THE CORNIFEROUS FAUNA 431 
recorded. That the Great Basin province had communication 
with the original province in which the Corniferous fauna had its 
development, is quite certain, although there was probably no 
direct communication between the Great Basin and the Appa- 
lachian provinces, notwithstanding the identity of many species 
in the two regions. 
There are also present in the Devonian faunas of the Great 
Basin province many species which are identical with Hamilton 
species in the Appalachian province, but they do not occur at 
any definite horizon in the Devonian of the region, but are dis- 
tributed from the bottom to the top. Among these species, 
however, in no case has there been recorded any of the typically 
southern hemisphere forms which are so characteristic of the 
Appalachian Hamilton fauna, all of the Hamilton species in the 
Great Basin Devonian being such as doubtless had their origin 
from members of the Corniferous fauna, and it is probable that 
the Great Basin province never had communication with the 
Southern Hemisphere province which sent its immigrants into 
the Appalachian province during Hamilton time. 
In the Devonian faunas of the Iowan or Northwestern prov- 
ince there is an element so strongly suggestive of the Cornifer- 
ous that Dr. Barris? at one time went so far as to refer some of 
the Devonian beds of eastern Iowa to the Corniferous. That 
there is a Corniferous element in these faunas, exhibiting itself 
especially among the corals, cannot be denied ; but associated 
with this element, either directly or in accompanying strata, 
there is another element so entirely foreign to the Corniferous 
that the reference of any of the Iowan Devonian strata to the 
Corniferous cannot be entertained. The Eurasian origin of the 
characteristic element of the Iowan Devonian faunas and of the 
upper Devonian faunas of the Appalachian province has been 
established, and the pathway of communication from the Eura- 
sian to the Appalachian province was through the Mackenzie 
basin of the northwest, which doubtless communicated with the 
Arctic province where originated the Corniferous fauna. It is 
t Proc. Davenport Acad. Nat. Sct., Vol. I, p. 261. 
