Permian of New Mexico. 393 



tened, the outer and obtusely pointed ; it merely touches the 

 intermedium. The ventral surface of all three of these bones 

 is flattened, the dorsal more rounded, that of the radiale obso- 

 lete. Especially remarkable is the fact that all of these proxi- 

 mal carpal bones save the ulnare are very small, smaller 

 than in Diadeetes even, and much smaller than in other known 

 Permian reptiles. 



The remaining bones of the right foot were found nearly all 

 connected, for the most part in the relations of the living ani- 

 mal. The foot had been slightly twisted in fossilization, dis- 

 turbing somewhat the relations of the metapodials. Of the 

 phalanges all were found in association save two terminal ones, 

 the distal phalanges somewhat confused in the three middle 

 fingers. The three distal carpal bones were found in the posi- 

 tions shown in the figure, but there were no traces of others, 

 and they could have hardly escaped notice had they been fos- 

 silized with the others. Evidently these nodular bones repre- 

 sent the centrale and the third and fourth carpalia. Fortu- 

 nately the bones of the left foot were found in the matrix in as 

 natural relations as one could wish, and they will be so retained 

 in the prepared skeleton. The block containing the distal 

 carpals and the digital bones had been separated in collec- 

 tion from that containing the fore-arm and proximal carpals, 

 and was not accurately readjusted. The three carpal nodules 

 are quite as iu the other hand with no traces of others; from 

 which facts I have no doubt that they were the only ones ossi- 

 fied, and they but imperfectly. Of the digits the bones of the 

 three middle toes were all in perfect articulation save the 

 ungual phalanges of the second and fourth digits, which are miss- 

 ing. Of the first digit, the ungual phalange is also missing and 

 the phalanges of the fifth have not been adjusted to the meta- 

 carpal. However, these digits were preserved in perfect artic- 

 ulation in the right foot. From these facts, which I have 

 given in detail because of their importance, it is certain that the 

 phalangeal formula is, as is seen in the figure, 2, 3, 4, 5, 3, 

 fixing for the first time the foot structure in an American 

 cotylosaurian, and save for Procoloplwn, which has been 

 referred (wrongly I believe) to another group, in a member of 

 the order. My figure was made by simply tracing the outlines 

 of the various bones as they lie in position and transferring them. 

 The only doubt that remains is the precise width of the space I 

 have left for the carpal elements, it may be a trifle too broad. 

 As is seen, the foot is remarkably broad and flat, lying in the 

 matrix in nearly one plane, with the phalanges short, the 

 ungual ones broad and hoof-like, as in Diadeetes, and probably 

 also Eryops. The foot resembles that of Diadeetes somewhat 

 save that the proximal carpal boues are large, and the distal 

 row seems to be fully ossified in that genus. 



