HELIX 1(39 



33. HELIX COLUMBIANA, Lea. 



Plate V. 



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

 bus sex, minutissime striatis ;^pira depressa, apice acumin- 

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



SYNONYMS AND EEFERENCES. 



Helioc- cohimbimm, Lea, Am. Phil. Trans. VI. 89, pi. 23, f. 75. 

 De Kay, Nat. Hist. New YorU, p. 46. 

 Pfeiffek, 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 

 aijgle 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. 43 



