48 HELICID A. 
6-7, tumid, slowly increasing, the last rather small; aperture 
semioval, oblique ; columella short, callous or distinctly dentate ; 
peristome expanded, the margins subapproximating and joined 
by a very thin callus, base frequently unidentate. H. arata, Sowb. 
(xevii, 4). 7 sp. Philippines, Formosa. 
Chrysallis, Albers, 1850. Shell perforate, conically ovate ; 
whorls 5-7, hardly convex; spire cylindrically conical, apex 
obtuse; columella strict, wide, subreceding; aperture oblong- 
ovate; peristome simple, widely expanded ; columellar margin 
dilated and reflected. H. chrysalidiformis, Sowb. (xevii, 5). 
4 sp. Philippines. 
Canistrum, Klein, Morch, 1852. Shell subperforated or 
imperforate, sometimes sinistral, oval-oblong or subfusiform ; 
whorls 6-7; columella straight, dilated, rarely arcuated ; aper- 
ture oblong, angular above ; peristome thick, more or less widely 
reflected, very rarely thin. H. Luzonica, Sowo. (xevii, 23). 18 
sp. Philippines. 
Prochilus, Albers,18¢0. Shell subperforate, ovately pyramidal 
or subfusiform ; whorls 53-7, rather flattened ; spire pyramidal ; 
columella slightly arcuate; aperture narrow, oblong-ovate; 
peristome somewhat thickened, widely expanded, and slightly 
reflected. H. virgata, Jay. 8sp. Philippines. 
Buurmus, Scopoli, 1787. 
Etym.—? Bou-imos, extreme hunger (in allusion to its 
voracity !) ; typographical error for Bulinus, Adanson. 
Syn.—Bulinus, Brod. 
Distr.—323 sp. Mostly South American. 
Shell oval-oblong or turriculated, solid, subperforate or imper- 
-forate ; whorls few, the last ventricose and large, aperture longi- 
tudinal; columella widened, rarely plicate ; peristome thickened, 
reflected ; the lips usually 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, COV ered by a yellowish epidermis, 
the last ventricose ; aper ture oval- oblong; columella nearly 
straight ; peristome thickened, reflected ; lips united by a callus ; 
columellar lip dilated, reflected. 33 sp. South America, B. 
oblongus, Mill. (xevii, 16). B. ovatus, Mull., which attains a 
length of six inches, is sold in the markets of Rio Janeiro; it 
Ov iposits 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- 
