Geol.— Vol. II.] ANDERSON— CRETACEOUS DEPOSITS. 57 



Chico of California. Mr. J. F. Whiteaves (1876-84, p. 179) 

 has published an extended list of species from the fossilifer- 

 ous beds of the Nanaimo and Comox sections, in which he 

 indicates the horizon of each, and its occurrence, when 

 known, in the Chico beds of the Sacramento Valley. 



Of the fifteen species of cephalopods occurring in these 

 lists, only three are known to occur also in the Chico. 

 Nearly one-half of the gasteropods and almost the same 

 proportion of the lamelHbranchs are abundant or common 

 in the Chico of California. The occurrence of the inter- 

 esting species, Inoceramus labiatiis, in the Lower Chico of 

 California, and in "Division ^" of the Queen Charlotte 

 Islands section, perhaps shows the equivalence not only 

 of these horizons, but also indirectly the equivalence of the 

 Nanaimo beds, and the uppermost beds of Queen Charlotte 

 Islands. It is an unusually interesting point, and one that 

 can furthermore be considerably strengthened by evidence 

 that is not quite so direct but entirely conclusive. It serves 

 also to correlate more satisfactorily the deposits of the 

 Pacific border with those of the interior basin. 



Inoceramus labiatus is abundant in the upper portion of 

 the Colorado group, but is rare outside of that horizon. In 

 the deposits of the Pacific border it is apparently confined 

 to the Lower Chico and to beds homotaxially equivalent. 



The upper beds of the Oregon Basin, including those that 

 have been referred to as the Phoenix and Henley beds, hav- 

 ing a stratigraphic position equivalent to that of the Chico, 

 contain not only Inoceramus labiatus, but also other forms 

 still more trustworthy for purposes of correlation. 



In the three basins, therefore, of the West Coast, the 

 Chico, the Nanaimo, and the Phoenix and Henley beds may 

 be shown to be homotaxially equivalent, and equivalent also 

 to the beds of the Colorado group in the interior basin. 



The faunal elements that appear to connect these hori- 

 zons in the Pacific border basins contain not only a general 

 paralleHsm of the broad classes of mollusks, but also repre- 

 sentative genera, and not a few species in common. The 



