1917 



Muenscher; Key to Phaeophyceae 



257 



4. SPHACELARIA Lyngbye 



1. Sphacelaria racemosa Grev. Scot. Cryt. Fl. 2:96. Fig. 7 



Plants composed of a small basal mass of cellular tissue from which 

 arise tufts of polysiphonous filaments. Filaments much branched, termi- 

 nated by a large apical cell which by transverse and longitudinal divisions 

 produces the cells of the polysiphonous filaments; sporangia on short few- 

 celled lateral branches. 



The species has not been found but var. artica has been reported from 

 the west coast of Whidby Island by Gardner (14). 



5. STRIARIA Greville 



1. Striaria attenuata Grev. (1830) Crypt. Fl. Synops. p. 44. Fig. 9 

 Plants filamentous, one to four dm. long, attached by a disc ; branches 

 opposite or alternate, one to five mm. in diameter, somewhat hollow, taper- 

 ing into hair-like filaments at both ends ; sporangia in groups forming trans- 

 verse lines on the thicker filaments. 



Reported from Orcas Island by Lyall in Harvey's (5) report, p. 167. 



Sphacelaria 

 racemosa 



Dictyosiphon 

 Chordaria 



Striaria 

 attenuata 



PLATE 49 



Fig. 7. Diagram of the end of a branching filament with apical 

 cells (a). X about 75. 



Fig. 8. a, Diagram of part of filament showing scattered groups 

 of sporangia; X about 25. b, Portion of branching filament; X about 

 0.25. 



Fig. 9. Diagram of portion of a filament with groups of sporangia 

 in transverse rows. X about 15. 



