(M. ) 



DESCRIPTIONS OF NEW OR LITTLE-KNOWN SPECIES OF FOSSILS 

 FROM ROCKS OF THE AGE OF THE NIAGARA GROUP.* 



Bt JAMES HALL. 



I. RELATIONS OF THE NIAGARA GROUP WITH THE LECLAIRE, RACINE AND 



GUELPH LIMESTONES. 



In the study of the fossils of the Niagara group and associated strata, 

 previous to the publication of the final Report on the Fourth Geological 

 District, and also to the publication of the second volume of the 

 Palceontology of New York, I separated a few species found in the impure 

 drab-colored limestone from Wayne county, New York. 



The limestone containing these fossils became exposed only in the bed 

 of the canal during its excavation ; and the low country, or deeply drift- 

 covered surface in the vicinity, did not admit of any exposure of the 

 rock in place. The materials were thrown out of the excavation in 

 connection with the soft marls of the Onondaga salt group, and the 

 specimens of rock containing the fossils preserved the peculiar cellu- 

 lii'erous structure and characteristic color of the argillaceous limestone of 

 that formation. Differing so essentially from any known beds in the 

 Niagara group, I did not hesitate to refer them to the Onondaga salt 

 group, since there was no evidence of any other formation in the 

 neighborhood.! 



* This Paper was originally printed in advance, in December, 1864, for the Eighteenth Report 

 on the New York State Cabinet. 



t The same reference of the species had, in fact, been made during the Geological Survey, and 

 they were thus published in the Report on the Foaith Geological District, in 1843. ^ 



