ALG-E. 19 



FLORIDE^E. (Red seaweeds.) Sexual reproduction car- 

 posporic, Don-sexual by tetraspores. (Genera not given.) 



•2 b. Color from yellowish brown to olive green or nearly 

 blach\ 



FUCACE^E. (Rockweeds and their allies.) Thallns at- 

 taehed by a disk-like base, usually branching dichotomously, 

 Often provided with air-bladders and with cryptostomata. Or- 

 gans of reproduction borne in conceptacles or cavities lined with 



Sterile filaments, and opening by a narrow pore, these concep- 

 tacles crowded in the swollen tips of branches. Reproduction 

 oosporie. Marine. (See page 20.) 



PH^EOSPOREiE. (Devil's Aprons and their allies.) 

 Thallns very various in form. Never with conceptacles as in 

 Fucacese. Reproduction by zoospores. Marine. (See page 20.) 



2 c. Color grass-green. 



CHARACE^E. (Stoneworts.) Thallns branched and rather 

 coarse, made up mostly of cells about 1 — 3 cm. long. Often with 

 deposits of mineral matter in the cell wall. Fruit formed of a 

 central cell and five elongated cells wound spirally around it. 

 (See page 21.) 



CHLOROSPORE^E. Thallns branched or simple, very 

 various in size and habit. Reproduction by zoospores. In 

 fresh and salt water. (O11I3* marine genera are here given. See 

 page 21.) 



ZYGNEMACE^E. (Brook-silks.) Thallns consisting of an 

 unbranched delicate thread made up of a chain of small cells of 

 uniform size. Chlorophyll sometimes disposed in spiral bands. 

 Reproduction by the conjugation of stationary cells to form 

 zygospores. In fresh water. (Genera not given.) 



lb. Unicellular; mostly of microscopic size; cells often 

 united into a colony. 



3 a. Color bluish orpinplish green. 



CYANOPHYCE^E. Often more or less gelatinous. Re- 

 production entirely non-sexual. (Genera not given.) 



3 b. Color yellowish or orange. 



