FOURTH ANNUAL REPORT 
Of the Survey of the Fourth Geological District, by 
James Hall. 
To His Excellency William H. Seward, 
Governor of the State of New- York. 
Sir: 
I have the honor to present the following report of the progress 
of the survey in the Fourth Geological District. 
The counties which form the subject of the present report are Steu* 
ben, Allegany, Cattaraugus, Livingston and Genesee. Erie and Chau- 
tauque still remain to be examined, besides some portions of Cattarau- 
gus, and a re-examination in other counties, which will be the subject 
of the next annual report. 
The rocks which come within the limits of the counties examined 
the past season are the Onondaga saliferous group, including the plas- 
ter beds, the hydraulic limestone, the Onondaga and Seneca lime- 
stones : to the last succeeds the thick group of fossiliferous shales, 
known as the Marcellus shales, dark slaty shale, compact calcareous 
blue shale, olive shale, the shales of Ludlowville, the shale of Moscow 
and the upper black shale.* 
With the absence of the Tully limestone, another stratum, though 
of inconsiderable thickness, becomes more fully developed. This 
is a crinoidal limestone, which always holds its place between the 
Moscow and Ludlowville shales, and extends throughout the fourth dis- 
* The Tully limestone does not form a member of the series in the counties under 
consideration, though its place next above the Moscow shale is easily identified. From 
the absence of this limestone the upper black shale succeeds the Moscow shale. 
