gelatine. Filaments simple or branched ; articulations more 

 or less filled with a granular coloured (mostly green) spo- 

 raceous mass, which affects various forms in different genera. 



63. Conferva. Filaments simple or branched, free (not 

 connected by transverse tubes) : articulations filled with a gra- 

 nular coloured mass ( Endochrome. J 



64. Mougeotia. Filaments simple, finally united by trans- 

 verse tubes. Endochrome granular, at length forming roundish 

 globules at the point of conjugation. 



65. Tyndaridia. Filaments simple, finally inosculating by 

 transverse tubes. Endochrome consisting of two roundish 

 masses in each joint. 



66. Zygnema. Filaments simple, finally inosculating by 

 transverse tubes. Endochrome forming dotted spiral rings. 



Tribe XVIII. Siphoned. Fronds tubular, filamentous, in- 

 articulate : filaments a horny or membranaceous substance, 

 hyaline, filled with a green colouring matter ; either free or 

 formed into sponge-like fronds. Fructification, externcd often 

 stalked vesicles full of granular matter. 



67. Codium. Filaments closely aggregated into a sponge- 

 like frond. Marine. 



68. Bryopsis. Filaments free, branched; branches pinnated. 

 Marine. 



69. Vaucheria. Filaments irregularly branched. Fructi- 

 fication : dark green vesicles attached to the frond. — Mostly in 

 fresh water, rarely in the sea. 



Tribe XIX. Oscillatorie.e. Plants of a gelatinous sttb- 

 stance and filamentous structure. Filaments slender, tubular, 

 continuous, filled with a coloured, granular, transversely striate 

 matter, seldom branched, though often agglutinated together so 

 as to appear branched, usually massed together in broad float- 

 ing or sessile strata of a very gelatinous nature ; occasionally 

 erect and tufted ; and still more rarely collected in radiating 

 series, bound together by firm gelatine, and then forming lobed 

 or crustaceous fronds. 



70. Rivularia. Frond firmly gelatinous, globose or 

 lobed ; composed of filaments set in gelatine, radiating either 

 from a fixed centre or base. 



71. Stigonema. Filaments tufted, branched; branches 

 transversely dotted. 



72. Scytonema. Filaments brown, branched, flaccid, tough ; 

 transversely striate. 



