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



the more characteristic species occurring in this zone are Area 

 montereyana Osmont, Chione securis (Shumard), Diplodonta 

 parilis Conrad, Acila conradi Meek, Area trilineata Conrad, 

 Mareia oregonensis (Conrad), Pecten propatulus Conrad, 

 Panope generosa (Gould), Phaeoides aeutilineatiis (Conrad), 

 Spisula albaria (Conrad), Crepidula praerupta Conrad, Fu- 

 sinus stanfordensis (Arnold), Polyniees saxea Conrad, Sinum 

 scopidosum (Conrad), Dentalhim eonradi Dall, Aturia an- 

 gustata Conrad, Pecten fucanus Arnold, Tellina aretata Con- 

 rad, Venericardia quadrata Dall, Venus olympidea (Reagan), 

 Venus clallamensis (Reagan), Ficus elallamensis Weaver, 

 Tellina nevadensis Anderson, Caiicellaria dalliana Anderson, 

 Cancellaria condoni Anderson, and Leda ochsneri Anderson. 

 This fauna presents a very strong similarity to that occurring 

 in the Monterey formation in California. 



YOLDIA STRIGATA ZONE 



The upper Miocene strata of western Washington every- 

 where rest with unconformity upon the older rocks. The fauna 

 occurring within these strata is very different from that of the 

 faunal zones just described. One of the most common and 

 readily recognizable species among this fauna is Yoldia stri- 

 gata Dall. It might be desirable to refer to this fauna as the 

 Yoldia strigata zone. 



Among the more characteristic species belonging to this 

 zone are Area trilineata Conrad, Cardium meekianum Gabb, 

 Macoma astori Dall, Mulinia densata Conrad, Pecten coosen- 

 sis Shumard, Solen sicariiis Gould, Siliqna nuttallii Conrad, 

 Yoldia strigata Dall, Argobnccininm cammani Dall, Chryso- 

 domns imperolis Dall, Phalium aequisulcatiwi Dall, Sinum 

 scopulosum (Conrad) and Scutella gabbii Remond. A com- 

 plete list of the species occurring in this zone may be found 

 in the faunal table. 



Strata containing fauna of the Yoldia strigata zone out- 

 crop in the Chehalis valley in the vicinity of Grays Harbor, 

 at the mouth of the Queniult River and in the lower valley 

 of the Quillayute River. The faunas of the Ouillayute and 

 Queniult valleys may represent a slightly higher position than 



