1^25] Setchell-Gardner: Melcmophyceae 445 



parenchyma cells and devouring their contents; cells 6-10/x long, 5— 8p 

 diam.; erect filaments 400-600/x Long, 6.5-8/m wide, attenuated above 

 into a hair, fasciculately branched at or near the surface of the host. 

 forming a compact mass of cells; zoosporangia broadly elavate, 

 60-100/a long, 15-30/x, broad; gametangia numerous, lateral on short 

 pedicels or sessile, narrowly cylindrical, blunt, 40-70/i. (up to 100/x) 

 long, 7-9/* diam. ; loculi mostly uniseriate. 



Growing on the outer ends of the leaves of eel-grass, in the lower 

 littoral and upper sublittoral belts. Sitka. Alaska. 



Setchell and Gardner, Phyc. Cont. V. 1922, p. 389, pi. 44. figs. 1, 2. 

 . Of all the species of Streblonema thus far discovered on our coast, 

 8. vorax is the most destructive to the host. Although the penetrating 

 filaments have abundance of chromatophores, the plants seem to be in 

 a large degree parasitic. The cells of the host are closely compacted, 

 and have thick walls, yet they are devoured in large quantities. We 

 suggest the possibility of the secretion of enzymes with digestive 

 power which act upon the cell-wall and its protoplasm, after which 

 they are absorbed. This plant is found in company with several other 

 small Melanophyceae, Chlorophyceae and Rhodophyceae. none of 

 which penetrate the host. 



5. Streblonema Porphyrae S. and G. 



Fronds mostly endophytic ; prostrate filaments very tortuous, pene- 

 trating the cell-walls of the host between the cells, freely branched ; 

 erect filaments pushing slightly beyond the surface of the host, occa- 

 sionally branched ; hair filaments unknown ; cells of the creeping fila- 

 ments 3-4/t diam., irregular in shape ; zoosporangia unknown ; game- 

 tangia terminal in erect filaments, extending slightly beyond the sur- 

 face of the host, fusiform to irregular in shape, 25-35/i. long, 5-8/* 

 broad. 



Growing in the parenchymatous base of Porphyra naiadum on 

 eel-grass. Pacific Grove, California. 



Setchell and Gardner, Phyc. Cont. V, 1922, p. 387, pi. 44, fig. 6. 



Streblonema Porphyrae is an exceedingly diminutive, though 

 apparently distinct, species, confined, so far as we know at present, 

 to the cushion-like bases of Porphyra naiadum. It ramifies deep into 

 the tissue, apparently not entering the cells. 



