84 HELIX-DENTELLARIA. 



cremental wrinkles, and under a lens showing nearly effaced traces 

 of spiral sculpture ; spire low, convex, very obtuse; apex flat; sut- 

 ures linear, or at the last whorl slightly impressed ; whorls 5, nearly 

 flat, gradually increasing, the last usually commencing subcarinate, 

 becoming rounded, somewhat gibbous and a trifle constricted behind 

 the aperture, and slightly deflexed above. Aperture transverse, ir- 

 regularly lunar, very oblique ; peristome white, very thick and 

 heavy, convex, a little expanded, basal margin reflexed, adnate, 

 thickened within and bearing a tooth at the junction of basal and 

 outer lips, its edge slightly irregular; outer margin thick, sometimes 

 bearing a slight lobe or tooth above ; terminations of the peristome 

 joined by a callus ridge, which bears a strong, oval, tubercular tooth 

 or lobe above, connected with the upper termination of the peri- 

 stome. Alt. 12, diam. 20-23 mill. 



Martinique ; Guadeloupe. 



H. obesa BECK, Index Moll. p. 35. PFR. in Conchyl. Cab. t. 62, f. 

 3, 4 ; Monogr. i, p. 307. REEVE, f. 282. H. punctata FER. Hist. t. 

 48, f. 3. (not punctata Born, nor Mull.) 



This shell is allied to H. parilis, but differs in the larger size, colora- 

 tion, and the tooth on the basal lip. From H. dentiens the tooth on 

 the upper parietal wall separates H. obesa. This tooth is often 

 brown, while the remainder of the peristome is white. In the devel- 

 opment of these callosities on the peristome and in the sculpture of 

 the shell, this and the preceding species of Dentellaria approach the 

 Canary Island group Hemicycla (H. malleata Fer. etc). There are 

 also a number of African Maeularice which have considerable re- 

 semblance to Dentellaria as far as the shells are concerned. 



H. DENTIENS Ferussac. PI. 28, figs. 10-15. 



Imperforate, depressed-semiglobose, solid, opaque, dark reddish- 

 chestnut, shining, with delicate incremental marks and generally 

 traces of spiral sculpture visible under a lens ; spire more or less 

 elevated, rounded, obtuse ; apical whorl flat ; suture linear, becoming 

 impressed at the last whorl ; whorls 5, scarcely convex, slowly widen- 

 ing ; body- whorl rounded at the periphery, or commencing angular 

 there, losing the carina toward its latter half; anteriorly deflexed, 

 with a prominent oblique gibbosity and then a constriction toward 

 the aperture ; aperture subhorizontal, small, truncate-oblong ; peri- 

 stome purplish-brown, thick, heavy, convex, upper and outer margins 

 not expanded, basal margin reflexed, adnate to the base, bearing 



