174 HELIX-LABYRINTHUS. 



H. ellipsostoma PFR., Proc. Zool. Soc. Lond. 1854, p. 288 ; Mono- 

 graphia Hel. Viv., iv, p. 3()7. REEVE, Conch. Icon., f. 1389. 



Evidently closely allied to H. yatesi. I have not seen the 

 species. 



H. LEPRIEURII Petit. PL 40, figs. 96-99. 



Umbilicated, depressed, obtusely angular at the periphery, rather 

 solid ; color deep brown, lighter at the keel ; surface delicately 

 striate, under a lens seen to be minutely granulate all over ; spire 

 low, obtuse at apex ; sutures lightly impressed ; whorls 4J to 5, 

 slightly convex, slowly widening, the last obtusely or obviously 

 angular at the periphery, suddenly, deeply deflexed in front, convex 

 beneath, constricted and deeply 2-pitted behind the basal lip ; aper- 

 ture nearly horizontal, ear-shaped ; nearly closed by the large teeth ; 

 peristome expanded, reflexed, white or fleshy-brown in color, con- 

 tinuous across the parietal Avail as an elevated callous-plate, from 

 the middle of which arises a sinuous, deeply entering erect parietal 

 lamina; basal margin sinuous, two-toothed, the outer tooth bifid, 

 situated within the ed ;-e of the aperture, the inner tooth on the edge, 

 a very heavy callous deeply entering fold ; umbilicus deep, rather 

 narrow. 



Alt. 9*, diam. maj. 19, rain. 17 mill. (Specimen.) 

 Alt. 10, diam. maj. 18J, rain. 161 mill. (Specimen.) 

 Alt. 11 5, diam. maj. 24, rain. 21 mill. (Pfeiffer.) 



French Guiana. 



H. Le Prieurii PETIT in Revue Zoologique, 1840, p. 74 ; H. le- 

 prieurii PETIT, Mag. de Zool., 1841, t. 32. PFEIFFER, Monographia 

 Hel. Viv., i, 400. REEVE, Conch. Icon., f. 560. H. auriculina 

 PETIT, Rev. Zool. 1840, p. 74, and Mag. de Zool., t. 33. PFEIFFER 

 in Conchyl. Cab., p. 207, t. 105, f. 5-7 ; Monographia Hel. Viv., i, 

 p. 400. REEVE, Conch. Icon., f. 562. 



This species is quite distinct in the developement of teeth. The 

 parietal lamina arises from the parietal wall of the peristome, is long 

 and sinuous; the inner basal tooth is very heavy and prominent. 

 The form called auriculina is more globose and less strongly 

 carinated than typical leprieurii. 



H. DUNKERI Pfeiffer. PL 41, figs. 1, 2, 3, 4. 



Umbilicated, depressed, flattened, acutely keeled, quite thin, 

 brownish horn-color, with a peripheral and a subsutural dark chest- 



