290 
[Assembly 
ing for mineral wealth in rocks where it does not exist. As for exam- 
ple, in digging for coal among the black shales of the Hudson river, and 
Western New-York, neither of which contain it; though externally they 
resemble the black shale of the coal measures. Numerous similar instances 
might be mentioned, where dependance on lithological characters has 
been attended with vexation and loss; while public confidence in sci- 
entific researches, which thus appear to have no sure basis^ is gradually 
diminished. 
The course of the rocks, as mentioned in a previous report, varies lit- 
tle from an east and west direction; each being limited on the south 
by the next successive and overlying member of the series; so that in 
going south we are constantly ascending in the chronological order, and 
in going north, every rock is an older one than the preceding. East or 
west the same rock may be found extending throughout the district. 
No important disturbances, arising from subterranean action, have 
yet been found to exist within the fourth geological district; those 
known are confined to a few undulations or slight^downheaves, affect- 
ing only a small extent of country, and producing no perceptible change 
in character or outline. 
I have made some attempts to procure topogi^aphical maps of the 
counties examined; but the present county maps are so inaccurate that 
little advantage can result from any constructed on these as a basis. 
They cannot be expected to give objects their true location within a 
mile or two, and can only present the prominent features of a country. 
Under these circumstances, I have thought it advisable to postpone the 
subject. A topographical survey of the whole State is a very desirable 
object and much needed, and to accomplish it in a proper manner, re- 
quires much expenditure of time with the necessary instruments to en- 
sure accuracy. 
Confined as the annual reports are to facts of utility, the rocks are 
described under the head of each county, with their localities, changes 
of character, and other important facts; and w^here the same rock oc- 
curs in more counties than one, reference may be made in the second to 
the previous description. Thus repetition will be avoided, and easy 
reference to particular localities secured. 
SENECA COUNTY. 
Saliferous group of Onondaga.^^ All that part of the county north 
of the Seneca lake outlet, with the exception of a small portion south 
of a line drawn from Waterloo in a northwest direction to Ontario 
