TURNATELLINA. 139 



Section TORNATELLINA a. sir. 



Tornatelliu* in which there is a strong, subhorizontal colu- 

 niellar lamella superposed upon the columellar fold ; palatal 

 teeth or plicae usually in vertical pairs, often standing on a 

 vertical callus, or scattered in two, an upper and lower, series. 

 Type T. bilamellata Anton. 



The columellar lamella is sometimes immersed and visible 

 only in an oblique vieAV in the mouth. 



Two groups of species are placed here, one contains rather 

 large species; the other (group of T. pcrplexa) consists of 

 small fragile forms, which in characters reach out towards 

 LameUina. 



Group of T. bilameUata. 



Four comparatively large forms which have never been 

 directly compared compose this group. Coining from widely 

 separated localities, they will probably prove to be distinct 

 though similar species. The immature stages are unknown. 



1. T. BILAMELLATA (AlltOll). PI. 34, figs. 9, 10. 



Oval, coiioidal, 5 to 6 flat, whorls, the last half the total 

 length, apex acute. Aperture long oval, very narrow, with 

 two lamellae on the columella and two delicate cords on the 

 anterior wall of the aperture. Glossy, transparent, extremely 

 delicate, brownish. Length 21/2, diam. 1% lines (Antan). 



Shell ovate-conic, very thin, striatulate, glossy, pellucid, 

 corneous. Spire conic, the apex acute. Whorls 6 to 7, the last 

 about three-sevenths the total length, rotund at base. Aper- 

 ture elliptical, narrow, obstructed by a moderate, suboblique 

 entering lamella on the parietal wall, a strong transverse 

 columellar fold and two delicate parallel palatal laminae. 

 Peristome acute. Length 5, diam. 3, aperture 2.5 mm. long 

 (F/r.). 



Opana (Rapa or Opara) Island (Anton). Juan Fernandez 

 (Pfr. ; Challenger Exped.). 



Strobilus bilamdlutus ANTON, Verzeichniss etc., l-s39. p. 

 46, no. 1694. Tornatellina clama BECK, Index Moll., 1837, 

 p. 80, teste Anton. PFR., Symbolae ad Hist. Hel., ii, p. 55.- 



