MELANIID. 253 
aperture ovate, base subproduced. Operculum three- to four- 
whorled, nucleus subcentral, rarely subbasal. J/. sulcospira, 
Mousson (Ixx, 81). East Indies. 
NIGRITELLA, Brot. Shell ovoid-turreted, smooth, but slightly 
granosely striate. Operculum subspiral, nucleus submarginal. 
M. decollata, Lam. (1xx, 82). Africa, Madagasear. 
MELANOIDES, Olivier. Shell turreted, usually large, elevately 
striate and plicate, plice usually tuberculose. Operculum sub- 
trispiral, nucleus excentric, sinistral. East Indies, Philippines. 
M. asperata. M.variabilis. M. episcopalis, Lea (1xx, 83). 
MELANIA, H.and A. Adams. (Ellipstoma, Raf.) Shell usually 
subulate, whorls numerous. Operculum paucispiral, nucleus 
submarginal. MV. hastula (lxx,84). M. Mindoroensis. M. acumi- 
nata. Kast Indies, Polynesia. 
STRIATELLA, Brot. Turreted, spirally more or less striate, 
sometimes longitudinally plicate, aperture rounded at the base, 
columella a little twisted. M. corporosa. WM. tuberculata (1xx, 
85). Java, Polynesia. 
PLoTIA (Bolten), H. and A. Adams. Shell medium or small, 
spirally closely striate or lirate; whorls angulate and spiny above; 
corneous, strigate or punctate with red. Operculum subspiral, 
nucleus submarginal, basal. MM. spinulosa. M. bellicosa, Hinds 
(Ixx, 86). 
PLoTIOPsIS, Brot. Shell like the preceding, but shortly tuber- 
culose (not spinose) at the angle. Operculum subspiral, nucleus 
submarginal. MM. Balonnensis, Conr. (1xx, 87). 
TIARA (Bolten), H. and A. Adams. (Amarvla, Sowb. Melas, 
Montf. Melacantha, Swainson. Paramelania, HE. A. Smith.) 
Shell usually large, mostly smooth, rarely with elevated cingule, 
whorls angulated and spinose above. Operculum paucispiral, 
nucleus submarginal. M.amarula. M. setosa, Swains. (1xx, 88). 
TIAROPSIS, Brot. Shell medium size, lirate or suleate; whorls 
with a single row of nodules or short spines above; margin of 
the aperture sinuous. M. Winteri, Busch (1xx, 89). 
TAREBIA, H. and A. Adams. Shell oblong or ovately turreted, 
granosely decussated; aperture-margin sinuous. Operculum 
paucispiral, nucleus submarginal. MM. Celebensis, Quoy (1xx, 90). 
SERMYLA, H. and A. Adams. Shell Tornatelliform, above lon- 
gitudinally costate, below with revolving lirz ; aperture-margin 
sinuous. Operculum paucispiral, nucleus submarginal. MM. tor- 
natella, Lea (1xx, 91). 
ONCOMELANIA, Gredler. Shell rimate, turreted, strongly 
ribbed, ribs pellucid; aperture scarcely effuse below, small; 
peristome continuous or connected by a columellar callus, 
widely sublabiate, with an exterior varix. l sp. China. The 
operculum is of the normal form. The position of this shell is 
