FAMILY CHLORANGIACEAE 



Plants in this family are globose, ellipsoid, or oblong, attached by 

 a stipe to other algae or to microfauna. They may be solitary or 

 colonial, arranged in such a way as to form false filaments (i.e., 

 series ) that may be simple or arbuscular. The cells are attached, the 

 anterior end downward, by a stalk-like extension of the sheath, in 

 which the protoplasts are inclosed. There is 1 cup-shaped chloro- 

 plast or 2 elongate parietal bodies, sometimes with a pyrenoid. 

 Usually there is an anterior pigment-spot. 



Key to the Genera 



Cells globose or ovoid; epiphytic in the mucilage 



of colonial blue-green algae Stylosphaeridium 



Cells elongate-ellipsoid or oblong-fusiform; 



epizoic on microfauna ., Chlorangium 



CHLORANGIUM Stein 1878, PL 19, Figs. 1-7 



Cells ellipsoid or spindle-shaped, solitary or in arbuscular series, 

 attached, anterior end downward, by mucilaginous (simple or 

 branched) stalks. Chloroplasts 2 laminate parietal plates; without 

 pyrenoids ( ? ) . Cells with 2 contractile vacuoles and a red pigment- 

 spot at the anterior end. Reproduction by longitudinal cell division 

 to form 2 or 4 daughter cells, which escape by the bursting of the 

 mother cell membrane that elongates and forms branching stalks 

 which result in arbuscular colonies. Biflagellate swarmers produced 

 by resumption of motility of vegetative cells. Gametes have been 

 reported. 



Chlorangium stentorinum (Ehrenb.) Stein 1878, PI. i9. Figs. 1-7 



PI. 46, Figs. 1, 2 



Characteristics as described for the genus. Cells 12-14/x in diam- 

 eter, 23-43 fx long. 



Widely distributed in the region, on microfauna in several types 

 of lakes. This species is not so common as Colacium spp. which also 

 attach themselves to Cladocera and copepods. Mich., Wis. 



STYLOSPHAERIDIUM Geitler & Gimesi in Geitler 1925, p. 608 



Cells globose or ovoid, solitary, attached by a slender stipe in the 

 mucilage of Coelosphaerium and Anabaena, and probably to other 

 Cyanophyta. Chloroplast solitary, massive, covering the posterior 

 (outer) portion of the cell wall, and containing a single pyrenoid. 



This genus should be compared with Peromelia, a member of the 



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