228 



Chlorophycece 



Genus Nephrocytium Nag., 1849. The cells are oblong, 

 ellipsoid or subcylindrical, slightly curved or sublimate, sometimes 

 almost reniform. There is at first a large expanded chloroplast in 

 each cell, furnished with a single pyrenoid, but later the chloroplast 

 fragments. The multiplication is by autospores similar to those 

 of Oocystis, and formed within the mother-cell soon after the 

 segmentation of the chloroplast. The young autospores are often 

 spirally disposed round the inside of the mother-cell-wall. The 

 genus is distinguished from Oocystis primarily by its curved cells 

 without any trace of apical thickenings. 



wo 



Fig. 98. A, Nephrocytium obesum West, from Angle Tarn, Cumberland. B, 2V. 

 ecdyxiscepanum West & G. S. West, from near Goring, Oxfordshire. C F, 

 N. hinatum West; C E, from near Bowness, Westmoreland; F, from near 

 Roundstone, Galway, Ireland. (All x 367.) 



N. Agardhianum Nag. (inclus. N. Nagelii Grun.) is a widely distributed 

 species in the stagnant waters of small pools and lakes; length of cells 12 

 22 p.; breadth 7 12 p. N. obesum West is the largest species, characterized 

 by the short, stout cells and by the great thickness of the mother-cell-walls ; 

 length of cells 34 42 /x ; breadth 24 28 ^ ; fig. 98 A. N. lunatum West is a 

 characteristic species (supposed by Chodat to be a stage of T. Agardhianum) 

 which is very local, but sometimes abundant among submerged Sphagnum ; 

 length of cells 14 18 /* ; breadth 4 6 '5 p ; tig. 98 C F. N. ecdysiscepanum 



