Faunal Provinces of America. — ScJiuchert. 151 
There is very little in the known fauna of the Dakota sea out 
of which that fauna could have developed. Ulrich and Schu- 
chert* therefore sought to bring this Atlantic fauna into the 
Mississippian sea in the region of >the Delaware and Chesapeake 
bays. This view is not known to be, so far as it concerns pre- 
Helderbergian time, without support as Willist has shown 
that during much of Devonic time there existed here the "Ap- 
palachian Highlands." Much information has accumulated 
since our view was expressed showing that many Atlantic 
invasions occurred during the Paleozoic and as late as the close 
of the Devonic. We are forced therefore to continue the search 
for the place of communication of the Mississippian sea with 
the North Atlantic and Europe. Apparently the only place 
for communication was to the north of Appalachia and in the 
region of the Catskill mountains where Devonic strata are now 
piled 4000 feet above sea level. Projecting these strata across 
the Hudson Valley and Taconic mountains it is not more than 
sixty miles to the "Connecticut Valley Trough" of Dana On 
the basis of paleontologic evidence there are now recognized 
in this trough, strata of Niagaran, Esopus, Onondaga and Up- 
per Devonic age.$ Regarding this and other New England 
troughs Dana§ writes : 
"The Acadian and the Gaspe-Worcester tronghs were 
sinking and receiving in some parts, if not generally, formation 
after formation, to the close of the Carboniferous period ; and 
the -Connecticut valley trough, to the middle or latter part of 
the Devonian era." 
The formations in the Connecticut trough arc of great thick- 
ness and as the Devonic fossils (certainly those of the Onon- 
daga) are those of New York, it is probable that all of the 
formations of the Catskill mountains above the "Hudson River" 
are also present in this trough. It seems to be true that all of 
these strata are now eroded away over the Taconic mountains, 
and all excepting the Helderbergian and Oriskanian in the 
Hudson valley. Accepting this as the place of communication 
between the Mississippian sea and the North Atlantic by way 
* Rep. N. Y. State Pal. 1902, pp. 633, 663. 
t Md. Geol. Surv., iv, 1902, p. 61, and paleographic map, pi. V. 
X Emerson, Mon. U. S. Geol. Surv., xxix. 1898, pp. 17, 259. Eli.s, .4m.. 
Rep. Geol. Surv. Canada, 1887-8, pp. 9k-llk. Esopus black shale with 
Caudagalli occurs at Sargent's bay, Lake Memphremagog according to Ami. 
§ Dana, Man. Geol., 4th ed., 1896, p. 715. 
