PLATE Xlll 
The dotted area indicates the distribution of the localities at which Strophomena 
halite has been found. The triangle within the limits of Madison county, Ken- 
tucky, indicates the only known locality for Strophomena tnillionensis . The 
limited area along the Ohio River, crossed by broken lines, includes the two locali- 
ties at which Strophomena higginsportensis is known. Strophomena halite and 
Strophomena millionensis occur in the Eden. The horizon of Strophomena higgins- 
portensis is either the basal Eden or the underlying part of the Cynthiana forma- 
tion. 
164 
