1925] Setchell-Gwrdner: Melanophyceae 473 



7. Compsonema Kuek. 



Fronds forming small cushions more or less circular in outline. 

 composed of a prostrate creeping, primary portion, giving rise to 

 numerous erect unbranched or branched filaments, with or without 

 hairs; prostrate portion monostromatic, composed of filaments quite 

 regularly radiating from a common center and usually with sub- 

 terminal branching, closely crowded ; reproduction by unilocular 

 zoosporangia and plurilocular gametangia with mostly pluriseriate 

 loculi. 



Kuckuck, Beitriige zur Kennt. Meeresalg., 1899, pp. 56-58 (90-92 

 inrepr.),pl. VI (12), figs. 6-9. 



The type species of Compsonema is C. gracile and the type locality 

 is Rovigno, on the east coast of the Adriatic Sea, where it was found 

 growing on stones in water 1-2 meters deep. 



The genus Compsonema was established by Kuckuck. We have 

 accepted the genus to include forms which, like Myrioncma, start from 

 a single cell that, by divisions, soon originates a series of closely 

 crowded, radiating filaments, forming a monostromatic basal layer 

 more or less circular in outline; and which, unlike Myrionema, pro- 

 duce on erect filaments numerous gametangia that develop pluriseriate 

 loculi. The genus is very closely related to the genus Myrionema on 

 one side and to Hecatom ma on the other. 



Key to the Species 



1. Erect sterile filaments branched 2 



1. Erect sterile filaments simple 5 



2. Creeping filaments with few subulate rhizoids 7. C. fasciculatum (p. 478) 



2. Creeping filaments without rhizoids 3 



3. Sterile branches short, high up, secund 4 



■3. Sterile branches long, low down, not secund 13. C. intricatum (p. 482) 



4. Erect filaments piliferous in part 17. C. ramulosum (p. 484) 



4. Erect filaments not piliferous 12. C. sporangiiferum (p. 481) 



5. Gametangia all terminal 6 



5. Gametangia terminal and lateral or intercalary 14 



6. Gametangia all sessile 7 



6. Gametangia pedicellate or in part sessile 8 



7. All erect filaments completely transformed into gametangia. ...2. C. sessile (p. 474) 



7. Gametangia intermixed with sterile filaments 6. C. tenue (p. 478) 



8. Prostrate filaments producing penetrating rhizoids 9 



8. Prostrate filaments not producing rhizoids 10 



9. Rhizoids abundant, straight, penetrating deeply into the host 



11. C. streblonematoides (p. 481) 



9. Rhizoids contorted, not penetrating deeply 5. C. pusillum (p. 477) 



10. Gametangia very abundant, of uniform height .4. C. fructuosum (p. 476) 

 10. Gametangia with pedicels very variable in height 11 



