322 GASTROPODA. [Pectinibranchia. 



Hab. Auckland Harbour, among shell-sand (Cheeseman) : AYka- 



-M. ^._i- .... i , i . . i t 



spiral sculpture, not shining. Sculpture consisting of rather distant, 

 oblique, thick, and denticulate axial ribs, continuous over the whorls 

 and extending over the base, angularly produced above, 13 to 16 

 on the last whorl ; interstices with 6 to 8 rounded and prominent 

 spiral ribs, with fine spiral striae between them ; base with a distinct 

 spiral keel. Colour white. Spire elevated conic, about five times 

 the height of the aperture ; outlines straight. Protoconch of 2 smooth 

 and strongly convex whorls ; apex sharply pointed. Whorls 10 to 11, 

 regularly increasing, convex ; base slightly concave. Suture very 

 deep, the costse passing angularly over it. Aperture almost circular, 

 oblique. Peristome continuous. The outer lip outside varicose and 

 denticulate. Basal lip slightly expanded below the pillar. Colu- 

 mella short, arcuate, rounded. Inner lip not expanded. Operculum 

 not known. 



Diameter, 8 mm. ; height, 24 mm. (type). Angle of spire, 28. 



Animal unknown. 



Type in the K.K. Hofmuseum, Vienna. 



Hab. Ahipara Beach ; Bay of Islands ; Whangarei Heads (C. 

 Cooper) ; Auckland Harbour, and dredged near Waiwera (Cheese- 

 man) ; off Great Barrier Island, in 110 fathoms ; Tauranga ; Stewart 

 Island ; Chatham Islands ; Kermadec Islands. 



Fossil. Miocene and Pliocene. 



Sect. 4. ACRILLUS, H. Adams, 1860. 



Acrillus, H. Ad., P.Z.S., 1860, 241. Type : Scalar in acuminate, Sow. 

 Shell moderately thick, turritelliform ; whorls united, with very 

 numerous filiform ribs, last whorl with subcarinated periphery ; lip 

 of aperture thin. 



