1920] Setchell-Gardner : Phycological Contributions 291 



Prasiola meridionalis sp. nov. 



Plate 25, figure 2 



Thallo usque ad 7 mm. alto, stipiti brevi latoque in laminam latam, 

 eordatam et rosulatam aut cucullatam abeunte, sordide viridi ; cellulis 

 neque in areolis distinctis ordinatis neque per vias interstitiales sepa- 

 ratis ; membrana 40-45/; crassa, in seetione transversali cellulas 14-18ju, 

 altas et 7-8/u, latas marginibus latis hyalinisque (usque ad 13/x erassis) 

 ostendente ; akinetis dispersis, magnis, parietibus erassis ; aplano- 

 sporis probabiliter 128-512 (4X4X8 aut 8X8X8) in aplanospo- 

 rangio singulo. 



Frond up to 7 mm. high, with short and broad stipe, soon expanded 

 into a broad, cordate, rosulate or cucullate blade, dirty green ; cells 

 neither arranged in distinct areolae nor separated by interstitial lines ; 

 membrane 40-45/a thick, section showing cells 14-1 8jii high and 7-8/a 

 wide with broad hyaline margins (up to ISfx thick) ; akinetes scattered, 

 large, thick walled; aplanospores probably 128-512 (4X4X8 or 

 8X8X8) from a single aplanosporangium. 



On exposed rocks or rocky islets above the high-water mark but 

 exposed to the force of the waves. Washington (Friday Harbor 

 and Neah Bay) to central California (entrance to Tomales Bay). 

 Type no. 3824, Gardner. 



The specimens taken as the type of this species were collected by 

 one of us (Gardner) at Neah Bay, Washington. We are also inclined 

 to refer here specimens collected at "Minnesota Reef" at Friday 

 Harbor, Washington, and at the entrance to Tomales Bay, California. 

 In the last two localities the species is associated with Gayella con- 

 stncta. Cultures, however, strongly indicate the independence of the 

 two plants from one another. 



Prasiola meridionalis comes near to P. horealis Reed, but the frond 

 of the latter is areolate and Avith more or less distinct intercellular 

 lines. P. horealis is, so far as found, infested with a fungus 

 {Guignardia alaskana Reed), while none of the three collections of 

 P. meridionalis shows any trace of such a parasite. 



Prasiola delicata sp. nov. 



Plate 22, figure Za-f, and plate 25, figure 1, and plate 24, figure 8 



Thallo 1-1.5 mm. alto, lato et breviter stipitato, in laminam late 

 oblongam aut eordatam expanso, marginibus crispatis et involutis, 

 atro-cyaneoviridi ; membrana 17-20/a crassa, cellulis neque in areolas 

 distinctas ordinatis neque per vias interstitiales separatis; akinetis 

 non visis; aplanosporis usque ad 512 e cellula singula (8X8X8) sed 

 frequenter tantum 128; cellulis valliformibus, in seetione transversali 

 verticaliter 10-12/x, 2-plo aut ultra diam. longioribus. 



