1922] Setchell-Gardncr : Fhycological Contributions 359 



we hold to the principal distinction between Compsonema and Myrio- 

 nema, it will be necessary to ally this species with the former. It was 

 found growing in company with Streblonema aecidioides f. pacificiim 

 S. and G., which gave to the host a roughened appearance, otherwise 

 it probably would not be noticeable without microscopic examination. 



Compsonema tenue sp. nov. 



Plate 37, figure 6 



Frondibus microscopicis, stratum plus minusve continuum in 

 hospite inter algas parvas alteras formantibus; filamentis repentibus 

 numerosis, ramosis, irregularitates superfices hospitis arete adhaeran- 

 tibus; filamentis erectis sparsis, simplicibus, apice basimque leviter 

 attenuatis, SO-lOO^u, altis; pilis veris sparsis; cellulis filamentorum 

 repentium forma magnitudineque irregularibus ; cellulis filamentorum 

 erectorum cylindricis, non constrictis, 7-8/x diam., 1.5-2.5-plo longior- 

 ibus; cellulis filamentorum piliferorum cylindricis, 5.5-6.5^ diam., 

 inferne exacte aut fere quadratis, superne 7-10-plo longioribus; zoo- 

 sporangiis( ?) clavatis, 24-28ju, longis, 8-1 0/t latis. sparsis; gametangiis 

 fusiformibus usque ad irregulariter conicis, in filamentis repentibus 

 sessilibus, numerosis, 22-28ja longis, 7-11/x latis; loculis plerumque 

 2-seriatis. 



Growing on the fruiting fronds of Cystopliyllum geminatum. 

 Sitka, Alaska. Type, Gardner, no. 3972 (Herb. Univ. Calif., no. 

 207040), July. 



Compsonema teyiue, though scarcely typical of the genus, seems to 

 possess affinities as closely allied to Compsonema as to any other 

 genus, and hence we are placing it here for the present. 



Compsonema nummuloides sp. nov. 



Plate 35, figures 5, 6 



Frondibus pulvinulos tenues orbiculares, 7-12 mm. diam. forman- 

 tibus; parte prostrata filamentis radiantibus, multo crispatis, dense 

 compactis, irregularitates superficies hospitis arete adhaerantibus 

 composita; filamentis erectis simplicibus, numerosis, 300-400ju, longis, 

 apice basimque leviter attenuatis; pilis veris deuntibus; cellulis fila- 

 mentorum repentium forma magnitudineque multo irregularibus; 

 cellulis filamentorum erectorum cylindricis, basim 6-7ju. diam., 3-8-plo 

 longioribus, in parte latissima 9-1 I/a diam., cellula apicali quadrata 

 6-7/x diam., 3-8-plo longiore ; zoosporangiis ignotis; gametangiis 

 plerumque sessilibus aut brevi-pedicellatis, nunc in filamentis erectis 

 terminalibus, 70-90/a (usque ad 140/a) longis, ll-15ju, latis; loculis 

 plerumque 2-seriatis. 



Growing on the pneumatocysts of Nereocystis Luetkeana. IVIoss 

 Beach, San Mateo County, California. Type, Gardner, no. 4318 (Herb. 

 Univ. Calif., no. 207041), July. 



