618 STUDIES ON AUSTRALIAN MOLLUSCA, 



order the gemmules are set in perpendicular rows. On the ante- 

 penultimate the median gemmules shrink in size, and a few 

 whorls higher up the median row pinches out. First whorl 

 dome-shaped; secondMnflated, with two small, sharp, plain spiral 

 keels; on the third the keels commence to resolve into gemmules, 

 after which the adult sculpture is assumed. Aperture rounded, 

 closed on the right by a spur crossing the pillar lip; anal notch 

 a deep subcircular orifice. Canal extremely short, recurved. 

 Length 4 "2; breadth 1-5 mm. 



In colour and contour this resembles T. ohesula, Jousseaume, 

 from which the protoconch and anal notch immediately separate it. 



Triphora kesteveni, n.sp. 

 (Plate xxxiii., fig. 45.) 



Shell acicular. Colour pale pink. Whorls tw^elve. Sculpture: 

 on the last whorl four, on the others three, smooth spiral ribs, the 

 uppermost the largest; interstices punctate. Length 6-5 mm. 



Hah. — Ladies Hall Beach, South Head, Sydney; one specimen 

 (H. L Kesteven). 



X y p e. — To be presented to the Australian Museum. 



This species so differs in form and sculpture from others known 

 from this coast that I have ventured to describe it from a single 

 worn and decollate example. 



EXPLANATION OF PLATES. 

 Plate xxix. 



Figs. 1, 2, 3. — Exterior and hinge of Mactra ahhreviata, Lanik. , var. 



Figs. 4, 5. — Adult, magnified sculpture and larval shell of Purpura pseud- 

 amygdala, Hedley. 



Fig. 6.—Assiminea pagodel/a, Hedley. 



Fig. 7. — Cacum lilianum, Hedley. 



Figs. 8,9. — 6'y^inr^?'o6u^/a^/?sc/ifri, Adams and Angas, viewed from above and 

 from the side. 



Figs. 10, 11, 12. — Various aspects of Endodonta otwayensis, Petterd. 



