294 Transactions. — Zoology. 



Art. XLIII. — Description of a new Crustacean^ Phronima novse-zealancUae. 



By LI. Powell, M.D. 

 Plate XXI. 



[Read "before the Pliilosopliical Institute of Cantcrhuryy I5l7i Septemher, 1874.] 



The little Crustacean I am about to describe belongs to a small family of 

 ampbipodous Crustacea wbicli are particularly interesting on account of tbeir 

 babit of wbat I venture to call eremidsm. Tbey are found almost invariably 

 inhabiting the cavities of tbe tests of certain tunicate mollusks, and wliat have 

 been described as Beroidse. 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-eigliths 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 incb in diameter, irregularly quadrangulai', one of the 

 angles slightly winged, the whole being wrinkled transversely. It is the test 

 of a tunicate mollusk, probably one of the Salpidce. 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 p)apillosum, Delia Chiaje. Our specimen, however, is not papillose 

 and differs in form. 



The Phroniina 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. llaast tells me that he has frequently found specimens of this little 

 Crustacean on the West Coast, always inhabiting a similar cell. 



Phronima nov^-zealandi^e, sp. no v. 



Cephalon very large, tumid above, tapering to the oral apparatus, finely 

 striated, the stria) being resolvable with a low magnifying power into rows of 

 pellucid dots. Auteuniu as long as the breadth of the cephalon at their 

 insertion, the first joint being very short. 



First pair of gnathopodu having the mcros slightly produced postero- 



