332 GASTROPODA. [Pectinibranchia. 



Remarks. The type, of the Chevert Expedition, is from Darnley 

 Island ; it is adorned with an additional narrow band upon the base, 

 which is wanting in my only specimen. 



6. Pyramidella tenuiplicata, Murdoch and Suter, 1906. Plate 16, 

 fig. 12. 



Pyramidella (Syrnola) tenuiplicata, M. & S., T.N.Z.I., xxxviii, 1905 (1906), 

 296, pi. 25, f. 39. 



Shell minute, subulate, irnperforate, white and porcellanous, with 

 a high spire and pointed apex. Sculpture consists of some microscopic 

 irregular spiral striae. Colour white, shining. Spire slender and 

 tapering, much higher than the aperture. Protoconch heterostrophe, 

 of 2 smooth whorls, the nucleus lateral. Whorls 7, regularly increas- 

 ing, lightly convex, body-whorl with a minute thread-like carina 

 only noticeable in front of the aperture ; base rounded. Suture 

 channelled. Aperture ovato-quadrate, vertical, angled above, slightly 

 effuse below. Outer lip sharp, curved. Basal lip sharp, produced, 

 and somewhat flattened. Columella vertical, with an indistinct plait. 

 Inner lip narrowly spread over the pillar, and lightly over the parietal 

 wall. Operculum unknown. 



Diameter. 0-82 mm. ; height, 3-21 mm. 



Animal unknown. 



Type in the Dominion Museum, Wellington. 



Hob. Off Great Barrier Island, in 110 fathoms. One specimen. 



Genus 2. TURBONILLA, Bisso, 1826. 



Turbonilla, Risso, Hist. Eur. Merid., Moll., iv, 1826, 224. Type : T. typica, 

 D. &. B. == T. plicatula, Risso ; not Turbo plicatulus, Brocchi, 1814. 

 Chemnitzia, d'Orbigny, 1839, not 1850. Pyrgiscus, Philippi, 1841. 

 Ortliostelis, Aradas. Euturbonilla, Semper, 1861. 



Animal with wide tentacles, mentum elongated, flattened, usually 

 bilobed in front ; foot large, anteriorly auriculated. 



Shell slender, elongated, many-whorled, generally costulate, apex 

 sinistral ; columella vertical, not plicate. Operculum horny, subspiral, 

 the columellar margin entire, face with a spiral groove. 



Distribution. Universal. 



Fossil. Tertiary. 



The species are very small and graceful ; the shells usually white. 



1. Turbonilla zealandica, Hutton, 1873. Plate 16, fig. 13. 



Chemnitzia zealandica, Hutt., C.M.M., 22 ; J. de Conch., 1878, 24 ; JI.N.Z.M., 

 72. Turbonilla neozelanica, Hutt,, P.L.S. N.S.W., ix, 934 ; Plioc. M., 

 56, pi. 7, f. 44. 



Shell small, subulate, white and shining, semitransparent, im- 

 perforate. Sculpture consisting of numerous, close, flattish, and 

 somewhat flexuous axial riblets, with narrower interspaces ; the riblets 



