CORRELATIONS. 461 



Chico does not represent the very latest Cretaceous time, perhaps not 

 later than the close of the Colorado epoch, or the Turonian and earliest 

 Senonian of Europe. 



For the jDresent, therefore, the Shasta-Chico series may be regarded as 

 representing the whole of the Lower Cretaceous and the earlier half of 

 the Upper Cretaceous, with the proviso that there may be still later Cre- 

 taceous beds in middle California where the Chico and Tejon are said 

 to be conformable and their faunas have been reported to contain a num- 

 ber of common species. 



Correlation of the Series. 

 nan a i mo and queen charlotte island groups. 



The earliest recognition of the Cretaceous upon the western coast of 

 North America was by F. B. Meek,^ who described some fossils from 

 Vancouver island. The paleontologists of the Geological Survey of Cali- 

 fornia t early recognized the beds from which these fossils came as Chico. 

 They contain valuable beds of coal, and have received much attention 

 from the members of the Geological Survey of Canada, especially from 

 James Richardson, Dr G. M. Dawson and J. F. Whiteaves.'j; The name 

 Nanaimo group was suggested § for the rocks in question, and the investi- 

 gations of the Canadian geologists, in connection with those of the United 

 States Geological Survey in California, Oregon and Washington, fully 

 confirm the view that the Cretaceous rocks of the Xanaimo region are 

 Chico. 



The Queen Charlotte Island group, division C, D and E of Dr Dawson, 

 has been correlated by Whiteaves with the Shasta. Our investigations 

 in California and Oregon have increased the number of common species 

 and leave no doubt that the Horsetown, and probably also the Knox- 

 ville portion of the Shasta-Chico series, is represented in the Queen 

 Charlotte Island group. || 



POTO.MAC. 



The Kootanie has been placed by Sir J. William Dawson^; on approxi- 

 mately the same horizon with Dr G. M. Dawson's subdivision C^'^ of the 

 Queen Charlotte Island formation. According to Fontaine ft and New- 

 berry XX the Kootanie and Great Falls beds of Montana are to be cor- 

 related with each other and also with the Potomac. This correlation, 



* Transactions of the Albany Institute, vol. iv, 1857, pp. 37-49. 



fOeol. Survey of California, Paleontoiogj-, vol ii, p. xiv. 



+ The Cretaceous System in Canada: Trans. Koy. Soo. of Canada, for 189;j, see. iv, 1S93, pp. 1-19. 



§ Am. Jour. Sci., vol. xxxix, March, 1890, pp. 180-183. 



Ii See ante, pp. 445, 446. 



^ Trans. Roy. Soe. of Canada, vol. iii, sec. 4, p. 20. 



** Am. Jour. Sci., vol. xxxviii, 1889, p. 12-?. 



ttProc. U. S. Nat. Mus., vol. xv (1892), pp. 487-49.5. 



XX Am. Jour. Sci., vol. xli, March, 1891, p. 193. 



