HELIX PLAGIOPTYCHA. 15 



less strongly rib-striate ; spire low conic, apex subobtuse, smooth, 

 shining, not darker than the remainder of the shell in color ; sutures 

 moderately impressed ; whorls 4*, moderately convex, the last 

 rounded or very obtusely subangular at the periphery, suddenly and 

 rather deeply deflexed anteriorly ; aperture quite oblique, lunate- 

 elliptical, peristorne white, simple above, reflexed beneath and thick- 

 ened within by a more or less developed elongated callous tubercle ; 

 columella reflexed partly over and nearly covering the narrow um- 

 bilicus. Alt. 7, diam. 10 mill ; alt. 8, diam. 13 mill. 



Hayti. 



H. indistincta FEE., prodr. 82 ; Hist, t. 38, f. 1. FFR.,Symbolce, 

 ii, p. 30; Monogr. i, p. 194; Conchyl. Cab. p. 153, t. 93, f. 5, 6. 

 REEVE, f. 770. CROSSE & FISCHER, Moll. Mex. et VAmer. cent., p. 

 299. JET. discttltts DESII. in FER., Hist., i, p. 95, t. 89, f. 6. PFR. 

 Malak. Bl 1858, p. 150 ; and Monogr. iii, p. 243. 



The internal callus or tubercle of the basal lip is not removed 

 from the edge of the aperture, as it is in many of the species ; nor 

 is it so much so as fig. 22 of the plate seems to indicate. Crosse and 

 Fischer are doubtless correct in discrediting the habitat " Mexico" 

 given by Pfeiffer. The following form is almost abnormally de- 

 pressed, but does not seem distinct. 



VAR. DISCULUS Deshayes. PL 12, figs. 41-43. 



Orbiculate-conoid, depressed, spire very flat ; whorls 5, wide, 

 finely and regularly striate, the last broad, perforate beneath, con- 

 vex, rather depressed ; aperture ovate-lunar, dilated, margins white, 

 reflexed ; peristome dilated and reflexed over the umbilicus, with a 

 submarginal tooth below. Alt. 6, diam. 15 mill. (Desk?) 



Hayti. 



Var. CHROMOCHILA Pilsbry. PL 19, fig. 30. 



Similar to the type, but with reddish apex and reddish-brown 

 peristome, more broadly expanded than in typical H. indistincta. 



Hayti. 



H. STRUMOSA Pfeiffer. PL 11, figs. 27-29. 



Umbilicate, depressed, thin, obliquely costulate, diaphanous, 

 scarcely shining, flesh-colored rufous, ornamented with a pale fascia 

 bordered above and below with reddish ; spire scarcely elevated, 

 rather obtuse; sutures profound; whorls 41-, slightly convex, sensi- 

 bly increasing, the last subangular above, deflexed anteriorly, behind 

 the aperture gibbous and then constricted, base convex ; umbilicus 



