84 



PROVISIONAL AID TO THE STUDY OF TASMANIAN MOLLUSCA. 



(xxvii.) Family Ianthinidte. 

 Genus Ianthina. Lam. (203-205.) 

 Shell thin, translucent, irocliiform or (/lobular-turbinate ; nucleus 

 minute, styliform, sinistral ; whorls few, rather ventri- 

 cose ; aperture four sided ; columella tortuous ; lip 

 thin, notched at the outer angle ; base of the shell 

 deep violet ; spire nearly white. Dist. — Pelagic in 

 Atlantic and Pacific Oceans. 



(xxviii.) Family Ttjeritellidjs. 



Genus Tubritella. Lam. (206-210.) 



Shell elongated, awl-shaped, many whorled, with revolving 

 striae ; aperture rounded ; operculum, many whorled, 

 with a fimbrated margin, usually whitish or brownish, 

 with sometimes red-brown spots or flames. Dist. — 

 World-wide, ranging from Laminarian Zone to 100 

 fathoms. 



(xxix.) Family Vebmetid^e. 



(G.) Shell (adult) irregularly spiral, or contorted tubular; 

 operculate. 



Genus Vermetus. Adamson. (211.) 



Shell irregularly spiral, adult stage, or contorted, tubular, 

 operculate. Dist. — Tropical and sub-tropical. World- 

 wide. 



Genus Siliquaeia. Brug. (212-213.) 



Shell tubular : spiral at first, afterwards irregular ; tube with 

 a continuous slit ; operculum spiral. 



(xxx.) Family Eulimid^;. 



(Shell turriculated or turbiniform, smooth, milk white, polished ; 

 aperture oval or rounded, sometimes angular in front ; 

 columella without plications ; operculum corneous, sub- 

 spiral, when present. 



Genus Euxima. Eisso. (214-220.) 



Shell small, white and polished ; slender, elongated, with numerous 

 level whorls ; spire often curved to one side ; obscurely 

 marked on one side by periodic mouths, which form promi- 

 nent ribs internally ; apex acute ; aperture oval, pointed 

 above ; outer lip thickened internally ; inner lip 

 reflected over the pillar ; not umbilicated ; operculum 

 horny, sub-spiral. Dist.— World-wide— 5 to 90 

 fathoms. 



