168 WISCONSIN PHJTOPLANETON 



PEDIASTRUM INTEGRUM Nageli. PI. 45, Fig. 7. 



Gatt. einz. Algen 97, pi. 5, figs. B4a-B4r. 1849. 



Coenobia 8-16-32-64-celled, circular or oval, without perforations. 

 Interior cells polygonal ; marginal cells 5-6 sided, at times with rudi- 

 ments of two projections that are sometimes reduced to a single wart, 

 but generally without projections. Cell wall smooth or punctate. 

 ( Tychoplanktont) . 



Diam. cells 15-30 /i. 



Soft (rrr). 



var. PRIVA Printz. PI. 45, Figs. 8-10. 



Skr. Vidensk. i Kristiana Mat.-Naturv. Kl. 1913 1 : No. 6: 73, pi. 5, fig. 147. 

 1914. 



Coenobia generally 8-celled. Marginal cells trapezoidal, without in- 

 cisions or processes. Interior cells polygonal, without incisions. Cell 

 wall smooth. (Facultative Planktont). 



Diam. cells 8-10 p. Diam. 8-celled coenobia 15-25 /*. 



Palmer (rr). 



The general shape of the cells is like that of P. tetras but since there 

 are no incisions in the cells they cannot be placed among the varieties 

 of P. tetras. 



PEDIASTRUM ARANEOSUM Eaciborski. PI. 45, Fig. 11. 

 Mem. Acad. Imp. Sci. Cracow 20: 84. 1890. 



Coenobia circular to oval, without perforations, of 8-16-32-64-128 

 cells. Interior cells in contact with 46 other cells, straight sided. In- 

 ner half of marginal cells similar to interior cells, outer half without 

 processes but with a deep emargination. Surface of cell covered with 

 a coarse reticulum of ridges. (Facultative Planktont). 



Diam. cells 15-32 /*. 



Birch Island (rr), Blue Gill (rrr), Boulder (rrr), Carson (rrr), Deer (rrr), 

 Devils (1) (rrr), Diamond (rrr), Dutchmans (rr), Horseshoe (1) (rr), Lake 

 of the Woods (rrr), Lindy (rr), Loon (rrr), Nicaboyne (rr), Nancy (r), Pine 

 Tree (rr), Pokegama (1) (rrr), Poor Farm (rrr), Sand (2) (rr), Wild 

 Goose (rr). 



var. RUGULOSUM (G. S. West) G. M. Smith. PI. 45, Figs. 12-13. 

 Bull. Torr. Bot. Cl. 43: 476, pi. 25, fig. 14. 1916. 



Sides of cells undulate where they are in contact with one another. 

 (Facultative Planktont). 

 Meta (r). 



