HELIX-LUCERNA. 105 



the lower surface; aperture large, trapezoidal, with a compressed 

 acute tooth to the right, and an equal one, flanked by one or several 

 denticles toward the columella ; peristonie flesh-colored, upper margin 

 slightly expanded, lower margin reflexed, adnate over the umbilicus, 

 and to the base for a longer or shorter distance. 

 Alt. 22-24, diam. 50-56 mill. 



Jamaica. 



H. chemnitziana PFR. P. Z. S. 1845, p. 43 ; Conchyl. Cab. p. 299, 

 t. 126, f. 1, 2 ; Monogr. i, p. 301. REEVE, f. 22Q.H.fluctuata C. B. 

 AD. Contrib. to Conch, no. 2, p. 29. 



Separated from H. patina, H. acuta, etc., by the decidedly undu- 

 lating lower part of each whorl. Large specimens are somewhat 

 dilated transversely. 



H. LUCERNA Miiller. PI. 30, figs. 46-49. 



Imperforate, depressed, more or less bluntly carinated, solid, 

 opaque, varying from yellowish to reddish-brown in color ; surface 

 granular all over, slightly shining, spire more or less depressed, 

 obtuse ; apex flattened ; sutures linear ; whorls 5, nearly planulate, 

 slowly widening, the last more or less carinated ; aperture transverse, 

 peristome white or brown, upper margin scarcely expanded, basal 

 margin reflexed, thickened, bearing two strong compressed subequal 

 teeth inside, near together, their positions marked behind the peri- 

 stome by large pits. Alt. 16, diam. 32 ; alt. 18, diam. 38 mill. 



Jamaica. 



H. lucerna MULL. Hist. Verm, ii, p. 13. FER. Hist. t. 56 B, f. 

 l_7._p FR Monogr. i, p. 315 ; Conchyl. Cab. p. 154, t. 20, f. 8, 9. 

 REEVE, f. 229. H. fuscolabris AD. Contrib. to Conch, no. 7, p. 120. 

 -PFR. Monogr. iii, p. 258 ; Conchyl. Cab. p. 466, t. 156, f. 24, 25. 

 H. julia FER. Prodr. p. 35 ; Hist. t. 56 B, f. 1. PFR. Monogr. v, 

 p. 315. 



This species is more nearly allied to the small blunt-keeled, 

 bidentate variety of H. acuta than to anything else; It may be 

 separated from all forms of H. acuta by the flatter base, more com- 

 pressed aperture, larger teeth, and especially the decidedly deeper, 

 larger constriction or scrobiculation behind the peristome. 



Var. JULIA Ferussac. PL 34, figs. 5, 6. 



Periphery rounded or very bluntly angled, encircled by a light 

 band ; spire elevated ; parietal callus strong ; basal teeth strong, 

 compressed, near together. Alt. 19, diam. 33 mill. Often smaller. 



