APPENDIX. 383 



panded, adherent to leaves, etc., of aquatic plants, formed 

 of jointed dichotornous filaments radiating from a centre, 

 more or less conjoin ted laterally, joints producing from 

 the back a slender truncate open tube from which a long 

 bristle is exserted. Spores and zoospores formed in the 

 joints. 



4. Ochlochcete. Frond discoid, appressed, filaments cyl- 

 indric, radiating, irregularly branched, of a single series 

 of cells, each of which is prolonged above into an inar- 

 ticulate bristle. 0. kystrix. 



4. COXFERVACE^E. In sea or fresh water, filamentous, 

 jointed, without evident gelatin. Filaments variable, sim- 

 ple or branched, cells more or less tilled with green, or 

 rarely brown or purple, granular matter, sometimes ar- 

 ranged in peculiar patterns on the walls, and convertible 

 into spores or zoospores. Not conjugating. 



1. Cladophora. Filaments tufted, much branched. Sea 

 and fresh water. Zoospores minute, many in a cell. 



C. cepagropila. Dense balls in lakes, etc. 

 C. crispata. Yellowish or dull-green strata. 



2. Rhizoclonium. Filaments decumbent, with small 

 rootlike branches. Zoospores minute, numerous. Sea, 

 brackish, and fresh water. 



R. rivulare. Filaments simple. Bright-green bundles, 

 two to three feet long, in streams. 

 R. tortuosum. In salt-water pools. 

 R. arenosum. Dirty-green strata, on sandy seashores. 

 R. obtusangulum. Sandy, seashores. 

 R. riparium. 



R. implexum. On mountain rocks. 

 R. arenicolum (ditto). 



3. Conferva. Filaments unbranched. Zoospores minute, 

 numerous in the cells. Sea, brackish, and fresh water. 



C. bombydna. Yellow-green cloudy stratum in stagnant 

 water. 



