268 STUART WELLER 
known from 200 feet of beds between 300 and 500 feet below the 
summit of the entire series. 
JUNCTION OF THE EASTERN CONTINENTAL AND INTERIOR CONTINENTAL 
PROVINCES 
As has been indicated in the previous discussion of the faunas of 
the Eastern Continental and Interior Continental Provinces, the time 
of the establishment of a path of communication between the two was 
at the very opening of the Upper Devonian, when the Cuboides fauna 
found its way into the East, but the relations of the lowan faunas with 
those of the East is not such as to suggest an entirely unobstructed 
intermingling of faunas even after this communication was finally 
established. Schuchert has suggested in his paleogeographic maps? 
that this communication was by way of a narrow and somewhat 
tortuous strait, the “‘ Traverse Strait,’’ which passed from southeastern 
Iowa in a general northeasterly direction, across Illinois through the 
Lake Michigan basin to northern Michigan. Within the limits of this 
strait occur the Devonian beds near Milwaukee, Wis., and those of 
the Grand Traverse region of Michigan, where there is a greater com- 
mingling of eastern and western forms than elsewhere, as might be 
expected under the circumstances. The waters of this strait were 
separated from those of the Eastern Continental basin by the compara- 
tively narrow Kankakee peninsula. 
THE WESTERN CONTINENTAL PROVINCE 
The Devonian strata of the Western Continental Province occur 
at various localities in the Great Basin region, and their faunas have 
been described by Walcott in his Paleontology of the Eureka District.? 
One hundred and eighty specifically identified forms are recorded, of 
which 61 are new and rig are identified with already known forms. 
The composition of the previously known portion of the fauna is as 
follows: 83 species are identical with forms from the Eastern Conti- 
nental Province, including New York, Michigan, and the Ohio Valley, 
the other 36 being known from Iowa and other parts of the Interior 
Continental Province. Of the eastern species 29 are found only in the 
Onondaga fauna, 21 only in the Hamilton, and 13 only in Devonian 
t Am. Geol., XXXII, Pl. 21; also, Za. Geol. Surv., XVIII, pl. 16. 
2 Monograph, U.S. G.S., Vol. VII. 
