INVERTEBRATES 
to that of many of the latter. They occur sporadic- 
ally in large numbers in pools that become dry dur- 
ing the summer months. Like so many of the fresh 
water animals they have resistant eggs which can 
withstand drought and frost and which are doubtless 
transported long distances by water birds. 
Pristicephalus gelidus (Hay)—Scarboro Junction. 
Lynceus gouldii (Baird)—Scarboro Junction. 
Eulimnadia agassizii Packard—Georgian Bay.* 
Cladocera. 
These minute water fleas flourish in abundance in 
fresh water everywhere. They form the chief food 
of the fry of many of our fishes. They are often 
seen swimming around in immense swarms. The 
only record is 
Daphnia pulex?—Tap-water (Acheson). 
Ostracoda. 
An examination of debris from the margin or 
bottom of any pool or stream will show numbers of 
these minute shelled Crustaceans scrambling over the 
other objects. The only record for Toronto is a 
Cypris (?) sp. by Nicholson. 
Copepoda. 
These “ oar-footed” water fleas are found in a 
variety of situations in our fresh waters. Best known 
is “the little Cyclops with one eye” that can be 
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