NATURAL HISTORY, TORONTO REGION 
found in almost any gathering of water. Our only 
record of the free-living forms is 
Cyclops quadricornis—Tap-water (Acheson). 
Many are parasitic in habit, attaching themselves 
to the gills or skin of fishes. They have been studied 
by Prof. Ramsay Wright. 
Ergasilus centrarchidarum Wright—on Perch, Rock 
Bass and Sunfish (Wright). 
Actheres micropteri Wright—Black Bass (Wright). 
Lernaeopoda edwardsii Olsson—on Brook Trout 
(Wright). 
Argulus stizostethii Kellicott—on Lunge and Rock 
Bass, Georgian Bay.* 
ANNELIDA. 
Oligochaeta. 
In addition to the well-known earthworms, of 
which there are no Toronto identifications, a large 
number of aquatic forms, mostly of small size, are 
to be found here. Only the following have been 
noted. 
Lumbriculus sp.—Toronto Bay (Nicholson). 
Saenuris canadensis Nichols.—Toronto Bay (Nich- 
olson). 
af sp-—Toronto Bay (Nicholson), 
Chaetogaster langi Bretscher—Aquaria, Biol. Dept. 
Nais tortuosa Walton—Aquaria, Biol. Dept. 
‘Pristina leidyi Smith—Aquaria, Biol. Dept. 
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