CLINTON CONGLOMERATES AND WAVE MARKS. 181 
creek a somewhat higher exposure shows four inches of chert over- 
lying 24 inches of the sandy stratified Clinton. The structure of 
these elements of the basal Clinton can be better understood by 
a reference to the Smart section, next given. ~Underneath the 
Clinton on the west side of the creek are four feet of a massive 
greenish rock, constituting the so-called Medina of northern sec- 
tions, and also containing the same annelid teeth, although in 
order to find these readily it is necessary to go southeastward to 
the southwestern angle of the hill caused by the cutting action 
of this small stream and the fork of Brush creek, a short dis- 
tance to the southward, into which the stream flows (locality 
12). Beneath the Medina are 22 inches of a bluish clayey 
material, which, however, has become somewhat indurated, and 
presents a shaly structure instead of the usual homogeneous 
clayey consistency. Quite a number of springs make their 
appearance between the Medina and this blue clay layer. Under- 
neath is the horizon of the Cincinnati group. 
Il. The J. V. D. Smart sections, including part of the former 
Charles Dalyrymple farm. Going from the center of Belfast 
south to the bridge, westward to the exposure of the basal Clin- 
ton, bending towards the southwest about a quarter of a mile, 
and then taking a road ata right angle to the latter, that is 
going northwestward, two sets of exposures are found before the 
abrupt turn of the road to the westward is reached, one of these, 
about half way along the northwest stretch of road, the other 
near its northern end. The first of these exposures (locality 13) 
is along a small streamlet, running only in wet weather; it is 
only a short distance east of the road. The uppermost layers are 
cross-bedded, and overlie a conglomeritic layer 12 inches thick, 
with many flat pebbles, some of which were four to six inches in 
diameter, and did not show signs of fossils. Farther north- 
ward at the second locality (locality 14) the conglomerate is 
exposed in the road bed. Here one of the pebbles, of whitish 
sandy limestone, stained brownish by iron compounds where 
weathered, contained a young Rhynchonella, which is probably 
Rh. scobina, and about half a dozen valves of Rhynchonella 
