94 NEW-YORK FAUNA — MOLLUSCA. 



M. gracilis. (Id. I.e. pi. 5, fig. 11.) Shell smooth, club-shaped, rather thin. Whorls S, con- 

 vex: spire acute; sutures impressed; aperture small, ovate. Color, horn; aperture white. 

 Length, - 75; diameter, - 32. Tennessee. 



M. subsolida. (Id. 1. c. pi. 5, fig. 12.) Shell smooth, subfusiform, somewhat solid; spire acute; 

 sutures impressed ; whorls subconvex ; aperture subelongated. Color, horn ; aperture purple, 

 white on the margin. Length, - 82; diameter, 0'32. Tennessee. 



M. ocoeensis. (Id. 1. c. pi. 5, fig. 13.) Shell smooth, conical, somewhat thick ; spire obtuse, 

 lined towards the apex ; sutures impressed ; whorls somewhat convex ; aperture small, ovate. 

 Color, dark-horn; aperture bluish. Length, - 92; diameter, 0" 32. Ten?iessee. 



M. subcylindracea. (Id. 1. c. pi. 5, fig. 14.) Shell smooth, subcylindrical, club-shaped, some- 

 what thick ; spire obtusely elevated ; sutures impressed ; whorls convex ; aperture small, 

 one-third of total length, ovate. Color, horn; aperture whitish. Length, - 85; diameter, 

 ' 32. Tennessee. 



M. sordida. (Id. pi. 5, fig. 15.) Shell smooth, conical, somewhat thick ; sutures impressed ; 

 whorls somewhat convex ; aperture rather large, somewhat rounded. Color, dark horn ; 

 aperture bluish. Closely resembling M. ocoeensis. Length, l - 02; diameter, - 4. Tennessee. 



M. regularis. (Id. pi. 5, fig. 16.) Shell smooth, conical, rather thick ; spire elevated; sutures 

 somewhat impressed; whorls 10? flat; aperture small, one-quarter of total length. Color, 

 dark horn. Length, 1" 22; diameter, - 4. Tennessee. 



M. fuliginosa. (Id. pi. 5, fig. 17.) Shell smooth, fusiform, subinflated, rather thick ; spire ob- 

 tuse ; sutures impressed ; whorls six, somewhat convex ; aperture large, angular at base and 

 channelled. Color, dark brown. Length, - S5; diameter, 0' 5. Tennessee. 



M. alvearc. (Conrad, Fr. Wat. Shells, p. 54, pi. 4, fig. 7.) Shell short, conical, ventricose. 

 Whorls flattened, with a line of wide compressed tubercles at the base of the penultimate 

 whorl: body-whorl angulated ; angle armed with prominent tubercles ; base hardly convex, 

 with about five prominent lines; aperture obliquely elliptical, less than half the length of 

 the shell. Alabama. 



M. annulifera. (Conrad, op. cit. p. 51, pi. S, fig. 2.) Shell subelevated, subconical, with flat- 

 tened whorls, and elevated distant ribs, alternately smaller ; about five on the body-whorl, 

 and three on the adjoining one : suture obsolete. Color, usually blackish without and pur- 

 plish within. Black-warrior river, Alabama. 



M. biteniata. (Conrad, op. cit. p. 52, pi. 8, fig. 6.) Shell conic, with convex whorls ; spires 

 short: one whorl entire, very convex; apex eroded; columella with a callus above, and ano- 

 ther near the base ; aperture half the length of the shell. Color, olive, with two broad purple 

 bands on the body-whorl, and one on the contiguous whorl ; within bluish with purplish bands. 

 Alabama. 



M. canaliculata. (Say, Ac. Sc. Vol. 2, p. 175. M. sayi, Conrad, p. 50.) Shell tapering. 

 Whorls about seven, slightly wrinkled : spire towards the apex, much eroded. Body with 

 a large groove which is obsolete upon the whorls of the spire, from the revolution of the 

 suture on its lower margin ; hence the upper margin only of the groove is seen in the form 

 of an obtuse carina. Lip slightly undulated by the groove, and with a distinct sinus at the 

 base of the columella. Color, brownish horn ; aperture bluish white, with one or more ob- 



