apical thickened plug; chloroplast (?); cells 13-15^ in diameter, 

 12-24/t long. 

 On filaments of Desmidium. Mich. 



Characium ornithocephalum A. Braun 1855, p. 42 

 PI. 46, Fig. 14 

 Cells broadly and unsymmetrically ellipsoid, convex on one side, 

 nearly straight on the other, abruptly narrowed anteriorly to form 

 a sharp apiculation, the cell body set at an angle and curved away 

 from a long stipe with a basal attaching disc; chloroplast laminate, 

 parietal, with a conspicuous pyrenoid; cells 25-33/x long, without 



stipe. 



On submerged plants, especially filamentous algae. Mich. 



Characium Pringsheimii A. Braun 1855, pp. 37, 106 

 PI. 45, Fig. 21 

 Cells narrowly elongate-ovoid to fusiform, erect but with a short 

 oblique tip; stipe short; chloroplast a laciniate plate with 1 pyrenoid; 

 cells 7.8-9/x in diameter, 13-16/x long. 



Attached to Tribonema filaments in a roadside fosse. Mich., Wis. 



Characium Rabenhorstii DeToni 1889, p. 625 

 PI. 46, Fig. 27 

 Cells elongate-fusiform or lanceolate; narrowed anteriorly but 

 with a bluntly rounded apex; narrowed below to a long slender 

 stipe, about 1/2 the length of the cell body, with a brown basal 

 attaching disc; cells 8-9/x in diameter, 16-18|U long. 

 On filamentous algae. Mich. 



Characium rostratum Reinhard 1876, ex Printz 1914, p. 41 



PI. 45, Figs. 22,23 



Cells lanceolate-falcate with curved apex; stipe long and slender 



from an attaching disc; chloroplast laminate, nearly covering the 



entire wall; cells 7.8/i, in diameter, 40-45/^ long, including the stipe. 



Attached to Tribonema filaments in a roadside fosse. Mich., Wis. 



Characium stipitatum (Bachm.) Wille 1911, p. 45 

 PI. 45, Fig. 15 

 Cells ovate to subspherical or pyriform; stipe slender and tapering 

 from the base of the cell, without an attaching disc; chloroplast 

 parietal along the apical wall, with 1 pyrenoid; cells S-S/x in diam- 

 eter; stipe 10-16/i, long. 



Epiphytic on Coelosphaerium Naegelianum; generally distributed. 

 Mich., Wis. 



[218] 



