Mr. F. P. Marrat on some new Species o/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. Duges was induced 

 to regard it, when in a state of immaturity, as identical with the 

 Segestria senoculata of authors (Annales des Sciences Naturelles, 

 seconde serie, Zoologie, tome vi. p. 169). 



XXIV. — On some new Species o/Oliva, and a new Trivia, 

 By Frederick P. Marrat. 



The 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 0. reticularis and 0. 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 creaTU-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, 



