Pie te AP Tee 
Mr. W. H. Benson on Ianthina, Bolten. . 405 
LI. — Notes on Ianthina, Bolten; and Indication of a new 
Species of the allied oceanic Genus Recluzia, Petit. By 
_ W. H. Benson, Esq. 
AN examination of Reeve’s Monograph of Janthina, published 
in 1858, and of Morch’s “ Matériaux pour servir A |’Histoire 
de la Famille des Janthines,’ contained in the ‘Journal de 
Conchyliologie’ for the present year, has suggested a few ob- 
servations with reference especially to the species in an exten- 
sive collection of pelagian shells made in 1834-35, during a 
voyage to Calcutta in the ‘Malcolm.’ My success in the con- 
struction of casting and towing nets of novel patterns, and the 
inspection of the curious forms captured, caused my example to 
be followed by other passengers in the ship; an opportunity 
was thus afforded for the examination of a larger number, and 
occasionally of finer specimens, of the shells obtained in my own 
nets, besides two genera which were missed by them. 
The first Janthine seen were accidentally enclosed in a casting 
net employed to procure specimens of the brilliant and active 
little Glaucus Forsteri, and proved to be a small variety of Jan- 
thina exigua, Lamarck. This species was observed during two 
days before the island of Madeira was sighted. I succeeded 
in keeping the animal alive in sea-water for ten days. Glaucus 
Forsteri lived for a longer period, and was found to feed on its 
less active shell-bearing fellow-prisoners. 
I. exigua was the most widely distributed species met with, 
occurring again near the equator, and continuing along the 
Brazilian portion of the Atlantic, towards the island of Tristan 
d’Acunha, where it attained a large size, as far as 39° of south 
latitude. Here it was again small; but a still larger variety, 
with a more rosy violet tint, appeared in the middle of the 
Southern Indian Ocean, north-east of the Isles of St. Paul and 
Amsterdam. Between this variety and J. capreolata, Montrouzier, 
I can find no sufficiently distinguishing character. Smaller 
specimens again occurred to the south of the equator, and at 
the head of the Bay of Bengal. 
A small and delicate variety of I. nitens, Menke, made its ap- 
pearance to the north of the Cape de Verde Islands. South of 
this group, the apical nucleus of the same species was taken ; 
and in 6° of north latitude the shell was captured fully grown. 
The peculiarities of the spire and float will be noticed in another 
part of this paper. 
- In 14° north lat., south of the Cape de Verde Islands, a small 
shell, which I think must be the young of Reeve’s I. Smithie, 
was found sparingly, as well as at the equator. 
Between 4° and 5° of north lat., I. planispirata, Adams & Reeve 
