224 LAND AND FRESH- WATER SHELLS OP N. A. [PART I. 



Fig. 381. 



Liagual teeth of Vwnella subcylindrica. 



Fig. 382. 



SuBGENrs ZUA, Leach. 



Shell ovate-oblong, imperforate, smooth, pellucid, glistening-, 

 dark horn-colored ; whirls rather convex ; 

 aperture less than one-half the shell's 

 length, ovate ; columella more or less 

 truncated ; peristome blunt, its margins 

 joined by callus. 



Animal short, stout, tail pointed ; eye- 

 peduncles long, stout, tentacles very short. 



Animal of Zua.^ 



Fig. 383. 



Cionella suTJCylindrica, Likn.— Shell small, thin, transparent, 

 oblong-oval ; epidermis smoky horn-color, smooth, very bright and shining; 

 whirls five or six, somewhat rounded, the last equalling 

 two-fifths the shell's length, rounded at base ; apex obtuse ; 

 suture somewhat impressed ; aperture lateral, oval, its plane 

 nearly parallel with the axis of the shell ; peristome simple, 

 thickened, often slightly rufous ; umbilicus imperforate ; 

 columella obsoletely truncated at base. Length 6, diam. 2| ; 

 aperture 2i long, J mill. wide. 



Helix subcylindrica, LiNN. Syst. ed. XII, II, 1248 (1767).— 



Not Mont. 

 Helix hthrica, MtTLLER, Verm. Hist. I, 104 (1774). 

 Bulimus lubriciis, Draparnaud, Moll. 75, pi. iv, 24. — Gould, 

 Invertebrata, 193, f. 124 (1841).— Adams, Shells of Vermont, 157 

 (1842).— DeKay, N. Y. Moll. 55, pi. iii, f. 43 (1843).— Bixney, Terr. 

 Moll. II, 283, pi. Iii, f. 4. 

 Achatina lubrica, Pfeiffer, Mon. Hel. Viv. II, 272.— W. G. Binney, Terr. 



Moll. IV, 138. 

 Zua lubrica, Leach, Moll. p. 114. — Gray, Man. 188. — Reeve, Brit. L. & 



Fr. W. Sh. 93 (1863). 

 Cionella lubrica, Jeffreys, Linn. Trans. XVI, 327. 



Zua subcylindrica, from Reeve, very much enlarged. 



