1917] Nomland: The Etchegoin Pliocene of Middle California 227 



species listed from that locality, twenty-six are also found in the 

 Etchegoin of Coalinga. Considering the distance by which these 

 localities are separated, a striking resemblance is evident. Among 

 the species strongly suggesting this close relationship may be men- 

 tioned Terebratalia smithi Arnold, Pecten healeyi Arnold, Pecten 

 oweni Arnold. "With these forms occur also several species unknown 

 except from the lower Fernando near Newhall and from the Etchegoin 

 near Coalinga; these are Chione elsmerensis English, Chione fernan- 

 doensis English, Turris coaling ensis Arnold, and Dosinia jacaUtosana 

 Arnold. Good specimens of Pecten estrellanus catalinae Arnold, listed 

 by Arnold from the lower Fernando near Newhall, have been obtained 

 by the writer from beds that appear to represent middle Etchegoin 

 at Big Sandy Creek on the west side of the Diablo Range. 



The fauna most closely related to the upper Etchegoin is undoubt- 

 edly that listed from the lower Pliocene beds at Sargent. Of the 

 thirty-eight species listed from that formation at Sargent, thirty are 

 found in the upper Etchegoin at Coalinga. The species in common 

 include Dendraster gibbsii (Remond), Pecten etchegoini Anderson and 

 its varieties nutteri Arnold and watt si Arnold. 



As will be seen by the Etchegoin fauna as summarized in this 

 paper, nearly one-half of the species reported from the Purisima and 

 more than one-half of the species reported from the lower Merced are 

 found in the Etchegoin near Coalinga. The characteristic species 

 common to the Merced, and especially those common to the Purisima, 

 seem to be such as are confined to the middle and upper Etchegoin. 

 It seems probable, however, that the Etchegoin and Merced basins 

 represent different faunal provinces. In the Merced are included 

 several species indicating a closer relationship to the northern forms 

 than the warm water Etchegoin fauna. 



Summary 



1. The accumulation of over 10,000 feet of Pliocene has occurred 

 under shallow marine or terrestrial conditions. 



2. In the period in which this accumulation took place the floor of 

 the basin of deposition was several times raised locally above sea-level. 

 After the prevailingly terrestrial conditions had begun marine depo- 

 sition occurred for brief periods. 



3. Diastrophic movements of great magnitude occurred in post- 

 Pliocene time in the Coalinga region. 



