WISCONSIN PHYTOPLA.NKTON 37 



to the base of the cells. Cell contents homogeneous; grey to pale or 

 bright blue-green, rose colored in rare instances. (Euplanktont). 

 Cells 1.5-2.5 /A broad, 1.5-4 p long. Colonies rarely over 40 /j. in diam. 



Bear (1) (rr), Beaverdam (c), Big McKenzie (ss), Blake (sss), Cochrane 

 (r), Deer (rr), Diamond (r), Dunham (c), Fish (c), Half Moon (rr), Island 

 (rr), Kawaguesaga (r), Lac Court Oreilles (ss), Lindy (sss), Little Bass (2) 

 (rr), Long (1) (rr), Loon (rr), Mendota (s), Mercer (ss), Middle McKenzie 

 (ss), Mudhen (ss), Nicaboyne (r), North Twin (r), Pardee (rr), Plum (rr), 

 Pokegama (3) (rr), Sand (1) (r), Sand (2) (rr), Sand (4) (rr), Spirit (r), 

 Squirrel (sss), Star (sss), Wolf (r). 



The colonies of this species resemble those of Coelosphaerium Kuetz- 

 ingianum in cell shape and arrangement but differ in the radiating 

 strands of gelatinous material running from the center of the colony 

 to the base of the cells. The gelatinous envelope is very delicate and 

 cells frequently break away leaving the central mass of gelatinous radi- 

 ations floating by itself. 



GOMPHOSPHAERIA APONiNA Kiitzing. PI. 4, Figs. 2-3. 



Decades 16: No. 151. 1836; G. S. West, Brit Freshw. Algae 349, fig. 163 B - 

 1-904. 



Colonies small, spherical to subspherical, with a fairly thick, hya- 

 line, homogeneous, gelatinous envelope. Cells pyriform to cuneate, 

 cardioid just before division; sparsely scattered and in a single layer 

 some distance beneath the periphery of the colonial envelope. Indi- 

 vidual sheaths of cells generally distinct, attached at the base to the 

 dense gelatinous strands radiating from the center of the colony. Cell 

 contents homogeneous or finely granulose; without pseudovacuoles ; 

 generally a bright blue-green. (Tychoplanktont). 



Cells 4-5 n wide at the greatest breadth, 8-15 //. long. Diam. colonies 

 50-90 /.. 



Beaverdam (sss), Big McKenzie (rrr), Browns (rr), Center (rr), Eagle 

 (rr), Elizabeth (rr), Hillman (rr), Kegonsa (rrr), Lower Nemahbin (rr), 

 Mendota (rr), Mary (rr), Monona (rrr), Mudhen (rr), North Turtle (rrr), 

 Otter (rrr), Pewaukee (rr), Pine (1) (rrr), Plum (rrr). Silver (2) (rr), Sil- 

 ver (3) (rr), South Turtle (rr), Waubesa (r). 



var. CORDIFORMIS Wolle. PI. 4, Fig. 4. 

 Bull. Torr. Bot. Cl. 9: 25, pi. 13, fig. 11. 1882. 



Cells considerably larger than in the typical form and markedly 

 heart shaped instead of pyriform. Individual sheaths of cells conspicu- 

 ous. Cell contents bright blue-green. (Tychoplanktont). 



Greatest breadth of cells 6-13 p, ; length 9-20 p.. 



Bloom (rrr). 



