WISCONSIN PHYTOPLANKTON 141 



KEY TO THE SPECIES. 



Cells lunate to sickle-shaped. 



Ends of cells pointed K. LUJTARIS 



Ends of cells rounded K. OBJCSA 



Cells arcuate, spiral, or vermiform cylinders. 



Breadth of cells 2 ^ or less K. CONTORTA 



Breadth of cells over 2 /j. K. ELONGATA 



KIRCHNERIELLA LUNARis (Kirchner) Mobius. PI. 34, Fig. 4. 



Abh. d. Senckenb. Naturf. Ges. 18: 331. 1894; Chodat, Mater, pour la fl. crypt. 

 Suisse I 3 : 202, figs. 12r-121 8 . 1902. 



Cells flattened, crescent-shaped, with apices some distance apart, 

 about twice as long as broad, ends tapering to a blunt point; irregu- 

 larly arranged in groups of four to eight within the gelatinous colonial 

 envelope. Chloroplast single, filling the entire cell with the exception 

 of a small part on the concave side; pyrenoid single. (Facultative 

 Planktont). 



Cells 3-8 n broad, 6-15 p. long ; colonies up to 250 p in diam. 



Bear (3) (rr), Beaverdam (rr), Birch Island (rrr), Blake (rr), Chain (ss), 

 Chetek (rr), Cochrane (rr), Crab (rrr), Deer (rr), Devils (2) (rr), Duck 

 (rr), Dummy (sss), Elizabeth (rr), Green (2) (rr), High (rr), Hillman (r), 

 Horseshoe (1) (rr), Jag (rr), Lindy (rrr), Little Crooked (rrr), Little Doc- 

 tor (rr), Long (3) (rrr), Loveless (rr), Lower Turtle (rrr), Lynx (rrr), Men- 

 dota (rr), Meta (rr), Mud (2) (rr), Nancy (sss), North Twin (rrr), Paddock 

 (rr), Pardee (rr), Pine Tree (rr), Pokegama (1) (r), Pokegama (3) (sss), 

 Poplar (rr), Prairie (sss), Round (3) (rrr), St. Croix (r), Shell (r), Spirit 

 (rrr), Squirrel (rr), Upper Turtle (rrr), White Ash (rr). 



The species differ from K. obesa in the pointed ends of the cells. The 

 two are widely distributed plankton .organisms but have never been 

 found in quantity in any lake of the state. 



var. DIANAE Bohlin. PI. 34, Fig. 5. 

 Bih. Kgl. Sv. Vet.-Ak. Handl. 23, Afd. 3, No. 7: 20, pi. I, figs. 28-30. 1897. 



Cells curved until the apices are almost touching, apices more pointed 

 and frequently slightly twisted. (Facultative Planktont). 

 Cells 3-5 p broad, 10-21 /t long. 



Hillman (rr), Pine (2) (rr), White Ash (r). 



The cell shape of this variety resembles that of Selenastrum but the 

 colony differs in being enclosed by a gelatinous envelope. The apices 

 are much sharper than in the typical form. 



