fragmentary remains of cell walls of previous generations, the 

 complex often forming a fan-like arrangement; cells (13)-15.6-18/a 

 in diameter, 30-32/^ long; colony of 4 cells about 60.4/x in diameter. 

 Rare; in lakes and swamps. Wis. 



Nephrocytium limneticum (G. M. Smith) G. M. Smith 1933, p. 503 



PI. 54, Fig. 18 

 Colony subspherical, composed of 4-8 curved, crescent- or 

 sausage-shaped cells with broadly rounded ends; mother cell wall 

 of previous generation completely gelatinized and not persisting as 

 a membrane; cells lAjx in diameter, 10-25;u, long. 



Reported as Gloeocystopsis limneticus G. M. Smith from Wis- 

 consin. 



Euplankter; in ponds and lakes. Mich. 



'Nephrocytium lunatum W. West 1892, p. 736 

 PI. 54, Fig. 19 

 Colony ovate, consisting of 4-8 lunate, bluntly-pointed cells 

 inclosed by a thin, hyaline membrane and arranged so that the 

 concave wall is directed toward the center of the colony; chloroplast 

 covering the cell wall; cells 4-5(U, in diameter, 14-18/a long. 

 Tychoplanktonic in swamps; in ditches. Wis. 



Nephrocytium ohesum West & West 1894, p. 13 

 PL 54, Fig. 20 



Colony broadly ovate, composed of 2-4 broadly ovate to hemis- 

 pherical cells inclosed by a thick membranous integument, the cells 

 broadly rounded at the poles and with one margin strongly convex, 

 tlie other straight or concave; chloroplast massive, somewhat 

 reticulate and covering the entire wall; cells 14-16-(28)|u, in diam- 

 eter, 30^3- (49) ;a long. 



This species should be compared with N. ecdysiscepanum. 



Tychoplankter; in ponds and lakes. Mich., Wis. 



LAGERHEIMIA (DeToni) Chodat 1895, p. 90 



[Chodatella Lemmermann 1898] 



A solitary, free-floating, moniliform, ovate, or ellipsoid cell with 



a rather thick wall beset with long, tapering, needle-like setae which 



are confined to the polar or to the equatorial region; chloroplasts 



1-4 parietal plates, with or without pyrenoids. 



Key to the Species 



1 . Cells moniliform L. citriformis 



1. Cells ovate or ellipsoid 2 



[249] 



