721 



STUDIES ON AUSTRALIAN MOLLUSCA. 



Part III. 



(Continued from p. 513. ) 



By C. Hedley, F.L.S. 



(Plate xlviii.) 



Mathilda rosae, n.sp. 



(Plate xlviii., figs. 13, 14.) 



Shell tall, turreted, upper whorls subulate, final whorls spread; 

 perforate only for the last two whorls. No perfect shell has come 

 under my notice. A survey of a series of imperfect shells of 

 different ages suggests that fourteen or fifteen whorls are the 

 proper complement. The youngest of the series has a hetero- 

 strophe apex; as growth proceeds the upper whorls are lost. Colour 

 white (bleached 1 ?). Suture channelled. Sculpture : longitudinal 

 sculpture is missing; on the last whorl are six sharp, elevated, 

 equidistant keels, their own breadth apart, the anterior keel the 

 largest, the posterior least, on preceding whorls are fewer keels. 

 Base smooth and flattened. Aperture very oblique, nearly tri- 

 angular, beaked on the exterior angle by the extension of the 

 peripheral rib, patulous at the junction of base and pillar. The 

 specimen drawn, of which only seven whorls remain, is 5 mm. in 

 length and 2-8 in breadth. 



Ilab. — Balmoral Beach, Middle Harbour, near Sydney; several 

 dead shells picked out of shell sand by the late Mrs. C. T. Starkey. 



The perforation, want of longitudinal sculpture and enlarge- 

 ment of the peripheral rib, ampl} 7 distinguish this species from its 

 congeners. It probably lives in deep water. 



The species is named in memory of my late friend Mrs. C. T. 

 Starkey, who made a large collection of the minute marine shells 



