May, 1917] The Algce of Michigan 221 



AKONT^. 



DESMIDIACE.E. 



Netrium digitus (Ehrcnb.) Itzigs. & Rothe. Bog near Caffey, 



Mackinaw Co., Aug. 13, 1915. 

 Penium margaritaceum (Ehrenb.) Breb. Small stream, New 



Buffalo, .May 31, 1915. 

 Penium spirostriolatum Barker. Bog north of Twin Lake, 



June 2, 1915. 

 Closterium angustatum Kiitz. Bog near Caffey, Aug. 13, 1915. 

 Closterium striolatum Ehrenb. Bog near Caffey, Aug. 13, 1915; 



railroad ditch, New Buffalo, May 31, 1915. 

 Closterium cuspidatum Bailey. Twin Lake, June 2, 1915. 



Probably should be in another genus. The terminal 



spines are 15-20/x in length, chromatophore with 6 prom- 

 inent ridges and several pyrenoids in each half. Outer 



margin about 180° of arc; greatest diameter about 85m> 



length between apices 165jU- 

 Closterium pseudodianae Roy. Pond near Orchard Lake, Aug. 



15, 1915. 

 Closterium intermedium Ralfs. Bog east of Caffey, Aug. 13, 



1915. 

 Closterium rostratum Ehrenb. Pond near Orchard Lake, 



Aug. 15, 1915. 

 Closterium ehrenbergii Menegh. Bog near Saugetuck, Allegan 



Co., June 1, 1915; Caffey, Aug. 13, 1915; pond near 



Orchard Lake, Aug. 15, 1915. 

 Closterium kuetzingii Breb. Bog near Caffey, Aug. 13, 1915; 



Seney, Aug. 12, 1915. 

 Closterium lineatum Ehrenb. Bog near Saugetuck, June 1, 



1915. 

 Closterium leibleini Kiitz. Bangor Lake, June 4, 1915. 

 Closterium acerosum (Schrank) Ehrenb. Breedsville, June 4, 



1915. 

 Closterium didymotocum Corda. Twin Lake, June 2, 1915. 

 Pleurotaenium nodosum (Bail.) Lund. Twin Lake, June 2, 



1915. 

 Pleurotaenium coronatum (Breb.) Rabenh. Twin Lake, June 



2, 1915. 

 Pleurotaenium truncatum (Breb.) Nag. Twin Lake, June 2, 

 1915. 



