422 
[Assembly 
At Moscow the locality which gives name to the upper member of 
this group of fossiliferous shales we have them exposed, containing the 
characteristic fossils in great perfection. These are the Calymene bufo, 
Cryphseus calliteles, Atripa affinis, A. prisca, and two or three species 
of Delthyris. The principal locahty 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 residence of the Hon. G. W. Patterson. These lo- 
calities are in a deep valley of denudation and much below the general 
elevalion of the surrounding country, the surface of which is occupied 
by the upper black shale. 
Upper Black Shale. — In the ravines both east and west of Moscow 
we find the Upper black shale, also in a hill crossed in going from Mos- 
cow to the new bridge across the Genesee, and in the hill side ascend- 
ing from the valley to Geneseo. The same shale is seen in Fall brook 
where the water leaps a hundred feet from the top of this rock. It un- 
derlies the village of Geneseo ; it is seen in many places on the road 
east from that place, and in the ravines between them and Conesus 
lake. In this neighborhood the black shale is succeeded by a thin 
stratum of impure limestone, which has been burned for lime at one 
place near Moscow. 
At the bridge crossing the Genesee near Mount Morris the black 
shale is exposed, possessing all its essential characters — being bitumi- 
nous, containing thin seams of coal, great numbers of septaria, some- 
times irregularly scattered, at other times in regular courses. 
The arrangement and distribution of these septaria depended upon 
the supply of material ; and the tendency to concretionary forms pro- 
ceeded from the amount of material being too small for a continuous 
stratum, which together with the homogeneous state of the particles 
caused them to take this form. Sometimes we see a single insula- 
ted mass and no others in the same parallel of stratification ; at other 
times we find them distant from each other but in the same plane 
of stratification. Again we may find a course of them in the same 
plane and each of them separated only a few feet from the other. 
Still again when the supply was greater we find a continuous stratum 
or bed, as in the case on Seneca Lake, where the regular course of 
septaria in the upper part of the black shale becomes, from increase of 
