180 



LAND AND FRESH- WATER SHELLS OF N. A. [PART T. 



Helix pandorcB. 



pressed ; aperture subcircular ; peristome narrowly reflected, white, its 

 ends approaching ; throat bluish ; columella thickened, 

 Fig. 315. rounded. Greater diam. 17, lesser IG ; height 14 mill. 



Helix pandorce, Forbes, Proc. Zool. Soc. 1850, 55, pi. ix, 

 f. 3, a, b. — Reeve, Con. Icon. 671. — Pfeiffer, Mon. 

 Hel. Viv. Ill, 127 ; in Chemnitz, ed. 2, III, 467, pi. 

 clvi, f. 17, 18 (1S53).— Gould, Terr. Moll. Ill, 15.— 

 W, G. BixNEY, Terr. Moll. IV, 18, pi. Ixxvi, f. 8. 

 Helix dama^cenus, Gould, Proc. Bost. Soc. Nat. Hist. Oct. 

 1856, VI, 11. 

 PuJij^iiita iiitiwo'ce, Tkyox, Am. Journ. Conch. II, 320, pi. vi, f. 8 (1866)^ 



Margarita Bay, Lower California. 



The specimen figured wants the characteristic revolving lines 

 and blotches. 



Helix levis, Pfeiffer. — Shell perforate, globose, thin, smooth, ob- 

 liquely striate, obsoletely granulated, white, varied with regular series of 

 spots or bauds of horn-color ; spire short, rather acute ; whirls five, scarcely 

 convex, the last inflated ; aperture roundly lunar, within 

 somewhat yellow ; peristome acute, somev»hat thickened 

 within, its columellar portion dilated above, arched and 

 reflected, almost covering the perforation. Greater diam. 

 16, lesser 14 ; height 13 mill. 



Var. S. The columellar portion of the peristome with 

 a single obtuse, tooth-like callosity. 



Helix levis, Pfeiffer, Mon. Hel. Viv. I, 154 ; III, 128 ; 

 Zeitschr. f. Mai. 1845, 152 ; in Chemnitz, ed. 2, I, 

 249, pi. xxxvi, f. 16, 17 (1846).— Reeve, Con. Icon. 1214.— W. G. 

 Binney, Terr. Moll. IV, 18. pi. Ixxvi, f. 10. 

 Pohjmita levis, Tkyon, Am. Journ. Conch. II, 320, pi. v, f. 21 ? (1866). 



Columbia River. 



Dr. Newcomb doubts its being a Californian or Oregon species. 



Fig. 316. 



Eelix levis, var. 



Subgenus TACHEA, Leach. 



Shell imperforate, globose or subdepressed, white or yellow, 

 ornamented with distinct bands ; whirls 5, the last convex, tumid, 

 descending at the aperture ; aperture broadly lunate, obsoletely 

 angular; peristome thickened, reflexed, its columellar margin 

 constricted, callous. 



Animal (of K horfensis) : head and neck blackish, with a 

 slight tinge of brown ; eye-peduncles smoky ; eyes black ; base 



