18 
CYPRAA APERTA. 
(Lot 317.) 
C. testd rosed, labis albis, strus levatis vix ad teste dorsum extensts, 
insignibus ; aperturd valde effusd. 
Shell rose-coloured, lips white, with elevated strie, extending 
nearly to the back of the shell; mouth very wide. 
A SHELL presenting a most unusual deviation from the 
general appearance of the Cyprae; it is of great rarity, 
and this is the only perfect specimen which I have yet seen. 
CONUS NOCTURNOUS. 
(Lot 310.) 
Tue specific characters which Lamarck and other writers 
have employed to distinguish this shell from C. Marmoratus, 
will be found insufficient; inasmuch as they do not apply 
(excepting that which regards the colour) to the variety 
figured in En. Méth. tab. 318, f. 1., which they have justly 
considered as belonging more to C. Nocturnus than to C. Mar- 
moreus: for the variety quoted by them has the short depressed 
spire and simple base of Marmoreus, with the precise dispo- 
sition of colour seen in Nocturnus. To this latter it is, how- 
ever, more closely allied, by having the spire transversely 
striated ; a character never observable in the varieties of 
Marmoreus, however nearly they may approach in colour 
to Nocturnus. An intimate acquaintance with the shells of 
this genus will prove, that no character is more decided 
than the particular sculpture or formation of the spire in 
each species, and that this part becomes, therefore, of the 
first importance in the discrimination of species: particu- 
larly as no shells vary more than the Cones in colour, in 
