igS H. B. Preston : New species of Shells. [VOL. II, 



Rissoina cylindrica, sp. no v. 



Shell somewhat cylindrical, white with a brownish infra- 

 sutural band ; covered with a dull chocolate-coloured periostracum ; 

 remaining whorls 5, rather flat, sculptured with fine, transverse 

 costse and minute, spiral strise, presenting a punctate appearance 

 between the former ; sutures impressed ; aperture ovate ; outer lip 

 broadly thickened and somewhat expanded, a well-developed cal- 

 losity joining the columella with the lip above. 



Altitude . . • • 5'5 nim. 



Diam., major . . . . 2 ,, 



Aperture, alt. . . . . 2 ,, 



• , , diam . . . i , , 



Habitat — Andaman Islands. 



Rissoina Iceta, sp. no v. 



Shell elongately fusiform, dull white ; whorls 7^, the first 5^ 

 very convex, the remaining 2 rather fiat, sculptured throughout 

 with fine, spiral striae and oblique costse, the latter becoming 

 finer and almost obsolete on the last two whorls; columella 

 descending rather obliquely and extending into a callus above ; 

 peristome varicosely thickened ; aperture ovate. 



Altitude 





6*5 mm 



Diam., major . . 

 Aperture, alt. . . 

 , , diam . 





2-25 ,, 



2 



I 



Habitat — Andaman 



Islands. 





Rissoina pupiniformis, sp. nov. 



Shell fusiform, somewhat flattened, semi-transparent white, 

 polished ; whorls 6, scarcely convex, encircled by a super-sutural 

 spiral groove ; sutures scarcely impressed ; aperture oval ; columella 

 slightly arched ; peristome simple, bearing one small basal denticle. 



Altitude 



Diam., major . . 

 ,, minor . . 

 Aperture, alt. . 

 ,, diam. 

 Habitat — Andaman Islands 



6 mm. 



o 



o 



Rissoina sculpturata , sp. nov. 



vShell decollate, fusiform, solid, whitish; remaining whorls 4J, 

 very flat, sculptured with transverse ribs interrupted by spiral ridges 

 presenting a coarsely cancellate appearance ; sutures scarcely de- 

 fined ; aperture ovate, oblique ; peristome varicosely thickened ; 

 columella descending obliquely and extending into a callus which 

 joins the lip above. 



