48 FURTHER ADDITIONS TO THE TASMANIAN MOLLUSCA. 



AMPHITHALIMUS ERRATICA, Sp. Nov. 

 PL II., fig. 7. 



Shell elongately pyramidal, or wedge-shaped, white, 

 glassy, and hyaline. Whorls fine, rather rounded, suture 

 well marked, the body whorl sub-angular at the peri- 

 phery. Aperture nearly round, the columella lip slightly 

 reflexed ; on a side view the outer lip slopes well back from 

 the perpendicular. The columella is simple in the type 

 and in some co-types, but in others a small tooth-like plait 

 appears, which, however, I think is not a. true plication, 

 but is certainly a remarkable feature. Length 2, breadth 

 1.3 mill. 



Locality — Type, with 20 others, from 100 fathoms, 7 

 miles east of Cape Pillar. This seems most nearly related 

 in form to R. flammea, Frauenfeld, but is longer, with an- 

 other whorl, and of a thin hyaline texture. 



RISSOA PERTKANSLUCIDA, Sp. Nov. 



PI. II., fig. 8. 



Shell broadly conoid, white, smooth, shining, and very- 

 transparent, the pillar being clearly seen through the shell 

 Whorls four, rounded, the suture deeply impressed. Aper 

 ture subquadrate, lip thin, slightly expanded ; pillar- 

 straight, behind which is a false umbilicus. Length 2, 

 breadth 1.5 mill. 



Locality — Type, with 15 others, from 100 fathoms, 7 

 miles east of Cape Pillar. This species has very much the 

 appearance of a Cyclostrema, but appears to be imper- 

 forate. 



