478 University of California Publications in Botany L VoL - 8 



6. Compsonema tenue S. and G. 



Plate 54, fig. 6 



Fronds microscopic, forming a more or less continuous stratum on 

 the host among other small algae; creeping filaments numerous, 

 branched, following closely the irregularities of the surface of the 

 host; erect filaments sparse, unbranched, tapering slightly at both 

 ends, 80-100/t high ; hair filaments sparse ; cells of creeping filaments 

 irregular in shape and size; cells of erect filaments cylindrical, not 

 constricted, 7-8/* cliam., 1.5-2.5 times as long; cells of hair filaments 

 cylindrical, 5.5-6.5/1. diam., quadrate or less below, 7-10 times as long 

 above; zoosporangia (?) clavate, 24-28/x long, 8-10/x, broad, sparse; 

 gametangia fusiform to irregularly conical, sessile on the creeping 

 filaments, numerous, 22-28/x, long, 7-11/t broad ; loculi mostly 2-seriate. 



Growing on the fruiting fronds of Cystophyllum geminatum. Sitka, 

 Alaska. 



Setchell and Gardner, Phyc. Cont. Ill, 1922, p. 359, pi. 37, fig. 6. 



Compsonema tenue, although scarcely typical of the genus, seems 

 to possess affinities as closely allied to Compsonema as to any other 

 genus, and hence we have placed it here for the present. 



7. Compsonema fasciculatum S. and G. 



Fronds forming microscopic tufts more or less confluent ; creeping 

 filaments tortuous, adhering to the host without rhizoicls; erect fila- 

 ments branched near the base, 90-130/* long, tapering at the apex and 

 at the base, not piliferous, constricted at the cross-walls; true hairs 

 absent ; cells of erect filaments 10-14/x diam. in the widest part, 1-2.5 

 times as long ; zoosporangia unknown ; gametangia somewhat irregular 

 in form, conical to fusiform, 35-45/x long, 12-18/t broad, mostly lateral 

 on short pedicels. 



Growing on Gigartina radula f. Pacific Grove, California. 



Setchell and Gardner, Phyc. Cont. Ill, 1922, p. 360, pi. 38, figs. 

 7-9. 



This species is allied here rather than with Ectocarpu-s because 

 of its extremely small size and its creeping fasciculate habit. 



