HELIX HEMITROCHUS. 29 



The H. tenuicostata does not seem to present any tangible points 

 of difference from H. troscheli. The original figures are copied on 

 my pi. 32, figs. 53-55. The original description ( translated ) is as 

 follows: 



Shell perforate, depressed-globose, rather solid, obliquely costu- 

 late-striate, white, with many brown bands ; spire elevated, wide- 

 conical ; whorls, 4?, slightly convex, sensibly increasing, the last de- 

 flexed anteriorly, aperture lunate-oval; peristome acute, labiate 

 within, right lip subexpanded, columellar margin reflexed, dilated, 

 appressed, nearly covering the umbilicus. Alt. 8, diam. 13 mill 



Mexico. 



Crosse and Fisher ( loc. supra cit.) discredit the occurrence of the 

 species in Mexico. 



The H. calacala of Weinland seems to be included in the range 

 of variation of the present form. I have examined several hundred 

 specimens and find numerous transition forms. The shell is some- 

 times small, solid, compact, globose, with very round aperture and 

 concave columella ; sometimes large, depressed, conical, with wide 

 aperture and oblique, straight columella. White examples are 

 usually touched with pink on apex and mouth. Although H. 

 troscheli is usually more widely umbilicated than H. gallopavonis, 

 I have seen nearly imperforate examples. Figs. 59-61 of pi. 20, 

 are drawn from specimens named by DR. PFEIFFER. 



VAR. CALACALA Weinland. PI. 12, figs. 38, 39. 



Subimperforate, conoidal, closely costulate-striate, pinkish-white ; 

 spire elevated ; whorls 5J, somewhat convex, the last descending ; 

 aperture diagonal, lunate-circular; peristome labiate within, ex- 

 panded, columellar margin rosy, dilated, reflexed. 



Alt. 13, diam. maj. 1.9, min. 17 mill. ( Weinland.) 



New Providence. 



A variety like calacala in the light color, solidity, and nearly im- 

 perforate base, but with strong, distant costulie on the surface, and 

 attaining only about 15 mill, diam., is before me. 



VAR. BROWNII Pilsbry. PI. 31, fig. 27. 



Depressed, thin, carinated, subimperforate, strongly, densely, cos- 

 tulate ; whorls 4A, the apex slightly prominent ; peristome expanded, 

 color brown above, with a darker supra-peripheral line ; base 

 whitish, Alt. 7-8, diam. 13 mill. 



Cat Island, Bahamas. ( legit DR. J. J. BROWN.) 



