118 Cincinnati Society of Natural History 



is overlaid by strata in which Plectambonifes is abundant. Both 

 Crepipora venusta and several specimens of Eridorthis were se- 

 cured near the top of the cut. Hehertella latasulcata and Stropho- 

 mena hallie are present. The basal coarse-grained limestone hori- 

 zon is not exposed above track level in this vicinity. The railroad 

 bridge crossing the pike in the southern part of Sadieville is marked 

 54.0 miles south of Ludlow. 



Although it has been possible to establish two Eridorthis hori- 

 zons, associated with two coarse-grained limestone horizons, in 

 the areas between Rogers Gap and Sadieville, the lithological 

 changes, even within this short distance of six miles, are suffi- 

 cient to suggest that, within comparatively short distances, strata 

 essentially equivalent to the Rogers Gap beds may show a some- 

 what different succession of faunal zones. 



C. Riverside station. 



Eridorthis is known also from Riverside station, one mile north 

 of Ford, in Clark County, Kentucky. Directly opposite the sta- 

 tion, Eridorthis nicklesi was found at track level, associated with 

 Bcllcrophon rogersensis. One foot above this horizon, but farther 

 westward, Eridorthis was seen in the same rock fragment with 

 Pcrenopora vera, the Rogers Gap form of DalmaneUa, Hehertella 

 latasulcata, Platystrophia colhiensis, and Hormofoma gracilis-siih- 

 laxa. The highest known range for Eridorthis at this locality is 

 stratigraphically two feet above the railroad track at Riverside 

 station. Between two and four feet above this highest Eridorthis 

 horizon, RaHnesquina is very abundant. In the overlying layers 

 Strophomena hallie, Hehertella latasulcata, and C yd on em a vari- 

 cosum-cincinnatense occur. These layers are regarded as corre- 

 sponding approximately to the layers above the upper coarse- 

 grained limestone, full of Plectanihonites, between Rogers Gap 

 and Sadieville. Clitaiubouifes rogersensis occurs at Riverside eight 

 feet below the level of the station, stratigraphically, but farther 

 southward, owing to the northward dip of the strata. The best 

 locality is near the first railroad switch. Directly beneath the Clit- 

 ambonites horizon, Platystrophia colhiensis is common. Specimens 



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