THE MARINE BOTANIST. 193 



Catenella. Frond filiform, branched^ constricted 

 into oblong articulations. 



Cruoria, Frond crustaceons, skin-like. 



Naccaria, Frond filiform, solid, cellular, tbe 

 ramuli only composed of radiating free filaments. 



Gloiosiphonia. Frond tubular, hollow ; the walls 

 of the tube composed of radiating filaments. 



Nemaleon, Frond filiform, solid, elastic, filamen- 

 tous 5 composed (externally) of free filaments, 

 and, internally, of closely packed filaments. 



Dudresnaia. Frond filiform, solid, gelatinous, fila- 

 mentous; composed (internally) of interlacing 

 filaments, forming a lax net-work; outer fila- 

 ments free. 



Crouania, Frond filiform, consisting of a jointed 

 filament, whorled at the joints with minute gela- 

 tinous ramelli. 



GRATELOUPIA. 



Named in honour of Dr. Grateloup, a French algologist. 

 Frond flat, pinnate, membranaceous, solid, and 



