Vol. IX] SMITH— CLIMATIC RELATIONS 153 



CalyptrcBa radians Lam., Cancellaria rapa Nomland, Cancel- 

 laria tritonidea Gabb, Conus species, Cyprcea fernandocnsis 

 Arn., Ficus nodiferus Gabb, Ficus pyriformis Gabb, Murex 

 eldridgei Arn., Pisania fortis Carp., Terehra martini Eng., 

 Terehratalia occidentalis Dall, Terebratalia smithi Arn. 



This decidedly indicates warm water, of a temperature not 

 much below 68° F. min., not strictly tropical, for reef-forming- 

 corals are lacking, and there are several northern types that 

 would hardly have lived in tropical waters. The abundant 

 Lyropecten, Janira, Ficus, giant Area and Miltha and the rarer 

 Astrodapsis, Chione, Dosinia, Murex, and Cyprcua, all speak 

 for a temperature considerably higher than that now prevailing 

 in the Santa Barbara Channel, or about 66° F. min. This 

 fauna was the northern limit of Astrodapsis, Cyprcea, giant 

 Area, Lyropecten, and Ficus, in the lower Pliocene. Of the 

 whole fauna, as now known, about 50% are extinct, which 

 agrees with that of the Santa Maria, the Purisima, and the 

 Wildcat faunas. 



Point Conception then played the part, now given to Cerros 

 Island (Lower California), as the dividing line between the 

 subtropical and the warm temperate zones. There was then 

 considerable telescoping of the isotherms, since the cold-water 

 belt came down to Cape Mendocino, and the warm temperate 

 met the subtropical belt at Point Conception, with much more 

 sharply defined climatic zones than now exist on the coast of 

 California. 



Carrizo (Imperial Co., Calif., and Cerros Island, Lower 

 California, lat. 33° N.-28° N.). This fauna was first described 

 by R. Arnold^", who correlated it with the Etchegoin of middle 

 California, a correlation which still stands. W. S. Kew^^ has 

 more recently described the fauna more fully, assigning it 

 definitely to the Pliocene. The following forms are known to 

 belong to the Carrizo: Area (giant), Cardium quadrigenarium 

 Con., Codakia cf. distinguenda Tryon, Metis alta Con., Ostrea 

 palmula Carp., Ostrea veatchi Gabb, Ostrea heermani Con., 

 Ostrea vespertina Con., Pecten carrizoensis Arn., Pecten 

 ashleyi Arn., Pecten cerrosensis Arn., Pecten deserti Con., Pec- 



="» Science (n. s.), vol. 19, p. 503 (1904); and U. S. Geol. Survey, Prof. Paper No. 

 47, (1906). 



'* Tertiary Echinoids of the Carrizo Creek region in the Colorado Desert. Univ. of 

 Calif. Pub. Bull. Dept. Geol. vol. 8, No. 5, (1914). 



