Vexillum.} GASTROPODA. 3('3 



bb. Suture not margined. 



c. With distinct spiral lirae ; dimensions 4 mm. by 



8 mm. . . . . . . . . . . rubiginosum. 



cc. With obsolete spiral lirte ; dimensions 6 mm. by 



14 mm. . . . . . . planatiim. 



1. Vexillum rnarginatum, Button, 1885. Plate 18, fig. 4. 



Turricula nmrginuin. Hutton, T.N.Z.I.. xvii, 1884 (1885), 315, pi. 18, f. 4; 

 Plioc. M., 47. Vvlpecula (Pusia) biconica, M. & S., T.N.Z.I., xxxviii, 

 1905 (1906), 289, pi. 23, f. 22. 



Shell very small, biconical, imperforate, a row of nodules on the 

 lower whorls, suture margined, aperture narrow, with 4 columellar 

 plaits. Sculpture : On the third to fifth whorls there are oblique 

 axial costse, produced into nodules on the angle of the whorls, below 

 the sutuie a broad rim, under the nodules of the last whorl 2 fine 

 spiral threads and several more towards the base. Colour white, with 

 fulvous on the nodules of the first half of the last whorl, continued 

 in broad zigzag lines down to the base on the second half. Spire 

 conoidal, of nearly the same height as the aperture ; outlines straight. 

 Protoconch of li whorls, papillate, smooth, glossy ; nucleus slightly 

 excentric, broadly convex. Whorls 5, rather rapidly increasing, 

 shouldered with about 14 short nodulous ribs, disappearing shortly 

 before reaching the outer lip ; base distinctly contracted. Suture 

 distinct, slightly impressed, broadly margined below. Aperture 

 somewhat oblique, narrow, with subparallel sides, slightly channelled 

 above, produced at the base into a distinct short open and recurved 

 canal, not notched at the base. Outer lip thin and sharp, subangled 

 above, contracted below. Columella subvertical, with 4 plaits, the 

 first and second nearly horizontal, the others oblique, the basal plait 

 very small. Inner lip narrow, forming a, white-enamel layer on the 

 concave parietal wall. 



Diameter, 2-8 mm. ; height, 5 mm. 



Animal unknown. 



Type, from the Pliocene, in the Canterbury Museum, Christ-church. 



Hob. Off Great Barrier Island, in 110 fathoms; off Cuvier 

 Island, in 37 fathoms (Captain Bollons) ; 21| miles north-east of 

 Wreck Reef, Stewart Island, in 50-54 fathoms (E. R. Waite) ; Port 

 Pegasus, Stewart Island, in 18 fathoms (Captain Bollons) ; Snares, 

 in 50 fathoms (Captain Bollons). 



Remarks. This species is exceedingly variable in the develop- 

 ment of the sculpture ; it is often very prominent and bold, but 

 may become rather inconspicuous. The nodulous sculpture and the 

 zigzag colour-markings are characteristic. The outer lip is some- 

 times very much contracted at the base; the canal, therefore, very 

 well marked. 



Fossil in the Pliocene of Wanganui. 



