Strophomena and Other Fossils 
21 
coral horizon may be traced southward as far as Marion, Boyle, 
and Casey counties, and eastward to Lincoln, Garrard, and Madi- 
son counties. At these more southern localities it forms a thin 
wedge, only a few feet thick, between the underlying unfossil- 
iferous argillaceous Waynesville strata and the overlying unfossil- 
iferous argillaceous strata which northward merge into the Saluda 
of southern Indiana. 
The Saluda represents another great period of deposition of 
argillaceous strata. Where it is more typically developed, in 
Jefferson and Clark counties, in Indiana, and in Trimble, Oldham, 
Jefferson, and Bullitt counties, in Kentucky, it is nearly or entirely 
unfossiliferous. This is practically its character also southward, 
in Nelson, Washington, and Marion counties, although there are 
local areas within which Tetradium and Stromatocerium are abun- 
dant at the extreme top of the Saluda. A relatively thin fossilifer- 
ous layer, the Hitz layer, occurs immediately above the Saluda 
also between the eastern part of Jefferson county, in Kentucky, 
and the southern limit of Ripley county. 
From the vicinity of Aladison, in Indiana, the fossil content of 
the Saluda, especially of the upper two-thirds, increases gradually 
northward, but as far as the extreme northern edge of Ripley 
county there is a band of shaly, unfossiliferous strata in the lower 
third of the Saluda, which is very characteristic of this horizon. 
North of Weisburg and Ballstown, in Ripley county, the Saluda 
has not as yet been traced with care. Owing to the rapidity of the 
increase of the fossil content on passing northward through Ripley 
county, and owing to the accompanying lithological changes, it is 
highly desirable that a more detailed study be made to determine 
what are the exact stratigraphical equivalents of the different 
parts of the Saluda north of Ripley county. 
For the present, it may be stated that while the lower part of 
the Waynesville was being deposited in Ohio and Indiana, the 
south-central part of Kentucky was practically devoid of life. 
Only the upper part of the typical Waynesville fauna reached 
Jefferson county, in Kentucky, and only the lower part of the 
Liberty reached Marion county, unless the great coral horizon 
is to be regarded as belonging to the top of the Waynesville. Be- 
fore the invading argillaceous deposits of the Saluda, the Liberty 
fauna retreated northward to the Ohio and Indiana basin, from 
