SYNOPSIS OF SEAWEED TRIBES. 15 



Kallymexia — Frond expanded, leaf-like, fleshy, membranous, 

 solid, of dense structure. 



Irid..ea — Frond expanded, leaf-like, thick, leathery, and fleshy. 



Catexella — Frond filiform, branched, constricted into oblong 

 articulations. 



Creoria — Frond crustaceous, skin-like. 



Naccaria — Frond filiform, solid, cellular, the ramuli only 

 composed of radiating free filaments. 



Gloiosiphoxia — Frond tubular, hollow, the walls of the tube 

 composed of radiating filaments. 



]Se:maleox — Frond filiform, solid, elastic, filamentous; com- 

 posed externally of free filaments, and internally of closely- 

 packed filaments. 



Dudresxaia — Frond filiform, solid, gelatinous, filamentous ; 

 composed internally of interlacing filaments, forming a lax 

 net-work ; outer filaments free. 



Crouaxia — Frond filiform, consisting of a jointed filament, 

 whorled at the joints, with minute gelatinous ramuli. 



GENERA OF THE GERAMIUM TRIBE. 



Ptilota — Frond compressed, inarticulate, distichous, pecti- 



nato-pinnate ; favellss stalked, involucrate. 

 aIicrocladta — Frond filiform, inarticulate, dichotomous ; fa- 



vellse sessile. 

 Ceramium — Frond filiform, articulate, dichotomous; tetra- 



spores mostly immersed. 

 Spyridia — Frond filiform, inarticulate, the branches clothed 



with minute bristle-like articulate ramuli; tetraspores sessile 



on the ramuli. 

 Griffithsia — Frond articulated, dichotomous, or clothed with 



whorled" dichotomous ramuli, rose red; favellx involucrated, 



sessile, or stalked ; tetraspores sessile on whorled ramuli. 

 Wraxgeeia — Frond articulated, pinnate; tetraspores scat- 

 tered in the ramuli. 

 Seirospora — Frond articulated; tetraspores inbead-like strings 

 Callithamxiox — Frond, at least the branches and ramuli, 



articulated, mostly pinnated; favellss sessile; tetraspores 



sessile or stalked, scattered. 



