4:!(i University of California Publication* in Botany [Vol. 8 



28. Ectocarpus ellipticus Saunders 



Fronds minute, about 1 mm. high, tufted, attached by numerous, 

 colorless, branched rhizoidal filaments ; erect filaments sparingly 

 dichotomous at the base, unbranched or with few unicellular branches 

 above, gradually attenuated upward, piliferous ; cells 9-12/x diam. 

 and 1-2 times as long as the diameter at the base of the filaments, 3 

 times as long above; "chromatophores thin branched bands, oval," 

 numerous ; zoosporangia sessile, ovate or ellipsoidal, 30-40/a long, 

 12-18/x broad; gametangia cylindrical to blunt-conical, 75-100^, (up 

 to 180/x.) long, 18-25/1. diam., borne laterally at or near the base of the 

 erect filaments, or occasionally arising directly from the creeping 

 filaments, sessile or on short pedicels below ; loculi one to few seriate. 



Growing in the conceptacles and cryptostomata of Fucus sp. 

 Pacific Grove, California. 



Saunders, Phyc. Mem., 1898, p. 149, pi. 14, figs. 6-9; Collins, 

 Holden and Setchell, Phyc. Bor.-Amer. (Exsicc), no. 527. 



Ectocarpus ellipticus is a curiously localized species growing upon 

 the inner margins of the openings of the cryptostomata and con- 

 ceptacles of Fucus at Pacific Grove, California. Transverse sections 

 of the fronds of the Fucus show that this Ectocarpus simply forms a 

 ring of growth just within the outer opening of the cryptostomata and 

 conceptacles just outside the hair-forming tissues. The rhizoidal fila- 

 ments of the Ectocarpus penetrate into the apparently looser tissues of 

 the ostiole of the cavities it inhabits. The gametangia. are all basal or 

 borne near the bases of the erect filaments. It seems to be a very 

 distinct species. 



29. Ectocarpus chitonicola Saunders 



Fronds small, 1-2 mm. high, tufted, creeping filaments numerous, 

 irregular, branched ; cells of the creeping filaments 11-15/x diam., 1-2 

 times as long as the diameter ; erect filaments mostly simple, 14/x diam. 

 at the base, somewhat narrower above, with cells 0.5-2 times as long 

 as the diameter below, 2-3 times as long above, not constricted at the 

 partitions ; chromatophores small oval disks, numerous ; zoosporangia 

 unknown ; gametangia subcylindrical to narrowly ovoid, obtuse at the 

 apices, 90-175/i. (up to 250/a) long, 25-35/a diam., borne laterally on 

 the erect filaments, or occasionally on the creeping filaments, the 

 lower gametangia on pedicels, the upper sessile. 



