1925 1 Setchell-Gardner: Melanophyceae 4sr> 



18-22/*. broad, or terminal and seriate with lateral secund prolonga- 

 tions; gametangia sessile near the outer ends of the erect filaments, 

 or on short pedicels from the creeping filaments, 90-110/4. long, 15-18/* 

 broad, nearly cylindrical, or terminal on the erect filaments, clavate, 

 often with lateral, tuberculate, secund prolongations, variable in 

 size. 



Growing on the pneumatocysts of Nereocystis Luetkeana. Central 

 California (San Francisco and Pacific Grove). 



Setchell and Gardner, Phyc. Cont. Ill, 1922, p. 366, pi. 37, figs. 4, 5. 



This form of Compsonema is to be distinguished by the great 

 predominance of relatively short terminal gametangia, and many 

 relatively large, lateral, secund, sessile gametangia which are curved 

 upwards. There are a few sessile or short pedicellate examples at the 

 base and a few lateral forms on short ramuli. Specimens taken in 

 December had the larger number of gametangia empty. 



16. Compsonema speciosum f. piliferum S. and G. 



Fronds forming cushions, more or less circular in outline, 5-8 mm. 

 diam. ; creeping filaments very irregularly and profusely branched, 

 following closely the irregularities on the surface of the host, at times 

 short branches penetrating among the injured cells of the host ; erect 

 filaments numerous, unbranched or bearing short, secund, fructiferous 

 branches or an occasional piliferous branch, 500-800/*. long, tapering 

 at the base, piliferous above ; cells of creeping filaments very irregular 

 in shape and size; cells of erect filaments cylindrical, 6-7. 5/x diam. at 

 the base, 9-12/*. diam. in the widest part, 1-3 times as long; cells of 

 hairs 5-6. 5/x diam., up to 15 times as long; chromatophores band- 

 shaped, few in a cell ; zoosporangia obovoid, 55-65/* long, 28-32/t broad, 

 rare; gametangia sessile or on shorter or longer pedicels from the 

 creeping filaments or lateral, secund, sessile or pedicellate on the erect 

 filaments or, more rarely, intercalary ; terminal gametangia 60-100/* 

 long, 14-18/* broad, secund gametangia variable, much smaller. 



Growing on the pneumatocysts of Nereocystis Luetkeana. Moclips, 

 Washington. 



Setchell and Gardner, Phyc. Cont. Ill, 1922, p. 356, pi. 38, figs. 1, 2. 



Compsonema speciosum f. piliferum seems undoubtedly to be very 

 closely related to Compsonema speciosum (Borg.) S. and G. comb, nov., 

 (Myrionenm speciosum Borgesen, 1902, pp. 421-424, which is the 

 Hecatonema speciosum (Borgesen) Cotton, 1912, p. 121 and the 



