NO. 2 A STUDY OF MENISCOTHERIUM — GAZIN 65 



directed posteriorly along the shaft of the ischium. The ischium is 

 elongate, straight, and comparatively slender, with a transversely con- 

 cave medial surface. The ischial spine is small but fairly acute; 

 however, the ischial tuberosity is prominently developed, accom- 

 modating the biceps femoris and other flexors of the leg. The shaft 

 of the pubis is somewhat flattened and slender. Unfortunately, the 

 ramus of this bone and that of the ischium are poorly represented 

 and badly preserved in the material at hand ; nevertheless enough 

 remains to indicate a large, oval-shaped obturator foramen. 



The M eniscotherium innominate bone is surprisingly like that of 

 Phenacodns, although the latter is relatively more elongate, and the 

 crest of the ilium would appear to be more flaring and recurved. 

 The ischial spine in Phenacodns is more rugged, but the ischial tuber- 

 osity may not be relatively so well developed. The anterior inferior 

 spine of human anatomy seems prominent on the acetabular border 

 of the ilium, but it may be noted that the "deeply impressed sub- 

 triangular fossa" described by Cope (1884b, p. 455) as located just 

 above the position of the anterior inferior spine and near the edge 

 of the acetabulum is much less significant in M eniscotherium. 



The Hyopsodus innominate bone is elongate and slender. The 

 ilium shows the similarly arcuate and flaring dorsal margin, but the 

 gluteal surface may be a little less concave. The anterior extremity 

 is missing in the specimen at hand. The base or posterior portion 

 of the ilium is a little less trihedral in cross section with the pubic 

 border on the ilium much more subdued than in M eniscotherium. 

 There is little or no evidence for an ilio-pectineal eminence on the 

 dorsal margin, although this is weak or subdued in M eniscotherium. 

 The anterior inferior spine on the acetabular border, however, which 

 supports the origin of the rectus femoris, is surprising well developed. 

 The ischium is slender but possibly a little less elongate than in 

 M eniscotherium. The ischial tuberosity is prominent and the ischial 

 spine perhaps more so than in M eniscotherium. Much of the pubic 

 bone is missing, as is the ramus of the ischium. The cotyloid notch 

 in the acetabulum for the ligmentum teres is constricted but directed 

 along the ischium much as in M eniscotherium. 



FEMUR 



The femur of M eniscotherium is comparatively robust, as noted by 

 cope in his very brief description, and its shaft is straight, although 

 proximally the anteromedial margin is decidedly curved as it 

 approaches the head (see pi. 8). The head may be somewhat oval 



