94 NEW-YORK FAUNA — MOLLUSCA. 
M. gracilis. (Iv. 1. c. pl. 5, fig. 11.) Shell smooth, club-shaped, rather thin. Whorls 8, con- 
vex: spire acute; sutures impressed ; aperture small, ovate. Color, horn ; aperture white, 
Length, 0°75; diameter, 0:32. Tennessee. 
M. subsolida. (Iv. 1. c. pl. 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, 0°82; diameter, 0°32. Tennessee. 
M. ocoeénsis. (Iv. 1. c. pl. 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, 0°92; diameter, 0°32. Tennessee. 
M. subcylindracea. (Ip. l.-c. pl. 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, 0°85; diameter, 
0°32. Tennessee. 
M. sordida. (Iv. pl. 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..ocoeénsis.. Length, 1°02; diameter, 0-4. Tennessee. 
M. regularis. (Ip. pl. 5, fig. 16.) Shell smooth, conical, rather thick; spire elevated; sutures 
somewhat impressed; whorls 10? flat ; aperture small, one-quarter of total length. Codor,. 
dark horn. Length, 1°22; diameter, 0-4. Tennessee. 
M. fuliginosa. (Ip. pl. 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, 0°85; diameter, 0°5. Tennessee. 
M. alveare. (Conrav, Fr. Wat. Shells, p. 54, pl. 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. (Conran, op. cit. p. 51, pl. 8, 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. (Conran, op. cit. p. 52, pl. 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, Conrap, 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- 
