HELIX. 047 



f. Aperture having one or more teeth or folds. 



73. HELIX INTERNA, SAY. 

 PLATE XXX. FIGURE 4. 



H. testa convexo-depressa, imperforata, rufa ; anfractibus 

 octo, valde striatis, striis eminentibus, crebris, obliquis ; aper- 

 tura transversal!, angusta ; labro simplici, acuto, intus incras- 

 sato et bidentato ; dentibus albis, laminatis ; basi Isevigato ; 

 regione umbilicali impressa. 



SYNONYMS AND REFERENCES. 



Ilclix inter?ia, SAY, Journ. Acad. II. 155. 



KIRTLAND, Ohio Report, 173. 



BINNEY, Boston Journ. Nat. Hist. III. 405, pi. 21, f. 1. 



DE KAY, Nat. Hist. New York, 46. 



CHEMNITZ, 2d ed. tab. 101, f. 1 -4. 



PFEIFFER, Monog. Helic. Viv. I. 183. 

 Helix pomum Adami, DOUGHTY'S Cab. III. 35. 



DESCRIPTION. 



ANIMAL. Head, neck, and tentacles bluish-black, or 

 slate-color, margin and posterior part of foot -white. 

 Superior tentacles very long, inferior very short ; body 

 narrow and delicate, in length not much exceeding the 

 diameter of the shell. 



SHELL depressed, slightly convex ; epidermis reddish- 

 brown, shining ; whorls eight, with regular, equidistant, 

 elevated, oblique, rounded ribs, separated by distinct 

 grooves ; suture deeply impressed ; aperture flattened, 

 transverse, narrow ; lip thin, acute, thickened internally ; 

 within the aperture, on the outer lip, somewhat distant 

 from the margin, are two prominent, sub-lamelliform, 



