88 Searle and Shephard, Visit to Lakes. [ v^xxxu 



tilling a pound jar with this mass, and adding some Formalin 

 as a preservative, the net was washed out and again set in 

 action, towing being timed one minute, and as a result a 

 4-oz. bottle was nearly half-filled with organisms. Finding 

 that if we continued operations with the tow-net we would 

 obtain an embarrassing supply of specimens, we tinned our 

 attention to hand-netting, and with the aid of sieves and 

 strainers endeavoured to separate the heterogeneous " takes " 

 until we felt satisfied we had secured a fair sample of the 

 plankton over a distance of two or three miles. 



On a previous visit one of us had met with the hydroid 

 Cordylophora, and, remembering this, a search was made, which 

 resulted in the discovery of abundant colonies attached to the 

 posts of the jetty and the stems of water weeds. This inter- 

 esting animal was at one time plentiful in the Melbourne Botanic 

 Gardens lake, but disappeared for nearly twenty years ; 

 curiously, it has again been found abundantly, since the ex- 

 cursion we are recording, by the members of the Victorian 

 Microscopical Society in the same place. 



Well pleased with our first day's collecting, we returned i<> 

 our hotel with an appropriate appetite for the evening meal. 

 Later, we retired to a room, and, as we each had a travelling 

 microscope and a dissecting stand, we were able to examine 

 our captures alive. We hold strongly that a zoologisl does 

 not know aquatic microfauna unless he can see the living 

 specimens. One great advantage of microscopic examination 

 on the spot is that if a new animal is observed a further supply 

 can be looked for before leaving. Our examination showed 

 that tin- most plentiful of the Cladocera was a variety oi tin' 

 widely-spread and variable species, Daphnia carinata, the 

 carapace being spineless, or at most pos 1 very short 



projection at the posterior end. Pseudomoina lentna was also 

 fairly numerous, and there was a good numbei ol Moina 

 australiensis. Among the ( opepoda, Boeckella <>hh>>ii;<i was 

 recognized, also a new species ol the same genus. two species 

 .,] Cyclops were noted, but not identified. Ostracoda weir not 



numerous, no doubt owing to the absence ol weeds, the boatman 



informing us that Black Swan-, had practically cleared them 

 from the lake. I in large and handsome CipHs Mytiloides was 

 the mosl noticeable, being found clustering among the alga 

 taken off the piles supporting the jetty. Only on< • ol 



rotifer w ved, but that was enormously numerous, and. 



although occurring as a free-swimming animal, was mostly 

 found attached to the carapace ol Daphnia carinata, not being 

 found on any othei entomostrat an 1 ollei ted. This attai nmenf 

 appeared to enable the rotifei to apply the 1 iliary a< tion ol the 

 i,., entirely to the $ei 111111- ol food, a. the Daphnia supplied 



