273 



ment or sometimes they are substituted by a branch. The tricho- 

 blasts are shed early and are mostly present only at the summit of 

 the filaments. The plant is repeatedly pseudodichotomously rami- 

 fied. The branches are erect, nearly parallel, 

 issuing at acute angles. 



The tetrasporangia (Fig. 270) occur in 

 the upper ends of the filaments, which are 

 often several times forked. They are placed 

 in a spiral line in long series. They are about 

 60 a in diameter. 



Fig. 268. Polysiphonia 



sphserocarpa nov. spec. 



Part of a female plant. 



(About 30:1). 



Fig. 269. Polysiphonia 

 sphserocarpa nov. spec. 

 Part of filament with 

 branch. (About 260:1). 



Fig. 270. Polysiphonia sphse- 

 rocarpa nov. spec. Upper end 

 of filament with tetraspor- 

 angia. (About 60:1). 



The cystocarps (Fig. 271) are nearly spherical, placed upon 

 a short, thick stalk. They are about 80//. long and of nearly the 

 same breadth. 



This plant seems to show much resemblance to P. fem- 

 lacea but it is in all respects a far more tiny plant. It was 



18 



