CLINTON CONGLOMERATES AND WAVE MARKS. 183 
a limestone that weathers into fragments one inch or slightly 
more in thickness, and four to six inches in length, tapering out 
more or less towards the edges, so as to totally destroy its value 
asa building stone. This limestone also contained siliceous and 
cherty nodules, and was in itself quite siliceous. Below this 
were 24 inches of poor shaly limestone, under which the so-called 
Medina made its appearance. Following the steep hill-sides 
along the southern side of this fork of Brush creek, eastward 
from this exposure, the basal portions of the Clinton and the 
underlying Medina are well shown as far east as the next bridge, 
where the pike from Belfast to Loudon and Locust Grove crosses 
the fork. 
Ill. Bridge exposure.—Along the pike leading from Belfast 
to Locust Grove, the locality mentioned just above (locality 18). 
Here the so-called Medina is well exposed; it is quarried, and 
is considered an excellent building stone. It will be remem- 
bered that it was quarried also at Arment’s quarry in the bed of 
Turtle creek, in the Sharpsville section. The top layers of the 
Medina here contained a considerable number of annelid teeth, 
and also a single but good specimen of Halysites catenulatus. 
Returning to Belfast from this bridge, the Clinton lime- 
stone is exposed on the side of the road, on the north side of 
the main valley formed by the fork (locality 19). The section 
on the Smart farm could be readily measured with proper instru- 
ments. The conglomerate layer is evidently nearly at the sum- 
mit of the Clinton. Estimates made by eye alone would hardly 
give the Clinton here a greater thickness than 35 feet. 
Elk Run.—Going north from Belfast, take the first road 
going east; two miles from Belfast the road crosses Elk Run, 
acrossran irom bridge, —Injtheibed of the creek the top, of the 
Clinton is shown (locality 20). At the top are 20 inches 
of ferruginous Clinton, showing cross-bedding, and a few peb- 
bles. Near the middle they contain also a thin layer of blue clay. 
If the memory is not at fault similar thin blue-clay layers are 
seen near the top of the Clinton in the Wm. Haigh section. The 
fact was not recorded at the time of observation. The fossils 
