644 Wisconsin Academy of Sciences, Arts, and Letters, 
Pediastrum duplex Meyen. 
Nova acta Phys. Med. Ac. Caes.-Leop. Nat.-Cur. 14®: 772. pi. 43, ^igs. 6-8. 
1829. 
II. Browns (rr), Center (r), Eagle (r). 
var. CLATHRATUM (A. Br.) Lagerheim. 
ofvers. Kgl. Vet. Ak. Fork. 39: No. 2: 56. 1882. 
II. Camp (s), Mary (r). 
III. Bear (rr), Beaverdam (sss), Chetek (s), Eice (ss). 
var. RETicuLATUM Lagerheim. 
ofvers. Kgl. Vet.-Ak. Fork. 39: No. 2: 56. pi. 2, /. 1. 1882. 
II. Camp (s), Center (s), Hooker (rr), Paddock (rr). 
III. Cketek (s). Island (sss), Little Eice (ss), Pokegama ss), Prairie 
(ss), Eice (s), Eeserve (rr), Wkitefisk (rr). 
var. ROTUNDATUM Lucks. 
Jakrb. d. Westpr. Lekrervereins f. Naturkde 2: 31. 1907. 
III. Horseskoe (rr). 
Pediastrum biradiatum Meyen. 
Nova Acta Ac. Caes.-Leop. Nat.-Cur. 14®: 775. pi. 43, iigs. 21-22. 1829. 
Lagerkeim, ofvers. Kgl. Vet.-Ak. Fork. 39: No. 2: 53. pi. 2, figs. 2-7,9,11. 
1882. 
The few colonies observed were of the same irregular type 
that Lagerheim has figured. 
III. Bear (rr). 
Pediastrum tetras (Ehr.) Ralfs. 
Ann. & Mag. of Nat. Hist. 14: 469. pi. 12, /. 4. 1844. 
II. Browns (rr). 
II. Beaverdam (rrr), Cketek (rr). 
Order ULOTRICHALES 
Family APHANOCHAETACEAE 
Genus APHANOCHAETE A. Br. 1851. 
Aphanochaete vermiculoides Wolle (Plate 5, fig. 1). 
Freskw. algae of U. S. 119. pi. 105, figs. 9-10. 1887. 
Herposteiron hyalothecae Hansgirg, Sitzbr. d. k. bohm. Ges. d. Wiss. 
Prag. 1891: 309. 1891. 
III. Beaverdam (rr). 
