2G2 NEW MELANIDJE OF fniE UNITED STATES. 



conical, sutures irregularly' impressed ;, whorls six, the last large and somewhat in- 

 flated ; aperture elongately rhomboidal ; whitish within and four-banded, channelled 

 and recurved at the base ; columella with double curve, thickened above ; outer lip 

 somewhat constricted, with an acute margin. 



Operculum small, ovate, dark brown, serrate around the base and outer margin, 

 with the polar point inside the Left edge about one-third above the basal margin. 

 Lithasia fusi/ormis, ,Proc. Acad. Nat. Sci., 1861, p. 54. 



Hob. — Coosa River, Alabama. E. R. Showalter, M. D. 



My cabinet and cabinets of Dr. Showalter and Dr. Lewis. 

 Diam. -30, Length -52 inch. 



Remarks.— Six specimens are before me. Neither, I think, quite full grown. This 

 species differs materially from Showalterii (nobis) from the same river. It is not quite 

 so large, is not inflated, but more constricted on the body whorl, and has rather dis- 

 tant, low, longitudinal folds, which in some specimens are scarcely observable. It 

 differs in having four brown bands, the Showalterii having but three. The most re- 

 markable character of fusi/ormis is the long recurved channel which brings it close 

 to the genus lo. All the specimens have transverse furrows, which are more strongly 

 developed in some of them than in others. The operculum is very remarkable, having 

 the margin from near to the polar point round to the upper part of the outer margin 

 completely serrate. Fortunately two of the specimens were found to have the oper- 

 culum adhering to the desiccated parts within, and both were found to possess 

 this peculiar character, which I have never observed in any other species of the 

 Melanidm. The aperture is nearly two-thirds the length of the shell. 



Lithasia Showalterii. PI. 35, fig. 72. 



l'i iia Uevi, ovato-cylindracea, subcrassa. luteo-cornea, vittata ; spira obtuse conoidea ; suturis valde irn- 

 prcssis ; anfraetibus senis, ultimo grandi et planulato ; apertura grandi, subovata, elongata, iutus 

 albida, tenebroso-vittata, ad basim obtuse angulatS ; columella inferno et superne incrassata, in- 

 curva ; labro acuto et subconstricto. 



Shell smooth, ovately cylindrical, rather thick, yellowish horn-color, banded ; spire 

 obtusely conical ; sutures very much impressed ; whorls six, the last large and flat- 

 tened ; aperture large, subovate, elongate, whitish within, dark-banded, obtusely 

 angular at the base, columella thickened above and below, incurved ; outer lip acute 

 and somewhat constricted. 



Lithasia Showalterii, Proc. Acad. Nat. Sci., 1860, p. 188. 



Hah. — Cahawba River, at Centreville, Alabama, E. R. Showalter, M. D. 



My cabinet and cabinet of Dr. Showalter. 

 Diam. "38, Length "70 inch. 



Remarks. — This species presents a number of varieties, but the character of the flat- 

 tened enlarged side, frequently producing quite a large shoulder, is generally preserved. 



