Smith—Phytoplankton of the Muskoka Region. 339 
The cells of this variety as found in Butterfly Lake were slightly 
longer than those from Lake. Monona in Wisconsin. A few cases 
of eight-celled colonies with the two-ranked arrangement shown 
in figure 4 were observed. 
SCENEDESMUS BIJUGA (Turp.) Lag. 
St. Mary (rrr), Vernon (rr). 
Scenedesmus ARCUATUS Lemm. 
Burned Rock (rrr), Butterfly (r), Vernon (rrr). 
var. platydisca G. M. Smith 
Butterfly (rrr). Gull (1) (rrr), Harbon (rrr), St. Mary (rrr), Vernon 
(rrr). 
Scenedesmus armatus (Chodat) Gr. M. Smith 
Butterfly (rr), Harbor (rrr), Pine (rrr). 
var. major G. M. Smith 
Burned Rock (rrr). 
Scenedesmus brasiliensis Bohlin 
Basil (rrr), Big Dudley (rrr), Black (1) (rrr). Clear (2) (rrr), Cor¬ 
nell (rrr), Little Dudley (rr), Loon (rrr), Mud (rrr), Portage (rrr), 
Silver (1) (rrr), Vernon (rrr), White (rrr). 
Scenedesmus hystrix Lag. 
Black (1) (rrr), Nine Mile (rrr). 
Scenedesmus denticulatus Lag. 
Big Dudley (rr), Black (1) (rrr), Cornell (rrr), Marion (rrr), Pine 
(rrr), Round (1) (rrr), Vernon (rrr), White (rrr). 
Scenedesmus abundans var. longicauda G. M. Smith 
Big Dudley (rrr), Clear (2) (rrr). 
Scenedesmus quadricauda (Turp.) Breb. 
Big Dudley (rr), Clear (2) (rrr), Harbon (rrr), Rowley (rrr), Silver 
(1) (rrr). 
var. quadrispina (Chodat) G. M. Smith 
Burned Rock (rrr). 
var. longispina (Chodat) G. M. Smith 
Black (1) (rrr), Brush (rrr), Butterfly (rrr), Harbon (rrr). 
