84 Cretaceous. 



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. At is extensively represented in Shasta and Butte counties, and 

 in the toot-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 Chico Group. It con- 

 tains fossils seemingly representing ages, from the Gault to the Neo- 

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

 northwest of the Sacramento valley. 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, eastof *Puget 

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

 the Chico Group, 



W. M. Gabb* described, from Shasta county, from Martinez, Benicia, 

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

 atus, Belemnites impresstls, Ammonites jugal is, A. stoliczkanus, A. 

 fraternus, Ancyloceras Uneatum, Diptychoceras laeve, If'nsus tumidus, 

 F. occidentalis, Neptunea cretacea, N. mucronata^ Palceatractus 

 crassKs, Surcula prceattenuata, 8. inconspicua, Heteroterma trochoidea-, 

 Bela clathrata^ Cordiera mitrmformis, Tritonium calif ornicu7n, T, 

 tejonense., T. fusiforme, Brachysphingus sinuatus.^ Bullia striata. 

 Turbinella crassitesta, JJrosyca caudata, Neverita globosa, Ampullina 

 striata. Terehra californica, Cyprcea mathewsoni, Anchura trans- 

 versa., A. carinifera, Helicaulax hicarinata, H. costata, Loxotrema 

 turrita, Atresius liratus. Turritella martinezensis, JSFerita triangulata. 

 Calliosloma radiatum, Ataphrus crassus, Margaritella angulata., 

 Acmoia tejonensis, Aetwonella oviformis, Liocium punctatum, Ringi- 

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

 ensis, Pleuromya papyracea. Arcomya undulata, Ilactra tenuissima, 

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

 teralis, 3feretrix '-fragilis, Thetis elongata, Cardium. translncidnm, 

 Crassatella compacta, JJnio Mihhardi, Ilodiola major, now Volsella 

 major, Meleagrina antiqua, Inoceramas elliotti, I. whitneyi, Tri- 

 gonia aequicostata^ JViicula soUtaria, Pecten martinezensis, P. com- 

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



* Pal. of Cal., vol.2. 



