Wood.] lo4: [June 18, 



trichomatibus nonuihil rotundatis, in ramulis saepe angularibus, plerum- 

 que compressis, diametro aequalibus — 4 plo brevioribus, terminalibus 

 cylindricis, obscure articulatis ; cellulis interstitialibus nullis ; vaginis 

 arctis, hyalinis, baud lamellosis ; cytioplasmate aerugineo vel brunneo, 

 minute granulate. 



S. immersed ; filaments very much branched, solitary or subsolitary ; 

 branches mostly unilateral, branched ; apices of the branches not atten- 

 uate, broadly rounded ; cells disposed in a simple series, in the trichoma 

 somewhat rounded, in the branches frequently angular, mostly com^ 

 pressed, equal to 4 times shorter than the diameter ; terminal cell cylindri- 

 cal, obscurely articulate ; interstitial cells none ; sheath close, hyaline, 

 not lamellate ; cytioplasm aeruginous or brown, minutely granulate. 

 Diam. trich. cum vag. y5\^"=. 00106" ; sine vag. .0008"- 

 Hab' In stagnis, prope Hibernia Florida. Mr. Wm. Canby. 



S. SCYTENEMATOIDES. Sj). Nov. 



S. strato submembranaceo, nigro-viride, saepe interrupto, cum super- 

 ficie inaequale ; trichomatibus saepe arete intricatis, flexuosis aut varie 

 curvatis,. baud rigidis, plerumque vix ramosis ; cellulis uniseriatis, 

 interdum interruptis, arctis, irregulare quadrangulis, diametro sub- 

 aequalibus aut 1-3 plo brevioribus, baud distincte granulatis, caeruleo- 

 viridibus ; vaginis amplis, haud distincte lamellosis, superficie enormiter 

 corrugatis et hirtis, achrois, plerumque coloris expertibus interdum 

 dilute brunneis. 



S. In a submembranaceous, blackish green, frequently interrupted . 

 stratum, with an uneven surface; filaments often closely intricate, flexuous 

 or variously cvirved, not rigid, mostly sparsely branched ; cells uniseriate, 

 sometimes interrupted, close, irregularly quadrangular, about equal in 

 length to their diameter, or about 1-3 times shorter, not distinctly gran- 

 ulate, bluish green ; sheaths ample, not distinctly lamellate, their surface 

 rough and corrugate, transparent, mostly colorless, sometimes light 

 brown. 



Diam. sine. vag. max. y-%/'=. 00066"; cum vag. max. y|g^"=.0013". 



CLASS CHLOROPHYLLOPHYCEAE. 



FAM. PALMELLACEAE. 



GEN. PALMELLA. 

 p. JESENII. 8p. Nov. 

 p. thallo indefinite expanso, initio dilute aut laete viride, molle, pellu- 

 cidulo ; aetate provecta firmo, tuberculoso, saturate olivaceo-viride ; 

 cellulis globosis vel ellipticis, — in thalli aetate immature, plerumque singulis 

 aut geminis, saepe distantibus, — in aetate provecta saepe in familiascon- 

 nexis, plerumque confertis ; tegumentis in thalli aetate immature plerum- 

 que diffluentibus, aetate provecta plerumque distinctis. 



Thallus indefinitely expanded, in the beginning soft and pellucid, after-- 



