CYCLOSTOMA. 
Prats IV. 
Species 16. (Fig. a, 6, Mus. Cuming.) 
CYCLOSTOMA PRINCIPALE. Cycl. testa modicé umbilicatd, 
globoso-turbinatd, nitente-albd, rufo-castaneo conspicue 
bifasciatd, anfractibus juxta suturas subplanulatis, 
deinde rotundatis, undique carinatis; apertura sub- 
oblique circulari, labro reflexo. 
THE PRINCELY CycLostoma. Shell moderately umbi- 
licated, globosely turbinated, shining white, encircled 
with two conspicuous red-brown bands; whorls rather 
flattened next the sutures, then rounded, keeled 
throughout; aperture rather obliquely circular, lip 
reflected. 
Prerrrer, Pro. Zool. Soc. 1859, p. 27. pl. 44. f. 7. 
Hab. Madagascar. 
The two bands of this species are situated one on the 
periphery and the other below it. The succession of keels 
with which the shell is sculptured throughout forms a 
very prominent character. 
Species 17. (Fig. a, 6, Mus. Cuming.) 
CYCLOSTOMA FULYVESCENS. Cyel. testi modicé umbili- 
caté, globoso-turbinatd, fulvescente-fusca, anfractibus 
rotundatis, liris linearibus undique dense spiraliter 
sculptis; apertura oblique circular, fauce rufo-cas- 
taned, labro tenué reflexo, albo, marginibus posticé 
subascendentibus. 
THE FULvYous CycLostoma. Shell moderately umbi- 
licated, globosely turbinated, fulvous-brown ; whorls 
rounded, everywhere densely spiraily sculptured with 
linear ridges; aperture obliquely circular, interior 
rufous-chestnut, lip thinly reflected, white, margins 
slightly ascending posteriorly. 
SowErsy, Pro. Zool. Soc. 1843, p. 63. 
Hab. Madagascar. 
In this species the spiral ridges are closer and more 
thread-like than in the allied species, and the shell is not 
banded. 
Species 18. (Fig. a, 6, Mus. Cuming.) 
CycLosTOMA OBSOLETUM. 
globoso-turbinatd, livido-cesid, fasciis wrregularibus 
purpureo-fuscis cingulatd, anfractibus superné declivi- 
Cycl. testé modicé umbilicata, 
planis, deinde rotundatis, levibus, obscure malleatis, 
ad suturas minuté plicatis, ultimo circa umbilicum 
lirato ; aperturd circulari, fauce purpureo-fusco tincld, 
labro tenué reflexo. 
THE OBSOLETE CycLostoma. Shell moderately umbili- 
cated, globosely turbinated, livid-grey, encircled with 
irregular livid-purple bands; whorls slopingly flat- 
tened round the upper part, then rounded, smooth, 
obscurely malleated, puckered at the sutures, last 
whorl ridged around the umbilicus; aperture cir- 
cular, interior stained with purple-brown, lip thinly 
reflected, white. 
Lamarck, Anim. sans vert. vol. vill. p. 355. 
Hab. Madagascar. 
The deep purple bands of this species are obscured and 
rendered more or less obsolete by an overlying milky- 
white deposit. 
Species 19. (Fig. a, 4, c, d, Mus. Cuming.) 
CycLostoma virtatuM. Cycl. testdé ampliter patente- 
umbilicatd, depressd, subdiscoided, purpurascente-albd, 
violaceo-purpureo undique spiraliter vittatd, anfrac- 
tibus angustis, supra planulatis, deinde rotundatis, un- 
dique lirato-striatis et malleatis ; apertura oblique cir- 
culari, fauce purpureo-castaned, labro modicé refleco, 
marginibus postice calloso-ascendentibus. 
‘THE RIBAND-BoUND Cyctostoma. Shell largely openly 
umbilicated, depressed, subdiscoid, purplish-white, 
everywhere spirally banded with violet-purple ; whorls 
narrow, flat above, then rounded, ridge-striated and 
malleated throughout; aperture obliquely circular, 
interior purple chestnut, lip moderately reflected, 
margins posteriorly callously ascending. 
SoweErsy, Species Conch. f. 91-94. 
Tab. Madagascar. 
A neatly banded species, of a more depressed discoidal 
form than usual, having a particularly open umbilicus. 
Species 20. (Fig. a, 4, Mus. Cuming.) 
Cycnostoma Moutinsit. Cyel. testd subampliter wmbi- 
licatd, depressd, albidd, ferrugineo-purpureo tincta, et 
spiraliter lineata et unifasciatd, anfractibus subangus- 
November, 1861. 
