Myxophycese, Heterocystidese, Nostoc. 42l 



crassis, eximie cylindiicis; articiilis sphserico-depressis, dianietro 

 brevioribus, arcte adha^rentibus; heterocystis 6 [x. crassis, subglo- 

 bosis; sporis ovalibus, 7 « 3 \).., epis[)orio levi, luteolo. 



Hab. saxis et lapidibus adfixuin, in rivulis rapide fluentibus 

 IslandifB (Lindsay), Norvegi* (Nordstedt), Suecite (Agardh, IjA- 

 GERHEiM), Fennise (Elfving), Rossi» (Iwanoff, Alexenko), Anglia; 

 (Hassall, Greville, Harvey, Cooke, T3ICKIE, West etc), Hibernia? 

 (Mackav), Scotiie (Lightfoot, Hooker), Germania! (Kuetzing, Kir- 

 chner, Lemmermann, Rabenhorst et alii), Austria' (Kalchbrenner, 

 Schiedermayr etc), Bohemia', Carinthiie, Dalmatiie (Hansgirgj, Bo- 

 snise (Protic), Tyroli?e (Pollini, Heufler, Kravogl), Italia; (Se- 

 gujer, Savi, Pollini, Cesati et De Notaris, Piccone, Macchiati, 

 De Toni, Forti et alii). ins. « del Giglio » (Sommier), Sardinicie (Gen- 

 NARi, Marcucci, Moris), Gnfciai (Bory), Corsicte (Debeaux, Le- 

 veille), Hispania? (Colmeiro), Galli;e (Lamy de la Chapelle, Bor- 

 NET, Flahault, Mougeot, Gomont, Belloc etc), Helvetia^ (A. Braun, 

 ScHAAFF, Schenk, Vaucher, Theobald, "Wartmann, Borge etc); 

 in lacubus Caucasicis (Schmidle), ins. Azoricis (Bohlin), Teneriffa 

 (Despreaux), in lacu Nyassa Africse (Schmidle); in rivulis Amer. 

 bor. (WooD, Wolle, Farlow etc), Regni Mexicani (Fendler), Ja- 

 maicae (Collins), .Equatoriie (Lagerheim), Uruguayae (Arechava- 

 leta), Fuegiie (Borge), ins. Reunion (Jadin), Australi;e (Nordstedt) 

 et Nov;e Zelandi;e (Lyall, Berggreen). — Var. pseudo-Zetterstedtii 

 Stockmayer in Sched. ad Kryptog. exsicc. VII, n. 631 in Ann. d. 

 K. K. Naturhist. Hofm. 1901, p. 71: differt a typo, thallo minore, 

 (magnitudine usque ad nucem Avellan;ej satis firmo, varie et pro- 

 funde dissecto; lobis irregularibus ; trichomatibus radiantibus in 

 dissepimenta magnis constrictis; articulis paulo longioribus. In 

 Tyrolia meridionali in rivulo frigido rapide tluenti in vico S. Zeno 

 Anauni.i' (S. Stockmayer). 



<. Nostoc amplissimum Setcliell in Erythea 1899, p. 50, Tab. II et 

 HI, Mc Clatch. et Setch. in Coll. H. et S. Phyc. bor. Amer. n. 558! 

 — Thallo initio sph;erico. deinde cavernoso, irregulariter verru- 

 coso, latissimo, usque ad 70 cm. expanso, demum saccato, mem- 

 brana 2-10 mm. crassa circumdato, gelineo, siiepe substantia ochra- 

 C9a consperso; trichomatibus numerosis, varie dispositis, rectis vel 

 irregulariter curvulis, ad peripheri;im magis intricatis, extus vaginis 

 brunneis, intus achrois circumfusis, centralibus diffluentibus; tri- 

 chomatibus torulosis; articulis subsphaericis v. cylindricis, 2-3 [i. 

 diam., 3,5-5 u.. longis; heterocystis 4 |a. diam ; sporis ellipsoideis, 



