630 . GEOLOGY OF OHIO. 
slate, the beds already described are almost, or altogether, destitute of 
fossils. The only organic remains found in the Waverly shales are sea- 
weeds, and these are principally found in the uppermost layers. The 
contents of the black slate are more varied and interesting, as has been 
already shown; but all the rest of the series thus far reviewed is desti- 
tute of plant or animal life. In the beds that remain to be character- 
ized, however, both vegetable and animal fossils occur in considerable 
abundance. The peculiar cock-tail fucoid (Spirophyton cauda-gallz) begins 
about three hundred feet above the base of the series, and is thencefor- 
ward abundantly met with. There is one well-marked fossiliferous stra- 
tum, in which mollusks and crinoids abound, about four hundred feet 
above the base. This is well shown in various exposures on Chestnut’s 
Mountain, Sunfish township. It is also found in all of the ground high 
enough to hold it to the northward, and also upon the east side of the 
river. No quarries have been opened at this horizon, and no Boos Oppor- 
tunities have been found for collecting fossils. | 
(2.) While shales and sandstones alternate through all the series, 
there seems to be in Pike county less of the former element, in propor- 
tion, above three hundred feet than below. In particular, the highest 
beds on the west side of the Scioto, as in the caps of the knobs, are quite 
firm in composition. They probably constitute the “‘ Logan Sandstone ” 
of Prof. Andrews. There are known to be scattered through this upper 
portion occasional valuable quarry courses, but they have not been 
worked enough to show their extent or availability. In all of the 
higher beds, so far as noted, the color of the solid courses is darker than 
that of the true Waverly quarries. A fawn-colored tint marks all of the 
highest beds. : 
On the east side of the river, in the central portions of the county, a 
very similar line of facts obtains; but in the north-eastern corner, and 
along the eastern border of the county generally, the Waverly system is — 
much reduced in thickness. In Jackson township it is not more than 
four hundre and fifty feet in thickness. The place of the upper beds is 
supplied by heavy deposits of Coal-Measure conglomerate. 
5. This conglomerate is a new element in the geological. scale of the 
county. As Prof. Andrews has shown in his report upon-the counties to | 
the eastward, the deposit is one of quite limited extent. It stretches in 
a north-easterly and south-westerly direction from the west side of Jack- 
son county into Scioto county. - It occupies all of the highest ‘ground of 
the four following townships in Pike county, viz., Jackson, Beaver, Ma- 
rion, and Union. In the first named township its outcrops in the hills 
that border the Scioto valley overhang the river. It has a thickness in 
