19 
the presence or absence of granulations, or even in the de- 
pression or prominence of the spire. The character, there- 
fore, by which, I believe, the two species are really dis- 
tinguished, rests alone on the spire, which, in C. Marmoreus, 
is concave and smooth, and, in C. Nocturnus, concave and. 
striated. 
PUPA VIOLACEA. 
(Lot 550.) 
P. testa purpurascente, nitidd, anfractibus (in etate provectis) ple- 
rumgue 7, obliqué subtilissime striatis ; apice truncato ; aperturd 
integra, edentuld. 
Shell shining, livid purple, when in an adult state, having about 
seven whorls, finely striated obliquely; the basal whorl cari- 
nated; tip of the spire truncated; aperture entire, without 
teeth. 
Berogse this shell arrives at maturity, it is furnished with 
what may be termed a second spire, very thin, and almost 
colourless, consisting of ten or twelve close set volutions, 
forming a lengthened point; which, as the animal increases 
in age, generally falls off, and leaves the obtuse spire, seen 
in this specimen. I am indebted to G. C. Bainbridge, Esq. 
of Liverpool, for the opportunity of ascertaining this fact by 
means of fine and well-defined specimens, received by that 
gentleman from Jamaica. Another species of this genus, 
also in his possession, has the same character, which, indeed, 
is not uncommon in several other terrestrial shells. 
