Chroococcus pallidus Naegeli 1849, p. 46 



PI. 100, Fig. 14 



Single-celled or, more frequently, a small colony of 2-4-(8) 

 spherical individuals inclosed by an oval or globose, wide, hyaline 

 or yellowish, homogeneous envelope of mucilage; individual cell 

 sheaths indistinct; contents pale blue-green; cells (5)-6-ll/i in 

 diameter without sheath. 



Plants of this species are to be found on moist aerial substrates 

 or scattered among algae in shallow water tychoplankton. Mich., Wis. 



Chroococcus Prescottii Drouet & Daily in 

 Drouet 1942, p. 127 



PI. 100, Fig. 13 



A free-floating colony of 4-16-32 spherical cells arranged in 2 

 planes to form cubes or sarciniform clusters, inclosed in a rectan- 

 gularly shaped, hyaline, colonial envelope which is often lamellated, 

 with individual cells or quartets of cells inclosed by a sheath; cell 

 contents bright blue-green; finely granular, cells S-S/a in diameter; 

 colony (of 16 cells) 18-22/a wide, 30-42//, long, and about as thick 

 as wide. 



This plant was questionably listed as Eucapsis alpina Clements 

 and Schantz by Prescott and Croasdale (1937). It should be com- 

 pared with that species, the cells of which are similarly arranged 

 but more numerous in the colony and in which the colonial sheath 

 is without lamellations. 



Not uncommon in the tychoplankton of acid habitats, intermin- 

 gled with dense growths of other algae, especially desmids, and 

 commonly associated with C turgidus. Mich., Wis. 



Chroococcus turgidus ( Kuetz. ) Naegeli 1849, p. 46 

 PI. 100, Fig. 19 



A free-floating colony of 2-4 ovoid or hemispherical cells inclosed 

 by a very wide (usually), hyaline, and lamellate colonial sheath; 

 cells bright blue-green, contents sometimes coarsely granular, in- 

 closed by individual sheaths, 8-32/x in diameter without sheath, 

 15-50/iA wide including sheath. 



Tychoplankter. Common in many lakes and in bogs. This is a 

 relatively large species, attaining maximum size and abundance in 

 Sphagnum bogs. Mich., Wis. 



[450] 



