412 HELICID^. 



Shell discoidal, globose, or conoid, aperture transverse, oblique, 

 lunate, or rounded, margins distinct. 



Jaw arcuate, vertically ribbed, margins crenulated. 



Lingual membrane broad, teeth numerous, centrals tricuspid, lat- 

 erals bicuspid, uncini denticulated or serrated, centrals and laterals 

 sometimes simply conical with an acute tip. 



Helix alternata. 



Fig. 114. 



Shell orbicular, depressed, fawn colored, barred with oblique, zigzag lines of 

 dusky; whorls five or six. with prominent wrinkles at the lines of growth; lip 

 simple ; umbilicus large and deep. 



Helix alteniata. Say, Nich. Encyc. iv. pi. 1, fig. 2, 1817, 1818, 1819 ; Journ. Acad. ii. 161, 

 1821 ; Bixxey's ed. 6, 21, pi. 69, fig. 2. — E.\ton, Zool. Text Book, 19-3 (1826). — 

 BixNEY, Bost. Journ. Nat. Hi,st. iii. 428, pi. 25 (1840) ; Terr. Moll. ii. 212, pi. 24. 



— GouLii, Inv. 177, fig. 114 (1841 ). — Leidy, Terr. Moll. U. S. i. 2.i.3, pi. 7, figs. 

 2-.') (1851), anat. — I)e Kay, N. Y. Moll. 29, pi. 2, fig. 9 (1843). — Adams, Ver- 

 mont Moll. 162, figure (1842). — Ferussac, Tab. Syst. 44; Hist. pi. 79, figs. 8, 9, 

 10. — PoTiEZ and Mkiiaud, Galcrie, 104. — Chemnitz, i. 2d cd. 181, t. 24, figs. 17, 

 18. — Pfeiffer, Mon. Hel. Viv. i. 102. — Deshayes, in Fer. Hist. i. 89. — Reeve, 

 Con. Icon. 670 (1852). —Billings, Canad. Nat. ii. 99, figs. 4, 5 (1857). — W. G. 

 Binney', Terr. Moll. iv. 98. — Bland, Ann. N. Y. Lye. vii. — Morse, Am. Nat. 

 i. 187, figs. 17, 18 (1867). 



Anguispira alternata, Morse, .Journ. Portl. Soc. i. 11, fig. 15 ; pi. 4, fig. 16 (1864). — Tky- 



ON, Am. Journ. Conch, ii. 261, pi. 4, fig. 47 (1866). 

 Helix scabra, Lamarck, An. sans Vert. vi. part 2, 88. — Deshayes, Encyc. Me'th. ii. 



219 (18.30) ; in Lam. viii. 66; 3d cd. iii. 292. — Chen u, 111. pi. 6, fig. 11. 

 Htli.c iiifcrta, Parreys MS. — Pfeiffer, Mai. Bl. 1857, 86 ; Mon. Hel. Viv. iv. 91, non 



Reeve. 

 Helix stromyhdes, Pfeiffer, Proc. Zool. Soc. 1854, 53 ; Mon. Hel. Viv. iv. 91 . — Reeve, 



Con. Icon. 1296 (1854) — T7* W. G. Binney, Terr. Moll. iv. pi. 77, fig. 8. 

 Helix mordax, Shuttleworth, Bern. Mitt. 1852, 195. —Gould, in Terr. Moll. iii. 19. 



— W. G. Binney, Terr. Moll. iv. 99. — Pfeiffer, Mon. Ilcl. Viv. iii. 635. — 

 Bland, Ann. N. Y. Lye. vii. (and vnr. fei-gnsoni). 



Helix dubia, Sheppard, Tr. Lit. Hist. Soc. Quebec, i. 194. — McCulloch, (where?) 

 teste Binney, Terr. Moll. i. 192. 



Shell orbicular, depressed, slightly convex above and l»clow ; gen- 

 eral tint a light fawn color, which, on the upper surface, alternates 

 in about equal proportions, with oblique, zigzag bars of dark-brown ; 

 these bars grow narrower and lighter on the lower surface as they 

 converge to the umbilicus ; they are generally interrupted by a light 

 colored zone which issues from the middle of the inner margin of 

 the aperture ; wiiorls five to six, flattened above, conspicuously 

 plaited at the lines of growth so as to produce a rough surface 



