40-44.4- (46) /A in diameter, 35-38- ( 44 )/x long. Oospores depressed- 

 globose; with a smooth wall; 36-38.5- (44)/* in diameter, (32)-36.5- 

 42^ long. Dwarf male plants short; usually 2-celled; on the sufiFultory 

 cell. Antheridia exterior; stipe of dwarf male 9-14.8)u, in diameter, 

 Antheridia 7-10/x in diameter, (6)-ll-16-(22)/^ long. 



On submerged aquatics in shallow water of a slough. Mich., Wis. 



Oedogonium subplenum Tiffany 1934, p. 326 

 PI. 40, Fig. 8 



Nannandrous; gynandrosporous or idioandrosporous. Vegetative 

 cells slightly capitellate, (7)-8-12/a in diameter, 23-80/i, long. 

 Oogonia solitary; depressed-globose or pyriform-globose; operculate; 

 division median; 29-35-(38)/x in diameter, (26)-29-33-(41)/i long. 

 Oospores globose; not filling the oogonia; 21-22.4-(28)/a in diam- 

 eter, 19-26yu, long. Dwarf male plants 1-celled; on the oogonia; 6-7/a 

 in diameter, 6-10/a long. 



In shallow water at edge of a Sphagnum bog. Wis. 



Oedogonium undulatum (de Breb.) A. Braun in DeBary 



1854, p. 94 



PI. 40, Figs. 3-5 



Nannandrous; gynandrosporous or idioandrosporous. Vegetative 



cells capitellate and 4-undulate, except the basal cell which is 



elongate and smooth; 15.6-18- ( 22 )/* in diameter, ( 15.8) -45-100- 



(110) /A long. Oogonia solitary (sometimes 2 together); globose or 



ellipsoid-globose; operculate, the division inferior; (48)-50.7-55yu 



in diameter, ( 50) -54.6-56- ( 75 )/x long. Oospores globose; filling 



the oogonia; wall smooth; 42-50/u, in diameter. Dwarf male plants 



on the sulfultory cell or nearby. Antheridia interior; 9/* in diameter. 



Very common in many soft water and acid habitats. Mich., Wis. 



Oedogonium undulatum fa. senegalense ( Nordst. ) Hirn 1900, p. 261 



PL 44, Fig. 4 



Vegetative cells with 3 median undulations and of somewhat 

 narrower proportions than in the typical plant; 18-20/x, in diameter, 

 48-80/i, long. Oospores 38/* in diameter. 



Attached to overhanging grass in a ditch through a Sphagnum, 

 bog. Wis. 



ORDER CHLOROCOCCALES 



This large order is composed of a great variety of plants which 

 are 1-celled or which form colonies of rather definite shape. The 



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