1914] Dicker son: Fauna of the Martinez Eocene of California 83 



TROCHOCYATHUS ZITTELI ZONE OF THE TYPE LOCALITY (Continued) 



Loc. Loc. 

 500-243 333 



Loc. 

 65 



Loc. 

 544 



Loc. 

 267 



Loc. 

 1547 



Naticina, sp 



Perissolax tricarnatus Weaver 



Einginella pinguis Gabb 



Siplionalia(?) lineata Stanton 



Surcula (Surculites) andersoni, n. sp 



Surcula merriami, n. sp 



Turbinella erassatesta Gabb 



Turris louderbacki, n. sp 



Urosyca caudata Gabb 



Urosyca robusta Weaver 



Hercoglossa merriami, n. sp 



Nautilus stephensoni, n. sp 



Shark tooth .. 



A comparison of this list with that of the Trockocyathus zitteli 

 zone north of Mount Diablo, as might be expected, will bring out some 

 differences. The following are common to the two localities : 



Flabellum remondianum Gabb 

 Trochocyathus zitteli (Merriam) 

 Cardium eooperi Gabb 

 Cucullaea mathewsonii Gabb 

 Crassatellites stewartvillensis, n. sp. 

 Tapes (?) quadrata Gabb 

 Tellina undulifera Gabb 

 Teredo, sp. 



Amauropsis martinezensis, n. sp. 

 Cylichna costata Gabb 



Ficopsis, sp. 



Fusus matthewsonii Gabb 

 Neptunea mucronata Gabb 

 Perissolax tricarnatus Weaver 

 Siphonalia(?) lineata Swanton 

 Surcula merriami, n. sp. 

 Turritella pachecoensis Stanton 

 Urosyca caudata Gabb 

 Xenophora zitteli Weaver 



Practically all of these species are common forms and, if they 

 occur at all, they are abundant. The lists appear quite different on 

 their face, but this difference is due almost wholly to the occurrence 

 of species of which but single specimens have been found. Thus, 

 among the Fusidae listed from the type locality only two, Fusus(f), 

 sp., a, and Fusus martinez Gabb, are reported from more than one 

 locality, and of the rest only individual specimens have been found 

 thus far. In many of the other cases the same thing is true. 

 Brachysphingus liratus Gabb is not reported from the type locality, 

 but it occurs at Selby, which is the same horizon without doubt. A 

 few widespread abundant forms are of more real value than forms 

 which occur occasionally. Thus, Trochocyathus zitteli (Merriam), 

 Amauropsis martinezensis, n. sp., Crassatellites stewartvillensis, n. sp., 



