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



For many years students of Triassic stratigraphy were 

 compelled to use in interregional correlation the lithologic 

 nomenclature of the deposits of the Germanic basin, the 

 faunas of which were scanty and of only local occurrence. 

 The only faunas known outside the Germanic basin were 

 in the Alpine province, but even here the complete series 

 was not well represented, and the order of superposition of 

 the faunas not clearly established. It was not until strati- 

 graphic and paleontologic studies were made in the Trias 

 of extra-Mediterranean regions that a clear idea was ob- 

 tained of the succession and relationships of the Mediter- 

 ranean faunas, especially of the Lower Trias. Hence 

 it is that in the nomenclature of stages and formations we 

 find such a mixture of Tyrohan, Italian, Indian, and 

 Siberian names; for the stages were named from their 

 most typical occurrence, in whatever part of the world it 

 happened to be; and these local names have become, by 

 common usage, interregional or international terms for 

 strata with a similar or a correlative fauna. 



The nomenclature used is, with some slight changes 

 necessitated by later studies, that of Mojsisovics, Waagen, 

 and Diener (27), in their attempt at a systematic classifica- 

 tion of the open-sea Triassic sediments and faunas of the 

 world. Such changes are due to Dr. A. Tornquist's find- 

 ing Ceratites nodosus in the Buchenstein horizon of the 

 southern Alps, and to the agreement of a majority of Aus- 

 trian geologists to substitute Ladinic for Noric, and Noric 

 for Juvavic in the Alpine section. These two changes 

 affect the stratigraphic nomenclature of Japan, California, 

 and Nevada, as well as of the Mediterranean region. 



The Low^er Trias or Scythic Series. 



Brahmanic Sta<>x. The lowest series of the Trias was 

 named by Waagen and Diener (27) from the region of its 

 most typical development in Asia. It is divided into two 

 stages; an older, or Brahmanic, named from India, where 

 its fauna is best developed; and a younger, or Jakutic, 



