Vol. VII] DICKERSON— CLIMATE AND OLIGOCENE FAUNAS 161 



Nyctilochus, species b. 

 Patella subquadrata, new species. 

 Seraphs andersoni, new species. 

 Strepsidura packi, new species. 

 Surcula dickersoni (Weaver). 

 Triforis martini, new species. 



Of these forms, Epitonium washingtonensis Weaver, 

 Epitonium condoni Dall, Surcula dickersoni (Weaver), Car- 

 dium lincolnensis Weaver, Leda washingtonensis Weaver, 

 Ostrea lincolnensis Weaver, Semele gayi Arnold, Solen 

 lincolnensis Weaver are characteristic of the Molopophorus 

 lincolnensis zone or Lincoln horizon of Weaver.^ In addition 

 to these previously described forms, Neverita nomlandi, new 

 species and Galeodea dalli, new species, occur at Pittsburg 

 Bluffs, Oregon, California Academy of Sciences Locality 163; 

 Barbatia gahbi, new species, at California Academy of Sciences 

 Locality 165, two and one-half miles southwest of Clatskanie, 

 Oregon; Pitaria clarki, new species, and Actceon paruum, new 

 species, at California Academy of Sciences Locality 166, near 

 Clatskanie, Oregon; Spisula packardi, new species, in the 

 Oligocene of San Emigdio, California. All of these localities 

 mentioned belong to Weaver's Molopophorus lincolnensis 

 zone. Haminea petrosa Conrad, Tellina obruta Conrad, 

 Tellina oregonensis Conrad, Pecten branneri Arnold are other 

 species which range throughout the Oligocene of Washington. 

 This fauna does not contain any of the characteristic species 

 of Weaver's middle and upper Oligocene, — Turritella porter- 

 ensis and Acila gettysburgensis zones — or the Twin River and 

 Seattle formations of Arnold and Hannibal,^ which are really 

 zonal designations, not formational — the equivalents of the 

 Acila gettysburgensis zone and, in part, the Turritella porter- 

 ensis zone of Weaver. 



No Tejon species occur in this fauna, yet its general cast 

 is eocenic and some of the species such as Exilia zvcavcri, 

 Galeodea dalli, Neverita nomlandi, Triforis martini, Solen 

 lincolnensis, are apparently congeneric with forms found in 



^ Weaver, C. E., Tertiary Faunal Horizons of Western Washington, Univ. Wash 

 Publ. vol. 1, no. 1, pp. 4-6, 1916. 



= Arnold, R., and Hannibal, H. The Marine Tertiary Stratigraphy of the North 

 Pacific Coast of America, Proc. Amer. Phil. Soc, vol. 52, pp. 579-585, 1913. 



