72 
BULLETIN OF THE LABORATORIES 
It is frequently supposed that the Clinton contains no regular seams, 
separating the strata. Whereas this is true in a general sense, as 
compared for instance with Cincinnati or Niagara formations, neyer- 
theless quite regular seams are occasionally found also in the Clinton 
group, especially in the section now under consideration. A long 
seam, followed with comparative ease for 175 ft. showed a dip of 3.29 
ft. in this distance. A comparison of this line with the base of the 
group shows that the strata thicken in the depressions of the underly- 
ing bed. This is also shown in the western half of the quarry, where 
the group is 14.4 ft. thick at the spring, and 15.6 ft. at a point 150 ft. 
north-west of the same, showing an increase of i ft. 2.5 in. The 
elevations at the spring are : top of Cincinnati group 192.63 ; of Clin- 
ton group, 207.01. Along the we.stern end of the quarry the eleva- 
tions of the Clinton: are 202.73 the S. W. corner, 200.07 
middle, 202,15 at the N. W. corner, 202.36 at a point east of the 
latter. Here the top of the Niagara reached 204.26 showing a thick- 
ness of 1.9 ft.; it is a yellow, somewhat shaly stone, becoming 
frequently quite hard. Taking the Niagara stone as shown at the 
Soldiers’ Home, Carrollton pike, and other quarries farther west, a 
good idea of the variability of the base of this group can be formed. 
In the western part of the quarry the base of the Clinton Group con- 
sists of a greyish or almost white stone, composed of finely comminuted 
organic remains, of which the structure has become more or less 
obscure. Here many bryozoans have been found in a fine condition. 
Clatlwapora Clintonensis and Reiepom angulata in fronds 2 feet and i 
foot in. diameter respectively have been seen here. Other fossils, 
however, are rather scanty in this stone. Most of the group, how- 
ever, is composed of a bluish solid limestone, becoming pinkish or red 
by oxidation, and abounding in fossil forms. The summit of the 
group in the north-western part of the quarry is especially prolific 
in various species of Orthis. dfiie summit of the Cincinnati Group is 
composed of blue, clayey shales, several feet thick, and very undulating. 
The notable fact is that these ’undulations are mostly local, the strata 
taken as a whole, maintaining a comparatively even inclination, as will 
be seen by a reference to the map. 
In the rocks of the Clinton Group, at Soldiers’ Home, so many 
species are found, and so much work has been done, that it would be 
difficult to mention the prominent features. Bryozoans, found here 
in numbers, are said to be still more common at the Eaton pike c^uarry. 
