356 University of California Puhlications in Botany [Vol.7 



Compsonema pusillum sp. nov. 



Plate 37, figure 3 



Frontlil)iis jnilvinnlos tenues dilute fuscos, linea exteriore irregu- 

 lares, 3-4 nun. <liam. fonnantibus; parte prostrata filamoutis tortuosis, 

 raniosis. irrc<rularitatos superficies hospitis arete adhaerante e latere 

 inlVro lilanicnta pauca. brevia, et inter eellulas hospitis penetrantia 

 emittente ; filamentis erectis simplicibus, cylindricis, 270-300/x longis ; 

 cellulis filanieutorum repentium maxime forma mafruitudineque irre^i- 

 larilms; cellulis filanieutorum erectorum cylindricis, 6-1 fx diam., 3-5- 

 plo lougioribu.s; cln-oniatophoris leviter interrupto-taeniatis ; zoo- 

 sporangiis sphaericis usque ad ovoideis, sessilibus aut pedicellis brevi- 

 bus e filamentis repeutibus oriundis sufiFultis, 18-25/x (usque ad 40/x) 

 lonjris. in-22/A latis; gametanj^riis cylindrico-couicis usque ad obtuse- 

 fusiformibus, sessilibus aut pedicellis brevibus e filamentis repentibus 

 oriundis sufiFultis, 40-60/^ longis, 10-12/x latis; loculis 1-2-seriatis. 



Growing on tlie pneumatocysts of Nereocystis Luetkeana. Carmel 

 Bay, :\Iouterey County, California. Type, Gardner, no. 3582 (Herb. 

 T^niv. Calif., no. 207036), January. 



Compsonema pusillum seems to overlap each of several genera. Its 

 zoosporangia, gametangia. and penetrating filaments ally it with 

 Strchlonema. Sauvageau (1897) has figured Myrioncma with rhizoids. 

 The gametangia are very small and have about as many uniseriate as 

 biseriate loculi. It might be considered a very minute creeping 

 Ectocarpus. We have placed it in the genus Compsonema on account 

 of the scarcity of fruit in ])roportion to the sterile tissue, and on 

 account of the monostromatic base, believing that the penetrating 

 filaments are more or less accidental on account of the injured con- 

 dition of the surface layer of cells of the host. 



Compsonema speciosum f. piliferum f. nov. 



Plate 38, figures 1, 2 



Frondibus pulvinulos linea exteriore plus minusve orbiculares, 

 5-8 mm. diam. formantibus; filamentis repentibus maxime irregulariter 

 et profuse ramosis. irregularitates superficies hospitis arete alhaeran- 

 tibus. interdum ramis brevibus inter eellulas incolunies hospitis pene- 

 trantibus; filamentis erectis numerosis, simplicibus aut ramos breves 

 secundo.s, fructiferos aut interdum ramum piliferum emittentibus, 

 500-800;a longis, ba.sim attenuatis, superne piliferis; cellulis filanieu- 

 torum repentium forma magnitudiueque maxime irregularibus; cellulis 

 filamentorum erectorum cylindricis, basim 6-7.5jit diam., in parte 

 latissima ^-Vlfi diam., usque ad 15-plo longioribus; chromatophoris 

 taeniatis. in cellula quaque panels ; zoosporangiis obovoideis, ^o-I^o/a 

 longis, 28-32/A latis, raris; gametangiis filamentis repentibus oriundis 



