112 



5*28. The os cuboides. There are two surfaces for two metatarsal bones on the 

 anterior part of this bone, which, therefore, with the os naviculare, shows 

 t£ that the hind-foot of the Glyptodon had five toes. The os cuboides of 



Glyptodon deviates still more than the scaphoid bone from its analogue 

 in the Armadillos in its remarkable antero posterior compression : it 

 presents an irregular oblong figure, thicker at its inner than its outer 

 margin ; the posterior surface presents a small convex articular surface 

 for that of the os calcis, like which, the curve of the lower part is slightly 

 angular ; this surface is situated near the upper and outer margin of the 

 bone ; on the inner margin there is a long, narrow, sub-elliptic facet for 

 the scaphoid. The inferior surface of the cuboid is divided by a deep 

 and wide groove for the tendon of the peroneus muscle ; above which is 

 the triangular surface for the metatarsals of the two outer toes, which is 

 bounded above by a rather sharp edge. The posterior part of the lower 

 surface of the cuboid, like the adjoining part of the calcaneum, has been 

 smoothed down by the play of the strong flexor tendons of the toes. 



Presented by Sir Woodbine Parish, K.H. 



529. The external cuneiform bone. This differs from the external cuneiform 



of the existing x\rmadiIlos in its remarkably compressed form ; it is, in 

 fact, a simple triangular plate of bone, with the posterior surface smooth 

 and very slightly concave for the articulation with the scaphoid ; and the 

 anterior surface very slightly convex for the articulation with the meta- 

 tarsal of the third toe : the outer contour of the bone is convex, the 

 inner one concave : the anterior articular surface encroaches a little on 

 this side to join a portion of the metatarsal of the second toe : on the 

 under and outer side of the bone there is a very small facet, which touches 

 the os cuboides. The external cuneiform bone of the Megatherium differs 

 from that of the Glyptodon in being thicker as well as broader at its 

 upper part ; but, upon the whole, the external cuneiform bone of the 

 Glyptodon resembles that of the Megatherium more than it does that of 

 the Armadillos. Presented by Sir Woodbine Parish, K.H. 



530. The metatarsal bone of the second toe. This is wedge-shaped, broadest 



at its lower and inner sides, and narrowest at its upper and outer sides ; 



