Cincinnatian and Lexington Fossils 21 



Saluda is not exposed. East of Weisburg. the total Liberty, with 

 the exception of the extreme top is exposed. 



Leptobolus lepis — cliftonensis, var, nov. 



(Plate II, figs. 20 A,B,C.) 



In the Saltillo limestone, at Clifton, Tennessee, there occurs a 

 species of Leptobolus evidently closely related to Leptobolus lepis, 

 Hall. Its outline is oval, or elliptical ovate, and pointed toward the 

 beak of the pedicel valve. A sharply defined median septum extends 

 from the anterior end of the pedicel groove forward almost to the 

 center of the pedicel valve. This septum widens moderately, and 

 is impressed along the median line by a sharp, narrow groove, 

 also widening anteriorly. This results in two very narrow, sub- 

 parallel grooves in the cast of this valve. The muscular impres- 

 sions on each side of this median septum are limited anteriorly by 

 a thickening of the interior of the shell which extends from the 

 anterior end of the median septum laterally across the valve. Onlv 

 a single narrow septal ridge is seen in the interior of a brachial 

 valve, and this follows the median line of the shell to within a 

 quarter of the length of the shell from its anterior edge. 



No trace of lateral septal ridges was found in the brachial 

 valves, and the septal ridges of the pedicel valve were not strongly 

 divergent as in the specimens of Leptobolus lepis figured by Hall 

 and Clarke. The Tennessee specimens agree more with figures 5 

 and 6, on plate 3, New York Paleontology, vol. VIII, figured by 

 Hall and Clarke from Covington. Kentucky. But in the Tennes- 

 see specimens, the septal ridges and intermediate groove of the 

 pedicel valve extend as far as the pedicel cavity, and are less 

 divergent anteriorly. The color of the Tennessee specimens varies 

 from dark brown to whitish, assuming the latter color in the coarser 

 grained limestone layers which are interbedded with the finer 

 grained limestones prevailing in the Saltillo bed. 



If the figures presented by Hall and Clarke are correct in the 

 details here mentioned, the Tennessee specimens are sufliiciently dis- 

 tinct to merit at least a varietal designation. 



A pedicel valve from the Fulton layer, west of Brent, Ken- 

 tucky, agrees with figure 5, on plate ^.Nezu York Paleontology, 

 vol. VIII, in having the two septal ridges with the intermediate 

 depression confined to the anterior part of the muscular area. The 



