462 
GEOLOGY OF THE FOURTH DISTRICT. 
bituminous character of the shale, thin seams of coaly matter and petroleum. T did not learn 
to what depth the excavation extended, but presume it to have been less than forty feet, for 
at that depth the Onondaga limestone would have been reached. The excavations were made 
at two places, one on each side of a small shallow valley which was originally worn in this 
shale. North of the valley, on the farm of Mr. M'Lean, the same shale was penetrated in 
digging a well. Some portions of the rock are so highly charged with bitumen as to burn 
when thrown into a hot fire. In these shales, as well as in the upper Genesee slate, nume¬ 
rous excavations for coal have been made, and, in each, alike fruitless. 
The Hamilton group is exposed in numerous localities in this county, and is everywhere 
highly fossiliferous. Their destruction has afforded the highly fertile argillaceous soil which 
is every where so productive of wheat in this part of the State, and perhaps nowhere more so 
than in this county. 
On Jacock’s run, the Ludlowville and Moscow shales can both be seen, separated by the 
thin mass of crinoidal limestone. Here as elsewhere in the district, the Moscow shale is 
known by its fossils, the Calymene and Cryphceus; while the Ludlowville shale contains 
Atrypa concentrica , and large numbers of Cyathophylli and other corals. These fossils are 
very characteristic of the two shales; still in some localities the Cyathophylli and smaller 
corallines occur in the Moscow shales, but are not characteristic of this mass. 
At York, the Ludlowville shale is exposed on a small stream near the village ; the fossils 
are chiefly Cyathophyllit.es and Favosites, both in great perfection and beauty. Among the 
former there is a specimen placed in the Stale Collection, consisting of twenty-six individuals 
of the species lurbinatum ? all closely grouped together. In ihe same ravine, several hun¬ 
dred feet lower, may be seen the hard calcareous shale, or shaly limestone, mentioned in the 
Report of 1839, as occurring at Tyler’s on Seneca lake, and at Orleans in Ontario county. At 
several other localities, these shales may be seen ; but being of little economical importance, 
they are described elsewhere. 
At Moscow, the locality which gives name 1o the upper member of this group of fossiliferous 
shales, they are exposed in great perfection, containing abundance of the characteristic fossils. 
These are the Calymene bufo, Cryphceus calliteles, Atrypa affinis, and two or three species of 
Delthyris. The principal locality is in the beds and banks of Beard’s creek, on the*land 
of Jerediah Horsford, Esq. More than fifty species of fossils have been found at this place. 
The Moscow shale is also exposed in a ravine, and the bed of a small stream, near the resi¬ 
dence of the Hon. G. W. Patterson. These localities are in a deep valley of denudation, and 
much below r the general elevation of the surrounding country, the surface of which is occu¬ 
pied by the Genesee slate. 
Genesee Slate. — In the ravines both east and west of Moscow, we find the Genesee slate; 
also in a hill crossed in going from Moscow to the new bridge across the Genesee, and in the 
hill side ascending from the valley to Geneseo. The same shale is seen in Fall brook, where 
