318 H. S. Williams—Channel-fillings in 
Art. XL.—Channel-fillings in Upper Devonian Shales; by 
H. Ss. WILLIAMS. 
In the midst of the fine shales marking the passage from the 
Portage to the Chemung groups, as they appear in the neigh- 
borhood of Ithaca, New York, are found narrow beds of sand- 
stone presenting several points of interest to the geologist. 
The first example studied -is seen at the mouth of the ravine 
opening where Junction, Elm and Hector streets meet at the 
foot of West Hill. 
n the faces of the cliff on the north of the ravine are seen 
what appear to be wedge-shaped beds of sandstone of a few 
feet extent in the shales which form the main mass of the rocks. 
Upon a close examination these wedge-shaped masses are seen 
to be sections, formed at different angles (by the joint-structure 
of the rocks) of a continuous narrow bed of sandstone, convex 
on the bottom and nearly flat and horizontal on the top, run- 
ning out to thin wedges at the sides, its longitudinal axis lying 
diagonally across both systems of joints. 
a reduction of the oblique sections as seen at several 
points of its exposure I determined the shape, size and direc- 
tion of these sandstone masses, which I have called channel- 
fillings. 
The first one studied is about six feet in width and nine 
inches thick at the center; the top nearly plane, while the 
prong surface curves quite regularly from the center to each 
side. 
The shales, in which the channel-fillings lie, are fine, evenly 
bedded, thin, fragile shales, the lines of stratification of which 
recognized in any cleavage of the rock. At the upper surface 
a wavy lamination is seen in the coloration, and also in the 
(to the south side of the ravine where the section was discov- 
ered in the bank by following out the determined direction 
