1925] SetchcU-Gardner: Melanophyceae 479 



8. Compsonema dubium S. and G. 



Fronds diminutive, forming small tufts among other microscopic 

 algae on the host ; prostrate portion composed of much contorted, 

 branched, creeping filaments; erect filaments unbranched, almost 

 cylindrical throughout, 275-350,;u, long, not piliferous; true hairs 

 absent ; cells of creeping filaments very irregular in form and size ; 

 cells of erect filaments cylindrical, l-^jx diam., slightly less at the base 

 and the apex of the filament, 2-3 times as long; zoosporangia (?) 

 ellipsoidal, terminal on short pedicels, 16-22ja long, 12-15fi broad ; 

 gametangia cylindrical to slightly fusiform, terminal on longer or 

 shorter pedicels from the creeping filaments, rarely terminal on the 

 long erect filaments, 50-75/a long, 8-llju, broad ; loculi mostly 2-seriate. 



Growing on the sterile base of Gigartina ra-dula f . Cypress Point, 

 Monterey County, California. 



Setchell and Gardner, Phyc. Cont. Ill, 1922, p. 365, pi. 38, fig. 6. 



Compsonema duhium, like C. coniferum and C. serpens, has close 

 affinities with small members of the genus Ectocarpus. Its relatively 

 long and narrow gametangia distinguish it from the two species here 

 mentioned with which it is frequently associated. 



9. Compsonema coniferum S. and G. 



Fronds microscopic, more or less confluent, forming a velvety 

 stratum on the host among other minute algae ; prostrate portion pro- 

 fusely branched, much contorted ; erect filaments numerous, simple, 

 slightly attenuated at both ends, not piliferous, 150-200/x high ; true 

 hairs absent ; cells of creeping filaments irregular in shape and size, 

 6-7.5/1. diam.. 9-12/x, long; cells of erect filaments cylindrical to slightly 

 doliiform. 8-10/x, diam. in widest part, 1-1.5 times as long ; chromato- 

 phores band-shaped ; zoosporangia unknown ; gametangia sessile or on 

 short pedicels on the creeping filaments, narrowly conical, 45-65/i, long, 

 15-18/t broad. 



Growing on the sterile base of Gigartina radida f. Cypress Point, 

 Monterey County, California. 



Setchell and Gardner, Phyc. Cont. Ill, 1922, p. 365, pi. 38, fig. 3. 



Compsonema coniferum seems to be a very close relative of C. 

 fasciculatum, found growing on the same host. The fronds are more 

 extensive, unbranched, and have larger gametangia. We consider this 

 species of Compsonema a very near approach to an Ectocarpus of 



