[Read before the Philosophical Institute of Canterbury, 15th September, 1874.]

The little Crustacean I am about to describe belongs to a small family of amphipodous Crustacea which are particularly interesting on account of their habit of what I venture to call eremitism. They are found almost invariably inhabiting the cavities of the tests of certain tunicate mollusks, and what have been described as Beroidæ. One described specimen, however, was found in the stomach of a shark, but whether inhabiting this curious residence from choice or necessity I do not know. Dr. Haast entrusted this specimen to me, Mr. A. E. Ross having found it on the Sumner beach, and presented it to the Museum, and I much regret that I have not the opportunity of showing the Phronima alive in its little crystal palace, but the small quantity of sea-water was unfortunately poured away, and we were obliged to transfer it to spirits.

The Phronima is about seven-eighths of an inch long when extended; it is as transparent as glass, the eyes alone being coloured red, and was contained in a little cask-shaped body, open at both ends, the openings being slightly contracted, one somewhat smaller than the other, composed of a perfectly transparent semi-cartilaginous substance. It is about three quarters of an inch in length, and half an inch in diameter, irregularly quadrangular, one of the angles slightly winged, the whole being wrinkled transversely. It is the test of a tunicate mollusk, probably one of the Salpidæ. A very similar structure associated with another Phronima, found in the Mediterranean, P. sedentaria, is figured in the British Museum Catalogue of Amphipoda under the name of Doliolum papillosum, Della Chiaje. Our specimen, however, is not papillose and differs in form.

The Phronima was doubled up in its cell facing one of the openings, and could not be dislodged without a good deal of pushing; when left at rest he immediately clambered back again.

Dr. Haast tells me that he has frequently found specimens of this little Crustacean on the West Coast, always inhabiting a similar cell.

Phronima novæ-zealandiæ, sp. nov.

Cephalon very large, tumid above, tapering to the oral apparatus, finely striated, the striæ being resolvable with a low magnifying power into rows of pellucid dots. Antennaæ as long as the breadth of the cephalon at their insertion, the first joint being very short.

First pair of gnathopoda having the meros slightly produced postero