BY C. HEDLEY. 603 



Serpulorhis, Sassi (1827), is, however, of later date thsiU Serpulus 

 proposed by Moiitfort (Conch. Syst. ii., 1810, p. 27). 



The species under discussion has been entered in local lists 

 under the name of Thylacodes decussaUis, Gmel. (Angas, Proc. 

 Zool. Soc. 1867, p. 211). 



ASSIMINEA PACiODELLA, n.sp. 



(Plate xxix., fig. 6.) 



Shell perforate, ovate, rather solid. Colour reddish-brown. 

 Whorls four, rapidly increasing, wound obliquely, spire pagodi- 

 f orm. The straight slope of the upper part of the last two whorls 

 ends in a sharp projecting rim, beneath which the perpendicular 

 periphery bears several small spiral threads diminishing succes- 

 sively. Base rounded. Umbilicus a narrow oblique perforation. 

 Aperture ovate, oblique, columella expanded and reflected, outer 

 lip simple. Height 1*96 mm., breadth 1*2 mm. 



Hab. — Manly Lagoon, in brackish water (H. L. Kesteven). 



Ty p e to be presented to the Australian Museum. 



Cecum lilianum, n.sp. 

 (Plate xxix., fig. 7.) 



Shell curved, tapering, pale brown, with about twenty broad, 

 projecting, regular, rounded, transverse rings about their own 

 breadth apart. Lip formed of a ring more massive than the rest. 

 Septum flat. Length 2-32, breadth at aperture 0*44, at truncated 

 end 0-28 mm. 



ffab. —Long Bay, near Sydney; one specimen, in shell sand; 

 collected by Miss L. Parkes. 



T y p e. — Miss Lily Parkes has generously presented the unique 

 specimen to the Australian Museum. 



This specimen resembles C. vertebrale, Hedley, from the Ellice 

 Islands, than which it is narrower, more curved and more tapering 



Hydatina tasmanica, Beddome. 



This species was figured in Part iii. of these Studies. I am 

 now able to add it to the fauna of New South Wales, having 



