HELIX-LABYRINTHUS. 165 



below the periphery ; surface obliquely finely striated and very 

 minutely granulated, slightly shining ; apical whorl flat, polished, 

 whitish ; sutures linear, not impressed ; whorls 5, flat, slowly widen- 

 ing, the last acutely keeled, abruptly deflexed anteriorly, concave 

 and constricted behind the peristome near the umbilicus, and with 

 a pit marking the place of the outer basal tooth behind the lip ; 

 aperture nearly horizontal, rhomboidal, brown inside showing the 

 bands ; peristome reflexed, white or light brown, continued across 

 the parietal wall as an elevated callous ; basal margin two toothed ; 

 the outer tooth is an entering angular fold which terminates at the 

 edge of the peristome in an acute slender curved projecting hook ; 

 inner tooth small, fold-like ; parietal lamella elevated, not reaching 

 the elevated parietal callous ; umbilicus open, rather broad (4 to 5 

 mill.). 



Alt. 11, diam. maj. 29, min. 25 mill. 



Alt. 11, diam. maj. 27, min. 23 mill. 



Panama. 



Caroeolla uncigera PETIT, Guerin's Mag. de Zool., 1838, t. 113. 

 PFEIFFER, Conchyl. Cab., p. 206, t. 104, f. 8-10 ; Mon. Hel. Viv., i, 

 p. 398. REEVE, Conch. Icon., f. 552. DOHRN, Jahrb. d. Mai. 

 Gesell., ii, 1875, p. 297. 



Perfectly distinct in the acute hook-like outer tooth of the basal 



HP. 



VARIETY. Spire more elevated ; larger than the type ; granula- 

 tion more pronounced on the last whorl above and below ; color 

 clear chestnut brown, without bands, darker behind the white lip. 

 Aperture and teeth typical but the basal margin more deeply arcuate. 

 Alt. 13, diam. maj. 38, min. 35 mill ; diam. aperture 19 mill. Dohrn. 



H. TRIPLICATA Martens. PI. 41, figs. 17, 18, 19. 



Umbilicated, depressed, obtusely angled at the periphery, rather 

 strong and solid but not thick, yellowish-chestnut-colored ; surface 

 lightly striate, sometimes subplicatulate beneath the sutures, very 

 densely microscopically granulated all over ; spire low, convex or 

 slightly conical ; apex planulate, whitish, polished ; sutures not 

 impressed or but very slightly so ; whorls 5, nearly flat, the last 

 subarigular at the circumference, deeply, abruptly deflexed anteriorly, 

 constricted behind the basal lip and 2-grooved there ; base convex, 

 generally lightly plicate around the umbilicus ; aperture subhorizon- 

 tal, oblong-ear-shaped, deep purplish-brown inside ; peristome flesh- 



