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 



tis " the little Cyclops with one eye " that can be 

 



