PLATE CCXXXI 



Pelvis and Sacrum Referred by Marsh to Brontotherium gigas 



U. S. National Museum. Plate prepared under the direction of Professor Marsh. One-fourth natural size. (See p. 694) 



1, Dorsal view; 2, posterior view, a, Acetabulum; c, crest of ilium; /, thyroid, or obturator foramen; /',/", vacuities, or unossified 

 regions in gluteal surface of ilium; p, pubis; il, ilium; is, ischium; p, pubis; s', caudosacral vertebra. 



