WISCONSIN PHTTOPLANKTON 1Q9 



TROCHISCIA RETICULARIS (Reinsch) Hansgirg. PI. 22, Fig. 2. 



Hedwigia 27: 129. 1888. 



Acanthococcus reticularis Reinsch, Ber. d. D. bot. Ges. 4: 242, pi. 12, figs. 

 1886. 



Cells generally solitary, spherical. Cell wall fairly thick and covered 

 with linear ridges that intersect to form 50-70 polygons on the surface 

 of the cell. (Tychoplanktont). 



Diam. cells 24-32 /*. 



Wildcat (rrr). 



Family AUTOSPORACEAE. 



Cells solitary or in colonies that are generally of a definite shape and 

 without a gelatinous envelope. Cells variously shaped; with a single 

 chloroplast and pyrenoid as a rule. Cells incapable of vegetative divi- 

 sion to form two similar daughter cells. 



Reproduction by division of cell contents into 2^-8-16-32-64 cells 

 which assume the shape of the mother cell before their liberation (auto- 

 spores). In the colonial species the autospores from any one cell are 

 organized to form the new colony (autocolony) before their liberation. 

 Motile asexual reproductive bodies or sexual reproduction unknown. 



KEY TO THE SUBFAMILIES. 



Cells solitary. 



Cells angular TETRAEDREAE 



Cells not angular. 



Ornamented with long spines or setae MICRACTINIEAE (p. p.) 



Not ornamented with spines or setae. 



Length of cells several times the diameter SELENASTREAE (p. p.) 



Length of cells not more than twice the diameter OOCTSTEAE (p.p.) 



Cells in colonies. 



Ornamented with long setae or spines. 



Coenobe capable of growth in three directions MICRACTINIEAE (p.p.) 



Coenobe a flat plate CRUCIGENIEAE (p. p.) 



Not ornamented with setae or spines. 

 Number of cells in coenobe always a multiple of two. 



Coenobe flat CRUCIGENIEAE (p. p.) 



Coenobe spherical or cells radiating from a common 



center i COELASTREAE 



Number of cells not a multiple of two in every case. 



Cells elongate, straight or curved SELENASTREAE (p. p.) 



Cells spherical, ovoid, or reniform OOCYSTEAE (p. p.) 



