1(34 T ransdctions. 



North Otago appears to be particularly favourable to Rotifers, and it is 

 iuteresting to note that most of the species are more numerous in the late 

 winter months than at any other time of the year ; indeed, they almost 

 entirely disappear in autumn and early winter. This is. I believe, just the 

 reverse of what takes place in Europe, and is probably due to the fact that 

 most of our ponds and streams dry up towards the end of summer. Low 

 temperatures seem to have very little effect on them, and it will be remem- 

 bered that Mr. James Murray, of the '' Nimrod " Expedition, found living 

 Rotifers frozen under 20 ft. of ice in a small lake at Cape Royds, South 

 Victoria Land. It is somewhat remarkable that there should be such a 

 dearth of new species in the locality under consideration. One might 

 imagine that in New Zealand especially there would be some departure 

 from the stereotyped forms of the Northern Hemisphere, but this has not 

 proved the case in our district at any rate, and it may be attributed to 

 the well-known fact that Rotifers and their eggs may l)e conveyed long 

 distances by wind and the feathers of migratory birds. 



For assistance in procuring specimens I wish to thank Miss (xore and 

 Miss Lory, of Oamaru : Mr. G. Howes, of Dunediii : and my assistant. 

 Arthur Willetts. 



Fam. Mkmcertidae. 



Limnias ceratophylli Schrank. 



In a small pond only a few yards hi extent, full of quantities of decaying 

 vegetable matter and muddy water. The tube-builders were in great num- 

 bers ; clusters consisting of three and four generations were common. There 

 were none in this pond the year previous. The largest measured -^^ in. 



Ardgowan, North Otago. 2.5th April. A few in the Oamaru Creek in 

 the beginning of November. 



Oecistes socialis Weber. 



These were found in great numbers in the Aidgowau pond referred to 

 above, the clusters, which were greenish-grey in colour, frequently measur- 

 ing 5 in. in length, and adhering to dead twigs at the bottom. As this was 

 the only occasion on which they were captured, they may l)e considered as 

 rare. The individuals measured ^^-^ in. in length. 



This species has been found in Victoria. Austiiilia. by Mi', .loliu 

 Shephard. 



Conochilus volvox Ehrenberg. 



i first made the acquaintance of this beautiful Rotifeion in the begin- 

 ning of July, 1909, when my assistant, Arthur Willetts. brought me a num- 

 ber which he found in a small pond in the centre of a ploughed paddock at 

 Waikakalii, about twelve miles from the mouth of the Waitaki River. He 

 had mistaken them for Volrox (/lohafor — a very natural error, seeing lie had 

 no microscope. The next specimen was procured in Heptember of the 

 following year in a gravel-pit at Tinwald. South Canterbury. They have 

 been found in several localities in the neighbourhood of Oamaru this year 

 during the months of October and November by members of the Micro- 

 .scopical Club, althougli T made diligent search foi' some years previously 

 without success. The colonies measure from ^V in. to nearly j^^ in. I have 

 noticed that some individuals appear to be shorter and more stoutly built 

 than others, the foot in particular being much shorter. 



