Geol— Vol. I.] SMITH— COMPARATIVE STRATIGRAPHY. 35 1 



At the base of the section seen on the Union Wash are 

 massive siliceous and calcareous beds supposed, on the basis 

 of fossils found in the float, to belong to the Carboniferous; 

 then several hundred feet of calcareous shales with obscure 

 traces of ammonites; then about fifteen feet of hard gray 

 siliceous limestone, from which all the fossils listed from 

 this horizon were taken. Above this limestone lie about 

 eight hundred feet of dark shales with a few impressions of 

 ammonites; then about five feet of impure earthy black lime- 

 stone with numerous ammonites, Ptychites, Himgarites, 

 Ac7'ochordiceras, Xenodisciis, thought by the writer to belong 

 to the base of the Middle Trias, or the Subrobustus beds of 

 the Oriental region. These latter will therefore be treated 

 under the Middle Trias. 



The fauna collected from the gray limestone by Dr. C. 

 D. Walcott, Mr. H. W. Turner, and the writer yielded the 

 following species : Sibiritesf s^. noY., Damibttes two ne.w 

 species, Lecanites sp. nov., Meekocer as g7'acilitattsWh\\.Q., 

 M. coni. falcatum Waagen, Af. conf. radiosum Waagen, 

 M. (Konmckites) mushbachanu?n White, M. (Koninckites ?) 

 conf. radiatmn Waagen, M. (Gyronites) aplanattmi White, 

 and six new species of Meekoceras, Prionolobus sp. nov,, 

 Aspidites two new species, Proptychites sp. nov., Xenasfis 

 two new species, Ophiceras conf. sakuntala Diener, and 

 three new species of this genus, Nannites sp. nov., Pseudo- 

 sageceras sp. nov., Clypitesf sp. nov., Ussuria sp. nov., 

 and Prosphingites sp. nov. In addition to these were found 

 also several new genera allied to the Pinacoceratidas. 



This fauna shows a considerable number of characteristic 

 species identical with forms from the Meekoceras beds of 

 the Aspen Mountains in Idaho, and a number possibly iden- 

 tical with species from the Lower Triassic Ceratite forma- 

 tion of the Asiatic regions ; it is therefore referred with cer- 

 tainty to the Brahmanic stage of the Scythic series, or 

 more exactly, to the equivalents of the Ceratite marls and 

 the lower part of the Ceratite sandstone of the Salt Range 

 of India. 



In the Lower Trias, Meekoceras beds, of the Aspen Moun- 

 tains of Idaho and the Inyo Range of California are found 



