338 
PALEONTOLOGY OF NEW-YORK. 
In the upper part of the Chemung group, and sometimes apparently 
near the summit of the formation, there is a grayish or ferruginous con¬ 
glomerate, often charged with fossil shells, among which there are usually 
few Brachiopoda; and in some localities the general aspect of the fauna 
is more nearly like that of the W averly sandstone of Ohio, some of the 
species being apparently identical with those of that formation and the 
western extension of the same. I have, however, detected in this con¬ 
glomerate casts of Spirifera mesacostalis and S. verneuili — S. disjuncta, as 
well as other forms which show its intimate relation with the Chemung 
group. 
These are the beds which I have heretofore indicated as those which 
may become expanded in their western extension,, and constitute in part 
the fossiliferous sandstones and shales of Eastern Ohio; while the Portage 
and Lower Chemung beds, which do physically extend into that part of 
Ohio, are less fossiliferous than in New-York, and their presence has 
been overlooked by some observers. At the same time, there is a dis¬ 
position not only to claim for the higher portions a distinct place in the 
series, but to refer these beds to a distinct system. By whatever name, 
however, they may be termed, they apparently constitute part of the great 
group of argillaceous and arenaceous shales and sandstones which began 
their deposition with the Marcellus shale, and terminate with the red 
shales and sandstones of Pennsylvania, or at the base of the conglome¬ 
rate of the Coal measures, as that formation exists on the borders of 
southern New-York and the adjacent counties on the south and west*. 
* I had intended, before the completion of the volume upon the Brachiopoda, to have made personal 
investigations to determine more accurately the relations of these formations; but have been for two 
years prevented from accomplishing any field work of importance. 
