132 MANUAL OE THE MOLLUSCA. 



hemimltra retiisa, Sw., and several others), referred to this genus, have a 

 concentric operculum, like paludina. 



Melanopsis, Lam. 



Types, M. buccinoides, M. costata. PI. VIII., fig. 30. 



Shell ; body-whirl elongated ; spire short and pointed ; aperture distinctly 

 notched in front ; inner lip callous ; operculum sub-spiral. 



Bistr., 20 sp, Spain, Asia Minor, New Zealand. 



Fossil, 25 sp. Eocene — . Europe. 



Suh-genus. Pirena, Lam. (faunus, Montf.) P. atra. PL VIII., fig. 31. 

 Spii-e elongated, many whirled ; outer lip of the adult produced. 



Dislr,, 4 sp. ? S. Africa, Madagascar, Ceylon, Philippines. 



EAMILY V. TURRITELLIDJS. 



Shell tubular, or spiral ; upper part partitioned off ; aperture simple ; 

 operculum horny, many -whirled. 



Animal with a short muzzle ; eyes immersed, at the outer bases of the 

 tentacles ; mantle-margin fringed ; foot very short ; branchial plume single ; 

 tongue aiTiied. 



TuREiTELLA, Lam. 



Etym., diminutive of turris, a tower. 



Syn., terebellum, torcula, zaria and eglisia. Gray. 



Type, T. imbricata. PL IX., fig. 1. 



Shell elongated, many-whirled, spiraUy striated ; apertiu'e rounded, mar- 

 gin thin ; operculum horny, many -whirled ; with a fimbriated margin. 



Jnimal mth long, subulate tentacles ; eyes slightly prominent ; foot 

 truncated in front, rounded behind, grooved beneath ; branchial plume very 

 long : lingual ribbon minute ; median teeth hooked, denticulated ; uncini 3, 

 serrulated. Carnivorous ? 



Bistr., 50 sp. World-wide. Ranging from the Laminarian Zone to 100 

 fms. W. Indies, U. States, Brit. (1 sp.), Iceland, Medit., W. Africa, China, 

 Australia, AV. America. 



Fossil, 170 sp., Neocomian — . Brit. &c., S. America, Australia. 



Suh-genera. Proto, Defr., P. cathedi-alis, PI. IX., fig. 3, aperture trun- 

 cated below. 



Mesalia, Gray, M. sulcata (var.) PL IX., fig. 2. Greenland— S. Africa. 



Fossil, Eocene. Brit., France, 



? AcLis, Loven. 

 Etym., A, without, Meis, a projection. 

 Syn,, alvania, Leach (not Risso). 

 Tyi^e, A. perforatus, Mont. PI. IX., fig. 4. 



Shell minute, like tm-riteUa ; spiraUy striated ; aperture oval ; outer lip ; 

 pronii:.ent ; axis slightly riniate ; operculate. '\ 



