Strophomena and Other Fossils 
79 
The horizon with Tetradium and Columnaria may be traced as 
far southward as the hill east of the Preachersville pike, 4 miles 
southeast of Lancaster, in Garrard county, where it is 70 feet 
below the Clinton, and to various localities east of Rowland, in 
the northeastern part of Lincoln county, where it is about the 
same distance below. 
In all of the preceding cases, the term Clinton implies the Brass- 
field member at the base of the Silurian of Kentucky, and not the 
equivalent of the typical Clinton of New York, which finds its 
representative in the Crab Orchard section of Kentucky, and in 
the immediately overlying West Union member. 
On the western side of the Cincinnati geanticline, a similar 
restriction in the vertical range of the brachiopod fauna of the 
Richmond takes place. At Madison, in Jefferson county, Indi- 
ana, and at Milton, on the opposite side of the river, in Kentucky, 
the lowest specimens of Dinorthis subquadrata occur about 75 
feet below the base of the Clinton, and Hebertella insculpta is 
found about 7 or 8 feet lower, at the base of the Liberty bed. 
Strophomena planumbona occurs in the lower part of the Liberty, 
and also in the upper part of the Waynesville, the lowest speci- 
mens being found 30 feet below the lowest specimens of Dinorthis 
subquadrata. At the mouth of Bull Creek, in Clark county, 
Indiana, the lowest specimens of Dinorthis subquadrata occur 63 
feet below the Clinton, and only the upper 20 feet of the Waynes- 
ville bed are richly fossiliferous, containing Strophomena elongata 
and Strophomena planumbona. Zygospira kentuckiensis occupies 
the underlying part of the section, 8 feet thick, and Tetradium is 
abundant from 8 to 12 feet lower. 
About 5 miles south of the mouth of Bull Creek, 2 miles 
northwest of Brownsboro, in Oldham county, the lowest speci- 
mens of Dinorthis subquadrata occur 60 feet below the Clinton. 
Strophomena vetusta occurs in the overlying part of the Liberty 
section, 12 feet thick, but no species of Strophomena was noted 
in the underlying fossiliferous section, the upper part of the 
Waynesville. Along the railroad from Jelfersontown eastward 
to Fisherville, in the eastern part of Jefferson county, in Kentucky, 
a conspicuous Columnaria vacua horizon is found below the 
richly fossiliferous Liberty section, which there includes Stropho- 
mena vetusta^ Dinorthis subquadrata, and, near the base, also 
Strophomena planumbona. Specimens of Strophomena planum-- 
