U. S. GEOLOGICAL SURVEY 



BULLETIN 612 PLATE XX 



A. A CREODONT, AN ANCIENT DOGLIKE ANIMAL, ONE OF THE ANCESTORS OF THE CARNIVOROUS 



MAMMALS OF TO-DAY. 



w 



After Osborn. Published by permission of The Macmilian Co, 



£. EOBASILEUS. ONE OF THE TYPES OF ANIMALS THAT BECAME EXTINCT AGES AGO 



After Osborn. Published by permission of The Macmilian Co. 



