OSTEOLOGY OF AMERICAN PERMIAN VERTEBRATES 385 



with them. Nor is there anything left in this specimen of the first 

 and second metacarpals and the first carpale. The second speci- 

 men includes the epipodial and mesopodial bones and the proximal 

 ends of the first and second metacarpals; the intermedium is nt)t 

 visible, possibly it is lost. There is also much more of the meta- 

 podials than in the other specimen, though none is complete. In 

 a separate piece of clay at least three fingers were lying in position, 

 but only the three metacarpals and some of their phalanges were 

 preserved in place. These have been added to the figure made 

 from the first specimen in dotted lines. The three specimens are 

 the same or nearly the same size. 



The ulnare is a stout, thick bone, which forms half of the articu- 

 lar surface for the ulna. It rests only slightly on the fifth carpale, 

 though more than is shown in the figure, since it underlaps it to a 

 small extent. At its lower, outer angle there is a small notch, all 

 that seems to represent the perforating foramen. Its outer border 

 is straight, and joins the inner border of the intermedium closely. 

 The intermedium is a cuboid bone, a little wider below than above, 

 with a considerable concave articular surface at each end, that of 

 the proximal end continuing smoothly the ulnar articular surface. 

 The radiale is seen only from the proximal side, as it lies back of 

 the other carpal bones at the ends of the radius and ulna, the ulna 

 partly rotated on its long axis. This surface shows an excavation 

 where it partly covered the centrale. On the ulnar border there 

 is a distinct notch between it and the intermedium that is puzzling. 

 Lying by the side of the radiale there is a small nodular bone which 

 must be either the first carpale or the first centrale; I have dotted 

 it as the centrale. The centrale is a narrow bone with peculiar 

 relations. At its inner side it articulates with the outer angle of 

 the fifth carpale. The fifth carpale is also unlike that of any other 

 Permian reptile that I know in its large size and relations with the 

 fourth carpale, which it excludes from the proximal bones. The 

 fourth carpale is small. It interlocks with both the centrale and 

 the fifth carpale. The third carpale has a flat, rectangular anterior 

 surface, a little longer than wide. It articulates above with the 

 outer end of the centrale, and on each side with an adjacent carpale. 

 The first carpale is a small bone. 



