20 Aug. F. Focrste 



lower 50 feet of rock exposed at Cincinnati, Ohio, and in the Sal- 

 tillo. Hermitage, and Logana limestones of Tennessee and Ken- 

 tucky, Dr. E. O. Ulrich is inclined to regard them all as approxi- 

 mately equivalent, an opinion which he finds fortified by the pres- 

 ence in the lower rocks at Cincinnati of various species, not here 

 listed, which occur also in the Logana limestone. 



Dystactospongia madisonensis^ Foerste. 



Along a branch of Laughery creek, a mile southwest of Balls- 

 town, Indiana, the so-called shale bed, in the low^er part of the 

 Saluda section, is underlaid by four and a half feet of soft clayey 

 material, and six feet of argillaceous rock w^ith an abundance of 

 Tetradkmi minus at various levels. This lower layer contains also 

 Rhynchotrema capax, Streptelasma vagans, Endoceras proteiforine, 

 the species of Byssonychia found at the same horizon two miles 

 south of Versailles, and also Dystactospongia madisonensis. The 

 latter was found about 2 feet from the top of this Tetradium sec- 

 tion. Dystactospongia madisonensis occurs also in the upper part 

 of the underlying section, a foot and a half thick, accompanied by 

 Calapoecia crihriformis; Tctradimn minus occurs occasionally in 

 the lower part. The basal part of the section, nearly three feet 

 thick, contains rather numerous large specimens of Colnmnaria 

 alvcolata, and Strophomena plamtmbona. Dystactospongia madi- 

 sonensis, associated with Calapoecia crihriformis, and Strophomena 

 vetusta, occur just below the Tetradium horizon also at the bridge 

 east of Ballstown. The horizon for Dystactospongia madisonensis, 

 therefor, appears to be at the base of the Saluda. The total thick- 

 ness of the Saluda west of Ballstown is 56 feet. The upper half, 

 28 feet thick, is formed by the mottled limestone, which overlies 

 the shale bed. 



At the railroad cut west of Weisburg, only the base of the 

 mottled limestone is exposed but here it contains numerous speci- 

 mens of Eutomis madisonensis, Eurychilina, striatomarginata, 

 Leperditia caecigena, Primitia cincinnaticnsis, and Primitia milleri. 

 Beneath this level are 1 1 feet of clay, overlying a thin limestone 

 layer containing Strophomena sulcata, Streptelasma vagans and 

 Streptelasma divaricans. It is underlaid by 9 feet of limestone near 

 the middle of which Tetradium occurs. The shale bed, six and a 

 half feet thick, occurs at the base of the cut. The base of the 



