Strophomena and Other Fossils 
43 
farther up the Ohio River. On the other hand, the typical 
lower Eden seems to disappear southward before reaching Scott 
county. As a matter of fact, similar faunal changes are noted 
in tracing the Fairmount fauna from Cincinnati southward. Pos- 
sibly the simplest explanation would be that quite dissimilar 
faunas existed practically contemporaneously in different parts 
of the Cincinnatian areas at different times. 
Directly north of Blanchet, in the southern part of Grant county, 
a species of Strophomena occurs, associated with Amplexopora 
septosa, Callopora nodulosa, Coeloclema alternatum, Constellaria 
plana, and Heterotrypa sp. Since Heterotrypa occurs also at the 
top of the fossiliferous part of the Eden beds, just beneath the 
Paint Lick or Garrard division, at the George Million locality, 
w^est of Richmond, the chief reason for regarding the exposures 
north of Blanchet as Mount Hope is the absence of Dekayella 
ulrichi, although it is regarded as very low in the Mount Hope, 
probably at its base. 
Possibly Strophomena hallie is the ancestral form of Stropho- 
mena maysvillensis. 
At Vevay, in Indiana, the upper Eden, containing Amplexo- 
pora septosa, and Dekayella ulrichi-rohusta, is estimated at 58 feet 
in thickness. Strophomena hallie occurs 16 feet below the top of 
the middle Eden, and also at various horizons between 40 and 58 
feet below' the top of this division. Aspidopora newherryi occurs 
60 feet below; Monotrypa turhinata, 65 feet below, and Stigma- 
tella nana, 68 feet below the top of the middle or Southgate divi- 
sion of the Eden. These bryozoans are regarded as lower Eden, 
usually. This gives such a great thickness of lower Eden as 
far w^est as Vevay that it is difficult to believe that the lower 
Eden practically has disappeared at Sparta, in the southwestern 
corner of Gallatin county, Kentucky, unless the bryozoans men- 
tioned have a greater vertical range than supposed hitherto. 
Aspidopora newherryi, Callopora onealli, and Crepipora venusta 
occur on the river bank, a quarter of a mile west of Alarkland, 
about 3 miles east of Vevay, at the base of the Eden section. 
Strophomena hallie was collected also about 60 feet above the base 
of the Eden, 8 miles east of Vevay, opposite Warsaw. 
At the junction of Mud Lick and South Fork, half a mile south of 
Milton, in Ohio county, Indiana, Strophomena hallie occurs about 
85 feet below the top of the Eden, in the upper part of the middle 
