EXPIiANATION OF PLATE 13. 



Sacrum of Cnmptoxaurux diftpar Marsh. No. 18T7r/, Yale IMnseum. About 

 I nat. size. Paratype: viewed from the left side. o. sacro-dorsal ; 1, 2, 3, and 

 -J, sacrals one to four, respectively. From a photograph. 

 318 



