1922] Setchell-Gardner : Phycological Contributions 413 



formibus, non constrictis, 22-28/x cliam., inferne 1-2-plo, superne 

 1-2-plo longioribus qiiam latis; chromatophoris parvis, in cellula 

 quaque paucis, cliscoideis ; zoosporaiigiis ellipsoideis, erectis, lateralibus, 

 alternis 1-2-cellulato-pedicellatis, interdum prope basim filamentorura 

 erectoriim sessilibus, 60-95/x longis, 35-50/^, latis; gametangiis fusi- 

 formibiis, sparsis, partes superiores filamentornm erectoriim occu- 

 pantibus, sessilibus aut 1-2-cellulato-pedicellatis, alternis 70-85/x, 

 longis, 25-30^ latis. 



Growing on Codium fragile (Suringar) Hariot, in companv M-ith 

 Ectocarpus glohifer Kuetz. and with various species of Myxophyceae 

 and Rhodophyceae. Redondo, California. Type, Gardner, no. 1947& 

 (Herb. Univ. Calif., no. 206987), March. 



Ectocarpus socialis seems to be a relative of the E. cylindricus 

 group. The chief distinctions are in the shape, size, and position of 

 the gametangia. 



Ectocarpus Taeniae sp. nov. 



Plate 46, figure 15 



Frondibus diffusis, 0.5-1.5 mm. altis, per filamenta superfieialia 

 repentia. profuse ramosa affixis; filamentis erectis simplicibus, basim 

 le^nter attenuatis. superne longe attenuatis. piliferis; cellulis. fila- 

 mentorum repentium cylindricis, 4-6jU, diam., filamentorum erectorum 

 8-lOju, diam.. inferne quadratis, apicibus 4-6-plo longioribus quam 

 latis; chromatophoris eurtis, comparate crassis. irregulariter taeniatis; 

 zoosporangiis ignotis ; gametangiis anguste ellipsoideis. interdum lente 

 curvatis, in filamentis repentibus et erectis plerumque sessilibus, 20-28ju 

 (usque ad -iOix) longis, 15-20/* latis. 



Growing on Taonia Lennebackerae. San Pedro, California. Type, 

 Gardner, no. 3561a (Herb. Univ. Calif., no. 206997), December. 



This species forms rather diffuse and even layers, mostly along the 

 margins of Taonia, over w^hose surface the creeping filaments spread 

 and give rise to gametangia or to erect filaments not over 1.5 mm. 

 high. In many ways it seems like a miniature Ectocarpus Padinae 

 (Buffh.) Sauvageau (1897, p. 30 et seq.). Our species, however, is 

 only about half as tall, the cells of the erect filaments about half as 

 broad, and the gametangia less than half as large as those of E. 

 Padinae. We have found gametangia only of the "antheridium" type. 

 Ectocarpus Padinae has its creeping filaments entirely endophytic 

 while E. Taoniae has them entirely epiphytic. 



