54 The American Geologist. July, i899 
This resume shows that probably there was an unbroken 
period of deposition tln'oughout the Oklahoma-Indian terri- 
tory region from the close of Cambrian to almost the close of 
Upper Silurian time. 
No positive data have been accumulated concerning the ex- 
istence of Cambrian in this region. The Devonian so far as we 
at present know is absent. 
Carboniferous. — The flaggy, argillaceous, cherty, Upper 
Silurian limestone is succeeded by calcareous clays, which con- 
tain near Stonewall large nodules. These are fossiliferous and 
have furnished the following species: 
Locality about 2^ miles west of Stonewall, Chicasaw Na- 
tion: Poseidonomya sp., Actinoceras sp., Goniatites choctaw- 
ensis Shum. Orthoceras sp. 
In nodules washed out of clay. Boggy creek, about 3 miles 
above Stonewall: Poseidonomya sp., Goniatites choctawensis 
Shum., Orthoceras sp. 
Actinoceras sp. is an unusually large form, about six inches 
in diameter. 
"The age of the shale in which these fossils occur has not 
yet been confidently determined, as the fauna is restricted and 
peculiar. The general facies is a Carboniferous one, and if the 
presence of Goniatites (Glyphioceras) choctawensis, which 
Shumard described as from the Coal Measures, and which is 
here identified with some confidence, be taken into account, the 
evidence might seem strong enough to warrant placing this 
horizon in the Coal Measures. But the possibility is enter- 
tained that Shumard may have been mistaken in referring G. 
(Glyphioceras) choctawensis to such a high horizon, and_ that 
this may be correlated with one of the black shales, as the 
Eureka or the Fayetteville, which have been recognized in Ar- 
kansas and in Indian Territory.* In this case the Mississip- 
pian era which so far as knowai does not otherwise occur, 
would be represented in this region. 
The fauna from the black shale in the Indian territory in 
some ways resembles that from the black shale of the White 
Pine district, Nevada, from which Meek described Poseido- 
*Leland Stanford Junior University Publications: Contributions 
to Biology from the Hopkins Seaside Laboratory, No. 14. 1898; A 
Geological Reconnaisance of the Coal Fields of the Indian Territory, 
by A. F. Drake, (reprint from Proc. Am. Phil. Soc, vol. 2,^, No. 156). 
