160 AhOM. 



cellular. Circumference composed of simple, clavate, torulosc, 

 verticillate filaments. 



25. Trichocladia. Frond filiform; axis loosely gelatinous, 

 filamentous. Circumference composed of branched, coloured, 

 torulose, verticillate filaments. 



26. Corynephora. Frond globose or tuberose, hollow (not 

 filled with gelatine.) 



Div. II. RhodospermEjE. Plants marine (except one or 

 two species o/"Trentepohlta), foliaceous, cylindrical, or filamen- 

 tous, of a rose-red, purple or red-brown colour. Fructification 

 in many genera double ; primary, contained in capsules, recepta- 

 cles, or immersed in the frond ; secondary (when present) gra- 

 nules forming sori, or placed in distinct receptacles : seeds red or 

 red-broivn. 



Tribe VIII. Gloioceade^e. Plants gelatinous, filiform, en- 

 tirely composed of articulated filaments, united into fronds by 

 a hyaline gelatine [except in Ch^etospora, in which genus only 

 the ramidi have this structure.) Fructification globules of red 

 seeds imbedded in the filaments of the periphery, to which they 

 are attached. 



27. Mesogloia. Frond solid, gelatinous ; the axis com- 

 posed of longitudinal hyaline fibres ; the periphery of radiating 

 coloured filaments. 



28. Gloiosiphonia. Frond tubular, gelatinous; the peri- 

 phery composed of radiating coloured filaments. 



29. Ch^etospora. Frond solid, subgelatinous ; axis laxly 

 cellular; the periphery membranaceous; ramuli composed of 

 branched radiating filaments. 



Tribe IX. Gastrocarpe^e. Plants carnose or gelatinoso- 

 membranaceous. Fructification : globules of red-seeds immersed 

 in the substance of the frond. 



30. Catenella. Frond filiform, contracted as if jointed, in 

 a moniliform manner. 



31. Dumontia. Frond cylindrical, tubular, membrana- 

 ceous, gelatinous within. Fructification: globules of seeds at- 

 tached to the inner surface of the membrane of the frond. 



32. Halymenia. Frond cylindrical, compressed, or flat, 

 gelatinoso-membranaceous. Globules of seeds imbedded in the 

 central substance of the frond. 



33. Irid^a. Frond carnose, expanded, flat (not gelatinous.) 

 Globules of seeds imbedded between the two coats of the frond. 



