408 University of California Puhlications in Botany T^'ol. 7 



divorf^'ciitcs vnlj,'o in ^MiiU'tan^nis tLTiiiinantcs t'lnitteutibus, basini et 

 apicc It'vitor attfimatis, noii piliferis; ccllulis filamentorum maturorum 

 28-40/1 (liaiii.. 0.5-1.25-plo longioribus quam latis, cylindricis, levissime 

 coiistrictis; chroiniitoplioris coinparate crassis. dense confertis. irretjii- 

 lariler laeiiiatis. sine pyrenoideis; zoosporangiis ignotis; gametangiis 

 iiiaxime niagnitudine foniiaqne variabilibus ant lateralibus et per 

 filainenta tota alternis ant interdnm in filamentis primariis terminal- 

 ilms et seriatis ])leniin(|ne pedicellis paneicellnlatis, lateralibus cylin- 

 drieis ns(|ue ad eylindrieo-eonicis, 150-280/a longis, 26-36/x latis, ter- 

 niinalilnis seriatis, 700-900/a longis, 15-20/a latis. 



Growing on C odium fragile in the lower littoral belt. Near the 

 entrance to Tomales Bay, Marin Connty, California. Type, Gardner, 

 no. 3448& (Herb. Univ. Calif., no. 206995), August. 



This very small species has the general appearance of a form of 

 Ectocarpus confervoides, but the cells are short and the filaments very 

 slightly constricted at the partitions. It seems, in these respects, nearer 

 to E. acutus and E. corticidatus, possibly bearing something of the 

 same relation to these species that the dwarf forms of E. confervoides 

 do to the typical form. Ectocarpus eramosus, however, is not readily 

 to be referred as a dwarf form of either E. acutus or E. corticulatus 

 and is consequently to be kept separate, at least for the present. 



Ectocarpus flagelliferus sp. nov. 



Plate 47, figures 2.5-27 



Frondibns dense floccosis, 3-5 mm. altis, per filamenta pauca 

 repentia et rhizoidea e cellulis inferis descendentia, decolorata affixis; 

 filamentis ereetis inferne simplieibus, superne sparse et alterne ramosis, 

 superne longe attenuatis, inferne abrupte contractis, juvenis piliferis; 

 cellulis filamentorum primariorum leviter doliiformibus, 25-35/a diam., 

 0.25-1.5-plo longioribus quam latis; chromatophoris parvis, irregu- 

 lariter taeniatis ant lamiiiaeformibus. pyrenoidis deniitibns: zoospor- 

 angiis ignotis; gametangiis magnitudine formaque variabilibus fusi- 

 formibus usque ad cylindrico-conicis, plerumque in pedicellis longis 

 lateralibus, interdum in filamentis curtis erectisque terminalibus, aut 

 in filamentis primariis longe-seriato-interealarilms, lateralibus 125- 

 200fjL longis, 28-40yx latis, terminalibus et intercalaribus usque ad 

 1.5 mm. longis. 



Growing on eel-grass. Sitka, Alaska. Type, Gardner, no. 3970 

 (Herb. T^niv. Calif., no. 206999), July. 



Thr species we have named Ectocarpus flagelliferus, while re- 

 sembling superficially some of the shortest plants of Ectocarpus 

 confervoides f. variahilis, presents several peculiarities whicli are 

 characteristic. The pbints of this species are attached, so far as the 



