PLATE LIV 



Upper and Lower Grinding Teeth of the Lower Eocene Titanotheres, Lambdotherium and Eotitanops 



Drawings by E. S. Christman. Natural size. (See pp. 279, 281) 



A, Lambdotherium popoagicum (Am. Mus. 2688), Huerfano Basin, Colo., upper fourth premolar and molars. 



B, L. popoagicum (Am. Mus. 4864 and 4880), m-, upper premolars and molars. 



C, L. primaevum, type (Amherst Mus. 254), Buffalo Basin, Wyo., upper molars. 



D, The same, lower molars. 



E', L. popoagicum (Am. Mus. 2989), Wind River Valley, Wyo., incomplete lower dentition in jaw fragment, external view. Pmj 



in this view is restored from Am. Mus. 4863, a somewhat larger animal. 

 &, The same, internal view. 



E, Eotitanops gregoryi, type (Am. Mus. 14889), Alkali Creek, Buck Spring, Wind River Basin, Wyo., upper level of "Big Red 



Pocket," 100 feet above heavj' red stratum, level Wind River B ("Lost Cabin"), second and third left upper molars. 

 G, The same, right lower premolar-molar series; drawing reversed. 

 H', E. borealis, type (Am. Mus. 4892), Wind River Valley, Wj'o., Wind River formation, level undetermined, right upper cheek 



teeth. 

 H^, The same, outer side of p* and m'. 

 I', E. borealis (Am. Mus. 14SS7), Dry Muddy Creek 12 miles above mouth, Wind River Basin, Wyo., Wind River formation, level 



undetermined, left upper premolar-molar series. 

 P, The same, outer side view of p^p'. 

 J, E. princeps, type (Am. Mus. 296), Wind River Basin, Wyo., Wind River formation, level undetermined, left lower grinding 



teeth, crown view; drawing reversed. 



