APPENDIX. 387 



2. B'yopsis. Filamentsgreen, free,primately branched ; 

 two or four ciliated zoospores in extremities of branches. 

 Marine. 1$. plumosa. B. hypnoides. 



3. Vaucheria. Filaments green, more or less branched, 

 continuous, producing in apices large solitary zoospores 

 covered with cilia, also bearing lateral, globose, sporangial 

 cells and hooklike antheridial cells (" horns "). Marine 

 or aquatic or on damp ground. 



4. Botrydium. Frond a spherical green vesicle on a 

 ramified filamentous base, the cavity of the whole con- 

 tinuous, the ramified base producing new vesicles (spor- 

 anges) by stoloniferous growth. Multiplied by granular 

 contents of vesicle discharged by rupture at the summit. 

 Damp grounds. 



5. Hydrodictyon. Frond a green baglike net, with 

 usually pentagonal open meshes, formed of cylindric cells 

 connected by their ends. Ciliated zoospores formed in 

 the " link "-cells, uniting and forming a miniature net be- 

 fore escaping from parent-cell. 



6. Achyla. Filaments colorless or light brownish (like 

 mycelia of fungi) ; free, slightly branched. Numerous 

 zoospores in apices of filaments, and spores in globose 

 lateral sporangial cells. On dead flies, fishes, or sometimes 

 on decaying vegetable matter in water. A. prolifera. 



8. OSCILLATORIACE.E. Sea, fresh water, or damp ground. 

 Gelatinous and filamentous. Filaments slender, tubular, 

 continuous, filled with colored, granular, transversely 

 striate substance, seldom branched, though often coher- 

 ing so as to appear branched ; usually massed in broad 

 floating or sessile strata ; very gelatinous ; occasionally 

 erect and tufted. More rarely in radiating series bound 

 by firm gelatin, and then forming globose, lobed, or flat 

 crustaceous fronds. Contents separate into roundish or 

 lenticular gonidia. 



* In fresh water or damp earth. 



