The Rogers Gap Fauna of Central Kentucky 129 



found at the railroad cut 57.5 miles from Ludlow. A second 

 specimen, more acute toward the beak, possibly a pedicel valve 

 of the same species, was found at 54.7. The thickness of the 

 shell from valve to valve was about 4.5 mm. The exterior is con- 

 centrically marked. Lingiila whitfieldi was described from strata 

 beneath the Fulton layer, a few feet above low w^ater, at Coving- 

 ton, opposite Cincinnati. 



12 — Lingula cf. proctcri, Ulrich. (Plate II, Fig. 7.) — A 

 brachial valve, 20 mm. long and 14 mm. wide, resembling Lingula 

 procteri in outline, was found at the railroad cut 55.8 miles from 

 Ludlow. Specimens which may belong to the same species occur 

 in the railroad cut one mile north of the railroad station at Cynth- 

 iana. In these the interior of the pedicel valve agrees fairly well 

 with that figured by Hall and Clarke (Paleontology of New York, 

 Vol. 8). There is the same broad, flat septal linear area separating 

 the cuneiform concrete laterals. The striae in front of the flat 

 septal area, however, are straight for a considerable distance for- 

 ward, and from this median area, as well as from the anterior 

 part of the concrete laterals, the other striae diverge. The in- 

 terior of the brachial valve bears only a moderate resemblance to 

 the figures published by LHrich and by Hall and Clarke. There 

 is a broad, flat, median septal area, fairly well outlined, as in the 

 case of the pedicel valve. On each side of this septal area is a 

 concrete lateral, convexly rounded antero-laterally, as in the fig- 

 ure published by Hall and Clarke. The anterior part of the con- 

 crete laterals is slightly more deeply impressed, and may corre- 

 spond to the centrals, as in the Lingula cincinnatiensis group. An- 

 terior to this part of the concrete laterals, the flat, median septal 

 area is prolonged as a somewhat narrower but more convex and 

 more prominent septum, narrowing in front and almost reaching 

 the anterior margin. This anterior septum, and that part of the 

 concrete lateral which may correspond to the centrals, are bor- 

 dered laterally by a narrow, shallow groove, outlining an area 

 somewhat similar to that figured by Ulrich. Between this groove 

 and the lateral margins there are two areas of vascular markings, 

 separated by a narrow, flat, smooth area, somewhat similar to 



