NEW PERMIAN VERTEBRATES 651 
Pelvic girdle and extremity (Fig. 5).—The left ilium was preserved 
attached to the sacral vertebra and rib, nearly or quite in normal 
position, but considerably eroded on its outer surface. The acetab- 
ular portion of the same side, found loose, shows also considerable 
erosion of the surface, and the precise connection with the ilium worn 
off; 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 (Fig. 5, 1) is preserved almost com- 
pletely, and with but little disturbance of its parts, lying partly upon, 
partly at the right side of the vertebral column, its ventral side upper- 
most, 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 expanded 
antero-posteriorly, so that the distal articular surface somewhat resem- 
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