230 The Ohio Naturalist. [V ol. XIV, No. 3, 



The Liberty or Strophomena planumbona beds were assigned 

 a thickness of about 35',* and the base was defined as the first recur- 

 rence of Hebertella insculpta. The top was not definitely located, 

 but by general agreement seems to have been taken as the base 

 of a 3'-4' bed of shales and soft, shaly, blocky limestones, contain- 

 ing Trochoceras baeri, and many characteristic Whitewater clams, 

 and with Pachydictya fenestellifomiis just above. 



The Whitewater or Homotrypa wortheni beds constituted the 

 remainder of the Richmond, until the distinct and even bedded 

 shales and limestones at the top were separated from the very 

 characteristic soft, lumpy, shaly limestones beneath, and called 

 the Elkhorn. 



Beginning with the detailed study of the formation at Madison, 

 the lower Columaria reef is here somatimes underlain by as much 

 as 10' of the general type of Saluda rocks, only rarely massive and 

 with more shale. These strata contain a few poorly preserved 

 Liberty fossils, Homotrypa wortheni, etc. It may be said here 

 that in Indiana the Trochoceras baeri bed is generally undefined, 

 and no sharp distinction can be made between Liberty and White- 

 water. These undefined strata have been named Versailles, from 

 Versailles, Ind.f 



The lower reef, like the upper, is quite variable in thickness. 

 Averaging 1' at Madison, it reaches 3^' in thickness on a north 

 branch of Razor Creek, five miles north, and then thins out and 

 occurs intermittently at several places northward before disap- 

 pearing. 



Between the reefs at Madison are 6' of shale. This shale is 

 4^' thick along the road following the valley of a westward 

 branch of Crooked Creek, three miles north of Madison. Five 

 miles north of Madison the thickness is only 2' 4". In the shale 

 are a few poorly preserved Hebertella sinuata, Platystrophia 

 acutilirata, and Dystactospongia madisonensis. 



The second reef thins from 2' at Madison to 1' toward Hanover, 

 where it has quite a percentage of Calapoecia cribriformis. At 

 the locality three miles north of Madison it averages only cS" 

 thick, and five miles north is represented only by a hard, tough, 

 irregular limestone 6"-10" thick with no distinct colonies. Like 

 the lower reef, the second occurs intennittently as far north as the 

 exposures below the road on the West Branch of Laughcry Creek, 

 four miles south of Batesville. Huge isolated colonies, sometimes 

 4' across, were seen near Versailles. 



Above the second reef are 3'-G' of shales and thin limestones, 

 in some places carrying a prolific mollusc fauna. Just at Madison 

 this fauna is almost absent, but three miles north were collected 

 Dystactospogenia madisonensis, Dowlsonia cycla, Tetradium 



*Nickles, American Geol. Vol. 32, 1903, Pp. 207-9. 

 fFoerste, Science, N. S., Vol. 22, 1905, P. 150. 



