140 WISCONSIN PH? TO PL AN ETON 



the long axes of the cells parallel to the long axis of the colony. Cells 

 lying in pairs, spindle-shaped; generally with one pole rounded and 

 the other pointed. The rounded ends of a pair of cells in apposition. 

 Chloroplast single, parietal, laminate; with one pyrenoid. Colonies 

 rarely containing over fifty cells. (Euplanktont). 



Cells 3-6 p broad; 15-25 /* long. Colonies 10-30 p. broad; 70-160 

 fi long. 



Crooked (rrr), Deer (rrr), Hillman (rr), Jag (rrr), Jennie (rr), Long (2) 

 (rrr), Long (3) (rr), Loon (rrr), Mudhen (rr), Pine (2) (rrr), Sand (2) 

 (rrr), Streitor (sss). 



The dimensions of the cells and the general appearance of the colony 

 in individuals that I have found is more like the Wests' description of 

 the alga as found in England. Wisconsin colonies rarely contain more 

 than sixteen cells. 



ELAKTOTHRIX VIRIDIS (Snow) Printz. PI. 33, Fig. 7. 



Skr. Vidensk. i Kristiania Mat.-Naturv. Kl. 1913 1 : No. 6: 31, pi. 1, figs. 9-12. 

 1914. 



Fusola viridis Snow, Bull. U. S. Fish Comm. 22: 389, pi. 2, figs. VP-VP. 1903. 



Colony free-floating or epiphytic, fusiform or irregular; gelatinous 

 sheath of colony sharply defined, frequently showing remains of old 

 cell wall at apex. Cells broadly fusiform, straight or sigmoid, with 

 acute apices. Chloroplast single, completely filling the cell; with one 

 or two pyrenoids. (Tychoplanktont). 



Cells 6-15 /* broad, 12-35 /* long. 



Soft (rr). 



KIRCHNERIELLA Schmidle 1893. 



Cells lunate to sickle-shaped with their apices almost touching; or 

 elongate, vermiform, arcuate, or spiral cylinders with rounded ends. 

 Associated without definite arrangement in colonies enclosed by a hya- 

 line, homogeneous, gelatinous envelope. Number of cells in young 

 colonies a multiple of two, in older colonies indefinite but rarely more 

 than seventy-five. Chloroplast single, parietal, on convex side of or 

 entirely filling the cell ; generally with a single pyrenoid. 



Reproduction by the division of any cell to form four or eight auto- 

 spores that are liberated by a rupture of the old mother cell wall but 

 remain within the gelatinous envelope of the colony. 



