284 Transactions. 



16. Pleurotoma (Hemipleurotoma) nodilirata, nom. mut. Plate 



XXII, figs. 10, 11. 



Pleurotoma tuberculata, T. W. Kirk, Trans. N.Z. Inst., vol. xiv, 

 p. 409, 1882 (not of Gray) ; Hutton, Plioc. Moll. N.Z., in 

 Macleay Mem. Vol., p. 50," pi. vi, fig. 29, 1893 (not of Gray). 



The species, described from a Pliocene specimen, requires a 

 new name, that proposed by Kirk being preoccupied by Gray, 

 and the above is offered. Kirk's description being rather scanty, 

 the following complement is now given, compiled from recent 

 specimens. 



Shell fusiform, biconical, with nodulous keeled whorls, pyri- 

 form aperture, and short open canal. Sculpture : Last whorl 

 with about sixteen tubercles on the keel, and a similar number 

 of spiral cords below, the upper six of which are widely spaced 

 and narrower than the interspaces ; those upon the base and 

 canal are smaller and crowded. Above the aperture is a single 

 chord, which persists on the whorl above, but disappears in the 

 suture of the next whorl. Monilo-spiral threadlets adorn the 

 sinus area, also the tubercles. All the upper whorls, except the 

 protoconch, have tubercles on the keel, and there is a row of 

 small nodules below the suture. The axial sculpture consists of 

 fine rather irregular incremental lines, which, however, become 

 more prominent on the lower whorls, connecting the small 

 tubercles below the suture with the larger ones on the keel. 

 Colour light-cream. Spire conical, about as long as the body- 

 whorl. Protoconch consisting of one and a half to two whorls, 

 nucleus obtuse, smooth, polished, the succeeding volution with 

 minute spiral striae. Whorls 7, slowly and regularly increasing, 

 with a strong carina below the middle, excavated above and 

 straight below the keel ; base convex, ending in a slightly twisted 

 rather short beak. Suture deep and margined below with a row 

 of small elongate gemmules. Aperture pyriform, rather narrow, 

 angular above, terminating in a short open truncated canal, 

 which has a slight turn to the right. Outer lip sharp, strongly 

 angled, and with a well-pronounced rounded sinus at the keel, 

 contracted towards the base. Inner lip forming a very thin 

 obliquely finely striated layer on the body and columella, the 

 latter nearly straight, slightly sinuated and pointed below. 

 Altitude, 19 - 6 mm. ; diameter, 8"5 mm. ; angle of spire, 42°. 



Type of P. tuberculata, Kirk, in the Colonial Museum, Wel- 

 lington. 



Obs. No perfect or live specimens were gathered, only a 

 small number of more or less damaged very fragile shells. 



Of this species a smaller form occurs, but similarly sculptured, 



