U S. NATIONAL MUSEUM 



PROCEEDINGS, VOL. 83 PLATE 28 



PLESIPPUS SHOSHONENSIS. 



Maniiibk's; 1, I'.S.N.M. no. 12560 (immature); 2, U.S.N.M. no. 12553; 3, U.S.N'.M. no. 12573. Occlusal 

 view.s. About one-flfth natural size. Hagerman lake beds, upper Pliocene, Idaho. 



