Strophomena and Other Fossils 
107 
distant. At the latter locality, this fossil occurs at the southern 
limit of extension of the Dinorthis suhquadrata and Strophomena 
vetusta fauna, these fossils occurring at Bardstown and other 
localities in Nelson county, farther northward. The horizon is 
regarded as about equivalent to the Liberty member of the Rich- 
mond, and as above the horizon of the Strophomena sulcata 
fauna at Dismukes Station. The nearest known locality of 
Strophomena sulcata at the Blanchester horizon probably occurs 
in southern Indiana, near Madison. 
In the Richmond on Manitoulin Island, Strophomena sulcata 
occurs at various levels between the Hehertella insculpta hori- 
zon and the rich coral bed, 40 or 50 feet farther up. It occurs at 
this horizon at Little Current, Kagawong, and Gore Bay. The 
strata are regarded as approximately equivalent to the Blanchester 
division of the Richmond. 
Geographically, Strophomena sulcata makes its first appear- 
ance near the base of* the middle or Clarksville division of the 
Waynesville, in Ohio and Indiana. It may have had an equally 
great distribution near the base of the upper or Blanchester 
division, but at present it is definitely known at this horizon 
only in a rather restricted area in southwestern Ohio. The fact 
that it occurs also at the Waynesville horizon near Gallatin, in 
northern Tennessee, is in favor of its migration from some region 
accessible to both areas. Judging from the discoveries on Mani- 
toulin, this Waynesville sea extended to the northern edge of 
Lake Huron. In the Liberty sea, Strophomena sulcata ranged as 
far south as Concord, on the Ohio River in eastern Kentucky, 
and to Raywick, in Marion county, in western Kentucky. In 
the Whitewater sea, its range extended as far south as Madison 
county, in eastern Kentucky, and as far as Ripley county, in 
Indiana. 
On the accompanying chart (plate XVIII), the range of Stro- 
phomena sulcata during the Waynesville is indicated by the areas 
crossed by diagonal lines. Its range during the Liberty and 
Whit.ewater is indicated by the much more extended area enclosed 
by the dotted line. Its range at the lower Hehertella insculpta 
horizon, at the base of the Blanchester, appears to have been more 
restricted than earlier, during the Clarksville period of deposition, 
although the species appears to be more constant in its occur- 
rence at the base of the Blanchester than at the lower horizons. 
