32 The AmericdJi (re<)lo(jist. July, is9G 
interest lies in the fact tiiat few identitieations of similar 
horizons have thus far ])een made in the Kooky mountain 
region. Unfortunately niost of these ar« more or less uncer- 
tain because based upon species having a considerable geo- 
logical range, and, therefore, not determinative. Apparently 
nothing short of a thorough study of these western faunas, 
to'-'ether with an abundance of material, will permit of exact 
correlations with geological standards elsewhere. 
This was shown conclusively by Walcott in the Canyon 
City section, Colorado, where the fossil faunas from the Har- 
ding sandstone and Fremont limestone have a distinct Trenton 
fades, although there is a decided commingling of what would 
be considered in New York state as typical Niagara species.* 
Therefore the discovery of Ilalysifes in the Wasatch range, 
by Hayden ; in the Wind Kiver mountains, by Comstock: in 
Nevada, by Hague; and in the Teton range by Bradley, does 
not necessarily imply the presence of Niagara strata at these 
localities. A knowledge of the complete faunas may show 
that some are Hudson and others Trenton, while still others 
may be really Niagara, as they appear at first sight. 
The fossils from the first locality to be noticed were collec- 
ted by ('apt. G. E. Bushnell, U. S. A., and presented to the 
Yale Museum. The specimens were obtained from near Buf- 
falo, Wyoming, on the eastern flanks of the Big Horn moun- 
tains, and occur in a hard yellow, siliceous dolomite, in which 
the organic remains are com})letely silicified. Corals are the 
most conspicuous and abundant forms. IlelioUtes Intersfinrfu.s 
L. and llaJysUes catenulattis L. being especially numerous. 
With them are also Faoasites and cyathophylloid corals of 
Zaphrentis and Ample.rus types. The onl^^ brachiopods are a 
fragment of a Tthyrichof reran related to 11. uicrebescejis, and a 
single small Scenidiuni-Uke shell, which may be the young of 
a large Or this. 
Were it not for the Lower Silurian (Ordovician) fauna at 
Canyon City, and the doubtful presence of R. increbesce)i.s\ 
these fossils would be unhesitatingly correlated with the 
Niagara, but in view of what is now known, the possibility 
must be admitted of their finally proving to be of Trenton or 
Hudson age, and without larger collections their precise hori- 
*Bull. G. S. A., vol. 3, pp. 153-172, 1892. 
