1920] SetcheU-Gardncr: ChloropJujceae 287 



De-Toni and Levi-Morenos, Fl. Alg. Venez., Ill, 1888, p. 171 

 (Repr.) ; Blackman and Tansley, Class. Green Alg., 1902, p. 138. 

 Chaetophoroideae Harvey, Man. Brit. Alg., 1841, p. 10 (in part). 



The Chaetophoraceae form a family of both fresh-water and marine 

 species. The latter are nearly all prostrate epiphytes or endophytes, 

 living upon the larger Chlorophyceae, Melanophyceae and Rhodo- 

 phyeeae. The species of one genus on our coast bores into shells. 

 There are doubtless a number of genera and species of this family on 

 our coast still awaiting discovery. 



The Chaetophoraceae are generally divided into five tribes, four 

 of which are represented on the Pacific Coast. Bulhocoleon represents 

 the Chaetoplioreae, Entocladia belongs to the Leptosireae, Ulvclla 

 Pseudiilvella and Pseudopringsheimia belong to the Ulvelleae, Gomon- 

 i'ui belongs to the Gomontieae, while Internoretia, Endophyton and 

 Pseudodictyon are not definitely placed as yet owing to a lack of 

 knowledge of the details of the processes of reproduction. 



Key to the Genera 



1. Cells dividing in one or two planes, forming simple branched filaments 2 



1. Cells dividing in three planes, forming solid branched filaments 



29. Intemoretia (p. 294) 



2. Cells occasionally piliferous 25. Bulbocoleon (p. 287) 



2. Cells never piliferous 3 



3. "Sporangia" with rhizoid-like projections (shell borers) 33. Gomontia (p. 300) 



3. "Sporangia" rounded, destitute of rhizoid-like projections (not .slicll Ixtrers).... 4 



4. Chromatophores destitute of pj^enoids 30. Ulvella (p. 295) 



4. Chromatophores provided with pyrenoids 5 



5. Cells not coalescing to form a pluristratose layer 6 



5. Cells coalescing to form a pluristratose layer, at least in center 8 



6. Filaments radiating, often coalescing in the central portion 



26. Entocladia (p. 288) 



6. Filaments not radiating, never coalescing 7 



7. Filaments anastomosing to form a network, endophytic 



28. Pseudodictyon (p. 293) 



7. Filaments free, not forming a network, endophytic 27. Endophjrton (p. 292) 



8. Thallus destitute of penetrating rhizoids 31. Pseudulvella (p. 290) 



8. Thallus provided with penetrating rhizoids 



32. Pseudopringsheimia (p. 299) 



25. Bulbocoleon Pringsheim 



Thallus minute, epi- or endophytic in various lubricous or 

 gelatinous algae of loose tissues; filaments creeping, branching, of 

 irregularly shaped cells, rounded or somewhat elongated horizontally ; 

 bearing on the upper sides of the filaments single or clustered rounded 

 cells prolonged into long, hyaline, unseptate hairs ; chromatophore of 



