192 WIESE [OOK INAIE (OUP (GIEOQILIOG Je, 
the base in Washington county ; also from Nelson county, both 
southwestern counties of the Blue Grass region. Their occur- 
rence in Nelson county seems to be extremely doubtful. At the 
top of the Middle Hudson, and the base of the Upper Hudson, 
are arenaceous elements which increase in thickness and coarse- 
ness going southwards. 
In the Upper Hudson wave marks appear in Oldham, Lincoln, 
Clark, Montgomery and Fleming counties of Kentucky and in | 
Adams county in Ohio. Pebbles occur in Clark and Montgom- 
ery counties in Kentucky, and in Adams county in Ohio. With 
the exception of Oldham, these are the eastern counties in Ken- 
tucky and the southeastern ones of Ohio, in the Lower Silurian 
FEStOn as 
At the top of the Lower Silurian comes in the Cumberland 
sandstone, which has its most marked development in the south- 
ern counties of Kentucky. 
The Oneida conglomerate is barely larece nied in Boyle, one 
of the southern counties of Kentucky. 
In the Medina, wave marks have been noticed only in one 
county, Lincoln, the most southern county of this region, and 
just southeast of Boyle. The Medina seems to increase in thick- 
ness southeastward in the eastern range of counties. 
In the Clinton, wave marks occur in Montgomery, Bath, 
Fleming and Lewis counties, Kentucky, and in Adams and High- 
land counties in Ohio. These are the most eastern of the Clin- 
ton group counties. [It is approximately the same area over 
which, later, the Corniferous failed to extend. On approaching 
this area, the Oriskany of Kentucky thins out; it is a part of the 
eastern set of counties over which the massive limestones of the 
Niagara fail to appear. | The odlitic iron ore has a somewhat 
great extension, being apparently present in Garrard, and cer- 
tainly in all the counties from Clark in Kentucky to Clinton 
county in Ohio. The Crab Orchard shales, which represent the 
Clinton in the southern counties, thicken going southward. 
Farther north they form only the lower part of the Clinton, and 
merge into the lower sandy limestone of this group. This 
