Mesogloia.] ALG1E RHODOSPERMEvE. 185 



fibres, originating from a centre point, which are analogous to the fila- 

 ments that constitute the axis of Trichocladia. The axis of this 

 genus must, therefore, be considered us punctiform, and this, indeed, 

 forms the only really structural difference between the two genera. 



Div. II. RHODOSPERME^E. 



Plants marine (except one or two species of Trentepohlia), 

 foliaceous, cylindrical or filamentous, of a rose-red, purple, or 

 red-brown colour. Fructification in many genera double ; 

 primary, contained in capsules, receptacles, or imbedded in the 

 frond ; secondary (when present), granules forming sori, or 

 placed in distinct receptacles. 



TRIBE VIII. GLOIOCLADE^E. 



Plants marine, of a rose-red or purple colour, giving out a red 

 juice on immersion in fresh water, of a gelatinous, lubricous sub- 

 stance, and filamentous, rarely cellular structure. Frond filiform, 

 branched, cylindrical, solid or tubular; the periphery (except in 

 Ckcetospora, in which genus, no parts, except the ultimate ramuli, 

 are composed of filaments, J consisting of coloured, branched, verti- 

 cillate fibres. Fructification: clusters or globules of red seeds, im- 

 bedded among the filaments of the periphery, to which they are 

 attached. In the British Flora, I used the name Gloiocladece in 

 a wide sense, applying it to all the Tribes of Algae, whose 

 fronds are invested with a definite gelatine. 1 now wish to re- 

 strict it to a tribe, which is very conveniently placed at the 

 commencement of this division, seeing it stands almost inter- 

 mediate in affinities between the Chordaricce and Gastrocarpece, 

 agreeing with the former in the formation of the frond, and 

 with the latter in colour and in the structure of the fruit. 



27. MESOGLOIA. Ag. Mesogloia. 



Frond filiform, solid ; the axis or central part gelatinous, formed 

 of longitudinal, hyaline, jointed fibres ; the periphery com- 

 posed of radiating, coloured, branched, articulated filaments. 

 Fruct.: globules of red seeds, imbedded in the filaments of the 

 periphery, to which they are attached. Name ; ftcaos, the 

 middle, and 7X0*05, viscid, from the gelatinous axis. 



1. M. multifida, Ag. Dichotomous Mesogloia. Frond dicho- 

 tomous, slightly branched, dull purple, elastic ; the axils 

 rounded. Harv. in Hook. Br. Fl. v. ii. p. 385. Berk. Ala. 

 t. 16. /. 1. 



