WISCONSIN PEJTOPLANKTON 



SCENEDESMUS QUADRicAUDA (Turpin) de Brebisson. PI. 40, Figs. 9-11. 



M6m. de la Soc. Ac. de Falaise 1835: 66. 1835; G. S. West, Brit. Freshw. Algae 

 220, figs. 92i>-92F. 1904. 



Coenobia flat, of 2-4-8-16 (generally 4) cells in a simple linear or 

 subalternating series. Cells cylindrical-ovoid, with rounded poles. Poles 

 of terminal cells with a single long straight or curved spine. Poles of 

 interior cells without spines. (Facultative Planktont). 



Cells 3.5-6 p broad, 11-16 /*, long. 4-celled coenobia 11-16 p. broad, 

 12-23 p. long. Spines 10-12 ^ long. 



Beaverdam (IT), Big Butternut (rrr), Blake (rr), Browns (rr), Camp (IT), 

 Chetek (rr), Clam (rr), Clear (rr), Eagle (rr), East (rrr), Fishtrap (rr), 

 Green (1) (rr), Hillman (rr), Horseshoe (2) (rr), Lac du Flambeau (rr), 

 Lindy (rr), Little Rice (2) (r), Lost (rr), Loveless (rr), Lower Nashotah 

 (rr), Lower Nemahbin (rr), Mary (rr), Meta (rr), Mud (1) (rr), Mud (2) 

 (rr), Muskallonge (r), Nancy (rr), Okauchee (rrr), Old Taylors (rr) Poke- 

 gama (I) (rr),Pope (rr), Poplar (rr), Poor Farm (sss), Rice (1) (rr), Round 

 (3) (rr), Sand (1) (rrr), Sand (4) (rr), Travis (ccc), White Ash (rr), Wild 

 Goose (rrr), Winnebago (rr). 



The most ubiquitous species of the genus. The presence of spines 

 on the poles of the terminal cells only is the distinguishing feature of 

 the species. Cultural work has shown that it is possible to recognize 

 several distinct varieties of this species. 



var. PARVUS G. M. Smith. PI. 40, Fig. 17. 

 Trans. Wis. Acad. Sci., Arts, & Lett. 18 2 : 480, pi. 31, figs. 162-166. 1916. 



Cells ovoid-cylindrical. Length of cells 2-2.5 times the breadth and 

 equal to the length of the spines. (Tychoplanktont). 



Cells 3-4 /*- broad, 5.5-8 ^ long. 4-celled coenobia 5.5-8 /x broad, 

 12-15 n long. Spines 4.5-8 /* long. 



Deer (rrr). 



var. QUADRISPINA (Chodat) G. M. Smith. PI. 40, Figs. 15-16. 

 Trans. Wis. Acad. Sci., Arts, & Lett. 18 2 : 479, pi. 31, figs. 167-171. 1916. 



Cells broadly ovoid, about twice as long as broad. Spines short, 

 about as long as the diameter of the cell. (Tychoplanktont). 



Cells 3.5-8 fi broad, 8.5-15 //. long. 4-celled coenobia 8.5-15 /i broad, 

 16-32 n long. Spines 2.5-5.5 /* long. 



Mill (rrr), Pine (rr), Pokegama (1) (rrr), Round (1) (rr), Tied Canoe 

 (rrr). 



