650 SUBANTARCTIC ISLANDS OF NEW ZEALAND. [Crustacea. 



looked the fact that, like most other Isopods, lais hatches out its eggs in an 

 incubatory pouch under its own body. It is evident that he knew that this was 

 actually the case in lais pubescens from his reference to the marsupium upon the 

 same page. The eggs are few in number (usually not more than five or six) and of 

 comparatively large size, in both respects, therefore, differing from the conditions of 

 things usually found in true parasites. The lais can evidently leave the Exosphaeroma 

 if it wishes to, as is shown by the fact that I have frequently taken it away from 

 the Exosphaeroma. It would be interesting to know whether this separation is 

 merely temporary for the purpose of seeking food, and if the lais returns to the 

 Exosphaeroma for shelter when danger threatens. 



During a recent visit to the Sounds on the west coast of New Zealand I found 

 lais pubescens in great abundance in nearly all of them. I seldom failed to find it at 

 the head of each Sound, creeping freely on the surface of stones at the mouths of the 

 fresh- water streams ; at low tide these stones would be washed with fresh water 

 only, and some were above the reach of ordinary high tides. At high tide the 

 animals would in most cases be covered with sea- water, but this at the head of the 

 Sounds is often more or less brackish. In most of these localities I did not see any 

 Sphaeromid from which the animal could have escaped. The Campbell Island speci- 

 mens were also mainly collected near the mouth of a small stream, but in a place 

 that would be completely covered with salt water at high tide. 



Mr. Stebbing's Ceylon specimens were obtained from Lake Negombo, which 

 Dr. Arthur Willey describes as " a salt-water lake having both fluviatile and marine 

 connections." 



It thus appears that lais pubescens is a species that can live either free or in 

 association with a Sphaeromid, and either in fresh water or in salt, and to this adapta- 

 bility to varying conditions it doubtless owes its wide distribution and abundance. 



Genus Haliacris, Pfeffer, 1886. 



Distribution. — Antarctic and subantarctic seas. 



I provisionally adopt this genus for the following species merely to draw attention 

 to its close relationship to H. antarctica, Pfeifer. The genus has been accepted 

 by Miss Richardson, and provisionally by Mr. Hodgson, but in his report on the 

 " Discovery " Isopoda he says, " It is much open to question if it is distinct from 

 Munna. I think not."* And with this opinion I quite agree. 



Haliacris neozelanica (Chilton). 



Munna neozelanica, Chilton, Ann. & Mag. Nat. Hist., ser. 6, ix, p. 1, pi. i, ii. 



Auckland and Campbell Islands ; also New Zealand. 



Several specimens — some males with the first pair of legs fully developed, others 

 females with eggs in the brood-pouch — were taken by Professor Benham under stones 

 on Masked Island, in Carnley Harbour, Auckland Islands. He had previously 

 sent me one male specimen collected at Campbell Island in February, 1907. These 

 specimens all agree closely with specimens from the type locality, Otago Harbour. 



This species is close to Haliacris antarctica, Pfeifer, from South Georgia, with 

 which H. australis, Hodgson, from Cape Adare, is now united by Hodgson. Judging 



* Quoted from a proof of his report, whicli Mr. Hodgson has kindly sent to me. 



