NEMATOPHYCE.E. 127 



ORDER IV. NEMATOPHYCEJZ. 



Mnlticellular algee, chloropliyllose, membranaceous or fila- 

 mentous, with or without branches. Vegetation either terminal, 

 limited or unlimited, forming an articulate thread, or in the 

 beginning terminal, and afterwards lateral, forming a mem- 

 branaceous thallus of a single stratum. Cell multiplication by 

 repeated division in one or two directions. 



Propagation by oospores, or by zoogonidia. 



Divided into the following families : 



A. Vegetation by division of the cells at first in one, and 

 afterwards in two directions, forming a membranaceous thallus. 



FAMILY I. ULVACEJI. Thallus membranaceous formed of one 

 stratum of cells, either plane or expanded, or tubular, or saccate. 



B. Vegetation by division of the cells in one direction, 

 forming a cellular series or articulate thread. 



FAMILY II. SPH^EROPLE^E. Articulate thread not branched, 

 articulations greatly elongated, cylindrical, multilocular, chloro- 

 phyll mass distributed in ring-like bands. 



Propagation by resting spores, which, before germination, 

 break up into zoospores. 



FAMILY III. CONFERVACE.E. Articulate thread, simple or 

 branched, vegetative articulations cylindrical, fructiferous always 

 more or less swollen. Chlorophyllose mass effused, or parietal, 

 often more or less regularly spiral. 



Propagation by macro- and micro -gonidia. 



FAMILY IV. PITHOPHORACE.E. Cladophora-like plants, 

 with terminal vegetation. Articulate threads branched. 



o 



Propagation by neutral, quiescent, cask-shaped spores 

 (agamo-hypnospores). 



FAMILY V. (EDOGONIACE^E. Articulate thread either 

 branched or not branched ; articulations short. 



Propagation by oospores after sexual fecundation. 



FAMILY VI. ULOTRICHE.E. Articulate thread not branched, 

 sometimes laterally connate ; articulations short, at times very 

 short. 



Propagation by macro- and micro -gonidia. 



FAMILY VII. CHROOLEPID^E. Aerial algaa. Articulate 

 thread branched, cell membrane firm, filled with an equally dis- 

 tributed oleaginous golden or reddish endochrome. 



Propagation by zoogonidia. 



FAMILY VIII. CHJSTOPHORE.E. Aquatic alge. Articulate 

 thread dichotomously branched, ramnli sometimes aggregated in 

 a fasciculate or penicellate manner. Chlorophyllose mass 

 usually collected in transverse bands. 



Propagation by zoogonidia. liabh. Alg. Eur. in, 286. 



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