HELICID^. 33 



Leptomeriis, Albers, 1850. Shell thin, subperfo rated or very 

 rarely imperforate, oval or oblong-conic; whorls 5-7, slightly 

 inflated below ; aperture oval or oblong, shorter than the spire ; 

 columella usually subarcuated ; peristome simple, thin and sharp ; 

 columellar lip a little reflected. B. Meridanus, Pfr. (xcvii, 19). 

 52 sp. South and Central America, West Indies. 



Neesiotus, Albers, 1850. (Omphalostyla, Schlutt., Ads., 1855.) 

 Shell subperforate, oval-conic or oblong-turreted, longitudinally 

 striated ; whorls 6-8; aperture oblong, angular at base, one-third 

 the length of the shell, columella vertical ; peristome simple, 

 sublabiate within ; lips subparallel, united by a small callus ; 

 columellar lip dilated above. B. rugiferuH^ Sowb. (xcviii, 35). 

 16 sp. Galapagos Isles. 



RhahdotuH^ AXbQVQ^ 1850. Lip not expanded nor reflected. B. 

 dealbatus, Say (xcviii, 34). 65 sp. Alabama, L. Cal., Mexico 

 to South America. 



Pleuropyrgus, Martens, Shell imperforate, turreted, rather 

 solid, with obtuse ribs ; whorls fifteen, convex ; aperture semi- 

 oval; peristome simple, the margin shortly expanded. B. Ghem- 

 nitzioides, Forbes. G-alapagos Isles. 



BOSTRYX, Troschel, 1847. Shell turreted, scalariform, with 

 wide umbilicus ; whorls six, the first four regular, the last two 

 shouldered, bicarinated; aperture subquadrangular; peristome 

 simple or slightly expanded, continuous. B. solutus, Troschel 

 (xcvii, 22^. 5 sp. South America. 



PLACOSTYLUS, Beck, 1837. Shell imperforate, oblong, conical, 

 longitudinally striate ; last whorl longer than the spire ; aperture 

 oval-oblong, irregular, angular above ; columella a little arcuated, 

 callous ; columellar lip wide, peristome thick, lips united by a 

 wide callus, shining and usually dentate or tuberculate. B. 

 insignis, Petit (xcvii, 6). 58 sp. Australasian and Polynesian. 



Euplacostylus^ Crosse. Edge of aperture thickened. Animal 

 with hinder part of body obtuse. B . fihratua^Maviyn. Terres- 

 trial. New Caledonia, Solomon's and Fiji Isles. 



Gharis, Albers, 1850. B. fulguratus, Jay. Fiji Islands. 



Apastus, Albers, 1850. Shell imperforate, fusiform, thin, 

 diaphanous, lightly striate ; whorls six, rapidly enlarging, the 

 last longer than the spire ; aperture oval-oblong, rounded at the 

 base; columella subarcuated; peristome labiate, reflected, lips 

 united by a thin callus. B. miUocheilus, Reeve (xcvii, 7). 

 Solomon Isles. 



AMPHiDROMUS, Albers, 1850. (Beddomea, Nevill.) Shell 

 dextral or sinistral, perforate or covered, ovate-conical or oblong- 

 ovate ; whorls 6-7^, scarcely convex ; columella dilated, twisted, 

 receding; aperture oblong, semiovate ; peristome thickened, 

 expanded, reflected, outer margin arcuate. Jaw feebly ribbed ; 

 dentition like Orthalicus. B. perversuH^ Linn. 47 sp. Java, 

 Siam, etc. 



