34 The American Geologist. January, 1895 
age of the Trenton. The intervening strata as known to exist 
in New York, i. e., the shales and limestones of Pulaski and 
Lorraine, etc., were not found. James Hall at first accepted 
the opinion that the Galena should be put in the Upper Silu- 
rian, as an eciuivalent, or a part of, the Niagara limestone. In 
1843 T. A. Conrad stated, on the evidence of fossils furnished 
him by Mr. J. N. Nicollet, that the Galena belonged in the 
upper part of the Trenton. In 1852, liowever. Dr. D. D. Owen, 
in his final tabulation of his results of the survey of the region, 
came to the conclusion that the Galena limestone is the west- 
ern representative of the Utica slate and the Hudson River for- 
mations of New York, the strata immediately underlying 
being named "St. Peter shell limestone," or Formation No. 3, 
and supposed to represent the Trenton. This was nearly in 
accord with Prof. Hall's later view that the underlying strata, 
with greater or less distinctness, represent, largely by paleon- 
tological resemblance, the Birdseye and Black River limestones. 
While the terms Blue and Buff, which have had varying for- 
tunes, and questionable value, have remained, in one form or 
another, as designations for the underlying limestones, there 
has been no disturbance of Mr. Conrad's general conclusion 
that the Galena is of the age of the Trenton, indorsed as it 
was by Hall and Whitney in 1870, until 1879, w^hen C. D. 
Walcott revived the idea of its representing the Utica slate,* 
and fortified it with evidence drawn from a comparison of the 
fauna of the Utica slate with that of the Galena. He also 
shows the extension of the fossils of the Utica into the Hud- 
son River above and the Trenton below. 
Until now there has been no published investigation into 
the paleontology of the Galena since that of Mr. Walcott. It 
is the purpose of this paper to siiow that Mr. Walcott's con- 
clusion can hardly be accepted. 
Mr. Walcott surveys the question both stratigraphicully 
and paleontologically. In the former survey he reaches the 
result that a general, widespread change in the nature of the 
sediments took place at the close of the Trenton, extending 
from New York to Tennessee and further southward. In Illi- 
*77<e Utica date and related formation. FohhUh of the Utica date, and 
metamorphoxes of lYiarthufsbecki. C. D. Walcott. 1879, Albany. Printed 
in advance of vol. x, of the Transactions of the Albany Institute. June, 
1879. 
