390 W. B. Dwight—Fossils of the Wappinger Valley Limestone. 
in size; they consist of the limestone and are evidently the 
fillings of the tubes of Receptaculites. They are so imbedded 
in the rock that I have not yet been able to detach any for 
special study, as I propose soon to do. 
y second trip to this locality, a week later, was made in 
company with Professor Dana. I found, at this time, another 
distinct specimen of Leptena sericea, one Hscharopora recta, one 
Ptilodictya acuta, a pygidium of a trilobite, several specimens of 
Orthis tricenaria, an Orthis pectinella, one Hndoceras twenty or 
twenty-five centimeters long, one small Orthoceras, two of Orthis 
testudinaria, and some Cheetetes of minute columnar structure. 
On the same occasion we visited a quarry on Wappinger 
Creek, about half a mile below Pleasant Valley, where Mather 
reported faint traces of shells to have been found, “ too imper- 
fect for identification.” We found abundant evidence of the 
fossiliferous character of the rock, the fossils being generally 
similar to those at Rochdale. In a subsequent examination of 
my specimens here collected, I obtained one well-defined spe- 
cimen, and several small fragments, of Strophomena alternata,— 
showing its characteristic arrangement of stri ; also, very abun- 
dantly, the Cheetetes found at Rochdale, from two inches to one- 
quarter or less in diameter. The large specimens are some- 
times semi-globular, and suggest Cheetetes lycoperdon, but for 
the microscopic tenuity of the columns; but other specimens are 
pyriform, and I am not certain as to the normal shape. e 
diameter of the columns is less than 1-200th of an inch. As it 
appears to be new, I propose for it the name Ch. tenuzssima. 
My subsequent trips have been taken alone. On the farm of 
Mr. Brittenberger, two miles southeast of Pleasant Valley, east 
of Wappinger Creek, I found a second and parallel outcrop of 
limestone, 1800 feet wide, separated by slate from the main 
body of the Wappinger Valley belt. "The rock is here filled 
with limestone pebbles of various sizes and lighter in color 
than the mass. Many of these may have been organic, an 
very likely corals, but crystallization has so obliterated the 4 
structure that if detected at all, it must be by microscopie 
examination. There was one specimen which is probably an 
encrinal column about seven centimeters long, and seven milli- 
meters wide. 
I have made examinations at Salt Point, on Wappinger — 
Creek, at the junction of Salt Point Creek, ten anda half miles 
northeast from Poughkeepsie, and also at a number of places — 
between Salt Point and Pleasant Valley. At Salt Point the 
limestone has a width of 2200 feet, and it is about that width, pf 
somewhat wider, toward Pleasant Valley. It is mostly on the 4 
west side of the creek, and for a distance of four miles south of 
‘Salt Point, it varies from the greater part of the outcrop by — 
