152 TltC American Geologist. September. 1903. 
of the Connecticut trough and the Gulf ot St. Lawrence, we 
can explain the make-up of the Mississippian faunas beginning 
with the Schoharie and closing with the Chemung. Through 
this same opening also came the Helderbergian and Oriskan- 
ian North Atlantic invasions of the Cumberland mediterran- 
ean of Ulrich and Schuchert. 
The southern portion of the Indiana basin also was open 
during Onondaga, Hamilton and Genesee time, establishing 
communication between the Mississippian sea and Brazil.* 
Evidence of this is seen not only in the very similar 
faunas of the Hamilton of the Misissippian 'sea and 
that of the Erere formation of the State of Para 
described by Rathbun and Clarke t but further in the 
Louisville phase of the Hamilton of Alabama. It is on Pra- 
ter's farm, two miles west of Piedmont, Alabama, that Cooper 
Curtice collected a Hamilton coral fauna with Spirifcr I'ari- 
cosus, Tropidoleptits carinatus, etc., and the writer found op- 
posite the city of Rome, Georgia, near the northeastern end of 
Horseshoe Mt. uplift, ostracoda and a few corals at the base 
of the Chattanooga black shale, indicating the same Hamil- 
ton fauna. In neither of these localities is the Onondaga 
known and it is certain that it does not occur about Rome. 
However, the Onondaga does occur farther northwest about 
Pegram, Tennessee,! attaining greater thickness in a westerly 
direction, and is present in considerable thickness near Grand 
Tower. Jackson county, Illinois. § As the Oriskany (Cam- 
den phase) is also present here with Amphigenia eurta, Ano- 
plia nucleoid, Leptocoelia Habellites, etc., II it seems reasonable 
* The writer is not yet certain that the great mediterranean of Neumavr 
named by Suess Tbthys was present in Devonic times. However, it seems 
probable that it was and the Indiana gulf connected with it. For other detail 
see So ESS, Nat. Science, ii, 1893, p. 1S3 Suess, Antlitz der Erde, iii, pt. 1, 
1901, p. 25. Kayser, Lehrbuch der Geo!., sec. ed., 1902, p. 175. Frech, 
Lethaea Geognostica, cited above. 
i'Archivos do Mas. Nac. Kio Janeiro, x, 1S99. Clarke here states that 
the Erere fauna is "a miniature of the Hamilton fauna." Associated with the 
sandstones of Erere are layers of dark shale having a few fossils regarded as 
the "equivalent of the Genesee shale fauna." Further, the Maecuru group is 
unmistakably of the facies of the Onondaga having that very diagnostic 
brachioport Amphigenia elongata besides Anoplia nucleata. Stropheodonta 
perplana, Tropidoleptits carinatus and Yitulina vustulosa. Too much value 
for limited stratigraphie correlation cannot be placed on T. carinatus as a single 
example has recently been found in the Oriskany of Maryland. Williams 
reports it from the Chemung so that it ;s now known to be nearly coexten- 
sive with the Devonic. 
t Foerste, Bull. Geol. Soc. Amer., xii, 1901, p. 4-24-42G. 
§ Wei.ler, Jour. Geol., v, 1897, p. 625. 
II Meek and Worthbn, Geol. Surr. Illinois, i, ii, iii; Safford and Schi- 
CHERT, Amer. Sci.Jour., vii, 1899, 4.29--132. 
