HELIX. 169 



32. HELIX COLTJMBIANA, LEA. 

 PLATE V. 



H. testa orbiculato-depressa, perforata, cornea ; anfracti- 

 bus sex, minutissime striatis ; spira depressa, apice acumin- 

 ato ; apertura transversa ; labro reflexo-; basi sub-depressa. 



SYNONYMS AND REFERENCES. 



Helix columbiana, LEA, Am. Phil. Trans. VI. 89, pi. 23, f. 75. 

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

 PFEIFFER, Monog. Helic. Viv. I. 343. 



DESCRIPTION. 



ANIMAL not hitherto observed. 



SHELL sub-depressed; epidermis rather smooth, cor- 

 neous ; whorls six, slightly rounded, very minutely stri- 

 ated, rising gradually, but regularly, one above the 

 other to an acuminated apex; suture strongly im- 

 pressed ; aperture transverse, a little contracted and 

 thickened, by a testaceous deposit or border, at the 

 angle of reflection of the lip ; lip -whitish, or brownish 

 white, reflected but not flattened, rather grooved on its 

 face, the basal margin horizontal in its direction, with a 

 slight thickening or projection before it reaches the base 

 of the shell; umbilicus open, partially hidden by the 

 reflected lip at its junction with the base ; base a little 

 flattened. 



Transverse diameter about five-eighths of an inch. 



GEOGRAPHICAL DISTRIBUTION. Found near Fort 



.' VOL. ii. 22 



