v.4<j 



UNITED STATES GEOLOGICAL SURREY 



CHARLES D. WALCOTT, Director 



THE CERATOPSIA 



BY 



JOHN B. HATCHER 



BASED ON PRELIMINAEY STUDIES BY 



OTHjSTIEL c. marsh 



EDITED AJSTT) COMPLETED BY 



RICHARD S. LULL 



WASHINGTON 



GOVERNMENT PRINTING OFFICE 



1 9 7 



