1922] • Setchell-Gardner : Phycological Contributions 407 



having apical growth. The growth in length of the erect filaments 

 in Choristocarpaceae is by the division of the terminal cell only, 

 whereas in E. cliantransioides the meristem extends over a number of 

 cells at the outer or apical end of the filaments. These cells, some 

 10 to 15 in number, are much richer in cell contents, the terminal cell 

 being the richest of all in the series. This is a very unusual condition 

 for an Ectocarpus. The nearly uniform diameter throughout of the 

 erect filaments and their method of branching resemble to a remarkable 

 degree those characters found in Chantransia. The gametangia are 

 typically those of Ectocarpus, and notwithstanding the other rather 

 unusual characters, it seems to be most closely related to that genus, 

 but a very distinct species. 



Ectocarpus commensalis sp. nov. 



Plate 48, figures 32-35 



Frondibus 200-400/* altis, dense fasciculatis. per filamenta rhizoidea 

 intricata, parce ramosa inter utriculos et usque inter filamenta medul- 

 laria hospitis penetrantia affixis ; filamentis erectis prope basim alterne 

 ramosis, superne simplicibus et leviter attenuatis. non pilif eris ; cellulis 

 filamentorum erectorum cylindricis, non constrictis, basim 12-18/i, 

 diam.", 1.5-2.5-plo longioribus quam latis; chromatophoris taeniatis, in 

 cellula quaque paucis; zoosporangiis ignotis; gametangiis obtuse fusi- 

 formibus usque ad cylindrico-conicis, brevi-pedieellatis. prope basim 

 filamentorum plerumque lateralibus, raro terminalibus, 60-lOOju, longis, 

 15-20/x latis. 



Growing on Codium Setchellii Gardner, Carmel Bay, and on 

 Codium fragile (Suringar) Hariot, Pacific Grove. Monterey County, 

 California. Type, Gardner, no. 3319 (Herb. Univ. Calif., no. 206994), 

 May. 



This minute species is one of several occurring on species of Codium, 

 both on this coast and on that of southwestern Europe. The colorless 

 rhizoidal filaments descend into the substance of the host even to the 

 central (or basal) medullary tissues. The smaller diameter of the 

 erect filaments and the more narrowly conical or fusiform gametangia 

 readily distinguish this species from the others. 



Ectocarpus eramosus sp. nov. 



Plate 47, figures 18-23 



Frondibus diffusis aut flocculosis. 1-3 mm. altis, per filamenta 

 rhizoidea irregulariter ramosa inter utriculos hospitis profunde pene- 

 trantes affixis; filamentis erectis eramosis aut raro ramos breves. 



