2S Th 6 x | merican Geologist. January, 1892 
found at but few localities; and as a rule the specimens are im- 
perfect, good specimens occurring at only a very few places. 
There is little room to suppose from the condition in which the 
plants are found that alternations of land, fresh and brackish 
water conditions caused the absence of animal life. It is certain 
that from the beginning of Oriskany to the end of Catskill, even 
during the formation of the Corniferous coral reefs, the Appa- 
lachian gulf was shallow everywhere. During the later time, 
when subsidence did little more than to keep pace with the inflow 
of sediment, the area nearest to the region of great drainage, 
whence large streams with rapid flow poured their material into 
the shallow basin, would show muddy bottoms and muddy, more 
or less brackish water, which would be unfavorable to animal 
life of Chemung types. As the Appalachian land became nar- 
rower southward, the untoward conditions are less marked in that 
direction. Within the portion of the area lying within south- 
sastern New York and the immediately adjacent portion of Penn- 
sylvania, these conditions may have been begun as early as the 
Hamilton, as suggested by Prof. Hall.* 
The molluscan fauna of the Chemung and Catskill is unques- 
tionably marine. Even the mollusks found in New York above 
the Oneonta sandstone belong to the ordinary forms. Of course 
it is possible, even probable, that at the extreme northeast there 
were small areas at the mouths of large rivers, where fresh water 
prevailed and fresh water mollusks lived; but positive evidence of 
this iswanting. The Amphigenia found in the Oneonta sandstone of 
New York may be a freshwater form, but it occurs in the Montrose 
sandstone in southern Pennsylvania so far away from the old 
shore line that freshwater conditions seem, certainly, improbable. 
The stratigraphical relations of the fishes have been generally 
misunderstood, The fishes exist for the most part not in the 
Catskill but midway in the Chemung; the celebrated /oloptychius 
Bed, is the second ore bed of the ‘Mansfield Reds,” and belongs 
at but a little way above the A//egrippus conglomerate, the Falls 
Creek sandstone of Bradford county. It has yielded large num- 
bers of fish remains at several localities and it Contains marine 
fossils.t The Coccostens bed of Warren county is taken by Prof. 
*“Setence 1880, p. 290. Prof. H. 8. Williams makes the same suggestion 
in Bulletin U.S. G.S. No. 41, but I have mislaid the references. 
*Sherwood in Report on Bradford and Tioga, pp. 63, 65, '79, 80. 
