74 



163. Plants mostly small, of a bright green color, but occasionally 

 red. Usually containing starch granules, with a nucleus in each 

 cell. Coloring matter not changed by acids or alkalies. Mostly 

 growing in fresh water. 165 



Plants mostly large, of a dark olive green color, growing in salt 

 water. 



MELANOPHYCE.E OR FUCOIDE.E. 



Frond formed of threads which are either single or united into a 

 bundle, or a compound body. 164 



Frond leathery or membranous, making a compact cellulai sub- 

 stance. All growing in salt water. 



Fruit contained in spherical cavities in the substance of the frond. 



Found in all seas. FUCACE^E. 

 Fruit attached to external jointed threads, which are either free or 



compacted into knob-like masses. Small plants found in all seas. 



SrOROCHNACEvE. 



Fruit attached to the outer surface of the frond. 



Sporanges arranged in patches of definite outline. More common 

 in warm regions. DICTYOTACEJE. 



Sporanges scattered in patches of irregular outline, or else cover- 

 ing the whole surface. Plants commonly very large. Nearly all 

 found in the northern hemisphere and in the colder waters. 



LAMINARIACEJK. 



164. Frond cartilaginous or gelatinous, the interior portion being 

 made up of thread-like, longitudinal cells, the exterior of short, 

 jointed, radial rows of cells. Sporanges scattered over the whole 

 frond, and immersed in its substance. CHORDARIACE^E. 

 Frond jointed, simple or branching. Sporanges single, on the ends 

 or sides of special shoots. 



Body and branches of the frond made up of cells in a single row. 

 Nearly all growing in salt water. Small and mostly parasitic. 



ECTOCARPACEJE. 



Frond made up of cells in several rows. Branches often ending in 

 an enlarged cell which has been changed by a parasitic plant. 

 Small plants growing in salt water. A few parasitic. 



SPHACELARIACE.E. 



