120 HELIX-CARACOLUS. 



H. CAROCOLLA Linne. PI. 21, figs. 1, 2, 5, 6, 7 ; pi. 24, fig. 89. 



Imperforate (rarely narrowly perforate), depressed-coDoidal, solid, 

 strong, opaque, lusterless, chestnut-brown, often with a slightly 

 darker zone below the periphery ; irregularly obliquely striate, un- 

 der a strong lens showing minute decussating short wrinkles ; spire 

 conical, obtuse, apex depressed, planulate ; sutures linear ; whorls 6, 

 gradually widening, the last not descending anteriorly, strongly car- 

 inated at the periphery, flattened beneath and indented in the cen- 

 ter around the axis ; aperture very oblique, subtriangular-lunar, 

 bluish or purplish-white within ; peristome white or slightly flesh- 

 tinted, upper and outer margins obtuse, not expanded, basal margin 

 slightly expanded, thickened, dilated over the umbilicus; margins of 

 peristome remote, ends connected by a thin callous. 



Alt. 25-30, diam. 50-60 mill. 



Porto Rico ; Vieque ; Crab Island ; fossil on St. Croix. 



H. carocolla LINN. Syst. Nat. x, p. 769. PFR. Monogr. i, p. 

 20 ; Conchyl. Cab, t. 8, f. 1, 2. FER., Hist., t. 59, f. 3-4. REEVE, 

 Conch. Icon. f. 227. Caracolus caracolla SEMPER, Reisen in Phil- 

 ippinen, Land-mollusken, ii, p. 104, t. 12, f. 13, t. 16, f. 8. 

 (Anatomy). H. tornata BORN, Mus. test. Cses. t. 14, f. 9. 10. 

 Carocolla albilabris LAM. An. s. Vert, ii, p. 96. Caracolus oculatus 

 MONTF. Conch. Syst. ii, p. 139. 



The outlines of the spire are straight or slightly convex, never 

 very noticeably concave. The whorls increase more gradually than 

 in H. insititia Shutt. 



H. EXCELLENS Pfeiffer. PI. 25, figs. 51-53. 



Imperforate, depressed, concave-conoidal, solid, slightly shining, 

 deep chestnut-brown, usually tinged with olive on the outer whorls ; 

 surface obliquely striatulate, smoother than in H. carocolla, and 

 generally showing under a strong lens minute decussating scratches ; 

 spire conoidal, with concave lateral outlines; ajex obtuse, subplan- 

 ulate ; sutures linear ; whorls 6, gradually widening, the last depressed, 

 carinated, wider than in H. carocolla, and flatter or subconcave on 

 its upper surface ; shortly deflexed anteriorly ; aperture triangular, 

 very oblique, very broad and low, transverse, livid within ; peristome 

 dark orange-brown or liver-colored, upper margin obtuse, straight; 

 basal margin slightly expanded, thickened, only slightly curved ; 

 parietal callus straight, dark colored. 



Alt. 25-27, diam 58-63 mill. 



HaytL 



