Geology of Eastern Nezv York. — Prosser. 383 
hawk and Hudson river valleys,* although in the last paper by 
Mr. Schuchert they are called Frankfort shales, f In the former 
paper Messrs. Clarke and Schuchert proposed the following ge- 
ographic names to replace names of stages which had not been 
so derived. Rondout waterlime for the Watcrlime, Manlius 
limestone for the Tentaculite, Coeymans limestone for the Low- 
er Pentamerus, and New Scotland beds for the Catskill or Del- 
thyris shaly limestone. These later names are now to be sub- 
stituted for the corresponding ones used in my sections of 
the Helderberg region. 
The upper part of the Manlius (Tentaculite) limestone 
has been termed transitional by the writer, meaning that the 
layers in general are thicker than those composing the lower 
and greater part of the Manlius and that a few species, which 
had been supposed to be confined to the superjacent Helder- 
bergian limestones, occur in these beds. These characters were, 
formerly, admirably shown in the extensive quarries at Howe's 
Cave, where there is a very marked line of division between 
the top of this zone and the Coeymans limestone. It was not 
intended to separate this zone from the Manlius limestone 
in which it was included and where the writer still believes it 
to belong. In the Countryman Hill section perhaps the top of 
the Manlius limestone is slightly higher than indicated by the 
writer, and yet the total thickness of this limestone in this 
section, 46 feet, agrees closely with that obtained by the writer 
and other geologists in the Helderberg region. At this locality 
the writer described the massive ledge of Upper Pentamerus 
limestone near the house of Mr. K. P. Parish, which he incor- 
rectly called the Becraft limestone. The Becraft limestone 
of professor Hall is composed in the Schoharie-Helderberg 
region of the Scutella and Upper Pentamerus limestones. The 
writer, however, only saw the Upper Pentamerus ; but he is in- 
formed by Miss Mignon Talbot, who has spent part of two 
summers in studying this section, that the Scutella limestone 
is well shown a little to the east and below the Parish ledge of 
Upper Pentamerus, with a thickness of about four feet. This 
thickness is to be added to the thirteen feet of Upper Penta- 
merus limestone making a thickness of seventeen feet for the 
* Science, N. »S'., vol. x, pp. S7G, STT. 
t Am. Geol., vol. xxxi, pp. 17U-174. 
