94 Cincinnati Society of Natural History. 



3. The Chico Group, one of the most extensive and important mem- 

 bers of the Pacific coast Cretaceous. It is on the horizon of either the 

 upper or lower chalk of Europe, and probably the equivalent of 

 both. It is extensively represented in Shasta and Butte counties, and 

 in the loot-hills of the Sierra Nevada, as far south as Folsom, occurr- 

 ing, also, on the eastern face of the coast ranges, bordering the Sacra- 

 mento valley at Martinez, and again in Orestimba canon, in Stanislaus 

 county. It includes all of the known Cretaceous of Oregon, and of the 

 extreme northern portion of California, and is the coal-bearing forma- 

 tion of Vancouver's Island. 



4. The Shasta Group, including all below the Ch,ico Group. It con- 

 tains fossils seemingh' representing ages, from the Gault to the Neo- 

 comien, inclusive, and is found principall}' in the mountains west and 

 northwest of the Sacramento valle}'. Two or three of its characteristic 

 fossils have been found in the vicinit}^ of Monte Diablo, and one of the 

 same species has been collected in Washington Territory, east of Puget 

 Sound. Few, or none, of its fossils are known to extend upward into 

 the Chico Group. 



W. M. Gabb* described, from Shasta count}', from Martinez, Benicia, 

 Colusa count}^, Tejon, and other places in California, Philoteuthis foli- 

 atus, Belemnites impressus^ Ammonites jiigidi^, A. stoliczkanus, A. 

 fraternus^ Ancyloceras UtLeatum^ Diptychoceras laeve, Fnsus tumidus, 

 F. occidentalism Neptunea cretacea, N. mucronata^ Palmatractus 

 crassus, Surcula prceatfemiata, S. inconspictca, Heteroterma trochoidea-, 

 Bela clathrata^ Cordiera mitrceformis, Tritonium californicum, T, 

 tejo7iense^ T. fusiforme^ Brachysphingus sinuatus^ BulUa striata. 

 Turhinella crassitesta, Urosyca caudata, Neverita globosa, Ampullina 

 striata, Terehra calif ornica, Cyprcea matheivsoni, Anchura trans- 

 versa^ A. carinifera, JSelicaulax hicarinata, H. costata, Loxotrema 

 turrita^ Atresius liratics. Turritella martinezensis, Nerita triangulata, 

 Calliostoma radiatum, Ataphrus crassus, Jfargaritella angvlata, 

 AcmoiG tejonensis, Aetmonella oviformis, Liocium punctatum, Ringi- 

 nella polita^ Solen cuneatus, Anatina quadrata^ Pholadomya oregon- 

 ensis, Pleuromya papyracea, Arcomya undulata, Mactra tenuissima, 

 Asaphis multicosta^ Tellina undulifera^ Donax latus, Venus aequila- 

 feralis, 3Ieretrix fragilis, Thetis elongata, Cardium translucidum, 

 Crassafella compacta, Unio hubhardi, Modiola major, now Volsella 

 major, Meleagrina antiqua, Inoceramus elliotti, 1. lohitneyi, Tri- 

 gonia aequicostata^ Nucula solitaria, Pecten martinezensis, P. com- 

 plexicosta, P. interradiatus, Neithea grandicosta, Lima shastaensis, 



* Pal. of Cal., vol. 2. 



