382 Transactions. 



are just as constantly colourless. Scissurella rosea, Hedley, 

 which Hedley surmised Smith might have confused with 

 /. lytteltonensis, Smith, does not occur in Lyttelton Harbour, 

 where the latter is common, and whence it was described. 

 Hedley further writes, " From the shell-characters of Incisura 



1 deduce it to be, if not sessile, yet of sluggish habits." 



This species lives on a species of Cystophora, and is certainlv 

 neither sessile nor sluggish. Three specimens I had under 

 observation moved about very rapidly, being as active as any 

 mollusc I have noted. 



Photinula decepta, n. sp. 



Shell small, globosely conoidal, imperforate, thin, fragile, 

 whorls 5, spire very short, last whorl very large, rapidly 

 descending, apparently smooth. Sculpture : Very finely spirally 

 striated, 30 striations being counted on the penultimate whorl, 

 obscured on last whorl by growth-lines. Colour variable ; 

 typical ; the two apical ' whorls white or pinkish -white ; on 

 the third whorl 2 purplish bands equidistant from the sutures 

 arise ; the fourth whorl is wholly purplish-black, as is the last 

 whorl. In some shells these bands persist on to the last 



2 whorls, additional bands arising so that on the last whorl 

 5 distinct bands can be counted ; rarely additional minute 

 bands can be seen between these principal bands. In some 

 cases the purple on the last whorl breaks up into irregular 

 dashes. 



The Shag Point shells are mostly light-coloured : some 

 have almost a white ground-colour, with 5 separate distant 

 bands ; others have a pinkish ground-colour, with darker mark- 

 ings between the principal bands ; whilst in some the bands 

 on the last whorl are broken up into dots. Sutures distinctly 

 marked. Columella subvertical, semicurved, expanding as a 

 callus over the umbilicus. Aperture large, round, outer lip 

 thin, edged with a thin band of white, inside iridescent. 



Altitude, 13 mm. ; diameter, 12 mm. Altitude, 11 mm. ; 

 diameter, 11 mm. 



Type to be presented to the Canterbury Museum, Christ- 

 church. 



Hob. — Sandfly Bay, Otago Peninsula (type) ; near Cape 

 Saunders, Otago Peninsula (syntype); Shag Point, Otago 

 (syntype). 



Cyclostrema corulum (Hutton). 



Scalaria corulum, Hutton, Trans. N.Z. Inst., vol. xvii, p. 322, 

 1884 (1885) ; Pliocene Mollusc;) of N.Z., in Macleay Mem. 



