I9I3.] STRATIGRAPHY OF PACIFIC COAST OF AMERICA. 693 



Macoma nasuta Conr., S.^^ 



Marcia oregonensis Conr. (M. subdiaphana Cpr.), S, E.^^ 

 Mulinia densata Conr., S, E. 

 Panomya ampla Dall {P. chrysis Dall), E.^^ 

 Paphia staleyi Gabb, S, E. 

 Paphia tenerrinia Conr., S.^- 

 Pecten caiirinus Gld., S, E.^"^ 

 Pecten dilleri Dall, E.^^ 

 Pecten healeyi Arn., S.^^ 

 Pecten nntteri Arn., 3". 

 Psephidia lordi Baird, 5", E.^^ 

 Schizothaerus nuttalli Conr., S.^^ 

 Schizothaerus pajaroanus Conr., E. 

 Siliqua nuttalli Conr., S, E.^^ 

 Solen sicarius Gld., S.^^ 



Spisula voyi Gabb (5". alaskana Dall), S, E.^^ 

 Tellina buttoni Dall, 5.^^ 

 Thracia trapecoidea Conr., E. 

 Venus securis Shum., S. 

 Gasteropoda : 



Caesia mendica Gld., Sfi"^ 



Chrysodovius stantoni Am., S.^^ 



Chrysodomus tabulatus Baird, S, E.^"^ 



Columbella gausapata Gld. (Astyris richihofeni Gabb), S, E.^^ 



Crepidula onyx Sby., S.^^ 



Crepidula princeps Conr., 5. 



Natica clausa B. & S., S, E.^^ 



Nucella decemcostata Midd. {Purpura lima auct.), S.^^ 



Nucella lamellosa Gmel., S, E.^^ 



Nucella saxicola Val., S.^^ 



Olivella biplicata Sby., S.^^ 



Polinices galianoi Dall, 5". 



Stylidium eschrichti Midd. (Bittium filosum Gld.), S.^^ 



SCAPHOPODA : 



Dentalium rectius Cpr., E.^"^ 



ECHINODERMATA : 



Echinarachnius gibbsi Rem., S.^^ 

 Scutella interlineata Stimp., S.^^ 

 Scutella oregonensis Clark, S, E. 



S — San Francisco Peninsula. E — Eel River Valley. 



Note. — This and succeeding lists from the Merced and Elk River forma- 

 tions should not be used as a basis for determining percentages of species 

 living or extinct. It has not been convenient to identify all the living species 

 in time to include them on the lists, and in addition a number of undescribed 

 extinct forms occur. 



^- Species still living. 



s^ Species characteristic of this horizor' 



