THE DISTRIBUTION OF LOWER TRIASSIC FAUNAS ms 
confusion of species might easily happen, under the conditions of 
collecting in that region. 
The Meekoceras fauna of southwestern Siberia, Thibet, and India 
is too well known to need further discussion here. It contains this 
same assemblage of genera already mentioned, mostly near allies 
of the genus Meekoceras. ‘This fauna has been described in numer- 
ous monographs by Waagen, Diener, Noetling, and Griesbach, 
and has become the standard of comparison for the rest of the 
world. 
The Meekoceras fauna in western America.—In southeastern 
Idaho and in the Inyo Mountains of California the Meekoceras 
fauna has been described in the works of C. A. White, Alpheus 
Hyatt, and the writer, with a wealth of genera similar to those of 
Asia, and some few identical species. The most characteristic 
genera are: Meekoceras, Aspidites, Flemingites, Hedenstroemia, 
Pseudosageceras, Cordillerites, Lanceolites, Xenodiscus, Nannites, 
Inyoites, Owenttes, and Lecanites. 
The writer has recently found this same fauna near the ranch of 
Henry Phelan, in White Pine County in eastern Nevada, about 
seventy miles south of Wells station on the Central Pacific Railroad. 
This locality is about half-way between the localities in California 
and Idaho, and distant over three hundred miles from each. The 
following is a preliminary list of the species identified: Meekoceras 
gracilitatis, M. ci. mushbachanum, M. cf. radiosum Waagen, Prop- 
tychites cf. Walcottt, Lanceolites sp. nov., Pseudosageceras intermon- 
tanum, Aspenites acutus, Inyoites owent, Owenites cf. koenent, 
Nannites dienert, Paranannites cf. aspenensis, Ophiceras sp. nov., 
Xenodiscus cf. whiteanus Waagen, X. cf. nivalis Diener, Pseudo- 
monotis ci. idahoensis. 
By a comparison with lists from Idaho and from California it 
will be seen that the affinities with the latter are closer than with 
Idaho, although the two provinces were intimately related, and the 
new locality in Nevada gives a perfect connecting link, as it should, 
from its geographic position. 
The Meekoceras fauna is one of the most distinctive and widely 
defined interregional correlation zones in the world, being known 
from Spitzbergen on the north, through the equatorial region of 
