NATURAL SCIENCES OF PHILADELPHIA. 59 



M. valida, Anthony. Shell ovate-conic, smooth, olivaceous, thick ; spire 

 obtusely elevated, decollate; whorls flat, only about 6 remaining; sutures dis- 

 tinct; lines of growth very strong, amounting to varices on the body whorl; 

 aperture ovate, bluish white withia ; columella strongly curved, or indented 

 about the middle, white; sinus well developed at base; body whorl obscurely, 

 concentrically striate, the striae forming faint nodules where they intersect the 

 varices. 



Hab. Tennessee. 



My Cabinet ; Cab. of H. Cuming, London ; A. N. S. Phila. ; State Coll. Alb. 

 N. Y. ; Smithsonian Collection. 



Obs. This species may be compared with M. tenebrocincta herein described 

 from that species it may be distinguished by its more robust form, uniform dark 

 olivaceous color and the absence of the dark bands so conspicuous in that 

 species. It has a very solid, compact form, and this with its regular, uniform 

 size up to the point of decollation, may serve to distinguish it from all others. 



M. gravida, Anthony. Shell ovate, smooth, thick; spire obtusely elevated; 

 whorls 7-8, nearly flat ; sutures well defined ; lines of growth fine, but very dis- 

 tinct ; body whorl large, subangulated ; aperture oval, livid inside ; columella 

 deeply indented, covered with a white callus ; outer lip curved forward, and 

 with the columella forming a small sinus at base. 



Hab. Alabama. My Cabinet. 



Obs. A stout, heavy shell, in form and color resembling in some degree 

 M. solida, Lea, but is more ovate than that species. Color light brown, 

 smooth but not very shining lines of growth very distinct and curved. A few 

 indistinct strice occur at the base of the shell the lower part of the columella 

 is often tinged with a golden hue. 



M. grossa, Anthony. Shell ovate, folded, thick ; spire obtusely elevated, com- 

 posed of about 8 convex whorls rapidly attenuating to an acute apex ; whorls 

 folded, except the last two ; body whorl tumid, smooth ; color of epidermis light 

 greenish olive; aperture elliptical, whitish inside ; columella rounded; outer 

 lip much curved, with a well marked sinus at base. 



Hab. Tennessee. My Cabinet. 



Obs. A shore thick species whose chief characteristics are its bulbous form, 

 and short but prominent ribs on the upper whorls. All the whorls but the last 

 are remarkably narrow and crowded lines of growth prominent 4 or 5 striae 

 revolve s-round the base or the shell. Resembles M. glandula, nob., in form, but its 

 different color and texture, with its prominent ribs, will at once distinguish it. 



M. ponderosa, Anthony. Shell conic, broad, smooth, olivaceous, thick ; spire 

 considerably but not acutely elevated; whorls 7-8, subconvex; lines of growth 

 curved and strong; sutures distinct; aperture rhombic, rather small, whitish 

 within ; columella indented, outer lips much curved forwards forming a broad 

 well marked sinus at base. 



Hab. Tennessee. My Cabinet. 



Obs. One of the most ponderous of the genus. In form it resembles JW. 

 canaliculata, Say, but has not the channel of that species, and differs also in the 

 aperture. The body whorl is strongly keeled about the middle and has another 

 and less clearly defined carina about midway between the first and the suture 

 above. The lines of growth are very strong and occasionally varicose. A 

 strong deposit of white callus is found upon the columella, which is much 

 thickened near the base. 



M. TvEniolata, A^nthony. Shell conic-ovate, striate, thick; spire elevated 

 but not acute, composed of 6-7, nearly flat whorls ; sutures not distinct ; aper- 

 ture sub-rhombic, small, banded within ; columella indented, callous at its lower 

 portion, and with a small but distinct sinus at base. 



Hab. Alabama. My Cabinet. 



Obs. A fine, showy, robust species, of a dark yellow color, enlivened by 

 I860.] 



