CRYPTOGAMIA ALG^E. 219 



the clusters of seeds arranged in concentric lines and im- 

 mersed. 



156. ULVA. Frond fistular or plane and expanded, membranous, 

 thin, cellular; seeds in minute innate clusters scattered 

 over the frond. 



********* Green ? capillary, branched, unjointed ; seeds in 

 capsules. 



157. VAUCHERIA. Fronds aggregated, tubular, continuous, 

 capillary, coloured by an internal green pulverulent mass ; 

 fructification dark green homogeneous vesicles attached 

 to the frond. 



Green 7 capillary, filaments jointed. 



158. CONFERVA. Filaments uniform, simple or branched, mem- 



branaceous; sometimes coloured ; fructification granules 

 scattered in the articulations. 



159. ZYGNEMA. Filaments simple, elongate, membranaceous, 



jointed, at length forming lateral unions by short tubes 

 passing from one filament to another ; fructification mi- 

 nute internal granules assuming some determinate form 

 or arrangement. 



160. BATRACHOSPERMUM. Filaments gelatinous, much branch- 



ed, jointed ; branchlets short, moniliform, placed in whorls 

 at the articulations ; fructification clusters of grains pla- 

 ced in the whorls. 



161. DRAPARNALDIA. Filaments gelatinous, branched, jointed ; 



branchlets jointed, in pencil-like tufts or scattered. 



162. LYNGBYA. Filaments simple, elongate, not gelatinous, 



marked with close transverse septa. 



******** * Olive-green or purplish) capillary, continuous, 

 with internal granules arranged in lines. 



163. BANGIA. Filaments capillary, mostly simple, flexile ; fruc. 

 tification granules disposed in regular transverse series. 



K2 



