HELIX. 415 



the throat, wc do not find the tooth-like thickening which exists 

 within the lower margin of H. pcrspectiim. Mr. Anthony also ob- 

 serves, that it is found in low lands, near running streams, and 

 never about rotten logs, the common residence of H. perspectiva. 

 This, however, does not accord with its habits in Massachusetts. 



Helix asteriscus. 



Shell urabilicated, depressed, with thin prominent ribs ; whorls four ; aperture 

 sub-circular ; peristome simple, acute. 



Helix nsffirisnis, Morsk, Proc Best. See. vi. 128 (1857). — W. G. Binney, Terr. Moll. 



iv. 10.3, pi. 77, tig. 9. — Blanu, Ann. N. Y. Lye. viii. 163, tig. 8. — Morse, Amcr. 



Nat. i. .')46, Hg. 43 (1867). 

 Pla)io;/;/m aslerisrns, Morse, Journ. Portl. See. i. 24, figs. .50 -.52; pi. 2, fig. 5; pi. 8, fig. 



5.3 (1864). — Tryon, Am. Journ. Conch, ii. 263, pi. 4, fig. 55 (1866). 



Shell widely uml)ilicated, orbicularly depressed, Fig. 675. 



light l)rown, decussated by delicate incremental and 

 revolving strice, and with from twenty-five to thirty 

 delicate, thin, transparent, prominent ribs, with wav- 

 ing edges, and inclined backwards, more like the 

 epidermis than the texture of the shell ; whorls four, 

 the upper ones flattened, the last gloljose ; suture 

 deeply impressed ; aperture sub-circular ; peristome 

 simple, acute, its columellar extremity sub-reflected. 

 Greater diameter, one and a half mill. ; height, one 

 half millimetre. 



The animal is described by Morse as bluish-white, with head, 

 neck, and eye-peduncles mottled liy streaks and dots. 



From Gaspe to the North of Lake Superior, and through New 

 England. 



Helix labyrintliica. 



Fig. 106. 



Shell minute, conic-globose ; whorls six, with conspicuous oblique lines ; lip 

 reflected ; aperture with one or two teeth prolonged within it ; umbilicus minute. 



Helix lahivinlhica, Sat, Journ. Phila. Acad. i. 124 (1817) ; Nich. Encyc. iv. 3cl ed. (1819) ; 

 ert. BiNNEY, 10. — BiNNEY, Bost. Journ. Nat. Hist. iii. 393, pi. 26, fig. 1 (1837) ; Terr 

 Moll. ii. 202, pi. 17, fig. 3. — Gould, Inv. 184, fig. 106 (1841). — Adams, Vermont 

 Moll. 160 (1842). — Ferussac. Tab Syst. 38 ; Hist. pi. 51 , fJ, fig. 1. — Pfeiffek, 

 Symbolic, ii. 31 ; Mon. Hel. Viv. i. 416. —Chemnitz, 2d ed. i. 382, t. 66, figs. 17-20. 

 -Reeve, Con. Icon. 728 (1852).— De Kay, N. Y. Moll. 39, pi. 3, fig. 31 (1843). 

 — Deshayes, in Fer. i. 210. — W. G. Binney, Terr. Moll. iv. 95. — Morse, 

 Amer. Nat. i. 545, figs. 41, 42 (1867). 



