Smith—Phytoplankton of the Muskoka Region. 
355 
Staurastrum protectum var. planctonicum var. nov. PL XII, 
figs. 8-12. 
Variety with simple verrucae irregularly distributed or in rings 
on the processes. Body of semicells smooth between the processes 
in front view. Vertical view with two emarginate verrucae be¬ 
tween the processes. Processes ending in two long divergent 
spines. 
Length (without processes) 22.5-27.5 /x, (with processes) 45-50 
/ 1 ; breadth (with processes) 58-69 /x; breadth isthmus 6.25-8.50 n . 
Basil (r), Black (1) (rrr), Burned Rock (rr), Echo (rr), Gull (1) (rr), 
Long (1) (rrr), Long (2) (rrr), Loon (r), McGowan (r), Muldrew (rrr). 
Nelson (rrr), Otter (rrr), Round (2) (sss), Rowley (rrr), Silver (1) 
(rr), Strange (rrr), Vernon (rrr). 
The verrucae on the processes are quite variable in distribution 
and may be in horizontal rows or unevenly distributed. The 
variety is also distinguished by the lack of ornamentation on the 
smooth sides of the semicells in front view. An abnormal cell is 
shown in figure 12 where instead of terminal spines there is a 
branching of the processes that ends in two or three minute spines. 
The alga should be compared with S. patens var. planctonicum G. 
S. West which has a somewhat similar cell shape but a different 
ornamentation. 
Staurastrum lacustre sp. nov. PL XII, figs. 13-15. 
Cells of medium size, a little longer than broad (with processes), 
deeply constricted, sinus broadly open and apex acute; semicells 
obversely triangular, apex slightly concave, with two emarginate 
verrucae, ventral margin straight, angles prolonged into long 
processes with straight, nearly parallel sides and terminating in 
two large divergent spines. Processes with 3-4 rings of simple 
verrucae, scattered verrucae, or 1-2 verrucae on the apical side 
only. Body of semicell smooth, or with a few scattered verrucae 
between the processes. Vertical view triangular, sides slightly 
concave, with two emarginate verrucae on each side between the 
angles, angles ending in processes with straight sides, ornamenta¬ 
tion of processes as in front view. Terminal spines of processes 
lying above one another. 
Length (without processes) 26-34 /x, (with processes) 68-85 /x; 
breadth (without processes) 22-24 /x, (with processes) 75-100 /x; 
breadth isthmus 8.5 /x; length terminal spines 9-12.5 /x. 
Big Dudley (s), Gull (1) (rrr), Loon (rrr), Mud (rrr), Nelson (rrr). 
Portage (rr), Silver (1) (rrr), Vernon (rr). 
