CYCLOSTOMA. 
Puate V. 
Species 23. (Fig. a, 6, Mus. Cuming.) 
CycLostomMa cARINATUM. Cyel. testé excavato-umbili- 
catd, depresso-globosd, fulvescente-albd, subopacd, ru- 
fescente tincté et obscuré fasciatd, anfractibus superne 
spiraliter tenuiliratis, juxta suturas undatis, deinde 
tricarinatis, carinis prominentibus, acutis, distantibus, | 
interstitiis levibus, concaviusculis, anfractu ultimo 
circa umbilicum validé excavato-lirato ; aperturd sub- 
circulari, labro modicé reflexo, ad carinas lacunato, 
marginibus junctis. 
TH KEELED CycLtosroma. Shell excavately umbili- 
cated, depressly globose, fulvous-white, rather opaque, 
stained and obscurely banded with reddish-brown, 
whorls spirally finely ridged round the upper part, 
puckered next the sutures, then three-keeled, keels 
prominent, sharp, distant, interstices smooth, rather 
concave, last whorl strongly excavately ridged around 
the umbilicus ; aperture nearly circular, lip moderately 
reflected, guttered at the keels, margins joined. 
Turbo curinatus, Born, Test. Mus. Vind. p. 353. pl. 18. | 
RE A 
Cyclostoma carinatum, Lamarck (not of Sowerby). 
Cyclostoma tricarinatum, Sowerby. 
Tropidophora carinata, Pfeiffer. 
Hab. Madagascar ? 
The habitat of this species has not hitherto been given, 
but I have a specimen before me from the collection of 
Mr. Hamilton, found in damp clay in a semifossil subde- 
composed state by his son, Lieutenant Hamilton, R.E., in 
a cave three miles from the sea, near St. Flacq, Mauritius, 
which there is every reason to believe had been conveyed 
thither from Madagascar. 
Species 24. (Fig. a, 6, Mus. Cuming.) 
Cyctostoma DrsHayestanum. Cycl. testé subampliter 
perspective umbilicatd, depressé orbiculari, crassiusculd, 
fulvescente-carned, versus apicem rosaced, anfractibus 
angustis, ad suturas planulatis, deinde rotundatis, ad 
peripheriam acutissimé carinatis, supra carino-liratis, 
liris duplicibus, infra densé requlariter striato-liratis ; 
apertura parva, labro crassé reflewo-fimbriato, fimbria 
posticé calloso-ascendente. 
DersHayns’ Cyctostoma. Shell rather largely perspec- 
tively umbilicated, depressly orbicular, rather thick | 
fulvous flesh-colour, tinged with rose towards the 
apex, whorls narrow, flattened next the suture, then 
rounded, very sharply keeled at the periphery, keel- 
ridged above, the ridges being duplex, densely regu- 
larly striately ridged below; aperture small, lip 
thickly reflectedly frilled, frill callously ascending 
posteriorly. 
Prrir, Revue Zool. Cuv. Soc. 1844, p. 3. 
Hab. North Madagascar. 
An exquisitely sculptured species from North Mada- 
gascar, partaking of the typical characteristics so beauti- 
fully developed in the following species from the adjacent 
islands. 
Species 25. (Fig. a, 6, Mus. Cuming.) 
CycLostoma CuvirrtanumM. Cyel. testd ampliter per- 
spective wmbilicatd, depressé orbiculari, livido-fulves- 
cente, ferrugineo tinctd, anfractibus plano-declivibus 
deinde acute laminato-bicarinatis, undique subtiliter de- 
cussatim striatis, ultimo circa umbilicum lirato ; aper- 
turd subcirculari, labro subampliter reflexo-fimbriato, 
ad carinas lacunato, marginibus posticé calloso-ascen- 
dentibus. 
Cuvier’s CycLostoma. Shell largely perspectively um- 
bilicated, depressly orbicular, livid-fulvous, tinged 
with rust, whorls flatly sloping, then sharply lami- 
nately two-keeled, everywhere finely decussately stri- 
ated, last whorl ridged around the umbilicus; aper- 
ture nearly circular, lip rather largely reflectedly 
frilled, guttered at the keels, margins callously ascend- 
ing posteriorly. 
| Perit, Revue Zool. Soc. Cuv. 1841, p. 184; Mag. de 
Zool. pl. 55. 
Tropidophora Cuvieriana, Troschel. 
Hab. Seychelle Islands. 
This magnificent species differs, it will be seen, in its 
typical structure from the old C. carinatum in being con- 
vexly, not concavely, excavated at the umbilicus. 
Species 26. (Fig. a, 6, Mus. Cuming.) 
CycLostoma occLusuM. Cycel. testd obtecté umbilicatd, 
depressé orbiculari, livido-fuscescente, ferrugineo tinctd, 
November, 1861. 
