•408 Proceedings of the Olilo Sfiite - leadeiiiy of Science. 



times small and slicjrt, sometimes long', attenuate, simpl}- incurved 

 or enrolled. .\]:)erture oval, or sub-circular; margin sharp, sinu- 

 ous. Surface marked by somewhat imbricated lines of growth 

 and several obscurelv defined longitudinal plications, the anterior 

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

 prominent subangular ridge [Keyes, i8';4|."' 



Length 12 mm.; diameter 7 mm. 



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

 denly expanded cone, and l)y its anterior ridge. 



Horizon and locality. — Maxville limestone. 

 Lower zone: Cut Xo. 4, 'Sit. PerrA'-Fultonham. 



STROPHOSTYLUS CARLEYANA-Hall. 



1856. Nafica Caiiyana. Hall, Trans. Alhany Inst., Vol. IV, p. 31. 



St. Louis limestone: Speroen Hill and Rloomington, Indiana; Al- 

 ton, Illinois. 

 1882. Naticopsis Carlcyana. Whitfield, Hull. .\m. Mus. Nat. Hist., Vol. 

 I, p. 71, pi. 8, figs. 2G, 27. 

 St. Louis group: Spergen Hill and I'loomington, Indiana; .Alton, 

 Illinois. 

 188:3. Naticopsis Carleyana. Hall, Ind. Geol. and Xat. Hist., 12th Rep., 

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

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

 Indiana. 

 1894. Stroplwsfylus ? carleyana. Keyes, Mo. Geol. Surv., ^^ol. V, p. 196. 



St. Louis limestone: Alton, Illinois. 

 1906. Siroplwstyliis carleyana. Cumings, Ind. Dept. Geol. Xat. Res., 

 30th Ann. Rept., p. 1340, pi. 2.",, figs. 26, 27. 

 Salem limestone: Spergen Hill and I'llnomington, Indiana; .Alton, 

 Illinois. 

 1909. Stroplwstyhis carleyanus. Graliau and Shimer, X. A. Index. Foss., 

 p. 678, fig. 949. 

 St. Louis limestone: Illinois anrl Indiana. 

 i911. .'^froplwstylus afT. carleyanus. CJirty, LI. S. Geol. Surv.. Bull. 439, 

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

 Moorcfield shale: Batesville quadrangle, Arkansas. 



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

 about three volutions, which increase very rapidly, the last 

 one extremely ventricose ; suture not distinctly defined; aperture 



