566 Cut PING 
out the season for Ephydra subopaca in both the larval and the adult} 
stages when active. The plancton enriching pools A to E gives color to 
the salt water in very different degrees. Plancton is the only organic 
material from which the inhabiting fauna obtains its subsistence. In th 
summer season the changing colors and varying content of the water in| 
these pools mark the increase and decrease in abundance of the micro 
scopic forms of one kind or another. During frequent surveys of pool 
A to F made in the middle and later part of the summer, it was found 
that the plant life therein included large numbers of Chlamydomonae, 
Navicula, and bacteria, and the animals, numerous Actinophrys an 
Monas, a few Astasia and amoebas, and a very few Halophrys an 
Ciliata. 
The green color of the water in the pools is due to the presence of an 
abundance of green algae, chiefly Chlamydomonae, and the brownis 
tinge is caused by the increase of diatoms, namely, some species of Navi 
cula and its allies. These are the two most prominent forms of plan 
life in the pools. 
As before stated, pools I and II were formed later than the others, and 
their water remains clear all the time; accordingly in them the biclogical 
content is more meager, consisting of a small number of Navicula, Chlamy- 
domonae, and one or two ciliated protozoa. In late summer, however, 
a noticeable change takes place. At the bottom of these pools a thin 
layer of brownish organic matter is formed, largely made up of Navicul 
with comparatively few Chlamydomonae. This deposit does not affec 
the transparency of the fresh brine water. 
Owing to the wide area and exposed surfaces which are easily reache 
by sunshine, thick, foamy, brown scums are found here and there on th 
surface of the shallow water in the overflowed areas. These scums affor 
the larvae, especially during early stages, shelter and shade when th 
sun’s rays at noontime are too strong; they act as a moisture retaine 
when the areas are rapidly drying up; and finally, for the larva as well a 
the adult, they constitute a main source of food supply. These floatin 
scum masses embody the entire fauna and flora in the shallow water. 
In comparing the two sets of pools—A to F, and I and II and the over 
flowed areas — it was found that in the former group green algae predomi 
nated, with the protozoa more numerous, while in the latter group th 
brown algae were in greater abundance. 
