Coelastrum microporum Naegeli in A. Braun 1855, p. 70 



PI. 53, Fig. 3 

 Coenobium spherical, composed of 8-64 sheathed globose cells 

 (sometimes ovoid, with the narrow end outwardly directed); cells 

 interconnected by very short, scarcely discernible gelatinous proc- 

 esses, leaving small intercellular spaces; cells 8-20/^ in diameter 

 including the sheath. 



Common in the tychoplankton of many lakes and ponds. Mich., 

 Wis. 



Coelastrum proboscideum Bohlin 1897, p. 33 



[C compositum G. S. West] 



PL 53, Figs. 4, 5, 8 



Coenobium pyramidal or cubical (rarely polygonal), composed 



of 4-8-16-32 truncate cone-shaped cells with the apex of the cone 



directed outward, the inner or basal wall of the cell concave, the 



lower lateral walls of the cells adjoined about a large space in the 



center of the colony; cells 8-15/x in diameter; 4-celled colony as much 



as 35yu, in diameter. 



In both tycho- and euplankton of several lakes; not as common as 

 other species of Coelastrum. Mich., Wis. 



Coelastrum reticulatum ( Dang. ) Senn 1899, p. 66 

 PI. 53, Fig. 6 

 Coenobium spherical, free-floating, composed of 8-32 globose cells 

 each inclosed by a gelatinous sheath and adjoined to neighboring 

 cells by 6 long, slender gelatinous processes, leaving large intercell- 

 ular spaces; outer free wall of the cells without protuberances or 

 processes; cells 8-20-(24)/x in diameter including the sheath. 

 Euplankter. Mich., Wis. 



Coelastrum scabrum Reinsch 1878, p. 238 

 PI. 46, Fig. 3 

 Coenobium spherical, composed of 8-16 angular-globose to 

 angular-depressed-globose cells which bear on their outer faces 4-6 

 short, wart-like and truncate projections; cells 8-10|U, in diameter. 

 Mackinaw City, Michigan. 



Coelastrum speciosum (Wolle) Brunnthaler 1915, p. 197 



Coenobium spherical, composed of 16-24 spherical cells, each at 

 the end of a slender gelatinous strand radiating from the center of 

 tlie colony; outer face of the cell with a single, short-truncate gel- 

 atinous projection; cells 10-12/x in diameter. 



Cheboygan County, Michigan. 



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