Rissoa.] GASTROPODA. 205 



is more prominent, and on the base is a fourth cord parallel to the 

 columella ; the entire surface is ornamented with dense axial folia- 

 tions, crenulating the spiral riblets. Colour white. Spire graduate, 

 much higher than the aperture ; outlines very little convex. Proto- 

 conch conspicuous, globular, of 1^ whorls. Whorls 4^, regularly in- 

 creasing, concave from the suture to the first cord, turned inward 

 in a straight line to the suture below ; base convex. Suture not much 

 impressed. Aperture subvertical, ovate, slightly angled above. Peri- 

 stome continuous, thick, and blunt. Basal lip slightly expanded. Colu- 

 mella very short, vertical, nearly straight. Operculum unknown. 



Diameter, 0-8 mm. ; height, 2 mm. 



Animal unknown. 



Type in my collection. 



Flab. Snares, in 50 fathoms (Captain Bollons). 



Remarks. Nearly allied to R. Suteri, Hedley, which, however, is 

 much broader, has a smooth protoconch, 2 strong spiral cords on the 

 third whorl, and lacks the foliated axial sculpture. 



10. Rissoa Suteri, Hedley, 1904. Plate 12, fig. 10. 



Rissoa Suteri, Hedley, Rec. A.M., v, 96, f. 23 in text. B. australis, 

 T. -Woods : Suter, P. Mai. S., iii, 4, not of T.-Woods. JR. Tenisoni, 

 Tate, Index, 77, not of Tate. 



Shell small, ovate, imperforate, very solid, gradate. Sculpture : 

 The third whorl is belted with 2, the fourth with 5 broad spiral flat- 

 topped bands, separated by deep sharp and equally broad interstices. 

 The uppermost band of each whorl is the largest, thence to the base 

 the others gradually diminish. Above the shoulder the concave sur- 

 face slopes upwards to the suture, and a single small spiral thread 

 interrupts this slope. Colour white. Spire conical, higher than the 

 aperture ; outlines slightly convex. Protoconch papillate, of 2 smooth 

 and rounded whorls. Whorls 4, rather rapidly increasing, gradate ; 

 base convex. Suture impressed. Aperture oval, oblique. Peristome 

 much thickened, externally polygonal from the junction of the spiral 

 ribs, internally duplicated by a small raised rim. Operculum unknown. 



Diameter, 1-4 mm. ; height, 1-8 mm. 



Animal unknown. 



Type in the Australian Museum, Sydney. 



Hab. Foveaux Strait, type (A. Hamilton) ; near the Snares, in 

 50 fathoms (Captain Bollons). 



Subgen. 4. CERATIA. H. and A. Adams, 1852. 

 Ceratia H. & A. Ad., A.M.N.H., x, 1852, 358. Type: R. proxima, Alder. 



Shell subcylindrical, thin ; whorls weakly spirally lirate, flatly 

 convex, with obtuse apex ; outer lip thin and sharp. 



Animal with flattened, mostly short and claviform tentacles, foot 

 bifurcate posteriorly. 



