Smith—Algae Found in 'Wisconsin Lakes 641 
Family PLANOSPORACEAE. 
Genus CHAEACIUM A. Br. 1849. 
Characium stipitatum (Bachm.) Wille. 
In Engler & Prantl, Nat. Pflanzenfam. 1^: (Naehtr.) 45. 1909; G. M. Smith. 
Bull. Torr. Bot. Cl. 43: 472. pi, 24, figs. 4-6. 1916. 
This species is confined exclusively to Coelosphaerium Naege- 
lianum Unger. 
III. Amicoy (r), Beaverdam (sss), Devils (ss), Horseshoe (ss). 
Characium curvatum sp. nov. 
Cells lunar or recurved, with acute or sub-acute apices. Stipe 
hyaline, thick, tubular or conical, frequently with an irregular 
outline. Chloroplast parietal, with or without a pyrenoid. 
(Plate 11, figs. 6-13). 
Length of cell (with stipe) 13-22/x, (without stipe) 8-18/x; 
Breadth 3-6 /x. Epiphytic upon Coelosphaerium Naegelianum 
Unger, Victyosphaerium pulchellum Wood, and Phaeococcus 
planetonicus W. & G. S. West. 
The general manner of growth suggests 0. stipitatum 
(Bachm.) Wille but this alga has curved cells and a much 
broader stipe. Whenever the host colony contains the alga, 
50-200 individuals are generally present. It has been found in 
the sheath of colonial forms of the Myxophyceae, Chlorophyceae 
and Phaeopnyceae, which further distinguishes it from C stipitor- 
turn that is confined to a single alga. 
III. Birch (ce), Chetac (a), Dummy (rr), Horseshoe (ss), Shell (ss). 
Characium limneticum Lemmermann. 
Bot. Not. 1903; 81. pi. 3, figs. 7-10. 
The dimensions of the alga found in Browns lake agree in 
general with those given by Lemmermann but the cells attain 
a larger size, the largest being 110 /x long and 12 /x wide. The 
chloroplast contains one and not two pyrenoids. The stipe of 
the Wisconsin form differs from that described by Lemmermann 
in being somewhat thicker and without a basal disc. Lemmer¬ 
mann thinks that the 4 band-shaped chloroplasts represents 
stages in the cleavage of the cell contents to form zoospores. I 
41—S. A. L. 
