HELIX-LAB YRINTHUS. 169 



Carocolla quadridentata Brod. Proc. Zool. Soc. Lond., 1832, p. 30. 

 H. quadridentata PFEIFFER, in Kiister's Conchyl. Cab., p. 271, t. 

 123, f. 9-11 ; Monographia Hel. Viv., i, p. 399. REEVE, Conch. 

 Icon., f. 557. Not, in my opinion, H. quadridentata HIDALGO, Viage 

 al Pacifico, Mol. p. 16, t. 1, f. 8, 9 (see under H. manueli Higgins). 



I am not satisfied that any of the several trays before me marked 

 " quadridentata " are really that species. I have therefore given a 

 translation of Pfeiffer's description, which agrees with Broderip's 

 short diagnosis. It seems to differ from leucodon in having the par- 

 ietal tooth not connected with the callous joining the terminations of 

 peristome, in this respect evidently nearing H. tamsiana Dkr., but 

 differing from this form again, in having a heavier shell, with stronger 

 lip development (teste Reeve). 



H. TAMSIAXA Dunker. PI. 41, figs. 5, 6, 7, 8. 



Umbilicate, depressed-conoidal, thin, light brown, acutely car- 

 inated ; surface somewhat shining, lightly obliquely striate, covered 

 with minute prickly granules; spire conoidal, apex blunt, apical 

 whorl prominent, whitish, nearly smooth ; suture very superficial ; 

 whorls 5, scarcely convex, slowly widening, the last acutely carinated 

 at periphery, very abruptly angularly and strongly constricted be- 

 hind the aperture and suddenly deflexed ; aperture nearly horizontal, 

 ovate-ear-shaped ; peristome expanded, subreflexed, white, thin, its 

 terminations joined across the parietal wall by a thin straight 

 elevated white lamina ; superior margin of outer lip toothless or with 

 a small denticle in the middle basal lip with two teeth rather near 

 to each other, the outer one compressed, a trifle entering, its 

 position marked behind the peristome by a slight pit; the inner 

 tooth tubercular, its position not indicated by a pit behind the lip ; 

 parietal wall armed with a small compressed oblique white lamellar 

 tooth, directed toward a point on the outer lip above the outer basal 

 tooth. 



Alt. 84, diam. maj. 16, min. 15 mill. 



Alt. 7$, diam. rnaj. 15, min. 14 mill. 



Vicinity of Porto Cabello, Venezuela. 



H. tamsiana DKR. in Zeitschr. f. Malak. 1847, p. 81. PFEIFFER, 

 in Conchyl. Cab., p. 466, t. 156, f. 28, 29; Monog. Hel. Viv., i, p. 

 399. REEVE, Conch. Icon., f. 556. MARTENS, Binnen-Moll. 

 Venezuelas, p. 13. 



