100 NEW-YORK FAUNA MOLLUSCA. 



M. salebrosa. (Conkad, 1. c. p. 51, pi. 4, fig. 5.) Shell short, suboval, thick, ventricose, with a 

 series of very elevated nodes on the shoulder of body-whorl, and usually two other smaller 

 series beneath : spire very short ; aperture contracted, and about half the length of the shell. 

 Columella with a callus above, and another near the base. Alabama. 



M. seviicarinata. (Say, Des. terr. etc. p. 16 ; Am. Conch, pi. 47. M. acuta, Lea, Am. Tr.) 

 Shell small, conic, turrreted, rather slender : spire attenuated, acute, the four apicial whorls 

 carinate below. Whorls 8, somewhat convex ; suture moderately impressed ; surface, espe- 

 cially of the body-whorl, slightly wrinkled ; lip a little prominent near the base. Color, 

 tinged with reddish brown within. Length, 0'5. Common. Kenticcky. 



M. shnplex. (Say, Ac. Sc. Vol. 5, p. 126.) Shell conic, rather rapidly attenuated to an acute 

 apex : suture not deeply impressed ; whorls about S, but little rjunded ; aperture longitudinal ; 

 lip with the edge not undulated, or but very slightly and obtusely so, near the upper termi- 

 nation. Color, blackish; within dull reddish. Height, 0'6; diameter, 0'3. Virgifiia. 



M. trilineata. (Say, Des. terr. etc. p. 19.) Shell subgloboss, oval : whorls four, rounded; spire 

 short, rather more than half the length of the aperture, which is much dilated, ovate, acute 

 above ; base slightly angulated, without any sinus or undulation ; lip widely and regularly 

 rounded. Color, yellowish ; three dark revolving lines on body-whorl, the upper only of 

 which revolves on the spire ; the middle band widest : occasionally all obsolete. Length, 0'5. 

 Ohio river, 



M. trockiformis. (Conk ad, op. cit. p. 56, pi. 8, fig. 11.) Shell short, conical, ventricose, tur- 

 reted : two spiral prominent lines on each whorl, the intervening spaces concave ; summits 

 of the whorls flattened, angulated ; body-whorl angulated, with the periphery carinate ; base 

 flattened; aperture small ; lip angulated in the middle. Alabama. 



M. troostiana. (Lea, Am. Phil. Tr. Vol. 6, pi. 23, fig. 86.) 



M. duttoniana. (Lea, Am. Phil. Tr. Vol. 8, p. ISS, pi. 6, fig. 54.) Shell tuberculate, fusiform, 

 rather thick : spire elevated, pointed at the apex ; sutures irregularly lined ; whorls seven, 

 depressed above ; aperture elongated, angular and channelled at the base. Color, yellow, 

 banded. Length, 1'09; diameter, 0' 57. Tennessee. 



M. holstonia. (Id. lb. p. 189, pi. 6, fig. 55.) Shell granular, conoidal, somewhat thick : spire 

 somewhat elevated ; sutures impressed ; whorls flattened above, with four series of small 

 rather sharp elevations round the whorls ; aperture ovate. Color, black ; within purple. 

 Length, 0"79; diameter, 0' 38. Tennessee. 



M. caliginosa. (Id. lb. pi. 6, fig. 56.) Shell cancellate, conoidal, somewhat thick, transversely 

 striated : spire elevated ; sutures irregularly and largely impressed ; whorls eight, subconvex ; 

 aperture small, about one-third of the total length, elliptical. Color, very dark brown ; 

 within purplish. Length, 0'91 ; diameter, 0-34. Tennessee. 



M. nodulosa. (Id. lb. p. 190, pi. 6, fig. 57.) Shell cancellate, conoidal, thick : sutures irregularly 

 impressed ; whorls subconvex ; aperture rather large, elliptical, subangular below. Color, 

 dark brown. Length, 0"82; diameter, 0" 34. Temiessee. 



M. hoyliiniana. (Id. lb. p. 22S, pi. 6, fig. 59.) Shell granulate, elevated, somewhat turreted, at 

 the carina tuberculate : sutures impressed ; aperture long, ovate, granulate ; revolving lines 

 generally bearing a brown line. Length, 0'94; diameter, 0' 38. Georgia. 



