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Mexania EpiscopaLis. M. testa plicatd, turritd, subcrassd, 
tenebroso-castaned ; spird elevatd ; suturis impressis ; anfrac- 
tibus subconvexis, prope suturam superiorem concavis ; plicis raris, 
subacuminatis ; aperturd magnd, ellipticd, intus ce@rulescente ; 
columella contorta. 
Hab. A sluggish river, Malacca. 
Length 2°4, diam. °8 of an inch. 
Remarks.—This is a remarkable and interesting species, and differs 
from any which has been described, in having rather large and 
somewhat distant folds rising on the upper part into nodular points, 
in all the four specimens submitted for examination. The apex of 
these specimens being truncated, the number of whorls cannot be 
ascertained. A perfect adult would probably present about ten. The 
folds are distinct on the four lower whorls only. On the middle of 
the lower whorl there is a slightly elevated line, below which are about 
six obscure strie. The aperture is large, and more than one-third the 
length of the shell ; it is twisted, and has an elongated base. The 
columella is whitish and very much incurved. The operculum is 
more spiral than usual, and the polar point more toward the centre. 
Metania BuattTa. M. testd plicatd, elongate conoided, crassd, 
castaneo-nigricante ; spird elevatd, crebré costatd; anfractibus 
planulatis, infra suturas concavis ; plicis crebris ornatis ; aper- 
turd magnd, ovatd, superne angulatd, ad basim rotundd, intus 
ceruled ; columella tortad, superné incrassatd. 
Hab. Rapid river and small streams, Luzon, Philippines. 
Length 2°6, diam. *7 of an inch. 
Remarks.—A very dark-coloured and remarkably fine species, 
with numerous, nearly parallel, perpendicular folds, which number 
some eighteen or twenty, and exist on every whorl in the eight speci- 
mens under examination. The four large ones are truncate, but the 
younger and more perfect would indicate the existence of about ten 
whorls. It differs from the episcopalis in being more attenuate, in 
having more folds and a much less twisted columella. The aperture 
is large, and rather more than one-fourth the length of the shell. 
MELANIA COSTELLARIS. JM. testd plicatd, superné striatd, acu- 
minatd, subcrassd, tenebroso-castaned ; spird elevatd ; suturis line- 
aribus ; anfractibus decem, subplanulatis ; anfractu ultimo magno, 
geniculato; plicis numerosis; aperturd parvd, dilatatd, ovatd, 
supern? angulatd, ad basim rotundd, intus cerulescente ; columella 
incurvd. 
Hab. Small streams in the islands of Negros, Tanhay, Siquijor ; 
Philippines, . 
Length 1°5, diam. *5 of an inch. 
Remarks.—The last whorl being angular gives this species a pe- 
culiar and remarkable character, and causes a channel immediately 
below the suture. Several of the specimens under examination have 
beautiful delicate impressed lines immediately above the sutures. In 
the superior whorls these lines cover the whole surface. The folds 
