REPTILIA : SPECIES INCERTAE SEDIS 139 



Radius 104 G (Plate XXXIII, Fig. 6).— This, the largest of the 

 radii preserved, indicates an animal of considerable size and 

 slenderness. The upper extremity has evidently been injured; 

 its expansion is nearly as great as that of the lower extremity, but 

 the long axis of its articular end is very oblique to the plane of the 

 lower end. The bone is very concave on its ventral side, the dorsal 

 border nearly in one plane or a trifle convex. A little above the 

 distal end on the ulnar side there is a sharp ridge; evidently the 

 small radius shown in fig. 5 belongs to the same species. 



Radius 104 H (Plate XXXIII, Fig. 10). — This small radius, 

 even though juvenile, is evidently of a different form from either of 

 those previously described. The two ends are expanded in the 

 same plane, the bone is nearly flat on the ventral side, and the lower 

 end is but slightly expanded. There are in addition to this, other 

 small radii of less slender form. 



Radius 104 I (Plate XXXII, Fig. 2). — It is not improbable that 

 this radius may belong with some one of the different forms of 

 amphibians represented by the femora and humerus described on 

 page 14. which I refer provisionally to Aspidosanrus or allied new 

 forms. It has, however, the same general characters of the more 

 slender radii described. 



Tibia 104 J (Plate XXXII, Fig. 5).— This tibia, of considerable 

 size, is very peculiar in the very much flattened upper end (the 

 lower end in the figure) with very shallow concavities on either side 

 of the cnemial convexity. It is not curved as much as the tibia 

 referred to Clepsydrops, and is very unlike that form. Its unlike 

 form also precludes the possibility of its being a juvenile specimen 

 of a Dimetrodon. 



Ilium 104 K (Plate XXXI, Fig. 1). — In much probability this 

 ilium belongs with femur 104 A. It is very unlike any ilium 

 hitherto figured or described from the Permian of Texas. The 

 upper helmet-shaped expansion is high and thin, the front border 

 is thicker and curved gently forward, the upper thin border convex 

 throughout. The posterior iliac notch is very small; the antero- 

 posterior diameter of the bone in its narrowest place much less than 

 that of the ilium referred to Clepsydrops (Fig. 2). The inner side 

 shows rugosities apparently for three sacral ribs, but this is not 

 certain. 



