Chilton. — On Neir Zealand Idoteidto. 189 



Art. XXII. — Bevision of the Neic Zealand IdoteidsD. 



By Chaelbs Chilton, M.A., B.Sc. 



[Read before the Otago Institute, 12th November, 1889.] 



During the past year I obtained some specimens that re- 

 vealed a few new facts bearing on the New Zealand Idoteidce, 

 and, as I had to examine some of the species pretty carefully, 

 I decided to overhaul all recorded from New Zealand ; and the 

 following paper is the result. 



I add one species — viz., Idotea 'pcronii, M. -Edwards — to 

 the list of those found in New Zealand; xeAwceEdotia dilatata, 

 Thomson, to a synonym of Idotea elongata, Miers ; and omit 

 Idotea margaritacea, Dana, as it is, according to Miers, in all 

 probability the same as I. mctallica, and in any case it belongs 

 to Australia rather than to New Zealand. At the same time, 

 I am able to settle a few points hitherto uncertain in the 

 synonymy of some of the species, and also to give some addi- 

 tional information regarding them. 



The species recorded from New Zealand are now eight (8) 

 in number — viz., seven Idoteas and one Cleantis — and of these 

 I have seen all but Idotea marina. It will be interesting to 

 recapitulate what is known of their distribution. Two — 

 /. marina and I. mctallica — are almost cosmoiDolitan, the latter 

 being pelagic in habit, but the former only has hitherto been 

 recorded from Australia ; three — 1. peronii, I. ungidata, and 

 I. elongata — are widely distributed in the southern seas, 

 I. ijeronii being known from Australia, Tasmania, New Zea- 

 land, and the Cape of Good Hope, I. ungulaia from the 

 Indian Ocean, the coasts of South America, Cape of Good 

 Hope, Australia, Auckland Islands, Falkland Islands, and 

 New Zealand, and /. elongata from New Zealand, the Auck- 

 land Islands, and the Falkland Islands, but not as yet from 

 Australia, though it is worth noting that the Australian speci- 

 mens of I. ungnlata that I have examined are to a consider- 

 able degree intermediate between that species and I. elongata ; 

 two species — Idotea f estiva and Cleantis tuhicola — are known 

 from New Zealand only, the latter apparently being closely 

 allied to C. granulosa, Heller, from St. Paul's; the remaining 

 species, Idotea lacustris, is found in New Zealand only, in a 

 lagoon of fresh water situated close to the ocean, and is 

 probably identical with a species, presumably marine, from 

 the Straits of Magellan. 



The distribution of these Idoteidce thus appears to confirm 

 the argument drawn by Professor Parker" from the distribu- 



* " Trans. N.Z. Inst.," xix., p. 154. 



