92 WISCONSIN PHYTOPLANKTON 



with a sublinear apex, isthmus narrow ; semicells obsemicircular, 

 with apices truncate ; angles continued in very long slightly attenu- 

 ated quadrispinate processes, superior and inferior margins of 

 processes crenulate, median portion at times with a row of granules; 

 processes at first outwardly divergent and then upwardly curved ; cell 

 apex with two emarginate verrucae in the median portion, cell body 

 without other ornamentation. Vertical view triangular, with the sides 

 of the body of the cell straight and the angles continued in long 

 straight processes with faintly undulate margins; body of the cell 

 with two intramarginal emarginate verrucae in the middle of each 

 side. Chloroplast with a small central mass and two short arcuate lobes 

 extending to each angle ; pyrenoid single and central. (Euplariktont.) 



Zygospores unknown. 



Cells 70-88 fx long with processes, 23-30 ju, long without processes ; 

 breadth with processes 81-100 /x,, without processes 20-24 ju, ; breadth 

 at isthmus 8-10 /m. 



Balsam (ss), Big Bass (r), Big McKenzie (rr), Birch Island (rrr), Blake (ss), 

 Carroll (c), Clear Crooked (rr), Cochrane (rr), Crooked (rrr), Deer (ss), Des 

 Moines (s), Dutchmans (rrr). Found (rrr), Grindstone (ss), Half Moon (s), 

 High (rrr), Lac Court Oreilles (sss), Lac du Flambeau (rrr). Long (s), Lost (r), 

 Loveless (rr), Mercer (ss), Middle McKenzie (ss). Mud (rr), Owen (cc), Re- 

 serve (sss). Round (s), Rudolph (rrr). Sand (rr), Squirrel (rr), Whitefish (ss), 

 Wolf (rrr). 



The species is dedicated to Mr. Charles Bullard in grateful appre- 

 ciation of many courtesies extended during the preparation of the 

 section of this work dealing with the Desmidiaceae. There is a cer- 

 tain suggestion of 8. paradoxuni var. longipes Nordstedt in the length 

 and delicate nature of the processes, but in the shape of the cell body, 

 apical verrucae, and curvature of the processes it is quite unlike it. 



31. Staurastrum vestitum Ralfs. PI. 75, Figs. 4-5. 



Brit. Desm. 143, pi. 23, figs. lA-lE. 1848; Delponte, Mem. d. R. Acad, d Sc. di 

 Torino 2 Ser., 28: 158, pi. 12, figs. 46-49. 1877 (sep.) ; Wolle, Desm. U. S. 138, 

 pi. 45, figs. 28-30. 1884. 



Cells of medium size, length about half the breadth (with processes), 

 deeply constricted, sinus widely open and with apex acuminate, isthmus 

 narrow ; semicells broadly obtriangular, with lateral margins and apex 

 straight, angles gradually attenuated into quite stout processes; 

 processes parallel, with four to five concentric rings of conical spines 

 that give the upper and lower margins a coarsely crenulate appearance, 

 ends of processes with three short divergent spines ; apex of semicells 

 with four emarginate verrucae, center of face of semicell with two 

 verrucae lying below the central verrucae of the apical series. Vertical 

 view triangular, with the sides straight and the angles with a process 

 that has the same appearance as in the front view ; median portion of 

 each side of the cell with two elongate bifid to emarginate verrucae 

 projecting at right angles to the cell wall, marginal verrucae some- 

 time flanked by similar but smaller verrucae ; interior of cell with an 



