May , 1 1) 17] The A Igcc of Michigan 225 



Mougeotia bicalyptrata Wittrock. Carp Lake, Emmet Co., 

 Aug. 9, 1915. Occurring with the last, with vegetative 

 cells 10 to 12 microns in diameter. The zygospores 

 resemble in every particular the type material for this 

 species. It is evidently closely related to M. calcarea, and 

 perhaps should be recognized as a variety rather than as a 

 distinct species. 



Mougeotia parvula Hassall. Small stream, New Buffalo, May 

 ;n, 1915. 



Mougeotia gracillima (Hass.) Wittrock. Bog north-east of 

 Twin Lake, June 2, 1915. 



Mougeotia elegantula Wittrock. Twin Lake, June 2, 1915. 



Mougeotia viridis (Kiitz.) Wittr. Bog stream, Saugetuck, 

 June 1, 1915. This material contains scattered aplano- 

 spores as well as zygospores, and adds another species to 

 the list in which both spore forms have been found. 



Mougeotia robusta (DeBary) Wittr. var. biornata Wittrock. 

 Railroad pool, New Buffalo, May 31, 1915. 



Mougeotia (?) genuflexa (Dillw.) Ag. Common in many of the 

 collections. The dimensions and genuflexing habit are 

 characteristic for this species, but I have not found any 

 spores. 



Mougeotia quadrangulata Hass. Railroad pool, Mackinaw 

 City, Aug. 9, 1915; pond, Saugetuck, June 1, 1915. 



Debarya decussata Transeau. Trout Lake, Chippewa Co., 

 Aug. 10, 1915. Abundant in all the collections from this 

 lake. The material contained only zygospores and veg- 

 etative filaments. 



Zygnema cyanospermum Cleve. Railroad ditch, Manistique, 

 Aug. 11, 1915; railroad pool, Mackinaw City, Aug. 9, 1915. 

 Previously reported only from Greenland. 



ISOKONT^. 



VOLVOCACEiE. 



Gonium pectorale Aliiller. New Buffalo, May 31, 1915. 

 Pandorina morum (Mull.) Bory. New Buffalo, May 31, 1915; 



Breedsville, June 4, 1915. 

 Eudorina elegans Ehrenb. Seney, Aug. 12, 1915; small stream, 



New Buffalo, May 31, 1915. 



