Gloeotaenium Loitelsbergerianum Hansgirg 1890, p. 10 



PI. 54, Figs. 13, 14 

 Characteristics as described for the genus; cells globose or ovoid, 

 18-25- ( 30 );u, in diameter; 8-celled colony as much as 70/a in diam- 

 eter, 80fx long. 



In tychoplankton of lakes, in soft or semi-hard water. Mich., Wis. 



NEPHROCYTIUM NaegeH 1849, p. 79 



A colony of 4-8 cells, varied in shape, ovate, fusiform, hemispheri- 

 cal, or oblong-ellipsoid to reniform, inclosed by the much enlarged 

 persistent mother cell wall, which may gelatinize and coalesce 

 somewhat, permitting daughter colonies to adhere together, thus 

 forming colonial complexes; occasionally 2 generations of cells 

 inclosed by 1 mother cell wall; chloroplast a parietal plate, which 

 becomes very diffuse in older cells; 1 pyrenoid. 



Key to the Species 



1. Cells broadly ovate or hemispherical, IJ2 times longer than wide 2 



1. Cells lunate, fusiform, or reniform, 2-3 times longer than wide 3 



2. Old mother cell walls gelatinized and persisting as fragments 

 about the colony; cells 13-18^ in diameter, 



broadly ovate or hemispherical ___. N. ecdysiscepanum 



2. Old mother cell wall firm and thick; cells hemispherical or 



very broadly ovate, up to 28^ in diameter N. obesum 



3. Investment of cells formed by gelatinized mother cell 



walls; cells curved or sausage-shaped... _ N. limneticum 



3. Investment of cells formed by persistent and firm mother cell walls 4 



4. Cells reniform .N. Agardhianum 



4. Cells lunate.— _N. lunatum 



Nephrocytium Agardhianum Naegeli 1849, p. 79 



[N. Naegelii Grunow] 



PI. 54, Figs. 15, 16 



Colony ovate, composed of 2-8 cylindrical or reniform cells, 



twisting so as to give a spiral arrangement within the old mother 



cell wall; cells 2-7 fx in diameter, 8-18/a long. 



Rather common in the tychoplankton of several lakes and ponds. 

 Mich., Wis. 



Nephrocytium ecdysiscepanum W. West in West & West 1896, p. 161 



PL 54, Fig. 17 

 Colony broadly ovate, composed of 4—16 ovate, ovoid, or nearly 

 hemispherical cells inclosed by the old mother cell wall, the family 

 adjoined or adhering to other families by the gelatinized and 



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