Myxophycese, Lyngbyese, Phormidiuin. 223 



Hdb. in humo uda ternu pr. «Abo» Africoe (Naumannj. — Ph. 

 lurido siniile et facie stratus et structura tricliomatum videtur. 



12. Phormidium rubrum Tilden Am. Alg. Cent. II, n. 180, 189G, Bot. 684 

 Gazette 1898, p. 100, t. IX, f. 18. — Strato subtili, miniato; fila- 

 mentis plerumque rectis; vaginis segre conspicuis; trichomatibus 

 fragilibus, frequenter interruptis, nec attenuatis neque curvatis, ad 

 genicula constrictis, 1 [i. diametro; articulis subquadratis vel dia- 

 metro paulo longioribus; dissepimentis aegre vel raro conspicuis. 



^a^. in fontibus calidis in «National Park» ditionis « Yellow- 

 stone » Amer. bor. (Tilden). 



13. Phormidium purpurascens (Kuetz.) Gom. in Journ. de Bot. IV, 58B 

 p. 355, 1890, Monogr. p. 166, t. IV, f. 19, Leptothrix parpura- 

 scens Kuetz. in Bot. Zeit. V, p. 220, 1847, Sp. Alg. p. 265, Tab. 

 Phyc. I, p. 39, t. 63, f. 5, Leptothrix purpurascens p iridea 

 Kuetz. in Bot. Zeit. V, p. 220, Hypheothrix Braunii y iridea Kuetz. 



Sp. Alg. p. 267, Hypheothrix purpurascens Rab. Fl. Eur. Alg. II, 

 p. 87, Lynghya purpurascens (Kuetz.) Hansg. Prodr. II, p. 86. 

 — Strato compacto, coriaceo, rufo-purpureo vel fusco-violaceo; filis 

 valde tortuosis arcte intricatis; vaginis initio arctis, papyraceis, 

 demum diffiuentibus et agglutinatis, chlorozincico jodurato non caj- 

 rulescentibus; trichomatibus pallide fusco-violaceis, apice nec atte- 

 nuatis uec curvatis, ad genicula haud constrictis, 1,5-2,5 ]i.. crassis; 

 articulis subquadratis vel diam. fere 2-pIo longioribus, 2-4,5 {j.. 

 longis; dissepimentis granulis quaternis refringentioribus notatis; 

 cellula apicali rotundata; calyptra nulla. 



Hah. m lapidibus ad Falaise Galliae (Brebisson), rupibus cal- 

 careis prope «Arncliff» Angliai meridionalis (West), thermis Ba- 

 densibus Germanite (von Martensj, rupibus dolomiticis Tyrolen- 

 sibus (Grunow, Hansgirg); in Bohemia passim (Hansgirg), in 

 thermis Euganeis (Meneghini), in Algeria (Debray) et € National 

 Park » Amer. bor. (Tilden). 



h) Stratum seruginosum vel olivascens. 



14. Phormidium valderianum (Delp.) Gom. Monogr. p. 167, t. IV, f. 20, b86 

 Johs. Schmidt Cyan. Dan. p. 65, Setch. in C. H. et S. Phyc. bor. 

 Amer. n. 1031 Butl. et Poli. in C. H. et S. P. Bor. Amer. n. 11051 

 Leptothrix Valderim Delponte in Garelli Gazzetta Med. ital. 1857, 



p. 35, Montagne in Ann. dc la Soc. hydrolog. medic. de Paris Tom. V, 

 p. 296, Ann. Sc. Nat., Bot, IV Ser., XII, p. 170, Perroncito e Va- 



