56 CALIFORNIA ACADEMY OF SCIENCES. [Proc. 3D Ser. 



1. The Sacramento Sections. 



The Sacramento sections, on account of their complete- 

 ness and simple stratigraphic succession may well become 

 standards of great value for the correlation of other Creta- 

 ceous deposits of the greater Pacific province ; but only 

 when they themselves become very much better known. 

 For the present, criteria must be sought by means of which 

 these sections may be studied. It is evident, too, that the 

 greater stratigraphic range of species in this basin will 

 always be a perplexing element in using any of these 

 sections as a standard for comparison. For that reason, 

 the plan of selecting deposits beyond the limits of this 

 basin, in which there are clear evidences of disturbance, 

 has here been attempted. 



For the Chico epoch this method is reasonably satisfac- 

 tory, and with our increasing knowledge of the Cretaceous 

 deposits of the Pacific Coast, it will become more so. Pos- 

 sibly when the Horsetown faunas of California and Oregon 

 become better known the same method will be found 

 equally applicable. 



In correlating widely separated deposits by purely 

 paleontological means, the safest conclusions are reached 

 by considering whole faunas, or the ruling classes, and 

 supplementing such evidence by the more direct comparison 

 of species, some of which have a wide geographical range. 



It is a surprising fact that the cephalopod faunas of the 

 Pacific Coast basins of America are not more closely 

 related, while some of them have comparatively strong 

 affinities with those upon the opposite side of the Pacific, 

 namely, of eastern and southern Asia. Already there are 

 many species known, either identically or representatively 

 common to the Cretaceous of Southern India, and to one or 

 more of the basins of the Pacific Coast of America; and 

 the same is true of the Cretaceous deposits of Japan. 



2. Equivalents of the Chico. 



It has been the custom of most writers upon the subject 

 to regard the Upper Cretaceous rocks of Vancouver and 

 the neighboring islands as homotaxial equivalents of the 



