48 HELICID^. 



G-t, tumid, slowly increasing, the last rather small; aperture 

 semioval, oblique ; columella short, callous or distinctl}' dentate; 

 peristome expanded, the margins subapproximating and joined 

 by a very thin callus, base frequently unidentate. H. arata, Sowb. 

 (xcvii, 4). T sp. Philippines, Formosa. 



Chrysallis^ Albers, 1850. Shell perforate, conically ovate; 

 whojis 5-^, hardly convex; spire cylindrically conical, apex 

 obtuse ; columella strict, wide, subreceding ; aperture oblong- 

 OA^ate ; peristome simple, widely expanded ; columellar margin 

 dilated and reflected. H. chrysalidiformis, Sowb. (xcvii, 5). 

 4 sp. Philippines. 



Ganistriivi^ Klein, Morch, 1852. Shell subperforated or 

 imperforate, sometimes sinistral, oval-oblong or subfusiform ; 

 whorls 6-Y ; columella straight, dilated, rarely arcuated ; aper- 

 ture oblong, angular above ; peristome thick, more or less wideh' 

 reflected, very rarely thin. H. Luzonica, Sowb. (xcvii, 23). 18 

 sp. Philippines. 



Prochilua, Albers, 18fi0. Shell subperforate, ovately pyramidal 

 or subfusiform ; whorls 5|^-7, rather flattened ; spire pyramidal ; ' 

 columella slightly arcuate; aperture narrow, oblong-ovate; 

 peristome somewhat thickened, widel}^ expanded, and slightl}^ 

 reflected. H. virgata, Jay. 8 sp. Philippines. 



BuLiMUS, Scopoli, nST. 



Etym. — ? Bou'imoH, extreme hunger (in allusion to its 

 voracity !) ; typographical error for Bnlinus, Adanson. 



Syn. — Bulinus, Brod. 



Distr. — 323 sp. Mostly South American. 



Shell oval-oblong or turriculated, solid, subperforate or imper- 

 forate ; whorls few, the last A'entricose and large, aperture longi- 

 tudinal ; columella widened, rarely plicate ; peristome thickened, 

 reflected ; the lips usuall}^ joined by a callus. Animal similar to 

 Helix; jaw simple, with parallel ribs (xiii, 60). 



BORUS, Albers, 1850. Shell solid, subimperforate, oval or 

 oval-oblong ; whorls five or six, covered by a 3'ellowish epidermis, 

 the last ventricose ; aperture oval-oblong ; columella nearly' 

 straight ; peristome thickened, reflected ; lips united b}' a callus ; 

 columellar lip dilated, reflected. 33 sp. South America. B. 

 oblongus, Miill. (xcvii, 16). B. ovatus, Miill., which attains a 

 length of six inches, is sold in the markets of Rio Janeiro; it 

 oviposits amongst dead leaves ; the eggs have a white calcareous 

 shell, are as large as those of the pigeon, and are eagerly sought 

 for food by the negroes (xvii, 100). Borus contains the largest 

 species of any group of Bulimus. 



ORPHNus, Albers, 1850. Shell imperforate, elongated-oval, 

 solid ; whorls seven or eight, with bordered sutures ; aperture 

 oblong-oval; columella usually plicate, callous; peristome thick- 



