674 Myxopliycese, Rivulariacese, Rivularia. 



fuscis, siibfibrillosis, ad 17 [j.. diaiii. ; beterocystis oblongis, articulis 

 basalibus ad 2-plo majoribus; sporis oblongo-cylindricis, fusce- 

 scentibus, granulosis, ad 9 \x. diam., o-4-plo longioribus. — lu li- 

 gnis et saxis subraersis plantisque aquaticis in Gerraania (Kuet- 

 zing) et Italia (Meneghini, Rabenhorst). — Obs. Cl. Hansgirg 

 varietatem quandam flagelliferam (Kuetz.j ex Li?nnactide flagel- 

 lifera [= Rivularia radians Thur. a. genuina fide Auctoris 

 ejusdem incl. Limnactide Schurmanni Fisch. et Kuetz. Tab. Phyc. 

 II, t. 66j describit: strato molli magnitudinem pisi tequante; cel- 

 lulis vegetativis 5-11 [x. diam., basim versus sesquilongis, cetera 

 ut in typo. — Passim cum specie typica. 

 31. Rivularia dura Roth Neue Beitr. zur Bot. p. 273 (1802) Desmaz. 1514 

 Cryptog. de France ser. I, n. 1602, Wolle Freshw. Alg. of U. S. 

 p. 249, t. 179, f. 1-3, Cooke Brit. Freshw. Alg. p. 279, t. CXV, 

 f. 2, Born. et Flah. Rev. II, p. 347, Hansg. Prodr. II, p. 47, J. 

 Schm. Cyan. Dan. pag. 119 (non Kuetzing nec Zanardini), Limna- 

 ctis dura Kuetzing Sp. Alg. pag. 335, Rab. Alg. exs. n. 1451 ! 

 Fl. Europ. II, pag. 211, non Rabenhorst Alg. exsicc. n. 235! nec 

 1451 ! nec Trevisan, Rivutaria radians Thur. c. dura Kirchn. 

 Algenfl. non Schles. p. 223, Dasyactis mollis Wood Freshw. Alg. 

 of U. S. p. 50, tab. IV, f. 5, Prodr. pag. 128 (fide Wollei). — ■ 

 Fronde parvula, nigro-viridi, densiuscula, calce indurata, ad '/^ mm. 

 lata; filis densis, vaginis arctis, hyalinis haud lamellosis, uuifor- 

 mibus; trichomatibus 4-9 [j.. crassis, ccrugineis, siccitate interduni 

 in violaceum colorem vergentibus, in pilum tenuissimum longe 

 productis; cellulis inferioribus, diam. «quilongis, superioribus, fere 

 3-plo brevioribus. 



Hah. ad caules vetustiores Charte hispidte in fossis aqua pura 

 repletis Gallise prope Falaise (Brebisson) et Saumur (Bornet), ad 

 oras lacus Zwischenahn in ditione Oldenburg GermanicC (Roth), 

 in Silesia (Kirchner), Bohemia (Hansgirg), in lacu Balaton Hun- 

 garise (Istvanfpi) et passim (Filarszky), in Suecia et Norvegia 

 (Nordstedt), in [>ceninsula Florida Amer. bor. (Harvey, Murray), 

 ad «Key west» Amer. bor. (Harvey, Farlow), in Pennsylvania 

 (Wolle) et in lacu Michigan (Wood). 



Species incertse. 



32. Physactls Wichurae v. Mart. Preuss. Exped. in Ostas. p;vg. 21, 15^^ 

 Tav. I, fig. 1. -— Fronde minutissima, hemisph^erica molli '/,-'/, 



