MANUAL OF THE MOLLUSCA. 
Faminty VI.—LITTORINIDZ.* 
The genera are— 
LirtormIna, including Tectaria, Modulus, and Risella ; 
LACUNA, and 
Fossarus, 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 one sub-genera. 
Mediterranean and tropical seas. 
Fossil, 4 species. Miocene. Europe. 
Sub-genera, Conradia, Couthouyia, Cithna, Gottoina. 
Fossarina, Adams, differs from Fossarus in the curved inner 
lip and circular aperture. 2 species. Australia. 
Isapis, H. and A. Adams. Colwmella with a plait; in J. 
anomala it is almost obsolete. 4 species. Jamaica and Mazat- 
lan. = 
LACUNELLA, Deshayes, 1864. 
Etymology, diminutive of Lacuna (see p. 258). 
Type, Li. 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. 
? RAULINIA, Mayer, 1864. 
Dedicated to M. Raulin. 
Type, Odostomia alligata, Deshayes. Eocene. Paris basin. 
Sheil 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. 
Evucycuus, H, Deslongchamps, 1860. 
Etymology, eu-kuklos, circling, in allusion to the numerous 
plications or rings of the spire and base. 
Examples, Turbo ornatus, Sow.; T. capitaneus, Minst. 
* See p. 250. 
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