344 CALIFORNIA ACADEMY OF SCIENCES. [Proc. 3D Ser. 



Fortieth Parallel studied it in the Humboldt Mountains of 

 Nevada, where Meek (18) thought he recognized some 

 Californian species. Shortly after this time Lower Trias 

 was discovered in southeastern Idaho, by the Hayden Sur- 

 vey, and described by Dr. C. A. White (40). 



The next publication on the American Trias was by 

 E. von Mojsisovics in "Arktische Triasfaunen " (20), in 

 which some of the species described by Gabb, Meek, and 

 White were compared with ammonites from Siberia, and 

 the relations of the American faunas to those of the Arctic- 

 Pacific region were discussed. 



Professor Alpheus Hyatt (13) next undertook a revision 

 of Gabb's work, visiting the original locality in Plumas 

 County, California, adding largely to the faunal list, and 

 especially to our knowledge of the stratigraphic distribution 

 of the species. 



In 1892 the writer's attention was called by Dr. H. W. 

 Fairbanks to a bed of ammonite-bearing limestone discov- 

 ered by him on Squaw Creek near Pitt River in Shasta 

 County, California; on examination, these fossils proved to 

 be of Upper Triassic age. This locality was soon after- 

 wards visited by the writer, who spent the field-season of 

 1893 at work in that region, and in studying the section in 

 Plumas County. This work brought to light a rich cepha- 

 lopod fauna, chiefly of Karnic age, and nearly related to 

 characteristic species of the Tyrolian Alps. The writer 

 has since spent a part of the field-seasons of 1895, 1898, 

 1901, and 1903 collecting in the Shasta region, and has had 

 several collections made there by others; these later collec- 

 tions have added greatly to the lists of fossils, and have 

 necessitated a revision of all the preliminary lists. A part 

 of the results of this work has already been published by 

 the writer (31-33). 



One of the most suggestive papers on American Triassic 

 stratigraphy is a chapter entitled " Die Meere der Trias 

 Periode," by Dr. E. von Mojsisovics (24), who on the 

 basis of the existing literature, communications of Professor 

 Hyatt and the writer, and a suite of fossils sent him by the 



