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 Ianthina, published in 1858, and of Morch's " Materiaux pour servir k PHistoire de la Famille des lanthines" 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 Ianthina 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 Ian-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. /, 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 1. 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 /. 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 /. Smithia, was found sparingly, as well as at the equator. Between 4° and 5° of north lat., /. planispirata, Adams & Reeve
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