PETERSON: A REVISION OF THE ENTELODONTIDA 127 
slightly deeper than that of Archwxotheriwm ingens from the lower Oligocene 
formation. The shortening of the pelvis is principally confined to the region 
back of the acetabulum. he ilium has nearly the same relative length as in the 
Oligocene genus, and its anterior plate is suddenly expanded into a strongly everted 
antero-inferior portion. The dorsal surface of the ilium is basin-like, the entire 
crest having a slightly everted border. Ventrally it is strongly convex and the 
greater portion of its surface is taken up with the attachment for the sacrum. The 
latter is so placed that when articulated with the vertebral column the pelvis 
has a more vertical position than in Archxotheriwm. The shaft of the ilium is 
relatively shorter than in Archxotheriwm, but has the same general trihedral out- 
Fia. 74. (1) Lateral View of Pelvis of Archeotherium ingens Leidy (Princeton Museum, No. 10885). (2) Lateral 
View of Pelvis of Dinohyus hollandi Peterson (Carn. Mus. Cat. Vert. Foss., No.2126). 3 nat. size. 
lines, while its ilio-pectineal tubercle on the inferior border is heavier than in 
the latter genus. The great sacro-sciatic notch has a heavy rounded border on its 
anterior margin, while further back the border becomes sharper, though not to the 
same degree as in Archwxotheriwm. The ventral or anterior border of the ilium has 
a sharper border than the notch above and is arched to a greater degree than in 
Archxotherium, which is chiefly due to the larger development of the ilio-pectineal 
eminence in the Miocene genus. In Hippopotamus the ilium is not very like that 
