5th August, 1890. 
Gentlemen, I have the honor to transmit Progress Report by 
Mr. Whitelegge on Alga; received from tlie Geological Survey 
Department, and handed to him for examination, and to recom- 
mend that it be published in the “ Records,” and a copy forwarded 
to the Department. 
I have the honor to be, Gentlemen, 
Your Obedient Servant, 
Ed. P. Ramsay, Curator. 
To the Trustees of the Australian Museum. 
A u s t ralian M useui 1 i , 
4tli August, 1890. 
To the Curator. 
Sir,— -I have the honor to report that some time 
ago I received from the Acting Curator a bottle containing a 
green unicellular Alga, obtained by Mr. David, the Acting 
Government Geologist, from the Maitland Waterworks, with 
instructions from the former to send in a Progress Report for 
the information of the Trustees. 
It appears that this particular Alga exists at certain seasons 
in such numbers as to seriously interfere with the pumping of 
the water, which it would probably render unpalatable, if not 
unfit for consumption. 
1 he plants are exceedingly small, somewhat ovoid in shape, 
and of a light pea-green colour. When found in large numbers 
they give oil a very unpleasant and fmtid odor, like that of many 
other plants rich in protoplasm, such as Nitella and Chara. The 
plant is evidently closely allied to, if not identical with 
Cldamydo'inonas pulvi&culus of Ehrenberg, but until the various 
stages of its life-history are known, it would be unsafe to give a 
definite opinion as to its sj^ecihc identity. From what I have 
seen of the same plant near Sydney, it passses some weeks in a 
free swimming condition, afterwards it loses its cilia and rises to 
the surface of the water, forming a thick scum of green powder. 
I his phase evidently represents one of the resting stages of the 
plant. When found in this condition it seems to repel the water 
and appears quite dry ; by the action of the wind it is blown to 
the sides of the dam, where it often accumulates to a deptli of 
several inches, ft is probable, that before the plants resume 
active growth again, a kind of drying process is necessary, and 
that they rest on the mud until the ensuing rainy season. 
