134 Cincinnati Society of Natural History 



21 — Pterinea {Caritodens) demissa, Conrad — A left valve, 

 measuring 45 mm. along the umbonal elevation from the beak to 

 the posterolateral outline, was found at the railroad cut 58.1 miles 

 from Ludlow. Pterinea demissa is not listed by Nickles from any 

 part of the Eden at Cincinnati. It is figured on plate II, of vol- 

 ume II, of the Paleontology of Ohio. 



22 — Byss onychia vera, Ulrich (Plate I, Fig. 15) — A species 

 apparently identical with Byssonychia vera occurs at the railroad 

 cut south of Rogers Gap, and also at 59.1, 58.5, 57.4, 56.4, 55.0, 

 and 54.3 miles from Ludlow. It possesses 50 radiating plications, 

 and has the same general outline as the Lower Eden form, but 

 the hingeline is somewhat longer and the posterior outline is more 

 erect where it meets this hingeline. 



23 — Byssonychia hyrnesi, Ulrich (Plate III, Fig. 6) — A 

 form resembling this species was found at the railroad cut south 

 of Rogers Gap. Since Byssonychia hyrnesi was described from 

 the beds below the Fulton horizon at Covington, opposite Cin- 

 cinnati, this reference probably is correct. 



24 — Anonychia flanaganensis, Foerste (Plate II, Figs. lA, 

 B) — This species is characterized by the long hingeline and the 

 very oblique anterior and posterior margins, producing an elong- 

 ate rather than erect form. The shell is strongly convex, the 

 anterior slope of the more gibbous specimens being practically 

 vertical, excepting where the protusion of the byssal opening takes 

 place. The shell is gibbous even at the beak, the interior cast of 

 which is pointed and curved toward the front. While the shell 

 anteriorly was very thick, posteriorly it seems to have been much 

 thinner. The radiating plications are very flat, and are separated 

 by very narrow and shallow grooves, so as readily to escape de- 

 tection in the specimens found so far. About five of these pli- 

 cations occupy a width of 4 mm. This species is very abundant 

 at the base of the Millersburg division of the Cynthiana lime- 

 stone, 2 miles north of Flanagan and 3 miles north of Paris. 



25 — Modiolopsi^ rogersensis sp. nov. (Plate III, Figs. 3 A, B, 

 C, D) — This species is fairly common at the railroad cut 59.1 

 miles from Ludlow, and occurs also at the cut south of Rogers 



