1922] Setchell-Gardner : Phycological Contributions 411 



gametangia of the same general type as found in that species, but con- 

 siderably smaller. The branching, however, is never opposite, and the 

 acute ramuli gradually attenuated upward recall those of E. acutus, 

 from which our species is amply distinct in both chromatophore and 

 characters of its gametangia. The branches, particularly the larger, 

 are very suddenly and considerably attenuated at the base, giving the 

 species a striking characteristic of its own, at least within the group 

 of species with discoid chromatophores. 



Ectocarpus Mesogloiae sp. nov. 



Plate 45, figures 5, 6 



Frondibus minutis, 0.75-1.5 mm. altis, per filamenta copiosa, dense 

 intertexta ramosa, rhizoidea, inter callulas hospitis penetrantia affixis ; 

 filamentis erectis sparse alterneque ramosis ; filamentis primariis et 

 ramulis superne longe attenuatis, acutissimis, non piliferis; cellulis 

 cylindricis, ad dissepimenta leviter constrictis, basi 15-18/a diam., 

 1-2-plo longioribus quam latis, apicibus filamentorum 4- 6/a diam. ; 

 chromatophoris tenuibus, irregulariter taeniatis, parietes cellularum 

 f ere tegentibus ; zoosporangiis ignotis; gametangiis anguste cylindrico- 

 conicis, 120-160|U, (usque ad 210./x) longis, 18-22/x latis, brevi-pedicel- 

 latis, raro sessilibus. 



Growing on Mesogloia Andersonii. Carmel Bay, Monterey County, 

 California. Type, Gardner, no. 2865a (Herb. Univ. Calif., no. 206989), 

 May, 1915. 



The general characters of this diminutive species ally it with the 

 E. confervoides group. "We have deemed it best to consider it a distinct 

 species on account of the small dimensions of all of its parts and its 

 penetrating habit. It has not been seen on any other host except the 

 one mentioned above. 



Ectocarpus Saundersii sp. nov. 



Frondibus floccos parvos 2-5 mm. altos formantibus, per filamenta 

 copiosa, ramosa, in superficiem hospitis repentia affixis : ramis alternis ; 

 ramis primariis longis divergentibusque ramulis ultimis sparsis. 

 brevibus, acuminatis ; cellulis filamentorum primariorum 25-40/i, diam., 

 inferne quadratis, superne brevioribus, ad dissepimenta leviter con- 

 strictis; chromatophoris numerosis, discoideis; zoosporangiis breviter 

 pedicellatis aut intercalaribus, globosis, ad 30/x diam. ; gametangiis 

 cylindricis usque ad ovoideis. obtusis aut acuminatis, lateralibus. 

 pedicellis longioribus aut brevioribus suffultis, 70-150/^ longis, 25-50/x 

 latis. 



