J48 CALIFORNIA ACADEMY OF SCIENCES [Proc. 4th Ser. 



lingense Arn., Cancellaria tritonidea Gabb, Cancellaria rapa 

 Nomland, Chrysodomus imperialis Dall, Chrysodomus portola- 

 ensis Arn., Ficus nodiferus Gabb, Miopleionia oregonensis 

 Dall, Nassa calif orniana Con., Thais etchegoinensis Arn., Thais 

 kettlemanensis Arn., Trophon coalingense Arn., Trophon pon- 

 derosus Gabb, Turritella vanvlecki Arn. 



Of the entire fauna about 40% are living, and 60% extinct. 

 The temperature was probably subtropical, as indicated by 

 Lyropecten, Ficus, Janira, Chione of the gnidia group, and 

 fluted Ostrea. 



One good reason for placing the Etchegoin below the greater 

 part of the Purisima zone is the fact that the Etchegoin fauna 

 still preserves more of the warm water elements and has fewer 

 of the boreal, Puget Sound, forms than the Fernando, although 

 it lies 200 miles to the north. The isotherm of subtropical 

 warmth had not yet moved to the south of Point Conception, 

 as it had in the Fernando-Purisima epoch. 



Near relationship between the Etchegoin-Jacalitos and the 

 Purisima-Fernando is shown by the following species which 

 range from Etchegoin into Purisima or Fernando, and are not 

 known to occur higher in the section: Cardium meekanum, 

 Chione elsmerensis, Chione securis, Cryptomya ovalis, Glyci- 

 meris coalingensis, Marcia oregonensis, Mulinia densata, 

 Mytilus coalingensis, Paphia staleyi, Pecten healeyi, Pecten 

 nutteri, Pecten wattsi, Pecten oweni, Spisula alharia, Venus 

 pertenuis, Zirphea dentata, Cancellaria rapa, Chrysodomus im- 

 perialis, Chrysodomus portolaensis, Nassa moraniana, Polinices 

 galianoi, Ficus nodiferus, Miopleionia oregonensis, Sinum 

 scopulosum. In addition to these, the following are known to 

 occur below the Etchegoin, and in the Purisima or Fernando 

 horizon, but not yet known in the Etchegoin: Cardium coo- 

 sense, Macoma astori, Miltha sanctcecrucis, Chrysodomus post- 

 planatus, Trochita inornata. These are nearly all Miocene 

 species ranging upward. 



The Oriental group. Pallium, group of Pecten swifti, is 

 especially abundant and characteristic in the Etchegoin fauna. 

 The relationship of the American to the Japanese fauna becomes 

 even more marked in the Purisima epoch, as it should, since the 

 latter is more northern in position, and cooler in temperature 

 than the Etchegoin. 



