498 LIST OF THE FRESHWATER RHIZOPODA OF N.S.W. 



disturbance as possible. By adopting this method many more 

 living forms will be obtained than would be the case if the 

 plants were lifted altogether out of water. 



In the examination of any material it will be most convenient to 

 use only such slips and covers as maybe used subsequently for mount- 

 ing purposes ; by so doing any object of interest can be mounted at 

 once. When any object of sufficient interest is seen it should be got 

 as near the centre of the cover glass as possible ; all surplus water 

 should then be removed from the edges, and one or two drops of 

 a 1 per cent osmic acid solution put on the slide and drawn in 

 under the cover by means of a little strip of blotting paper placed 

 on the opposite side ; after wiping round the edges to remove any 

 water or acid that may remain, the cover may then be luted 

 round with very stiff shellac cement, made by dissolving shellac 

 in spirit. If too much, acid is used the objects will become quite 

 black and useless. 



I have prepared a goodly number of slides in this manner, of which 

 some mounted over twelve months ago show no signs of deterior- 

 ation. The objects include — Collared and Flagellate Monads, 

 Amoeba, Arcella, Difflugia, Clathrulina, Infusoria, Rotifers, 

 Desmids, Diatoms, and many other microscopic organisms. Rhi- 

 zopods and Heliozoa are with a little care easily fixed and 

 preserved with their pseudopodia fully extended. 



The classification adopted is that given by Prof. Leidy in his 

 magnificent work on the "Freshwater Rhizopods of North 

 America." After each species the author's name with references 

 to descriptions is given, and then follow the numbers of page, 

 plate, and figures in Leidy's monograph, which is the most com- 

 plete work on the subject in English, and will, I have no doubt 

 be the standard book of reference for many years to come. 

 When the numbers are interrupted, as in the case of Difflugia 

 corona in which on pi. xvn of Leidy the figures are from 

 1 to 14, whereas the numbers in this list are 1, 2, 5, 6, 9, it 

 means that those forms indicated by the figures only have been 

 seen by me. 



