252 S. W. WILLISTON. 



shallow fossa on each side of it. The pubo-ischial suture is, ap- 

 parently, a little back of the pubic foramen, running transversely 

 across. It is not at all distinct, and I am not sure of it. Lying 

 in the median emargination of the pubes there are three or four 

 very slender ventral ribs, and by their side, a fragment of what 

 appears to be a thin plate, which may have articulated with the 

 thickening of the front margin before mentioned, a thickening 

 characteristic of all the smaller cotylosaurs, apparently. The 

 pelvis, so far as it can be seen, is almost identical with that of 

 Labidosaurus , and other Permian cotylosaurs, forms of which 

 will be figured later. 



Legs. As stated, the hind legs are both preserved, trailing 

 backward from the acetabulum, both of them somewhat bent 

 at the knee. The femur of the right side suffered somewhat in 

 the fracture of the nodule, and is only partly preserved. That 

 of the left side, so far as it can be seen partly embedded in the 

 matrix, agrees quite with that of Labidosaurns, though more 

 slender. The tibia, also shown best on the left side, offers noth- 

 ing unusual. The fibula, hitherto unknown in the cotylosaurs, is 

 strongly curved, with a considerable expansion at its lower ex- 

 tremity, and with a small, rounded upper end. The feet, unfor- 

 tunately, have both been preserved lying more or less on their 

 fibular side, and in consequence with the toe bones more or less 

 concealed. However, it is quite certain that no force was brought 

 to bear upon them to displace them, save that of their own weight. 

 The lower leg of the right side and the tarsus are spread out 

 flatly, but with the digits piled upon each other. A large, flat fibu- 

 lare articulates with the fibula of the right side in position, closely 

 articulating on the inner side with another large bone, evidently 

 the united tibiale and intermedium. Four tarsal distalia are visible. 

 The shapes of the bones distinguished agree in general so well 

 with those of Labidosaurus as figured by me, that I have no hesi- 

 tation in giving the others from the same genus, shaded in the 

 figure. The tibiale, however, must have been shorter than in 

 Labidosaurus. As regards the toes, all five metatarsals are visible 

 on one or the other side, and many of the phalanges, save those 

 of the fifth toe. In the figure given in the restoration, the un- 

 shaded phalanges of the other toes are given precisely in the 



