EPILCON LINPNDLAETSZA "OP JURASSIC AGE 247 
bedding planes of the sandstone are oblique to the beds above 
and below. Succeeding the sandstone above is 6" of sandstone 
in very thin layers, with lignitic seams along its horizontal but 
wavy bedding planes. The above is overlain by 4" of conglom- 
erate followed by 1’ of sandstone with oblique bedding planes. 
Overlying this layer is a thin layer of sandstone in which the 
bedding planes are horizontal. The remainder of the stratum is 
made up of sandstones with the thicknesses and bedding planes 
as follows: 1’ oblique; 3" horizontal; 2’ oblique; and finally 3” 
horizontal. 
The beds furnished in one place the trunk of a large fossil 
tree and a large number of fossil cycads. Fragments of wood 
were found in a number of places, but cycads in only the one. 
Fragments of a hollow-boned Dinosaur were secured from one 
place in the horizon. 
19. Drab-colored clay, 30’ to 40’. This stratum contains 
the remains of Srontosaurus and Morosaurus. Otherwise it 
appears to be unfossiliferous. 
20. Fissile, brownish sandstone, 4’ to 5’. No fossils were 
found in this sandstone, and a most characteristic feature about 
it is its uniformly brown color. It seems to be moderately per- 
sistent, as it was noticed in many places in the hills. 
21. Bluish-green clay, containing very small concretions, 30’. 
In the bone quarries of this horizon, which furnished species of 
Brontosaurus, Morosaurus and Diplodocus were found specimens of 
Lioplacodes (Planorbis) veternus Meek, and Valvata leer Logan. 
This is the lowest horizon at which any of these non-marine 
invertebrates were noticed. It is very probable that they will 
be found in the beds below as they indicate similar conditions of 
deposition. 
22. Brown to bluish-gray arenaceous limestone, 8” to 1’. 
This stratum contains the following non-marine invertebrate 
forms: Unio knighti Logan; Unio williston’ Logan; Unio baileyi 
Logan; Valvata leei Logan; and Lioplacodes (Planorbis) veternus 
Meek. Species of the same genera have been described by 
Meek from a similar stratum of limestone in the Black Hills. 
