46. S. flavo-viride. 



88 i<:d. bori^et i:t ch. vlaiiault. 



nescens; fila 1-3 niillim. alla, in 



fasciculos coalila, 7-15 (A crassa. . . . 13. S. Hofmanni. 

 Crustaceo-orbicularis fusco-nigrescens ; 



fila in fasciculos coalita, millim. alla, 



6-9 p. crassa 14. S. ambiguum. 



Sectio II. Vaginic lainellosse, stratis divergen- 



tibus ; rami plerumque gemini, an- 



gulo fere recto egredientes Myochrotes. 



Gaîspitosa, natans, radiatim expansa ; 



fila 10-15 |j. crassa; vaginse parce 



lamellosiB 15. S. tolypotrichoides. 



Natans, filis 12-18 [x crassis; vagina3 



crassse lamellosse; trichomata pas- 



sini incrassata (9-15 [i.) 



Terrestris, pannosa expansa; fila 15-21 [>. 



crassa. Vaginse hic illic lamellosse, 



in vertice ultimœ cellulae tenues. ... 17. S. figuratim. 

 Terrestris, pannosa expansa; fila 18-36 [>. 



crassa; vaginse usque ad verticem 



ultimai cellulae crassaî, pluries 



ocreatœ 18. -S. Myochrous. 



Sectio 111. Vaginœ crass£e, lamellosa;, e stratis 



pliiriinis ocreatis formatae; ramifi- 



catio duplex : rami inferiores gemini 



(scytonematoidei), superiores solitarii 



(lolypolriclioidei) heterocysta basilari 



pra'diti Petalonema. 



Caîspitoso-crusiacea nigra ; fila 0,5-2 



millim. alla, 15-30 \j. crassa; rami 



gemini inlerne coaliti, demum liberi. 19. S. crustaceum. 

 Csespitoso-pulvinata nigra; fila in fasci- 

 culos coalita, 3-5 millim. alla, 12-30 [x 



crassa; cellulœ (in sicco) subsphse- 



ricaî 20. S. velutinum. 



Planta in stratum spongiosuin compac- 



tumviridi-fuscum expansa; fila coalita, 



2-3 millim. alta, 15-30 [i. crassa ; va- 



ginarum strata interiora ilava, exte- 



riora liyalina, mollia, ambitu irregu- 



lari 21. S. involvens. 



Pulvinata, nigra; fila libéra, millim. 



alla, 27-45 (j. crassa; vaginse multi- 



