May, 1 U 1 7 1 The A I gee of Michigan 223 



Micrasterias americana (Ehrenb.) Ralfs. Railroad ditch, New 



Buffalo, ^lay 31, 1915. 

 Micrasterias denticulata Breb. var. angulosa (Hantzsch) W. & 



G. S. West. Twin Lake, June 2, 1915. 

 Micrasterias torreyi (Bailey) Ralfs. Twin Lake, June 2, 1915. 

 Micrasterias truncata (Corda) Breb. Bog near Carp Lake, 



Aug. 9, 1915; railroad pool near Seney, Aug. 15, 1915; 



bog near Caffcy, Mackinaw Co., Aug. 13, 1915. 

 Cosmarium subcostatum Nordst. Carp Lake, Aug. 9, 1915. 

 Cosmarium taxichondrum Lund. Twin Lake, June 2, 1915. 

 Cosmarium cyclicum Lund. Carp Lake, Aug. 9, 1915. 

 Cosmarium botrytis Menegh. Carp Lake, Aug. 9, 1915; bog 



pond near Mackinaw Cit3^ Aug. 9, 1915. 

 Cosmarium portianum Arch. Twin Lake, June 2, 1915. 

 Cosmarium pachydermum Lund. Bog north of Balney, Aug. 12, 



1915. 

 Xanthidium antilopaeum (Breb.) Ktitz. Twin Lake, June 2, 



1915. 

 Staurastrum meriani Reinsch. Small stream, New Buffalo, 



Berrien Co., May 31, 1915. 

 Staurastrum punctulatum Breb. Small stream, New Buffalo, 



May 31, 1915. 

 Staurastrum arctiscon (Ehrenb.) Lund. Twin Lake, June 2, 



1915. 

 Arthrodesmus triangularis Lagerh. forma triquetra W. & G. S. 



West. Twin Lake, June 2, 1915. 

 Cosmocladium constrictum (Arch.) Josh. Pool near Seney, 



Schoolcraft Co., Aug. 12, 1915. 

 Cosmocladium pulchellum (Arch.) Josh. Twin Lake, June 2, 



1915. 

 Sphaerozosma excavatum Ralfs. Twin Lake, June 2, 1915. 

 Spondylosium papillatum W. & G. S. West. Trout Lake, 



Chippewa Co., Aug. 10, 1915. 

 Spondylosium pulchellum Archer. Twin Lake, June 2, 1915; 



bog near Caffey, Aug. 13, 1915. 

 Hyalotheca dissiliens (Sm.) Breb. Railroad pool, Manistique, 



Aug. 11, 1915; Twin Lake, June 2, 1915; bog near Sauge- 



tuck, June 1, 1915; bog north of Blaney, Aug. 12, 1915. 

 Desmidium baileyi (Ralfs) De Bary. Railroad pool, Seney, 



Aug. 12, 1915. 



