430 University of California Piidlications in Botany [Vol. 8 



broad ; chromatophores disk-shaped, several in each cell ; zoosporangia 

 unknown; gametangia from nearly spherical to broad ovoid, about 

 62fjL long, 57/A broad. 



On Chnoospora pacifica. West coast of Mexico (St. Augustin). 



J. G. Agardh, Nya Alger fran Mexico, 1847, p. 7, Sp. Alg., vol. 1, 

 1848, p. 16 ; Kuetzing, Spec. Alg., 1849, p. 453 ; Borgesen, Mar. Alg. 

 Dan. West Indies, pt. 2, 1914, p. 173, fig. 136. Ectocarpus hamatus 

 Crouan, in Maze et Schramm, Ess. Class. Alg. Guad. (ed. 2), 1870-77, 

 p. Ill (fide Borgesen) ; Vickers, Phyc. Barbad., pt. 2, 1908, pi. 29. 



Ectocarpns hreviarticulatus J. Ag. is known to us as a member of 

 our flora only from the literature and particularly from Borgesen 's 

 {Joe. cit.) account of it. It seems closely related to E. oviger, from 

 which it differs chiefly in size and branching, and slightly in dimen- 

 sions of filaments and gametangia. Both Kuetzing and Borgesen 

 state that they have examined cotypes and may be, therefore, con- 

 sidered to have spoken with authority. We have been enabled to 

 study what certainly seems to be this species in material from 

 American Samoa (cf. Setchell, Veg. Tut. IsL, p. 171, fig. 37). 



21. Ectocarpus chantransioides S. and G. 



Fronds arising from contorted creeping filaments, forming dense 

 hemispherical cushions 4-8 mm. high; branching profuse, alternate 

 below, mostly secund above; main filaments and branches not atten- 

 uated; cells 8-10/x diam., 2-3 times as long as the diameter below^ 

 quadrate above ; chromatophore band-shaped ; zoosporangia unknown ; 

 gametangia mostly sessile or on short pedicels, narrowly cylindrico- 

 conical, 80-IIOjM, long, 16-20/a broad at the base. 



Growdng on boulders in the lower littoral belt. Three miles north- 

 west of Santa Monica, California. 



Setchell and Gardner, Phyc. Cont. VI, 1922, p. 406, pi. 48, figs. 

 28-31. 



The habit of Ectocarpus chantransioides distinguishes it at once 

 from all other species of the genus with the exception of E. hemi- 

 sphericus Saunders. The latter species is always found, so far as our 

 knowledge is concerned, epiphytic on Fucaceae, while the former 

 species is confined to rocks. Ectocarpios chantransioides has also more 

 slender filaments than has E. hemisphericus, not at all tapering, and 

 has distinct apical growth. The gametangia are differently shaped, 

 being longer and more slender. It is therefore very distinct even 

 from E. hemisphericus. It resembles the genus Choristocarpus of the 



