Geol— Vol. I.] SMITH— COMPARATIVE STRATIGRAPHY. 359 



called on account of the presence of fossiliferous rocks 

 of that system), we found a bed of slates containing Halo- 

 bia, occurring in banks as did the Monotis below on the 

 Triassic spur." It is, however, not likely that the upper 

 series would be represented in one place by unfossiliferous 

 quartzites and a mile or so away by thinly bedded cal- 

 careous shales, nor that the Halohia slates should rest in 

 one place on the eroded surface of the Carboniferous and 

 in another place a few hundred yards away on a thick 

 series of calcareous shales with Upper Triassic fossils. In 

 fact, the Halohia beds seem to be the oldest Trias present 

 in the Genesee Valley, and the Swearinger slates are 

 probably brought down to their position by faulting. 

 Rhabdoceras and Halorites are uniformly characteristic of 

 higher horizons than the Trofites subbullatus fauna in the 

 West Humboldt Range of Nevada, as well as in the Alps. 

 Dr. E. von Mojsisovics (24) has shown in his discussion 

 of the sequence of faunas of the Trias that the Pseudo- 

 7nonotis beds belong to the Bajuvaric series, and conse- 

 quently above the Karnic horizon, to which the Halobia 

 slates and the Hosselkus limestone belong. This view is 

 also in accordance with the section described by the writer 

 in Shasta County, California, where the Psetidoinonotis 

 shales were found above the Hosselkus limestone. In all 

 probability no Trias lower than the Karnic occurs in the 

 Genesee section. 



Mr. J. S. Diller (7) has described from the Taylorsville 

 region, under the name of Foreman beds, a series of slates 

 and conglomerates with plant remains, assigned by Profes- 

 sor W. M. Fontaine to the Rhaetic. It seems then that in 

 California the Triassic marine history ended with the 

 Psetidomonotis beds, and that during Rhaetic time the land 

 had encroached still further on the sea by the progressive 

 westward uplift. 



The Upper Trias of Shasta County, California. In 1892 

 Dr. H. W. Fairbanks discovered some ammonite-bearing 

 limestones about nine miles northeast of Copper City, 

 Shasta County, on the divide between Squaw Creek and 



( 4 ) July 9, 1904. 



