252 
leys, except where the streams have been forced to cut new courses through 
morainic material or because of the obstructions offered by such material 
have been turned aside to make new rock cuts. The latter is probably the 
case with the lower courses, at least of the north Chuctanunda and Evakill, 
for while they are at present making rock cuts, their banks show deep cuts 
through boulder clay, and their beds are in no respect those of mature streams, 
both from the abdundance of water-falls and the irregularity of their slope. 
The northwestern portion of this region is heavily covered with drift and the 
topography is more angular on this account. The limestone area is sheard 
off by the Hoffman ferry fault, along a line running nearly straight from the 
western central part of Charlton township to a point about one mile south- 
west of Pattersonville. The topography is also distinctly different upon the 
adjacent shales (Canajoharie and Schnectady) that abut the entire east face 
of the fault as shown on the Amsterdam sheet, except at the north where a 
small area of Trenton is found east of and adjacent to the fault. 
TRENTON FALLS SECTION. 
1. Sherman Fall. 
The lowest strata that outcrop in the Trenton Falls gorge are those at 
the water level of the pool at the base of the Sherman Fall. They are com- 
pact, bluish grey, thin bedded limestones interstratified with coarser-grained 
layers containing numerous well preserved specimens of Prasopora simula- 
trix. The Prasopora beds form the entire fall. The upper layers of this fall 
are thin strata, 3 to 5 inches thick, which form a somewhat clearly defined 
band 23 feet thick. About the middle of the breast of the falls the Prasopora 
are much larger than elsewhere, forming a distinct layer. The second Pra- 
sopora zones are the fossiliferous layers just above the crest of Sherman Fall 
and forming the base of High Falls. 
The lists of fossils below were identified from the collections made by 
Prof. E. R. Cummings in the summer of 1914. 
a =abundant 
e =common 
r=rare 
i.” Calymene ‘senarma, Conrad. /.. sor oe 80 co ne eee @ 
2. Corynotrypa miata, (hall)? .,, 7.725032 Bae oe eee r 
Bem CONNIE /SCOMICTIUS fire artis ao, «lp cs faee ELE Ware ete eee a 
