252 MELANIID. 
diately separable from the peculiarly North American group 
Strepomatide, which they much resemble in the characters of 
the shell. Mainly of Indo-Pacific, African and Polynesian dis- 
tribution, they number several hundred existing species, besides 
a number of fossil forms commencing with the jurassic period. 
PaLupoMus, Swainson. 
Htym.—FPalus, a marsh, and domus, home. 
Syn.—Rivulina, Lea. 
Disir.—25 sp. Ceylon, India. P. conteus, Gray (1xx, 74). 
Shell Paludiniform; columella callous, scarcely planulate. 
Operculum concentric, with spiral, sinistral, subecentral nucleus. 
PHILOPOTAMIS, Layard. (Heteropoma, Benson.) Shell fre- 
quently globose, but spire exserted ; columella callous, scarcely 
planulate. Operculum subspiral; nucleus basal, dextral, sub- 
marginal. Distr.—9 sp. Ceylon, Sumatra. P. nigricans, Reeve 
(hex; 75). 
TANALIA, Gray. (Ganga, Layard. Serenia, Benson.) Shell 
globose, neritiform; columella wide, planulate. Operculum 
lamellated, nucleus dextral, median, marginal. Dzistv.—T sp. 
Ceylon. P. loricata, Reeve (1xx, 76). 
STOMATODON, Benson. Shell globose, columella wide, base 
truncate and furnished with a prominent tooth. Operculum (7). 
Distr.—P. Bensoni, Brot. (xx, 77). Southern India. 
Meant, Lam. 
Etym—Melania, blackness (from melas). 
Distr.—400 sp. So. Europe, India, Philippines, Pacific Islands. 
Shell turreted, apex acute | unless eroded); whorls ornamented 
with stris or spines; aperture oval, pointed above; outer lip 
sharp, sinuous. Operculum subspiral. 
MELANELLA, Swainson. Shell ovoid, with elevated spire; 
aperture large, its base subproduced and rounded. Operculum 
paucispiral, nucleus subspiral. J/. glans, von dem Busch (1xx, 
78). Java. Includes M. Hollandri, Fer., and M. parvula, 
Schmidt; EHuropean species. 
AcRostoMA, Brot. Shell fusiform, subbiconic; aperture 
angulately produced at the base. Operculum (?). MM. Hiigeliz, 
Phil. Java, India. 
pAcHycHiLus, Lea. Shell turreted or subfusiform; aperture 
ovate, its base subproduced, peristome usually thickened. Oper- 
culum three- to four-whorled, with subcentral nucleus. Mexican, 
Central American. WM. levissima, Sowb. (1xx, 79). 
AYLACOSTOMA, Spix. (Aulacostoma, Agassiz.) Whorls cari- 
nated or shouldered near the suture. South America. J. 
scalaris, Spix (1xx, 80). 
sULCOSPIRA, Troschel. Shell ovately turreted, sulcate-striate ; 
