152 Trans. Acad. Sci. of St. Lows. 
River, and several lagoons and numerous ditches. The 
brick-yard ponds, the ages of which varied from less than 
a year to more than twenty years, lay in a flood plain; but, 
since there had not been a large flood for twenty years, 
they furnished an excellent opportunity for the study 
of the succession of entomostracan life in fresh water 
ponds. When the work had been in progress a few 
months, there occurred a large flood, which, temporarily, 
turned all of these ponds into one vast lake. This com- 
mingling of the waters of the several ponds defeated the 
most important aim of this series of studies. For this 
reason, no mention of the relative ages of the different 
ponds is made in this communication. Since no collec- 
tions were made at the time of the flood nor for several 
weeks after it had completely subsided, it is thought that 
the data giving the entomostracan associates of each form 
are reliable. 
The tables that are found in the body of this communi- 
cation record things as they were in Augusta at the time 
of this investigation; but, they do not pretend to predi- 
cate what must be the conditions elsewhere. Indeed, since 
the period of study extended over only a little more than 
one year, it would be claiming too much to insist that the 
conditions here recorded must be invariably the case even 
in Augusta. However, such facts as are recorded are 
positive and it is thought that they will be of some value 
to future students of the ecology of the Entomostraca. 
One fact that I noticed deserves more than passing at- 
tention. Not once in my Augustan experience did I find 
a cladoceran bearing ‘‘winter eggs.’’ It is well known 
that, in warm climates, the Cladocera do not form ‘‘win- 
ter eggs’’; but, since many of my collections were made in 
water with a temperature of a little above zero centi- 
gerade, the result just recorded was not expected. In- 
deed, I often broke a thin layer of ice in order to make 
my collections. In Ohio, where the winters are much 
more severe than they are in Augusta, I have often found 
cladocerans bearing ‘‘winter eggs’’ in water that was 
