Smith—Phytoplankton of the Muskoka Region . 353 
var. longipes Nords. 
Basil (rr), Clear (2) (rrr), Corner (rrr), Echo (rr), Henshaw (rrr), 
Long (1) (r), Long (2) (s), Loon (sss), Otter (r), Portage (ss), Rosseau 
(rr), Rowley (rr), Silver (1) (rrr), Silver (2) (sss), Vernon (ss). 
Staurastrum subiongipes n. sp. PI. XI, figs. 15, 16. 
Cells of fairly large size, about twice as broad as long (with 
processes), moderately constricted, sinus obtuse angled and widely 
open; semicells cyathiform, with concave apices, ventral margin 
smooth, apical margin with a single emarginate verruca, angles 
prolonged into long gradually tapering processes that are smooth 
on the lower surface and denticulate on the upper, processes 
terminating in three small spines. Vertical view triangular, with 
a single emarginate verruca on the body of the cell between the 
angles; processes with a double row of spines; the angles of one 
semicell alternating with those of the other. 
Length (without processes) 37-40 /a, (with processes) 55-65 y . 
breadth (without processes) 18-20 /a, (with processes) 80-105 y; 
breadth isthmus 8.7 /a. 
Burned Rock (r), Corner (rrr), Gull (2) (rrr), Joseph (rr), Lake of 
Bays (ss), McGowan (rrr), Muskoka (rrr), Pine (r), Rosseau (ss). 
Round (2) (rr), Rowley (c), iSt. Mary (r), Silver (2) (r). 
The species has a considerable resemblance to S. paradoxum var. 
longipes , but differs in the shape of the upper portion of the semi¬ 
cells and the apical verrucae. 
Staurastrum cingulum (W. & G. S. West) comb. nov. 
Staurastrum paradoxum var. cingulum W. & G. S. West, Jour. Linn. Soc. 
Bot. 35: 548. PI. 18, figs. 6, 7. 1903. 
Gull (1) (rr), Hamer (r), Leech (rr), Muskoka (sss), Otter (rrr), 
Rosseau (rrr), Rowley (rr), Silver (1) (r), Vernon (rr). 
Study of the plankton of the Ontario lakes shows that there 
are a number of closely related forms that are characterized by 
a ring of small spines at the base of the semicells. These seem to 
form a natural group and the only named form, which has been 
considered a variety of S. paradoxum , is taken as the type for the 
species. 
var. tortum var. nov. PI. XII, figs. 1, 2. 
Semicells with the processes at the cell corners curved upwards 
in the outer half only. Processes of one semicell alternating with 
those of the other semicell. 
23—S. A. L. 
