33^'^ The American Geologist. J"'-^^- i^'^^- 
rate form of Flatystrophia lyii.v is rather common in a layer 
of limestone occurring thirty-four feet above the level of the 
river. Three feet farther up, there is a coarse limestone layer, 
its upper surface strongly wave-marked, the trend of the 
ridges approximately north and south. Three and a half feet 
above the wave marked layer, l.eptaena rhomhoidalis occurs. 
Four feet above the wave-marked layer, Dinorthis retrorsa is 
rather common, and its range extends fully six feet above this 
level. 
Above the Dinorthis retrorsa la\ers. in the Lebanon sec- 
tion, there is blue clay, sixteen feet thick, soft near the base, 
nodular near the top. Overlying the clay is nodular clayey 
limestone, three and one-half feet thick, which may be regarded 
as forming the top of the Warren bed. The topmost layer is 
wave-marked in places, the trend of the ridges being approx- 
imately north and south. The nodular character of the rock 
and the wave-marking suggest turbulent waters during the de- 
position of the upper \A'arren beds. This was followed by a 
change of fauna inaugurating the Richmond age. 
TJie base of the Lozvcr Richmond. 
Zygospira kentuckioisis has been foimd in Oldham and 
Jefferson counties in Kentucky, and at the mouth of Bull creek, 
in the northeastern part of Clark county in Indiana. At the 
last named locality it occurs at the contact of the Lorraine with 
the Lower Richmond. At Clarksvillc, Ohio it occurs in the 
upper part of the Lower Richmond, about four feet b^low the 
horizon of Herhertella insculpta. 
The nodular, clayey limestone at the top of the Warren bed, 
in the Lebanon section is overlaid by thin, well bedded lay- 
ers of clay and limestone ; the total thickness is four feet ; the 
top is formed bv a four inch layer of hard limestone. Immedi- 
ately above, in the blue clay and in the interbedded thin lime- 
stone layers, DaJmancUa jngosa is common. Nine feet above 
the Warren bed there is a more massive layer of limestone, 
four to nine inches thick, containing great numbers of this 
fossil. 
In the gulley back of the blacksmith shop, at the north end 
of Oregonia, a station formerly known as Freeport, Dinorthis 
retrorsa occurs seventy-eight feet above the level of the river. 
The base of the nodular clavev limestone occurs sixteen feet 
