346 The American Geologist. J""^- i^^^^- 
The chief thing which is characteristic of the occurrence 
of these corals at the hase of the Upper Richmond in southern 
Indiana is their great abundance and large size at this partic- 
ular horizon, indicating the presence of a coral reef. This 
coral reef is occasionally followed at intervals oi several feet 
by other beds in which the same species of corals occur, but 
in these beds the corals are less numerous and usually much 
smaller. Elsewhere in Indiana and Ohio these corals occur 
only as occasional specimens not forming reefs. 
Along Elkhorn creek, four miles south of Richmond, the 
highest exposures containing Strophoinena vetusta, Dinorthis 
subqiiadrata, Rhynchotrema dentata, and Strophoinena sul- 
cata occur between fifty and sixty feet below the Clinton. The 
upper beds of the Richmond are more richly fossiliferous along 
Elkhorn creek than at any other locality in Indiana and Ohio, 
so far examined. 
The top of the Upper Richmond. 
At most localities almost the entire Upper Richmond sec- 
tion is unfossiliferous. The coral bed and the layers immedi- 
ately above often contain a few fossils. At Madison, a whitish 
band of calcareous rock six feet above the coral bed contains 
Cyrtolites ornatus, Bcllerophon niohri, Lophospira bozvdcni, 
Hormotonui gracilis, Ischyrodonta niiscneri, and a small vari- 
ety of PlatystropJiia'^' three quarters of an inch in width, the 
hinge line scarcely exceeding the general width of the shell. 
In the sandy layers immediately, above. Rhynchotrema capax, 
Strophoinena sulcata, Hchcrtella siniiata, and large, branching, 
nodular specimens of Heterospongia aspera are found. In the 
southern half of Ripley county, in Indiana, the middle part of 
the Upper Richmond section contains a considerable bryozoan 
fauna, although the number of species is apparently small. 
Hchcrtella siniuifa and Byssonyehia radiata are fairly common. 
Near Versailles the upper part of the Upper Richmond con- 
sists of sandy clay containing in addition to numerous speci- 
mens of bryozoa, also Streptelasma nisticum, Protarea ■z'ctns-ta, 
Hchcrtella. occidcntalis, Strophoinena sulcata, and the small 
Platystrophia with a short hinge line, which occurs also lower 
in the section. Along Elkhorn creek, four miles south of Rich- 
* "The Morphogenesis of Platvstrophia," E. R. Cumings, Am. Jour. Sci., 
1903. p. 25. 
