HELIX PLAGIOPTYCHA. 19 



horn colored ? ; spire short, apex obtuse ; whorls 5, rather convex, 

 the last descending at the aperture, obsoletely angular at the periph- 

 ery, base subplanulate ; aperture oblique, lunate-rounded ; peristome 

 with the margins approximating, right margin somewhat expanded, 

 columellar margin much dilated above, reflected, nearly covering 

 the perforation ; basal margin with a lamelliform callus within. 



Alt. 8, diam. maj. 15, min. 13 mill. (Bland.} 



This, in general form is much like H. duclosiana Fer. but the 

 interior projecting tooth is wanting, and the callus on the basal 

 margin is more developed. (Bland.) 



Little Inagua, Bahamas. 



H. sargenti BLD. Ann. Lye. N. H. of N. Y., xi, 1876. p. 79 PFR. 

 Monographia vii, p. 472. 



H. DUCLOSIANA Ferussac. PI. 11, figs. 30-32 ; pi. 31, figs. 1-3. 



Umbilicate, depressed, thin, subtranslucent, very smooth and shin- 

 ing all over, light brownish straw-colored ; surface with minute 

 oblique growth-lines ; spire very low-conical, apex subobtuse ; sutures 

 impressed ; whorls 5, slightly convex, the last depressed, deeply de- 

 flected anteriorly, flattened beneath ; subconstricted and more or less 

 excavated behind the peristome on the base ; umbilicus with a slight- 

 ly marked spiral furroAV within ; aperture truncate-oval, very oblique ; 

 peristome thin, upper margin simple, outer and basal margins ex- 

 panded, the ends converging ; base with a deep-seated, strong, white, 

 triangular tooth within, its position marked outside by a shallow 

 rugose depression. Alt. 8, diam. 18 mill.; alt. 7, diam. 13 mill. 



New Providence, Bahamas. 



H. duclosiana FER., Hist., t. 51A, f. 6. (1832) DESHAYES, in 



FER. Hist., i, p. 207. PFR., Monogr., iii, p. 243. Cox, Austr. Land 



sh., p. 47, t. 11, f. 2. (from Fer.) (H. macrodon MENKE, teste Desh.?) 



-H. salvatoris PFR. Malak. Bl. 1867, p. 127; and Monographia v, 



p. 245. MARTENS, Conch. Mittheil., i, t. 2, f. 1, p. 3. 



This shell is rather large, generally flat, but sometimes small 

 specimens are quite conoidal, narrowly umbilicated and very smooth 

 and shining. I separate the bahamensis of Pfeiffer from duclosiana 

 on account of its more strongly striate, less shining surface. 



Var. SALVATORIS Pfeiffer. PI. 11, figs. 13-15. 



This form may be distinguished by its less tubercular, more elon- 

 gated callus within the base, nearer to the margin than in typical H 



