408 Proceedings of the Ohio State Academy of Science. 



times small and short, sometimes long, attenuate, simply incurved 

 or enrolled. Aperture oval, or sub-circular ; margin sharp, sinu- 

 ous. Surface marked by somewhat imbricated lines of growth 

 and several obscurely defined longitudinal plications, the anterior 

 one being usually larger than the others, and often forming a 

 prominent subangular ridge [Keyes, 1894]." 



Length 12 mm.; diameter 7 mm. 



The species is readily distinguished by its open coil, its sud- 

 denly expanded cone, and by its anterior ridge. 



Horizon and locality. — Maxville limestone. 

 Lower zone : Cut No. 4, Mt. Perry-Fultonham. 



STROPHOSTYLUS CARLEYANA— Hall. 



1856. Natica Carlyana. Hall, Trans. Albany Inst., Vol. IV, p. 31. 



St. Louis limestone : Spergen Hill and Bloomington, Indiana ; Al- 

 ton, Illinois. 



1882. Naticopsis Carleyana. Whitfield, Bull. Am. Mus. Nat. Hist., Vol. 



I, p. 71, pi. 8, figs. 26, 27. 

 St. Louis group: Spergen Hill and Bloomington, Indiana; Alton, 

 Illinois. 



1883. Naticopsis Carleyana. Hall, Ind. Geol. and Nat. Hist., 12th Rep., 



p. 369, pi. 31, figs. 26, 27. 

 St. Louis group: Alton, Illinois; Spergen Hill and Bloomington, 

 Indiana. 

 1894. Strophostylus ? carleyana.' Keyes, Mo. Geol. Surv., Vol. V, p. 196. 



St. Louis limestone: Alton, Illinois. 

 1906. .Strophostylus carleyana. Cumings, Ind. Dept. Geol. Nat. Res., 

 30th Ann. Rept., p. 1340, pi. 25, figs. 26, 27. 

 Salem limestone : Spergen Hill and Bloomington, Indiana ; Alton, 

 Illinois. 

 1909. Strophostylus carleyaniis. Grabau and Shimer, N. A. Index. Foss., 

 p. 678, %. 949. 

 St. Louis limestone: Illinois and Indiana. 

 j.t)ll. Strophostylus aff. carleyaiius. Girty, U. S. Geol. Surv., Bull. 439, 

 p. 94, pi. 7, fig. 6. 

 Moorefield shale : Batesville quadrangle, Arkansas. 



Description. — "Shell sub-globose; spire short, consisting of 

 about three volutions, which increase very rapidly, the last 

 one extremely ventricose ; suture not distinctly defined ; aperture 



