X SYNOPSIS OF THE 



LXXV. Naccaria. Frond filiform, solid, cellular ; the ramuli (only) composed 

 of radiating, free filaments. 



LXXVI. Gloiosiphonia. Frond tubular ; the walls composed of radiating fila- 

 ments. 



LXXVII. Nemaleon. Frond filiform, solid, elastic ; the axis composed of 

 closely packed, vertical filaments ; the periphery of moniliform, free, hori- 

 zontal filaments. 



LXXVIII. Dudresnaia. Frond filiform, solid, gelatinous ; the axis composed 

 of a net-work of anastomosing vertical filaments ; the periphery of monili- 

 form, free, horizontal filaments. 



LXXIX. Crouania. Frond filiform, consisting of a jointed filament (axis), 

 whorled at the joints with minute, multifid, moniliform, free, horizontal fila- 

 ments (or ramelli). 



Order 13. Ceramiace^. Rose-red or purple seaweeds, with a filiform frond, 

 consisting of an articulated, branching filament, composed of a single 

 string of cylindrical cells, sometimes coated with a stratum of smaller 

 polygonal cells. Fructification double : 1. Favellae, berry -like receptacles, 

 toith a membranous coat, containing ?iumerous angular spores. 2. Te- 

 traspores, attached to the ramuli, or subimmersed in their substance, 

 scattered. 



LXXX. Ptilota. Frond compressed, inarticulate, distichous, pectinato-pinnate. 

 Favellce stalked, involucrate. 



LXXXI. Microcladia. Frond filiform, inarticulate, dichotomous. Favellce 

 sessile, involucrate. 



LXXXII. Ceramium. Frond filiform, articulate, dichotomous ; the nodes opake. 

 Favellce sessile, mostly involucrate. Tetraspores immersed or subimmersed. 



LXXXIII. Spyridia. Frond filiform, inarticulate ; the branches clothed with 

 minute, setiform, articulated ramelli. Favellce stalked, involucrate. Tetra- 

 spores sessile on the ramelli. 



LXXXIV. Griffithsia. Frond articulated, dichotomous, or clothed with 

 whorled, dichotomous ramelli. Favellce involucrated, sessile, or stalked. 

 Tetraspores sessile, on whorled ramelli. 



LXXXV. Wrangelia. Frond articulated, pinnate. Favellce terminal, involu- 

 crated, containing tufts of pear-shaped spores. Tetraspores sessile, scattered. 



LXXXVI. Seirospora. Frond articulated. Tetraspores disposed in terminal, 

 moniliform strings. 



LXXXVII. Callithamnion. Frond (at least the branches and ramuli) arti- 

 culate, mostly pinnate. Favellce terminal or lateral, sessile, without invo- 

 lucre (except in C. Turneri) Tetraspores sessile or pedicellate, scattered. 



Sub-class III. CHLOEOSPEEME,E OE CONFEEVALES. 



(Grass-green* Seaweeds.) 



Order 14. Siphon ace^e. Green, marine, or fresh-water Algce, composed of 

 continuous, tubular, simple, or branched filaments (elongated cylindrical 

 cells), free, or variously combined in cylindrical or expanded fronds. 



LXXXVIII. Codium. Filaments combined into a spongy frond.. 



LXXX1X. Bkyopsis. Filaments free, pinnated. 



* A few Ulvacecc and Oscillaiuriaccrt are purple. 



