1918] Gardner: New Pacific Coast Marine Algae III -ilo 



Rivularia mamillata Sotchell et Gardner sp. nov. 

 Plate 40, fig. 19 



Thallis 0.5-1 mm. diam., laete coerideo-vii'idibus aut fiiscescent- 

 ibiis, sphaericis aut difformibus, plus minusve coutluentibus, strata 

 C'ongesta et pulvei-ulenta formantibus aut Mvxophyceis aliis sparse 

 immixtis; fiilis repetite pseudoramosis, superne late divergentibus ; 

 vaginis inferne hyalinis, superne luteo-fuscis, inferne distinctis 

 superne tenuibus, oereatis ; trichomatibus e basi superne lente et longe 

 attenuatis, in pilis hyalinis longisque abeuntibus, basim 4^5^ diam., 

 leviter torulosis; cellulis 2-5/a longis, coeruleo-viridibus, distincte 

 granulatis ; heterocystis s]ihaerieis ad truncato-conieis, 5.5-8/x diam. 



Thallus 0.5-1 mm. diam., bright blue-green or brownish, spherical 

 or irregular in outline, more or less confluent, forming congested, 

 pulverulent layers, or scattered among other ]\Iyxophyceae ; filaments 

 repeatedly false-branched, spreading widely above; sheath hyaline 

 below, yellowish brown above, distinct below but very thin above, 

 ocreate, trichomes tapering gradually from the base upward, terminat- 

 ing in a long hyaline hair, 4— 5/j, diam. at base ; cells 2-5/a long, slightly 

 torulose, blue-green, decidedly granular ; heterocysts spht^rical to 

 bluntly conical, 5.5-8ju, diam. 



Growing on decaj^ing logs along high-tide level in somewhat shaded 

 localities. Cape Flattery, Washington. Type no. 3829, Gardner. 



This species is closely related to R. ttitida Ag. but has more dis- 

 tinct, ocreate sheaths, larger trichomes Avith shorter cells, and a less 

 ample thallus. 



Brach5rtrichia afiinis Setchell et Gardner sp. nov. 

 Plate 41, figs. 27, 28 



Thallis parvis, 0.5-2 cm. diam., profunde plicatis, bullatis, caver- 

 nosis, cartilagineis, dilute caeruleo-viridibus aut aetate provecta fus- 

 cescentibus ; fills intricatis, inferne laxe intertextis, superne densissime 

 stipatis parallelisque et in pilis tenuibus abeuntibus ; cellulis filorum 

 interiorum inferiorum leviter ventricosis, 4-5/^ diam., 1.5-2-plo longi- 

 oribus; cellulis iniVi'iiis filorum erectorum sphaericis aut.doliifonnibus, 

 7-9/x. diam.; supernis l/x diam.; heterocystis sphaericis aut leviter 

 depresso-sphaericis. 



Thallus small, 0.5-2 cm. diam., deeply plicate, bullate, cavernous, 

 cartilaginous, light blue-green or brownish with age; filaments in- 

 tricate, loosely intertwined below, very densely crowded and parallel 

 above and tapering gradually into delicate haii-s ; cells of the lower 

 interior filaments slightly vontricose, 4-5/a diam., 1.5-2 times as long 

 as broad ; cells of the erect filaments spherical or doliform toward the 

 base, 7-9/x diam., terminal cells 1/u, diam. ; heterocysts spherical or 

 slightly compressed. 



Growing in rock pools in the middle littoral belt. Laguim Beach, 

 Orange County, California. 



