HELIX, 



13 



columella subreflected. Greater diameter 21, lesser 18 ; height 10 milli- 

 metres. 



Helix strigosa, Gould, Proc. Bost. Soc. Ng,t. Hist II, 166 (1846) ; Expl. 



Exped. Moll. 36, f. 41 (1852) ; Terr. Moll. II, 210, pi. xxvi, a.— 



Pfeiffer, Mon. Hel. Viv. I, 121 ; IV, 91 ; Mai. Bl. 1857, 321.— W. 



G. BiNNEY, Terr. Moll. IV, 23. 



Anguispira strigosa, Tryon, Am. Journ. Conch. II, 261, pi. iv, f. ^0 (1866). 



From the Rio Piedro of western New Mexico to the Big Horn 

 Mountains, Nebraska. It seems to inhabit all the central basin. 

 Apparently viviparous (see Bland, Ann. N. Y. Lye. YII, 3G7). 



Helix alternata, Say.— Shell broadly nmbilicated, orbicularly- 

 depressed, thill, smoky horn-color varied with red, interrupted, obliquely 

 arranged patches and spots, roughened by crowded, 

 elevated rib-like strise, smoother below ; whirls five Fig. 122. 



and one-half, flattened, the last sometimes obtusely 

 cariuated at its periphery ; umbilicus large, pervi- 

 ous ; aperture very oblique, lunately-rounded, banded 

 within ; peristome simple, acute, its terminations 

 joined by a very thin, transparent calhis, that of the 

 columella subreflected. Greater diam. 21, lesser 19 ; 

 height 10 mill. 



Jlelix alternata, Say, Nich. Encycl. pi. i, f. 2 (1817, 

 1818, 1819); Journ. Philad. Acad. U, l(;i 

 (1821) ; Bisney's ed. 6, 21, pi. Ixix, f. 2.— 

 Eaton, Zool. Text-Book, 193 (1826).— Binney, 

 Bost. Journ. Nat. Hist. Ill, 428, pi. xxv (1840) ; ffelix alternata. 



Terr. Moll. II, 212, pi. xxiv, — Gould, Invert. 

 177, f. 114 (1841).— Leidy, T. M. U. S. I, 253, pi. vii, f. 2-5 (1851), 

 anat.— DeKay, N. Y. Moll. 29, pi. ii, f. 9 (1843).— Adams, Vermont 

 MoUusca, 162, fig. (1842).— Ferussac, Tab. Syst. 44 ; Hist. pi. ixxix, 

 f. 8, 9, 10. — PoTiEZ & Michaud, Galerie, 104. — Chejinitz, 2d ed. I, 

 181, tab. xxiv, f. 17, 18.— Pfeiffer, Mon. Hel. Viv. 1, 102.— Deshayes 

 inFER. Hist. I, 89.— Reeve, Con. Icon. 670 (1852).— Billings, Canad. 

 Nat. II, 99, f. 4, 5 (1857).— W. G. Binney, Terr, Moll. IV, 98— 

 Bland, Ann. N. Y. Lye. VII.— Morse, Araer. Nat. I, 187, f. 17, 18 

 (1867). 

 Anguispira alternata, Morse, Journ. Portl. Soc. I, 11, f. 15 ; pi. iv, f. 16 



(1864).— Tryon, Am. Journ. Conch. II, 2f!l, pi. iv, f. 47 (1866). 

 Helix scabra, Lamarck, Anim. sans Vert. VI, part 2, 88. — Deshayes, 



