l8 CALIFORNIA ACADEMY OF SCIENCES. [Proc. 3D Ser. 



Cretaceous of the Sacramento Valley, to which they will be 

 compared in more detail in another section. Similar beds 

 are found in northern California. 



In Douglas County, near Riddles, is a syncline of Creta- 

 ceous strata folded between areas of older metamorphic and 

 intrusive rocks. Lithologically it is a repetition of the 

 equivalent portion of the Shasta-Chico series at the south, 

 consisting of shales, sandstones, and conglomerates. The 

 conglomerates are said by G. F. Becker (1891), who first 

 described the section, to predominate in the upper part of 

 the series, and to be very extensive. Only the middle por- 

 tion of the Sacramento section is represented in these beds, 

 which are in part Knoxville and in part belong to the 

 Horsetown. Chico strata have not been reported for this 

 immediate locality, but they occur at some distance to the 

 southeast on tributaries of Rogue River. 



These Oregon deposits, especially the lower strata, 

 appear to belong to an embayment distinct from that of the 

 Sacramento Valley; but they show a similar transgression 

 of the later members of the series, only in this case the 

 expansions were toward the southeast. 



4. British Columbia. 



Upon the mainland and islands of British Columbia the 

 Cretaceous deposits form a series of considerable impor- 

 tance, which, while not so connected as that of California, 

 is almost as complete, and is, perhaps, entirely comparable 

 to it. Aucella-hQ.'A.x'wi^ strata which perhaps form the bottom 

 of the series are found both upon the mainland and upon 

 the Queen Charlotte Islands. The following tabular view 

 after Dawson (1889, P- ^27) represents the Cretaceous 

 series of these islands, to which are annexed a few of 

 the fossil species characteristic of each division. 



