MORPHOLOGICAL REVISION 137 



"The two extremities of the right ulna were found free in the wash, 

 distinguished from the reptilian ulna found with the specimen by their 

 much smaller size and the less produced olecranon. The proximal portion 

 is convex on the inner side, thinned above and below. The outer side is 

 concave for the radius, with the humeral articular surface, or sigmoid cavity, 

 showing more from that side. The olecranon is rugose. The distal extremity 

 is but slightly expanded, a little thickened in the middle at the end, gently 

 convex on the dorsal, and concave on the palmar surface. 



"The extremities of what I believe to be the radius are among the 

 fragments recovered in the wash, but the present impossibility of distin- 

 guishing them from the reptilian remains renders their description inad- 

 visable. I have outlined the bone in the restoration from Eryops. 



"A mass of matrix containing nine carpal bones united in their proper 

 relations was secured. Their distinction from the reptilian specimen is 

 assured by their smaller size, and the determination of the carpal bones in 

 that specimen. Their relative size and position, as I determine them, will 

 be seen in the restoration. It is evident that two of the proximal bones 

 are missing, and they are shown in shaded outlines in the figure. 



^''Pelvic girdle and extremity: The left ilium was preserved, attached to 

 the sacral vertebra and rib, nearly or quite in normal position, but con- 

 siderably eroded on its outer surface. The acetabular portion of the same 

 side, found loose, shows also considerable erosion of the surface, and the 

 precise connection with the ilium worn oflF; the symphysial portion, also, of 

 both ischium and pubis is wanting. The ilium resembles somewhat that 

 part in Eryops, but is broader, less elongate, and thinner. The acetabular 

 part is quite similar to that of Eryops, and it is quite probable that the 

 missing portion below will be found also like that of Eryops. The acetabulum 

 is large and shallow, with a thickened rim in front, a rounded protuberance 

 at the upper part, and a thickened margin at the lower posterior part. The 

 pubic foramen below the anterior part of the acetabulum opens on the inner 

 side toward the front margin. 



"Femur: The left hind leg is preserved almost completely, and with 

 but little disturbance of its parts, lying partly upon, partly at the right 

 side of the vertebral column, its ventral side uppermost, the femur much 

 flexed and inclined over the vertebrae to meet the acetabulum, which was 

 lying nearly horizontally. The femur resembles in miniature that of Eryops. 

 Its proximal extremity is thickened, transversely convex above, much 

 thickened on the inner side, less so on the outer, and with a shallow fossa 

 behind, externally. The shaft is much narrowed from side to side at the 

 lower third. The 'lesser trochanter' is robust, beginning about one-third 

 the length of the bone; its face is oval in outline, with a longitudinal groove, 

 and is directed proximally and ventrally. The 'linea aspera' continues 

 the trochanter as a high, thin longitudinal crest, curved somewhat outward, 

 to end near the beginning of the last fourth of the bone, in the upper part 

 of the popliteal surface, about midway between the lateral margins. The 

 distal extremity of the femur is expanded to the full width of the proximal 

 extremity, chiefly on the inner side, the internal border of the bone forming 

 a deep concavity above, while the external border of the bone is gently 

 concave on the middle two-fourths, the first and last fourths gently convex 

 in outline. The distal border of the inner condyle is nearly transverse and 

 straight, thickened internally; the external condyle is narrow, and greatly 



