74 WISCONSIN PHYTOPLANETON 



DINOBRYON STIPITATUM Stein. PI. 13, Fig. 11. 



Der Organismus der Infusionstiere 3: pi. 12, fig. 5. 1878; Pascher, D. Siiss- 

 wasserfl. Deutschl. osterr. u. d. Schw. 2, Flagellatae 2: 73, fig. 118. 1913. 



Cells always in narrow, fairly dense, free-floating colonies. Recep- 

 tacles of individual cells elongate-conical, with bases produced into stipes 

 with nearly parallel sides. Sides of receptacle not undulate. Indi- 

 vidual receptacles of colony not divergent from one another. Seasonal 

 variation chiefly in elongation of apical cells of colony. (Facultative 

 Planktont). 



Receptacles 68 p. broad ; 5696 p, long. 



Marl (ss), Oconomowoc (cc), Round (4) (sss), 'South Turtle (IT). 



DINOBRYON SOCIALE Ehrenberg. PI. 13, Fig. 12. 



Abh. d. k. Ak. d. Wiss. Berlin 1833: 279. 1835; Die Infusionsthierchen 125, 

 pi. 8, fig. 9. 1839; Pascher, Siisswasserfl. Deutschl. osterr. u. d. Schw. 2, 

 Flagellatae 2: 73, figs. 116-117. 1913, 



Cells in free-floating colonies. Individual receptacles somewhat di- 

 vergent from one another and producing a fairly loose colony. Recep- 

 tacles conical, sometimes slightly constricted below the open mouth, with 

 bases gradually tapering to a sharp point that is not extended to form 

 a process. (Facultative planktont). 



Receptacles 7-8 /* broad, 30-70 /* long. 



Beasley (ss), Green (1) (ss), Green (2) (cc), Mill (c), North Turtle (rr), 

 Oconomowoc (cc), Silver (2) (s), Trout (rr). 



DINOBRYON SETULARIA Ehrenberg. PL 13, Fig. 13; PI. 14, Fig. 1. 



Abh. d. k. Ak. d. Wiss. Berlin 1833: 280. 1835; Die Infusionsthierchen 124, 

 pi. 8, fig. 8. 1838. 



Cells in free-floating, densely branching colonies. Receptacles cylin- 

 drical-campanulate, with the convex bases tapering abruptly to a sharp 

 point. Cells with shorter and broader receptacles than the other species. 

 Seasonal variation not so pronounced as in other species. (Facultative 

 Planktont) . 



Receptacles 10-14 p, broad, 30-44 p long. 



Devils (1) (ccc), Kawaguesaga (ss), Long (4) (ss), Lost (ss), Lower 

 Nemahbin (ss), Rock (ss), Round (3) (ss), Winnebago (rr). 



