HELIX. 413 



above, but nearly smooth beneath ; the shell has a sharp dividing- 

 line between the npj)er and lower surfaces in all its 

 earlier stages, which disappears only at maturity, 

 forming a circular aperture, slightly modified by 

 the preceding whorl ; lip simple and delicate ; um- 

 bilicus large and deep, exhibiting all the volutions. 

 Greater diameter, twenty-one mill. ; lesser, nineteen 

 mill. ; height, ten millimetres. 



Animal with the head and eye-peduncles of a 

 light slate color, back brown, remainder of the up- 

 per surface brownish-orange ; eyes black ; base of 

 foot drab colored ; collar saffron. Eye-peduncle one ' " ""'" "' 



third of an inch long, Idackish at tip. Foot not much exceeding 

 the diameter of the shell, terminating in a broad, flat, obtuse tip ; 

 a light marginal line runs along the foot from the head to the pos- 

 terior tip. 



Found everywhere in old forests and in moist situations under 

 decaying logs and stumps. In this f^tate it is not often found near 

 the sea-coast. Dr. Yale, however, has observed numerous dead 

 specimens on Martha's Vineyard. Also over the whole of Eastern 

 North America as far north as Labrador. It occurs commonly in 

 the post-pleiocene beds of the Mississippi Valley. 



The shell varies in being more or less depressed, and the wrinkles 

 more or less obvious ; sometimes no bars are observable on the 

 lower surface. 



The animal and its eye-peduncles are proportionally shorter than 

 in our other species. Its habits are gregarious, so that several are 

 usually found in company. 



Helix striatella. 



Fig. 112. 



Shell small, orbicular, depressed, rufous ; whorls six, with prominent lines 

 of growth; aperture declining, rounded; lip simple; base widely and deeply 

 umbilicated. 



Helix striatella, Anthony, Best. Journ. Nat. Hist. iii. 278, pi. 3, fig. 2 (1840). — Binxet, 

 Bost. Journ. iii. 432, pi. 21, fig. 5 (1840) ; Terr. Moll. ii. 217, pi. 30, fig. 2. — Gould, 

 Inv. 178, fig. 112 (1841). — Ad.\ms, Vermont Moll. 162 (1842). — De Kay, N. Y. 

 Moll. 43, pi. 3, fig. 40 (1843). — Chemnitz, 2d ed. ii. 11.5, t. 8.5, figs. 36-38.— 

 Pfeiffer, Mon. Hel. Viv. i. 104. — Eeeve, Con. Icon. 727 (18.53). — W. G. Bin- 

 NEY, Terr. Moll. iv. 99. — Morse, Am. Nat. i. 545, fig. 40 (18G7). 



Helix ruderata, Ad.vms, Sillim. Journ. [1] 40, 408, not Studer. 



