TRIAS OF NEVADA AND IDAHO. 399 



By comparing the statements made in this paper with the table given 

 in my article, " Jura and Trias at Taylorville, California," * it will be 

 seen that the Swearinger slates were divided into Monotis beds, Daonella 

 bed, Rhabdoceras bed and Halohla bed, and the whole group was referred 

 to the Upper Noric. 



The succession of the Monitis and the Daonella bed is similar in Amer- 

 ican and in Sailors canyon, but above this, parallelism ceases. 



The development of unquestionable Triassic types in the Tajdorville 

 region leaves no room for doubting the system to which the rocks con- 

 taining them belong, and they also indicate the particular series to which 

 strata may be referred. These differences and the entirely distinct spe- 

 cies of the two localities, even in the genera Monotis and Daonella, show 

 that there were two distinct faunal areas, and that there could have been 

 no communication between them during the time of the deposition of 

 the Monotis and Daonella beds, even if it is admitted that they were con- 

 tem])oraneous in deposition, an opinion which cannot be maintained by 

 any facts now known. 



Trias of Nevada and Idaho. 



The Whitney collection of fossils contains a specimen of Arcestes {au-s- 

 seanus) gabbi, Meek, from Volcano mining district, thirty miles southeast 

 of Walkers lake, Nevada, which is quoted by him j as characteristic of 

 the Trias at that locality, and also a slab of Daonella having the same 

 catalogue number and apj^arcntly from the same locality. This species 

 is identical with the Halobia dubia, Gal)b, which is equivalent to Halubia 

 {^Daonella) lommeli, Meek.;]: The Trias is therefore present attliis localit}'^, 

 and these two forms indicate a fauna similar in part at least to that of 

 the Trias of Humboldt county, Nevada. There is also in this collection 

 a few fossils from New pass, Desatoya mountains, Nevada, indicating 

 that there is a rich Triassic fauna at this locality of approximately the 

 same age as that of the Star Peak range, that is to say, Muschelkalk. 



The following is quoted from my former paper, " Jura and Trias at 

 Taylorville, California : " § 



"The Trias of Idaho (Asi)eii mountains, near Soda springs) has a well-marked 

 Triassic fauna, with fossil cephalopods recoonized in Europe by Mojsisovics, Stein- 

 mann and Karpinsky as belonging to the lower part of tlie Triassic system, and, 

 after careful reexamination of the fossils, I find strong grounds for thinking that 

 this opinion is probably correct. This fauna appears to be more nearly the equiva- 



* Bull. Geol. Soc. of Am., vol. .3, p. 412. 



t Descriptions of Secondary Fossils, etc: Am. Jour. Condi., vol. v, p. o. 



+ Exploration of the Fortieth Parallel, p. 100, pi. 10. 



I Bull. Geol. Soc. Am., vol. 3, p. 40u. 



