Murdoch and Suter. — Results of Dredging. 285 



and it seems scarcely worth a varietal name. It is also found in 

 the Wanganui blue clay of Pliocene age. The recent specimens 

 are imperfect in outer lip and spire, but with the aid of fossil 

 individuals the accompanying sketch (fig. 11) is derived. The 

 larger type specimens in the Colonial Museum are from the 

 Petane Pliocene ; in these, as also in the smaller form, the 

 tubercles are less strong and more numerous than in recent 

 examples. 



17. Pleurotoma (Hemipleurotoma) alticincta, n. sp. Plate XXII, 



figs. 12, 13. 



Shell small, turriculate, subcylindrical, with a long spire, 

 deeply sulcate whorls, an oblong aperture which is slightly 

 shorter than the spire, and a short canal. Sculpture : On the 

 upper spire-whorls a few minute spiral striae, the next with four 

 distinct cinguli, on the succeeding a minute fifth spiral arises 

 at the suture, which on the penultimate strengthens and about 

 equals the adjoining revolving ribs ; the cinguli are strong, 

 rounded and adorned with minute spiral threadlets, absent in 

 the grooves ; the latter are deep, somewhat square-cut, and 

 narrower than the ribs ; the last whorl with ten ribs and a 

 number of minute threadlets upon the back of the canal, added 

 to which are the oblique lines of old beaks ; grooves and ribs 

 about equal, but the former sometimes broader as they proceed 

 anteriorly. The longitudinal growth -striae are minute, slightly 

 irregular in strength, and giving in places (usually upon the 

 upper whorls of the spire) a slightly clathrate appearance. 

 Colour : There is only one young specimen that has a somewhat 

 fresh appearance, it is light horn-coloured ; all the others are 

 greyish-white. Spire long, gradate, turriculate, with an obtuse 

 rounded apex. Protoconch of about two convex turns, slop- 

 ing!}- shouldered, with minute spirals the precursors of the 

 adult sculpture ; nucleus central, depressed-globular, smooth. 

 Whorls 7, flattened, strongly shouldered at the suture, first 

 slowly then more rapidly increasing, the last a little longer than 

 the spire. Suture deep, margined above on the lower whorls. 

 Aperture elongate, somewhat narrow, slightly contracted in 

 front and forming a short open canal, which is truncated and 

 slightly sinuate at the base, bent backward and a little to the 

 left. Outer lip slightly thickened, descending with a light 

 downward sweep, crenulate on the margin ; the sinus indis- 

 tinct, situated on the uppermost cingulum. Inner lip forming 

 a broad callus through which on the body the three cinguli 

 appear as folds, with a distinct edge, which is slightly raised, 

 connected above with the outer lip ; columella excavated in 



