818 The American Naturalist. [September, 
quarry has been but little worked, and the grooves could not be 
followed for any distance on account of the overlying gravel. 
The direction of the face of the sandstone is S. S. W., and the 
grooves and strie cut the face at an angle of about 60°, their 
direction being about S. E. by S., practically at right angles to 
the glacial border. The direction of the old valley is here nearly 
north and south, hence the grooves and striz cut the valley at 
an angle of nearly 45°, and must have ended abruptly on the 
cliffs of the rock-gorge. 
The largest groove is about five feet in width and eighteen 
inches in depth, the entire surface being striated in the direction 
of the groove. The smaller grooves lie in the same direction, 
and the entire surface seen (some forty feet) is uniformly scratched. 
No indications of cross striation were seen on the rock in place, 
but on a loose fragment (4’ X 3’) left in quarrying some indica- 
tions of cross strize were visible. ; 
Some ten or twelve rods to the south, in another quarry, striz 
were also seen, running in the same direction; here they were 
visible for some fifteen feet. The sandstone at this point is a 
Conglomerate, the pebbles reaching three-eighths of an inch in 
diameter. Here the surface is filled with pot-holes, from one to 
five feet in diameter, and from one to two feet in depth. None 
were seen entire, all the exposed ones being more or less shat- 
tered in quarrying. The pot-holes are not in anywise striated, 
nor does the striating agent appear to have affected the edges of 
the holes, which are as sharp as those now forming in similar 
sandstones. The general appearance of the pot-holes indicates 
that they were made by a north-flowing stream, and we believe 
they are older than the striae, though the evidence is as yet 1- 
complete. 
Beaver, Pa., July 29, 1890. 
