & XXI. fig. 1 7, i) articulates with the trapezium , 

 and touches the trapezoid and the base of the second metacarpal : this {ib. n) is sup- 

 ported by the trapezoid. The base of the middle metacarpal {ib. m) is notched for a 

 firmer articulation with the magnum, as that of the fifth metacarpal {ib. v) is for the 

 outer division of the distal surface of the large unciform. The first, second, fifth, 

 and fourth metacarpals progressively increase in length, with similar proportions as 

 to thickness ; but the middle metacarpal is double the length of the second, and 

 suddenly contracts into a shaft more slender by half than the contiguous metacaipals. 

 The proximal phalanx of the thumb is the shortest ; that of the index is one-third 

 longer ; that of the minimus is rather thicker, and is one line longer than that of the 

 index ; that of the annulus is rather thicker, and is one-third longer than that of the 

 minimus. The proximal phalanx of the middle finger is a slightly bent filamentary 

 bone, about two lines shorter than that of the fourth finger. The second phalanx of 

 the fifth is 1^ line longer than that of the second ; that of the fourth finger is almost 

 twice the length of that of the second ; the filamentary one of the third is not longer 

 than that of the fifth finger : all these phalanges are slightly bent, concave towards the 

 palm. The ungual phalanges are all modified for the support of claws, are short, 

 and are less unequal in length, that of the thumb being the shortest and broadest. The 

 hand is the longest segment of the fore limb ; it exceeds that of the ulna by 1 inch. 



Bones of the hind limb. — The pelvis is long and narrow ; the os innominatum equals in 

 length the last five lumbar vertebrae. 



The ilium (PI. XIX. 62, P]. XXI. figs. 19, 20, 62) is a long narrow bone, slightly 

 expanded at both ends, and subcompressed at its upper half, where the sides look 

 outward and inward, the borders forward and backward ; of these the anterior one is 

 the thinnest, and is slightly concave. The ilium articulates with the two first sacral 

 vertebrae, just touching the second by a projection above its middle {ib. fig. 19, 62); 

 about half an inch of the lamelliform part of the bone {ib. fig. 20, I, 62) projects freely 

 in advance of this attachment, on each side the transverse processes of the last lumbar 

 vertebra, with a slight divergence. The iliac bones incline to the acetabula at an 

 angle of 140° with the lumbo-sacral axis. There is an elongate tuberosity above 

 the acetabulum for the origin of the rectus femoris. The ischia {ih. 63) are continued 

 almost in a line with the ilia, the posterior contour describing a very feeble curve con- 



