452 The Ohio Naturalist. [Vol. XII, No. 3, 



toccrium is present in the Mount Auburn bed. In southern 

 Kentucky, along the Cumberland river, it occurred already 

 during the upper Fairmount, often in great numbers. During 

 the deposition of the Waynesville and later deposits of the Rich- 

 mond, the species has a much wider geographical distribution. 



In the table of Cincinnatian strata, the temi Laughery is used 

 to include the Waynesville and Liberty members of the Richmond, 

 the Saluda being regarded as deposited during one of the more 

 important diastrophic movements during this period. The typical 

 exposures occur along the Laughery creek, in Ripley county, from 

 the vicinity of Versailles to Osgood, Indiana. 



On the accompanying charts, the letters designate the localities 

 at which the writer found the species in question. The letters 

 have the following signification: 



D — Dinorthis carleyi. 



R — Rhynchotrema dentata — arnheimensis. 



L — Leptaena richmondensis — precursor. 



P — Platystrophia ponderosa. 



A — Dalmanella jugosa, var. 



S — Stroinatocerium huronense. 



Platystrophia and Leptaena occur also 10 miles south of the 

 southern margin of the area covered by these charts, in Adair 

 county, Kentucky, as indicated by the direction of the small 

 arrow on the charts. (See plates XX, XXI.) 



