1925] SetcheU-Qardncr: MeUinoplnjcrar 471 



20. Myrionema globosum f. affine S. and G. 



Fronds microscopic 200-300//. diam., irregular in outline, inter- 

 mixed with other small algae; prostrate filaments much distorted, 

 freely branched; erect filaments fasciculately branched, 100-140/t 

 long, tapering upwards, piliferous in part ; true hairs 300-400/1 long ; 

 cells of prostrate filaments 4-6/t diam., variable in shape ; cells of 

 erect filaments cylindrical, 4-5/x diam. ; zoosporangia unknown ; game- 

 tangia cylindrical, 35-45/*. long, 4-4.5/x broad, sessile and lateral on 

 the erect filaments or rarely terminal ; loculi uniseriate. 



Growing on the leaves of eel-grass. Sitka, Alaska, to central Cali- 

 fornia (Point Carmel, Monterey County). 



Setchell and Gardner, Phyc. Cont. II, 1922, p. 342, pi. 33, fig. 16. 



We have no measurements in detail for the parts of Myrionema 

 globosum, this seemingly distinct species. Reinke (1889a, p. 46) states 

 that the plants are one-half to one millimeter in diameter. Our plants 

 seem much smaller, in general. It is difficult to make out the size on 

 account of their being so intimately intermixed with other small algae. 

 This is the case in both collections of plants which we have examined, 

 one from Sitka, Alaska, and the other from Point Carmel, California. 



21. Myrionema strangulans Grev. (in scnsit strict lore) 



Plate 35, fig. 12, and plate 40, fig. 51 



Fronds forming very irregularly shaped cushions, 1-2 mm. diam., 

 firmly adhering to the surface of the host, without rhizoids ; prostrate 

 portion composed of regularly radiating filaments with apical growth 

 and branching, producing dichotomous filaments, strictly monostro- 

 matic; cells of prostrate filaments 4-4.5/x diam., 1-2 times as long, 

 cylindrical or slightly doliiform; hairs, 1-1.5 mm. long, cells of hairs 

 up to 100/A long at the apices, 5/* diam., quadrate and with short sheath 

 at the base ; erect filaments clavate, longest in the center of the frond, 

 diminishing in length toward the periphery, 55-65/* (up to 110/x) 

 long, 4/* diam. at the bases, Bp. at the apices; basal cells cylindrical, 

 terminal cells subspherical ; chromatophores spherical, several in a 

 cell; unilocular zoosporangia numerous, interspersed among the erect 

 filaments, sessile or on 1-celled pedicels on the creeping filaments, 

 ellipsoidal to obovoid, 38-46/* (up to 60/*) long. 18-24/* broad; game- 

 tangia unknown. 



