Geol.— Vol. I.] SMITH— COMPARATIVE STRATIGRAPHY. 353 



new species and genera from the Humboldt Range; these 

 were described by F. B. Meek (18) and referred to the St. 

 Cassian formation of the Upper Trias, although Professor 

 Alpheus Hyatt, who also examined all the collections, 

 always adhered to the opinion that the fauna belonged to 

 the Middle Trias, or Muschelkalk. The most characteristic 

 genera obtained by the two surveys were Orthoceras, 

 Arcestes, Proirachyceras, Ceratites, Daniihites, Etito7noceras, 

 Sageceras, Eudiscoceras, and Daonella, an association suffi- 

 cient to stamp these beds as either Muschelkalk or the lower 

 part of the Upper Trias. 



The general section of the Trias in the West Humboldt 

 Range, as determined by the Geological Exploration of the 

 Fortieth Parallel is as follows : 



6. Quartzite 2200 ft. 



5. Limestone probably 1000 ft. 



4. Thinly bedded quartzite 1000 ft. 



3. Ferruginous limestones 2000 ft. 



2. Slaty quartzite 1500 ft. 



I . Argillaceous limestone, full of fossils 1 500 ft. 



Metamorphic Koipato group, unfossiliferous 6000 ft. 



All the Triassic fossils from the Humboldt region de- 

 scribed by the Geological Survey of the Fortieth Parallel, 

 came from limestone No. i, although probably several dif- 

 ferent horizons are represented in this series. Most of the 

 fossils, however, were taken from the base of the for- 

 mation. 



W. M. Gabb (9) cites ^^ Ammonites ramsatieri,'" Am- 

 monites homfrayi, and Pseiidomonotis siibcirciilaris Gabb 

 from the Humboldt region ; all these species are characteristic 

 of the Upper Trias of California. It therefore seems cer- 

 tain that the Upper Trias is represented in the upper lime- 

 stones of the Humboldt Range. 



In 1888 Professor Alpheus Hyatt visited the West Hum- 

 boldt Range and made collections from the Daonella beds. 

 These, together with the original Whitney collections and 

 those of the Survey of the Fortieth Parallel, were placed 

 at the writer's disposal for study, and much undescribed 



