Smith—Algae Found in Wisconsin Lakes 627 
polygonal chloroplasts, each containing a single pyrenoid. 
Reproduction by liberation of daughter colonies through break¬ 
ing down of gelatinous sheath. 
Planktosphaeria gelatinosa n. sp. 
Characters the same as genus. Diam. cells 25-4.5/x; diam. 
colon, up to 150/A (Plate 10, figs. 8-11). 
The numerous parietal chloroplasts form the distinguishing 
characteristic of the genus. At first glance this condition 
might be considered a division stage in the reproduction of a 
Sphaerocystis cell, but I am convinced that it is the normal state 
of the adult cell. The very young cells have a single parie¬ 
tal bell-shaped chloroplast but as the cell grows the number of 
chloroplasts increases. 
I. Mendota (rr). 
II. Browns (rr). 
Genus ASTEROCOCCUS Scherffel 1908. 
Asterococcus limneticus n. sp. 
Colonies spherical, rarely ovoid, of 4, 8, or 16 cells widely 
separated within a hyaline, unlamellated, gelatinous matrix. 
Chloroplasts, star shaped, with 4-8 rays coming from a central 
mass and ending in a disc at the cell wall. Pyrenoid, single, at 
the center of the rays. (Plate 10, figs. 3-6). 
Diam. cells 7. 5-23/x; diam. colon, up to 125/x. 
The genus Asterococcus was described by Scherffel (Ber. d. D. 
bot. Ges. (26A: 762. 1908.) because Fleurococcus superhus Cienk. 
differs so markedly from other species of that genus. The 
two distinguishing characteristics of Asterococcus are a lamel- 
lated gelatinous envelope around the cells, and a single star^ 
shaped chloroplast in which strands ending in discs run from 
the center of the cell to the periphery. There is but one pyre¬ 
noid at the center of the cell. Scherffel’s figures for the vege¬ 
tative cells are not particularly good but Chodat (Bot. Ztg. 53: 
pi. 5, figs. 6, 9,19, 21,1895).has given some very characteristic 
figures of A. superhus (Cienk) Scherffel as stages in the life his¬ 
tory of Eremosphaeria. 
The species that I have described above does not have the 
