1914] Dickerson: Fauna of the Martinez Eocene of California 87 



of several species which occur in the middle or Trochocyathus zitteli 

 zone is the noteworthy feature of the Solen stantoni beds. Among 

 these are Trochocyathus zitteli (Merriam), Crassatellites unioides 

 Stanton, Glycimeris veatchii var. major (Stanton), Leda alaeformis 

 (Gabb), Meretrix stantoni, n. sp., Paphia(t) clarki, n. sp., Amauropsis 

 martinezensis, n. sp., Discohelix calif ornica Weaver, Neptunea cretacea 

 Gabb, and XcnopJiora zitteli Weaver. 



Martinez at Benicia 



The Martinez at Benicia is a continuation of the eastern limb of 

 the Muir syncline, a portion of the type section. The best exposures 

 are found in the Arsenal Grounds. Basal beds of the Martinez are 

 exposed in a rock quarry about one hundred yards west of the 

 Arsenal Reservoir Hill. They are composed of about twenty feet of 

 conglomerate, upon which is laid about fifty feet of fine-grained white 

 foraminiferal shale with strike N 60° W, dip 55° W. Unfortunately 

 minor faulting has so complicated the structure that the relation to 

 the underlying Chico is not clear. The basal beds are non-fossiliferous, 

 but the glauconitic sandstone beds one thousand feet above the base 

 contain fossils. 



The following species have been reported from this locality : 



Flabellum remondianum Gabb 

 Terebratulina tejonensis Stanton 

 Cueullaea mathewsonii Gabb 

 Glycimeris veatchii var. major 



(Stanton) 

 Leda gabbi Conrad 

 Leda alaeformis (Gabb) 

 Meretrix cf. dalli, n. sp. 

 Meretrix, sp. 

 Meretrix stantoni, n. sp. 

 Nucula truncata Gabb 

 Phacoides diaboli, n. sp. 

 Pholadomya nasuta Gabb 



Tapes(?) quadrata Gabb 

 Tellina(?) undulifera Gabb 

 Tellina(?), sp. a 

 Actaeon lawsoni Weaver 

 Ampullina (conf.) striata Gabb 

 Brachysphingus liratus Gabb 

 Discohelix californica Weaver 

 Natica, sp. 



Perissolax triearnatus Weaver 

 Turbinella crassatesta Gabb 

 Turritella infragrannlata Gabb 

 Urosyca eaudata Gabb 



Cassidaria tuberculata was in the old collections made by Dr. 

 Weaver, but it may have been mixed in from a Tejon collection. Its 

 sandstone matrix appears different from the Martinez sandstone. 



All of the other forms occur in the Trochocyathus zitteli zone either 

 at the type locality or in the area north of Mount Diablo. Meretrix 

 stantoni, n. sp., Meretrix dalli, n. sp., Tellina, n. sp., a, Discohelix cali- 

 fornica, Turbinella crassatesta, Terebratulina tejonensis, Glycimeris 



