WISCONSIN PE7TOPLANETON 101 



GLOEOCYSTIS GIGAS (Kiitzing) Lagerheim. PI. 19, Fig. 2. 



ofvers. kgl. Vet.-Ak. Forh. 40: No. 2: 63. 1883; G. S. West, Brit. Freshw. 

 Algae 245: figs. 113F-113H. 1904. 



Cells spherical; solitary or in families of 2-8; enclosed by a thick, 

 distinctly lamellated, gelatinous envelope. Chloroplast of young cells 

 cup-shaped, of older cells diffuse. (Tychoplanktont). 



Cells 9-17 p in diam. ; colonies 45-95 p. in diam. 



Mendota (IT), Oconomowoc (rr). 



SPHAEROCYSTIS Chodat 1897. 



Colonies spherical with the cells in groups of 4-8-16-32 and disposed 

 towards the periphery of a hyaline, homogeneous, gelatinous envelope 

 and with the envelope surrounding each group of cells distinct or con- 

 fluent with the colonial envelope. Colonies sometimes forming palmella 

 stages where the cells are irregularly disposed. Cells spherical ; chloro- 

 plast cup-shaped or filling the entire cell, with one pyrenoid. 



Reproduction by the liberation of a group of cells through the soften- 

 ing of the colonial envelope. Zoospores of two sizes have been observed. 



SPHAEROCYSTIS SCHROETERI Chodat. PI. 19, Figs. 3-4. 



Bull. Herb. Boiss. 5: 119, pi. 9, figs. 1-12. 1897; G. S. West, Jour. Linn. Soc. 

 Bot. 39: 76, figs. 9A-9F. 1909. 



Characters the same as those of the genus. ( Euplanktont) . 

 Diam. cells 6-22 /* ; diam. colonies 50-500 /*. 



Balsam (rr), Bear (2) (ss), Bear Trap (sss), Beasley (rr), Big (sss), Big 

 Butternut (rr), Birch (1) (rr), Birch (2) (ss), Birch Island (rr), Boulder 

 (ss), Browns (rr), Camp (rr), Carson (rr), Catfish (rr), Center (rr), Chetac 

 (ss), Chetek (cc), Clam (rrr), Clear Crooked (s), Crab (r), Cranberry (rr), 

 Deer (rr), Devils (1) (sss), Eagle (rr), East (rr), Elizabeth (sss), Found (r) 

 Fowler (rr), Green (1) (rr), Half Moon (rr), Hillman (rr), Hooker (rr), 

 Kimball (rr), Kitten (rr), Lac Court Oreilles (rr), Lac du Flambeau (r), 

 Lac la Belle (ss), Little Bass (1) (ss), Little Butternut (r), Little Doctor 

 (rr), Little Wood (rr), Long (1) (ss), Long (2) (rr), Long (3) (rrr), Love- 

 less (rr), Lower Nashotah (rr), Lower Nemahbin (cc), Lower Turtle (r), 

 Mary (ss), Mendota (r), Meta (ccc), Mill (sss), Monona (r), Mud (1) (rr), 

 Mudhen (sss), Nicaboyne (r), No Mans (rr), North Turtle (rr), North Twin 

 (rr), Number One (cc), Oconomowoc (ss), Okauchee (ss), Old Taylors (rr), 

 Pike (rr), Pine (2) (rr), Pine Tree (rr), Pokegama (1) (ss), Pokegama (3) 

 (sss), Poplar (ss), Prairie (ss), Rainbow (rr), Rice (1) (ss), Rock (r), 

 Round (1) (rrr), Round (2) (rr), Rudolph (rr), Sand (3) (rr), Sand (4) 

 (rrr), Shell (ccc), Silver (2) (r), South Turtle (r), Tamarack (rr), Upper 

 Nemahbin (rr), Upper Turtle (rr), Waubesa (rr), Winnebago (r). 



