Ophiocytium desertum Printz 1914, p. 47 

 Cells cylindrical, attached by a short, relatively stout stalk and 

 a thick adhesive disc ( usually on filamentous algae ) ; cells truncately 

 rounded at the anterior end, without a spine; 9-14)U, in diameter, 

 30-60/* long. 

 Mich. 



Ophiocytium desertum var. minor Prescott 1944, p. 362 



PL 96, Figs. 2, 3 

 Cells attached, cylindrical or sausage-shaped; basal stipe with 

 a flattened disc-like attaching organ; anterior end broadly rounded; 

 4-9ja in diameter, 58-65|a long. 



In swamps; tychoplanktonic in lakes. Wis. 



Ophiocijtium elongatum West & West 1907, p. 232 



Cells free-floating, irregularly curved, twisted at one end, or 

 sometimes nearly straight, with a short spine at one end, truncately 

 rounded at the other; 5-5.5fi in diameter, up to 70 times the diameter 

 in length. (Typical form not found in our region.) 



Compare with O. Lagerheimii Lemm. and O. ma jus. 



Ophioctjtium elongatum var. major Prescott 1944, p. 362 



PI. 94, Figs. 13, 14 



A variety differing from the typical by its much greater size; 

 cells free-floating, cylindrical, straight, curved or hooked at one end 

 which is truncate, the other bearing a stout spine, not coiled; 

 chromatophores 16 parietal discs; cells 10-12/t in diameter, 400-420/x 

 long without the spine, which is 10-12/* long. 



This species should be compared with O. cochleare, which is 

 smaller and has arcuate or coiled cells. O. elongatum, originally 

 described from Burma, is coiled although not closely. 



In soft water or in acid swamps. Wis. 



Ophiocytium gracilipes Rabenhorst 1865, p. 68 

 PI. 95, Figs. 35, 36 



Cells cylindrical, straight or somewhat curved, attached by a 

 stipe 2—4 times the diameter of the cell in length, and basal ad- 

 hesive disc, forming colonies by the germination of spores at the 

 rim of the anterior open end of a mother cell; the young plants 

 attached by strongly curved stipes; chromatophores (2)— 4 parietal 

 plates; cells 5—7/* in diameter and up to 40/* long. 



The basal stipe is longer and more slender than in the common 

 O. arhuscula. 



Rare; on filamentous algae. Mich., Wis. 



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