NO. 2 



A STUDY OF MENISCOTHERIUM — GAZIN 



49 



forward. The ventral surface of the centrum is broad and only 

 moderately keeled. 



Sacrum. — The sacrum includes four well-coalesced vertebrae which 



Fig. 8. — Meniscotherium robuslum Thorpe. Lumbar and sacral vertebrae, and 

 pelvic girdle (U.S.N.M. 18283, ilium restored from U.S.N.M. 19555) ; a, 

 dorsal view; b, ventral view. %X, natural size. Knight member, Wasatch for- 

 mation, Green River Basin, Wyo. 



ventrally appear to have about the same length each as the lumbars. 

 Cope considered that the number of sacral vertebrae was three, but 

 his specimen may have been incomplete. Certainly Marsh's sacrum 

 of "Hyracops socialis" with four sacrals does not differ from the 



