Ö24 Algen. 



heterocystas, rarius sub heterocystis egredientes. Geuns: 6. Scytonema Ag. (Subg,. 

 Mijodirctos, Elise ytonema). 



2. Subtrib. Tolypotricholdeae Hansg. Pseudoramuli solitarii, laro gemini, 

 sub ))eterocysti.s, rarius inter hetei'ocystas formati. Genus : 7. Tolypothrix Ktz. 



3. Subtrib. Plectonemeae Hansg. Fila scytonemacea pseudoramosa ; hetero- 

 cystis et sporis adhnc non observatis. Genus : 8. Plectonema Thr. (Subg. Eu- 

 plectoneraa, Glaucothrix). 



II. Trib. Coleodesmeae Bzi. 



1. Subtrib. Desmonemeae Hansg. Fila saepe plura*) (2 — 8) in vagina 

 eommuni inclusa, erecta vel subflexuosa, repetite subdichotome pseudoramosa, 

 beterocystis basilaribus. Genus : 9. Desmonema Berk. et Thwait, 



2. Subtrib. CystocoUae Hansg. Fila saepius plura vel bina, in vagina 

 eommuni inclusa, submoniliformia; lieterocystis intercalnribus. Genus: 10. Hydro- 

 coryne Schwabe. 



3. Siibtrib. Dlplocoloneac Hansg. Fila repetite pseudoramosa , in vagina 

 eommuni plura , flexuoso'curvata, subnostochacea ; pseudoramis in intervallum 

 heterocystarum , rarius sub heterocystis egredientibus. Genus: 11. Diplocolon 

 Näg.**) 



2. Farn. Rivulariaceae (Stiz.) Rbh. 



1. Subfam. Rivularieae Ktz. 



I. Trib. Eurlvularieae Bor. et Flah. Genera: 12. Josactis Thr.; 13. 

 Rivularia (Roth) Ag. ; 14. Gloeotrichia J. Ag. 



II. Trib. Brackytr/'chieae Bor. et Flah. Genus: 15. Brachytrichia 

 Zanard. 



2. Subfam. Mastichotrichieae Ktz. 



I. Trib. Encalotrichieae Hansg. Fila ramosa , vaginis firmis , arctis, 

 Ulis subcylindricis. Genus: 16. Calothrix Ag. (Subg. Somoeofhrix, Eucalothrix, 

 Dichothrix, Polythrix). 



II. Trib. Sacconemeae Hansg. Vagiuae filorum gelatinosae saccato- 

 ampliatae, Ulis moniliformibus. Genus: 17. Sacconema Bzi. 



3. Subfam. Lepitodiaeteae Bor. et Flah. 



Geneva: \S. Lcptochaete hzi.x 19. Amphithr ix {Ktz.) Bor. et Flah. ; 20. Micro- 

 chaete Thr. 



3. Fam. Xostoceae Bzi. 



1. Subfam. Eunostoceae Hansg. 



Trichomata flexuoso-curvata, submoniliformia, vaginis gelatinosis vel indi- 

 stinctis, cellulis vegetativis globosis, oblongis, subquadrangularibus, subcylindraceis, 

 Rarius depresso-quadratis. Genera: 21. Nostoc Vauch. (Subg. vide Thuret et 

 Bornet); 22. Anahaena (Bory) Ktz. (Subg. Trichormus, DoUchospermum, Sphaero- 

 zlga, Cylindrospernu(m). 



2. Siibfam. Nodularieae Hansg. 



Fila subrecta vel leviter flexuosa, vaginis membranaceis vel mucosis, cellulis 

 vegetativis subcylindricis, compresso-disciformibus vel depresso-globosis. Genera:' 

 23. Nodularia Mert. ; 24 Aulosira Krch. 



4. Fam. Lynghyaceae (Thr.) Hansg. 



1. Subfam. Micro>-oleae Hansg. 



Fila bina vel plura, in vagina eommuni inclusa , fasciculos vel caespitulos 

 procumbentes vel erectos , adnatos, rarius fluctuantes formantia. Genera: 25. 

 Microcoleus Desmaz. (Subg. Chthonoblastus, Schizothrix, Hydrocoleum) ; 26. Inactis 

 (Ktz.) Thr. (Subg. Euinactls, Inomeria). 



2. Subfam. Lynghyeae Hansg. 



Fila solitaria vel aggregata, vagina firma, membranacea inclusa vel tegumento 

 mucoso praedita, mobilia vel immobilia, libera vel adhaerentia. Genera: 27, 

 Symploca Ktz. : 28. Lyngbya (Ag.) Thr. (Subg. Leibleinia, Eulyngbya, Oacillaria, 

 Spirulina, [^ Borzia, Gliothrix, Agonium, T}-ichodesmium]). 



*) Ueber das Latein des Verfs. (er schreibt z. B. constant „pluria") Hesse 

 sich manches sagen. 



**) Die Aufstellung dieser Subtribus , die fast immer nur eine Gattung ent- 

 halten, ist wohl kaum nothwendig. Ref. 



