REPTILIA : SEYMOURIA 61 



broad, the border sloping upward in a curve from the ischiadic 

 suture; the hind end of the process reaches as far back nearly as the 

 hind end of the first caudal vertebra. The ilia are in perfect 

 articulation with the sacral ribs which were attached high up, 

 their upper margins even showing above the iliac border in its 

 middle. The proximal end of the rib of the first presacral vertebra 

 lies against the upper front margin of the ilia, evidently extending a 

 short distance beyond the margin freely in life. The inner side 

 of the pelvis of course cannot be seen, and the acetabula are par- 

 tially rilled by the proximal ends of the femora. It is apparent, 

 however, that the pelvic opening was large and roomy. The femora, 

 as has been stated, lie in close articulation with their respective 

 acetabula, both directed upward, forward, and a little inward, the 

 knee on each side precisely reaching the end of the posterior zyga- 

 pophyses of the fourth presacral vertebra; and their positions 

 are identical on the two sides, the large digital fossa looking almost 

 outward and slightly ventrad. The femur agrees closely with the 

 one referred by me to Desmospondylus n. sp. in the cited paper from 

 the Cacops bone-bed, save that it is slightly larger. In the accom- 

 panying figure the femur is shown in the position in which it lies 

 on the left side ; with it is a figure of the ventral side of the Cacops 

 bone-bed specimen a little more enlarged. Like the diadectid, 

 limnoscelid, and eryopid femora, it is remarkable for the enormous 

 size of the digital fossa and the high adductor crest. On the two 

 sides the bones of the forelegs are in close articulation with their 

 respective femora, both flexed at an angle of very nearly forty-five 

 degrees, and directed a little outward. Evidently they had lain 

 closely by the side of the abdomen; and the posterior ribs are yet 

 hidden between the forelegs and the vertebra in large part. The 

 tibiae, so far as they have been exposed, agree well with the one 

 figured of Desmospondylus. They are remarkably short and stout 

 bones. The upper ends of the fibulae are yet partly hidden below 

 the tibiae, with which they are in perfect association; distally they 

 are remarkable for their great expansion, indicative of a broad foot. 

 On the left side the proximal tarsal bones are nearly in position 

 with the ends of the leg bones, and in close union with each other. 

 They are remarkably small. The tibiale is subcircular or sub- 



