6o CALIFORNIA ACADEMY OF SCIENCES. [Proc. 3D Ser. 



Island of Ezo. Oregon Basin. 



Desmoceras gaudama (pars), rel. Desmoceras hoffmanni Gabb 

 Desinoceras siigatiiui = Desmoceras sugatmn Forbes 



Lyioccras sacya (pars) = Lytoceras sacya Forres 



Lyioceras sacya (pars) cf. Lytoceras jukesi Sharpe 



PachydiscHS arrialoorensis cf. Pachydiscus henleyensis, sp. nov. 



Phylloceras villcdce, near rel. Phylloceras ramosuvi Meek 



Inoceranius naiiinaniii rel. Iiwceraniiis klatnathcnsis, sp. nov. 



Inocerainics sp., rel. Liioccrainiis ivhitneyi Gabb 

 Ciicullcea sachalinense {!), cf. CuciUUca truncata Gabb 



Nucula picttiraia, cf. Nucula truncata Gabb 



The Turonian aspect of at least the upper portion of the 

 Chico is very clear, as has already been pointed out by 

 different writers. It is further emphasized by some of the 

 above forms, which are known for the first time from the 

 Pacific border province in the Phrenix beds of Southern 

 Oregon. And to these may be added the great develop- 

 ment of the gasteropod and bivalve classes and many 

 aberrant forms of Helicoceras and Hamitcs, among which 

 is to be noticed an Jlclicoceras related to //. retisianwm 

 d'Orb., while the Turonian species, Inoceranuis lahiatus^ 

 and many others ally these beds to the Turonian of Euro- 

 pean Cretaceous. But there are also contained in them 

 many forms that belong to a higher, as well as a lower, 

 horizon. BaciiUtes chico'cnsis and B . fairbanksi are both 

 closely akin to B. vagina Forbes, which is thought to be a 

 Senonian species. Numerous forms of Pachydiscus are 

 found in the Chico and its equivalents which would be 

 expected in Senonian equivalents; while the large develop- 

 ment of gasteropods and lamellibranchs shows a late period 

 of the Cretaceous. On the other hand, there are not a few 

 undoubted Cenomanian forms in the Lower Chico beds 

 which incline one to refer them to a lower position than the 

 Turonian. Among such forms are certain species of 

 Acanthoceras and some of the forms of Schlocnhachia. 



In this connection also it ought to be said that the closest 

 relationship seems to exist between some of the forms of the 

 Lower Chico and some from the Ootatoor beds of Southern 

 India. Inoccrainus labiatiis is associated with Acanthoceras 



