350 LAND AND FRESH-WATER SHELLS OF N. A. [pART IV. 



Genus MESESCHIZA, Lea. 



Mcseschiza, Lea, Proc. Acad. Nat. Sci., p. 2, Jan., 1864. 



Description. — Shell fusiform, imperforate : aperture rhom- 

 boidal, below canaliculate ; lip expanded, slit in the middle ; 

 columella smooth, incurved. 



Operculum corneous, spiral. — Lea.* 



1. M. Grosvenorii, Lka. 



Meseschiza Grosvenorii, Lea, Proc. Acad. Nat. Sci., p. 2, Jan., 1864. Obs., xi, lOiJi 

 t. 23, f. 67. 



Description. — Shell smooth, fusiform, thin, obtusely conical, purple 

 or banded ; spire obtusely conical ; sutures slightly impressed ; whorls 

 Fiff 6G6 ^t)out seven, scarcely convex ; aperture large, rhonboidal 

 generally banded within; outer lip acute, slightly notched in 

 the middle ; columella slightly thickened and twisted. 



Operculum ovate, light brown, rather thin, having several 

 volutions, and with the polar point well removed from the left margin. 



Habitat. — Wabash River, Indiana; II. C. Grosvenor. 



Diameter, -27 ; length, -43 of an inch. 



Observations. — I have thirteen specimens of this remarkable shell. 

 Eight of them have a well defined, though delicate notch, on the edge, 

 at or near to the periphery of the last whorl. In some this notch is 

 a little above the periphery, and in others a little below. Five of the 

 specimens have no notch, which probably arises in four of them from 

 not being fully grown, and in one from having the thin, delicate edge 

 broken off. The specimens vary in color, some being light horn- 

 color with few or many bands, others more or less purple and with or 

 without bauds ; others again have obscure, longitudinal thickenings, 

 which being whitish give the specimens the appearance of being 

 folded. In all the specimens there is a light line under the sutures, 

 and some have six or seven brown bands, which are distinctly seen 

 on the inside. The channel at the base is small, but well defined. la 

 outline this species reminds one of Goniobasis Vaiixiana (nobis) and 



*Only a single species of this genus li.is been described, and aU the specimens are young 

 shells and from .1 single locality. I have examined thcno carefully and I have discovered 

 in every one of those exhibited to nie by Mr. Lea, the evidence of diseased growth; undei 

 these circumstances I think the genus may fairly be considered a doubtful one. April, 1873. 



