316 [Assembly 
the alluvium; as in most localities east of Canadaigua lake, it is almost 
destitute of fossils. On the south bank near Mallory^s, a road cut 
through the shale exhibits it to great advantage; also Bruce's ravine far- 
ther south. Next succeeds the Tully limestone seen at Wait's mill, where 
the water of the outlet falls over it. Thence it dips east for more than half 
a mile and disappears, and shortly afterwards it reappears, dipping to 
the east. No dislocation or disturbance of the rocks is visible at any 
point, and the change appears to be owing to an undulation, similar to 
that observed on Seneca lake, which is at right angles with this. The 
ascent of the limestone to the east, or its dip west, is about ten feet 
in the mile, as ascertained by tracing it through that distance. At 
Hopeton, the limestone is sixty or seventy feet above the bed of the 
stream, and about one hundred feet above the lake. Beyond thii^ 
point, it has been entirely swept off by the waters of the original 
outlet. 
The Moscow shales are seen at Wait's mill, and also at Mallory's 
mill, and along the bank of the stream to within half a mile of the 
lake shore. At Hopeton, about sixty feet of it is visible, containing 
the usual fossils in abundance. Here the shales and Tully limestone 
are beautifully exhibited in a little conical hill, which stands isolated in 
the valley of the outlet, a monument of the power of ancient waters. 
The hill is about one hundred feet broad at the base, and perhaps eighty 
feet high. The first sixty feet are of the shales last described; then 
succeeds the Tully limestone, and the top is capped with a few feet 
of black shale. 
The same undulations as those noticed on the east of the lake, occur 
on its western shore south of Dresden. The Tully limestone and black 
shale soon disappear below the level of the lake, and the next series 
continues to dip in the same direction, till within one or two miles of 
Big Stream point, or about eight miles from Dresden. Here the rocks 
begin to ascend to the south, and half a mile south of Big Stream, the 
black shale appears above the lake, and continues rising for a mile or 
more, where it attains an elevation of forty feet above the water, and 
begins to descend southward. 
A circumstance worthy of notice is that at this point, and extending 
as far as the shale continues above the level of the lake, this rock con- 
tains within five or six feet of its upper surface, a concretionary mass 
of silico-argillaceous limestone, from three to five feet thick, consisting 
of three layers divided by interposed seams of shale. The lower stra- 
