Strophomena and Other Fossils 
77 
The first appearance of Strophomena planumbona, in Cincin- 
natian areaSj appears to have been about 1 or 2 feet above the 
Orthoceras fosteri horizon, a clay section which, in Clinton and 
neighboring counties, in Ohio, immediately underlies the middle 
or Clarksville division of the Waynesville. Strophomena plan- 
umbona occurs at this horizon at Clarksville, in Clinton county; 
and at Fort Ancient, Oregonia, and li miles south of Mount 
Holly, in Warren county. This probably is the horizon of the 
first specimens along Bush Bun, 1 mile northeast of Somerville, 
in the southern edge of Preble county; and the first specimens 
seen in the section along the stream east of Moores Hill, in 
Dearborn county, Indiana. The first specimens seen at Con- 
cord, in Lewis county, and at Sunset and Wyoming, in Fleming 
county, Kentucky, probably belong in the upper part of the Clarks- 
ville division. In fact, Strophomena planumbona is widely dis- 
tributed in the upper part of this division, and becomes abundant 
at certain horizons in the Blanchester division, and in the Liberty 
member. 
At Concord, in Lewis county, Kentucky, and at Sunset, in 
Fleming county, Strophomena planumbona occurs as low as 27 
feet below the base of the Liberty. At Wyoming, in Fleming 
county, it is found 22 feet below the Liberty. At Owingsville, 
in Bath county, it occurs immediately below the Strophomena 
neglecta horizon, 16 feet below the lowest Dinorthis subquadrata 
specimens. 
Along the pike, east of Howards Mill, in Montgomery county, 
Strophomena planumbona, perhaps accompanied by Strophomena 
vetusta, occurs 52 feet below the Clinton. Half a mile west of 
Spencer, in the same county, Strophomena planumbona, also pos- 
sibly accompanied by Strophomena vetusta, occurs 48 feet below 
the Clinton. A mile and a half northwest of Indian Fields, in 
Clark county, Strophomena vetusta occurs 55 feet below the 
Clinton, and Strophomena planumbona, associated with Rhyncho- 
trema capax, ranges from 10 to 18 feet lower. At Merritts Ferry, 
at the mouth of the Bed Biver, in the southern edge of Clark 
county, the layer containing Tetradium, Stromatocerium, and 
Columnaria occurs 90 feet below the Clinton. North of Ophelia, 
4 miles north of Bichmond, in Madison county, the additional 
presence, at the same horizon, of Calapoecia, and Beatricea, 
associated with Strophomena planumbona, Rhynchotrema capax, 
