Strophomena and Other Fossils 
105 
blance to the brachial valves of Strophomena planoconvexa. The 
pedicel valves of these specimens are unknown, and there is no 
reason as yet for regarding them as anything more than aberrant 
individuals of Strophomena sulcata in which the sinuate flexure 
of the anterior half of the shell failed to develop. 
A mile and a half southwest of the railroad station at Fort 
Ancient, in Warren county, Ohio, Strophomena sulcata ranges from 
1 to 4 feet above the Orthoceras fosteri clay layer. 
East of Moores Hill, in the western part of Dearborn county, 
Indiana, Strophomena sulcata also occurs in the lower part of the 
Clarksville division, over strata containing Strophomena planum- 
hona. Both Strophomena sulcata and Strophomena planumhona 
have an extended vertical range in the Richmond, and both are 
seen first in the lower part of the Clarksville division, but Stro- 
phomena sulcata appears to have arrived a little later. 
Strophomena sulcata recurs at the lower Hehertella insculpta 
horizon, at the base of the upper or Blanchester division of the 
Waynesville bed. It occurs at this horizon at Stony Hollow, 
northwest of Clarksville, also along Sewell Run, southeast of 
Clarksville, and along Second Creek, northeast of Blanchester, 
in Clinton county, Ohio. It occurs at the same horizon along the 
creek miles southeast of Fort Ancient, in Warren county; 
half a mile south of Mount Holly, in the northern part of Green 
county; at Miamisburg, in Montgomery county; and along Dry 
Fork of Elk Run, IJ miles south of Jacksonburg, in the northern 
part of Butler county, Ohio. At Concord, in Lewis county, Ken- 
tucky, it occurs 18 feet below the upper Hehertella insculpta hori- 
zon, or 3 feet below the Strophomena neglecta layer. This should 
place it near the base of the Blanchester division. 
In the Liberty member, Strophomena sulcata occurs in Clinton 
county, Ohio, at various levels between the base and top. West 
of Camden, in Preble county, it occurs in the lower part of the 
Liberty, and it is found in the same position also at Concord, in 
Lewis county, Kentucky. Westward, it occurs apparently at 
least as far as Madison, in Jefferson county, Indiana. 
In the Whitewater member, Strophomena sulcata occurs in 
Clinton county, Ohio, at various levels from the base to the top. 
While abundant also at other levels, it has been noted especially 
near the top of the Whitewater member, from Clinton county, 
Ohio, as far south as the locality west of Spencer in Montgomery 
