PLATE Til. 



MIot'KNK I'liCTENS. 



[Unlt'ss ntluTwisi- stated all tigiires are a;>j>ri>xiinately natural size.] 



Page. 



Fi<;. 1. Fecleii ( I'alinOjKden ) jiropatulus Conrad. X.^. C f)4 



Mold of interior of rij^lit valve, showing a portion of the inulmnal areaand ear.-;; altitude 

 ilO iinii. Astoria formation (Miocene), Astoria, Ores;. (11. I 



Fi(i. 2. I'lcUn ( I'litiiiojiirli'ii ) njosi'iisix Shumard. U. S. N. M. 1077:M (il 



Exterior of right valve, anterior ear slightly broken; altitude lo:i nnii. Eiuiiire fnniiatidii 

 (Miocene), Coos Hay, Oreg. (M. P. ) 



EiG. li<(. Same specimen as tig. 2 Gl 



Protile of laitli \alves, viewed from rear. 



168 



