Am. Jour. Sci., Vol. L, October, 1920. 



Plate II 



Plate III. — Well known types reproduced from Marsh (1893, Pis. VIII, IX). 



A, Archceotherium marshi, sp. nov., holotype, commonly known as the 

 apotype of A. crassum Marsh. Cat. No. 12025. One eighth nat. 

 size. 



B, Telonax bathrodon (Marsh). Holotype. Cat. No. 12030. Three 

 views of third lower molar. One half nat. size. 



C, Ammodon leidyanus (Marsh). Views of genoholotype, P 4 , Cat. No. 

 12040; and D, paratype, M :J , Cat. No. 12041. Both one-half nat. 

 size. 



