CLINTON CONGLOMERATES AND WAVE .MARKS. 59 
run north and south, are often three inches above the troughs, 
and are usually about 30 inches apart. Plenty of fossils occur 
just beneath the sand forming the wave ridges themselves, and 
they protrude through the same. On going down the stream 
lower horizons are met, and wave marks are also found at these 
lower levels. Farther down stream the wave marks run north 50° 
west and are not so fine as those first described. Still farther 
down stream are plenty of good pebbles caught up in the layers 
beneath the wave marks. The pebbles are often six, and occa- 
sionally eight and ten inches in diameter. They evidently 
were derived from the sandy, stratified, less fossiliferous beds of 
practically the same age which occur immediately beneath. 
While there was not found the same direct evidence of the deri- 
vation of these pebbles from other localities in the immediate 
vicinity, as opposite Cincinnati, this was probably due chiefly to 
less favorable exposure, those at Elk Run occurring chiefly in 
the creek bed, and those at West Covington being exposed on 
the steep banks of the Ohio in almost vertical section. While 
the pebbles were, as a rule, not richly fossiliferous, yet owing to 
their great abundance their identity could be readily established. 
All fossils found belonged to the horizon of the general matrix 
in which they were inclosed, showing their derivation from rocks 
of but slightly lower horizon. 
Below the first house on the west side of the creek very good 
wave marks are again seen running north and south for a con- 
siderable distance. Farther down are others less good but dis- 
tinct, running north 30° west. Within half a mile of the bridge, 
farther down, opposite a house on the east bank, plenty of peb- 
bles) occur ime the jock) Some vor these pebbles) are slabs 16 
inches in diameter, and about an inch to an inch and a-half thick. 
Just below, the wave marks run north 20° west. At a very con- 
siderable distance down the creek are loose slabs containing 
pebbles of moderate size, two to three inches in diameter. Far- 
ther down are poor wave marks, the usual distance apart and 
running north 45° east. Just below these are good wave marks 
running north 20° east. Some distance beyond this, Elk Horn 
