manual of the mollusoa. 



Family YI. — Littorinld^.* 



The genera are — 



LiTTORDfA, including Tedaria, Modulus, and Risella ; 

 Lacitna, and 



FossAHUS, Philippi (p. 253). 



Synonyms, Phasianema, "Wood; Maravignia, Arados. 



Shell perforated, sculptured ; inner lip thin ^ aperture semi- 

 lunate ; operculum not spiral. 



Animal with two frontal lobes between the tentacles. 



Distribution, 43 species, including species of the sub-genera. 

 Mediterranean and tropical seas. 



Fossil, 4 species. Miocene. Europe. 



Sub-genera, Conradia, Couthouyia, Citlina, Gottoina. 



Fossarina, Adams, differs from Fossarus in the curved inner 

 lip and circular aperture. 2 species. Australia. 



Isapis, H. and A. Adams. Columella with a plait ; in /. 

 unomala it is almost obsolete. 4 species. Jamaica and Mazat- 

 lan. 



LACinoiLLA, Deshayes, 1864. 



Etymology, diminutive of Lacuna (see p. 255). 



Type, L. depressa, Desh. Eocene. Paris. 



Shell ovate, thin, pellucid, shining, very depressed; apex, 

 obtuse ; aperture large, dilated ; outer lip thin, reflected ; colu- 

 mella narrow, thin, concave, grooved, with the base perforated. 



PEattlin-la, Mayer, 1864. 



Dedicated to M. Eaulin. 



Type, Odostomia alligata, Deshayes. Eocene. Paris basin. 



Shell turbinated, oval-oblong, moderately thick, spirally sul- 

 cated ; whorls rapidly increasing, convex ; last whorl very 

 large ; aperture large, angulated posteriorly, expanded in front ; 

 columella broad, arcuate, flattened, with a prominent tuber- 

 culous tooth. 



Etjcycltjs, E. Deslongchamps, 1860. 



Etymology, eu-Tiuklos, circling, in allusion to the numerous 

 plications or rings of the spire and base. 



Examples, Turbo ornatus. Sow. ; T. capitaneus, Miinst. 



» See p. 250. 



32 



