Trachychloron depauperatum Pascher 1939, p. 507 

 PL 95, Figs. 43, 44 

 Cells ovate or broadly ellipsoid, with broadly rounded poles; wall 

 finely (sometimes faintly) sculptured, making very close serrations 

 at the wall margin; 1 chromatophore, vase-shaped or ring-like, 

 making a parietal fold within the cell wall; cells 4—8/* in diameter, 

 8-(10)-12/. long. 



In shallow water of an acid bog. Mich. 



FAMILY GLOEOBOTRYDACEAE 



The cells in this family are spherical or ovate, arranged in 2's and 

 4's or sometimes many within a hyaline mucilage. Most species are 

 planktonic, but some are sedentary palmelloid gelatinous masses. 

 In the few-celled colonies the mucilage is lamellated but is scarcely 

 or not entirely so in the multi-celled thalli. Reproduction is by zoo- 

 spores or autospores, formed 2-4 within a cell. Gametic union is 

 unknown. 



To this family are assigned the genera Chlorobotrys and Gloeobo- 

 trys. Until recently the former was included with Centritractus and 

 Botnjococcus in the Botryococcaceae, but the latter genus has been 

 transferred to the Chlorophyta and Centritractus has been placed 

 in its own family (Pascher 1937-1939). 



Key to the Genera 



Cells 2-4 (rarely 6-8) in globular or ovoid, gelatinous, 



lamellated sheaths; free-floating Chlorobotrys 



Cells many within unlamellated gelatinous 



sheaths; free-floating or sedentary Gloeobotrys 



CHLOROBOTRYS Bohlin 1901, p. 34 



A colony of 2-4-8 spherical or ovoid individuals inclosed and 

 usually evenly spaced in a wide, gelatinous lamellate envelope; the 

 cell wall thick and impregnated with silicon; chromatophores 2-4, 

 yellow-green, parietal bodies without pyrenoids; starch not present; 

 a red pigment-spot often visible (not interpreted as an eye-spot 

 comparable with the organ present in other algal groups); repro- 

 duction by autospores. There is but one species in our collections. 



Chlorobotrys regularis ( W. West) Bohlin 1901, p. 34 

 PI. 93, Figs. 26, 27 

 A spherical colony of 2-8 (rarely more) globose cells regularly 

 arranged within a hyaline, gelatinous envelope; chromatophores 



[355] 



