No. 275. j 329 
mass of ore has passed to about the position held by the purple shale at 
the Shakers' mill. 
At the latter place, and at sereral localities farther west, no indica- 
tions of ore could be discovered in the position of that first mentioned, 
or immediately below the Rochester shale. The mass at Cental's mill 
holds the same place as that at Ontario, Rochester, and other places 
where it has been observed. 
I have ascertained by this examination, that the ore bed occupies two 
positions, one above and the other below the pentaraerus limestone. 
The lower bed extends from Cental's mill westward to the Genesee ri- 
ver; and the upper bed from near Sodus bay to the eastern limit of the 
county. Thus far, I have not been able to ascertain the existence of 
the ore below the pentamerus limestone throughout this distance, though 
there are some indications of it in one or two places. From the situa- 
tion of the rocks being near the lake level, boring would be required to 
ascertain the fact. 
The facts relating to this ore, and the rocks of the group containing 
it, will be given more in detail hereafter. 
In this examination, several fossils have been added to those already 
collected in Wayne county, and which may perhaps serve to identify 
these rocks hereafter. Among them is the Graptolite,* which occurs 
abundantly in the green shale above the pentamerus limestone, at the 
Shakers' mill. It is also found farther west, and one or two specimens 
have been seen in the same shale at Rochester, which is there characte- 
rized by the Agnostis pisiformis. 
JJlluvium. All the counties examined are more or less covered with 
alluvial deposits, which in some places merely form a thin covering of 
the subjacent rocks, and in others rise into hills or fill deep valleys, 
caused by the removal of rocky strata. The more elevated parts of the 
southern counties exhibit least of this deposit, while the northern ones 
art n many places deeply covered. 
It is often difficult for the student in Geology to conceive of water 
flowing over the suface of a country 60 much elevated above the sea; 
* The Graptolite has been found in fine bituminous shale in Norway and Sweden, in rocks 
of the same age as those of Western New- York; those found in Wayne county nearly resem- 
ble the figure of this fossil given by Mr. Lyell, in his Elements. " These bodies are supposed 
by Dr. Beck, of Copenhagen, to be fossil Zoophytes, related to the family of sea pens, of 
which the living animals inhabit mud and slimy sediment." Ste Lyell, Elements of Geology, 
page 462. 
f Asscm. No. 275.] 42 
