Mr. F. P. Marrat on some new Species of Oliva. 213 
capture at Plymouth. The additional evidence supplied by 
Mr. Parfitt of its claim to be regarded as indigenous to Britain 
is highly interesting. 
As the falces of this species do not appear to acquire their 
brilliant green hue till it becomes adult, M. Dugés was induced 
to regard it, when in a state of immaturity, as identical with the 
Segestria senoculata of authors (Annales des Sciences Naturelles, 
seconde série, Zoologie, tome vi. p. 169). 
XXIV.—On some new Species of Oliva, and a new Trivia. 
By Freperick P. Marrart. 
Tue Cones, Cowries, Mitres, and many other genera have 
been carefully studied, and the result is that a large number of 
_ species have been described belonging to each genus. The 
Olives have scarcely had twenty new species described in as 
many years: but this is not all; the species that were known, 
and many of those that were described, have not been brought 
under the notice of conchologists. I am now alluding to the 
shells figured by Duclos, in his excellent work published in the 
year 1835. 
The following new species have been named in my cabinet for 
_ several months, and during that time I have found no reason 
for altering my views respecting the validity of the species now 
described. 
1. Oliva violacea, Marrat. 
Shell ovate- fusiform; spire exserted, conical, canaliculate, 
impressed ; colour white, with pale zigzag lines and numerous 
halfmoon-shaped dots ; interior of aperture and base of pillar 
beautiful violet. 
_ Obs. Intermediate between O. reticularis and O. episcopalis ; 
differs from both in having the folds at the base suffused with 
beautiful violet. Loc. unknown. 
2. Oliva jamaicensis, Marrat. 
Shell cylindrically fusiform; spire short, canaliculate, rather 
flattened ; colour reddish brown, with triangular cream-coloured 
spots and two broad indistinct bands ; ; mouth purple; pillar 
reddish brown on the plaits at the base. 
Jamaica. 
Obs. Somewhat intermediate between O. splendidula and O. 
reticularis, approaching the former in form and the latter in 
markings. 
3. Oliva polita, Marrat. 
Shell elongately fusiform ; spire much produced, canaliculate, 
