THE FORE FEET. lOT 



The Pyramidal. 



(Plate XXXII, figures 1-6, Plate LIV, figure l,p; 

 and woodcuts 117-118, below.) 



The pyramidal bone in the Dinocernta bears a considerable 

 resemblance to the corresponding bone in the elephant, and has, in 

 general, a similar shape, and similar arrangement of articular faces. 



Plate XXXII, figure 1, represents the outer, or dermal, sm-face of the 

 bone, as seen in its natural position in the foot, and shows a portion only 

 of the saddle-shaped articular face for the nlua. 



■ Tlie anterior view of the bone (figure 2) shows but little of the 

 articular faces, although, on the side turned toward the lunar, may be 

 seen a short articular face running along the distal portion of the surface. 

 This face is seen more clearly in figure 3, and is confluent with the lower, 

 or distal, face supporting the unciform, but makes a considerable angle 

 with it. 



In the posterior view of the bone (figure 4), the oblique articulation 

 for the jiisiform is sliown. This articular face, like most of the lateral 

 ones among the carpal bones, is of variable shape, and often fails to show 

 the deep emargination at the side, seen in the specimen figui-ed. Along 

 the upper margin, where this face is confluent with the ulnar articular 

 face, the two are separated by a nearly straight, prominent, rounded ridge. 



The proximal surface of the bone (figure 5) shows principally the 

 sub-triangular saddle-shaped face for articulation witli the ulna. 



The distal surface of the bone (figure 6) presents, also, a somewliat 

 triangular and saddle-shaped face, for the suppoi't of the unciform bone, 

 and, in the specimen figured, an additional, distinct, oval, and convex face, 

 giving support to the metacarpal of the fifth digit. 



In other specimens, this face is present, and well developed, but 

 confluent with that sup})orting tlie unciform, as sliown in the woodcuts 

 below, figures 1,17 and 11<S. 



