[Pboc. Roy. Soc. Victoria, 26 (N.SJ, Pt. I., 1913]. 



Ak'I'. V\. — Oii tSome New ISpeclea <ind Varietle,s of Victorian 

 M< 1 1 ■ ii I ('. MoUiisccL 



HV 



.J. H. GxiTLIFF 



AND 



0. J. GABRIEL. 



(With Plate VIII.). 



;;Read 12th .lime, 1913]. 



This paper contains descriptions of three new species of Rissoa, 

 one variety^ and a new variety of BvUinella pygmaea, A. Adams; 

 also remai-ks on and figures of Nissoa hicolor. Petterd. 



Rissoa iravadioides. sp. nov. (Plate VIII., Fig. 1). 



Shell minute, cylindrical, of four and a-half slightly convex lirate 

 whorls; exclusive of the embryonic whorl, which is smooth; the fol- 

 lowing whorls are each encircled by about six flatly-rounded spiral 

 lirae, equally spaced, the intervening grooves are concavely rounded, 

 and of the same width as the lirae, the upper portion of the whorl 

 is slightly t.abulate below the suture, which is incised. The obliquely 

 pyriform aperture is in the plane of the axis, and is laterally 

 extended to the right, beyond the l)ody of the shell, periphery 

 rounded. Colour, cream-white. 



Dimensions. — Length, 1.55; breadth, .55 mm. 



Locality. — Dredged off Wilson's Promontory (type), also in 8 to 

 10 fathoms, Westein Port. 



Ohs. — In general appearance somewhat resembling shells of the 

 genus Iravadia. 



Type in Mr. J. H. Gatlift's collection. 



Rissoa janjucensis, .sp. m(.v. (Phite A^III., Fig. 2). 



Shell minute, sub-cylindrical, smooth, of five and a-half whorls, 

 including the embryonic wliorl. which is small; sutures linear, well 

 defined; whorls flatly convex. Aperture in the plane of the axis, 

 roundly pyiiform. laterally extended to ttje riudit, peristome com- 

 plete. Colour, pale yellow. 



