22 FAUNA Oi' A MADRAS POND AND ITS VARIATIONS. 
became much reduced in numbers at certain periods. I 
proceed to enumerate with notes the organisms I found 
and determined. 
Pkotozoa. — Rhizopoda, Amoeba j Pelomyxa viridis, Bourne. 
Infusoria, Vorticella ; Paramoeciuin ; Ghilodon ; 
Euglena ; Monas and various gregarines para- 
sitic in other organisms. 
'J'bese ai'e the only Protozoa which I found so that the 
group is very poorly represented. One of these forms — 
Pelomyxa viridis is a new species and possesses peculiar 
interest. I first noticed it lying* on the surface of the mud 
which I had placed in a dish. There were a large number 
of specimens and they looked like eggs, rounded or oval in 
shape and greenish in colour. I pointed them out to Dr. 
Bourue who found that when mounted on a slide they 
exhibited amoeboid movements — the organisms being large 
enough and these movements rapid enough to be seen with 
the naked eye. Dr. Bourne has figured and described 
tlie organism as Pelomyxa viridis and his paper will 
appear in a forthcoming number of the Quarterly Journal 
of Microscopical Science. It is therefore unnecessary for 
me to refer further to it here. Most of the Infusoria were 
found throughout the year, they do not appear to be 
affected by changes in the weather and their miscroscopic 
size and consequent limited requirements are always 
satisfied by the conditions of the pond so long as any 
water remains. 
Pelomyxa viridis Avas not to be found throughout the 
year. I first found it in January li^90 and it was to be 
found, though in diminishing numbers up till the end of 
May, from June till the end of October it was uoc to be 
found either in the water or the mud i^f which latter I sifted 
great quantities through fine sieves. In November and 
December I saw it again and found a few speeinious. Early 
