118 BRITISH SEA-WEEDS. 



Order VIII. LAURENCIACE^. 



Bose-red or Purple Sea-weeds with rounded, or more or less 

 flattened, hranching fronds, not jointed, lut sometimes 

 constricted, and composed of many-sided, small cells. Fruc- 

 tification of two kinds on different plants : — 1. Pear-shaped 

 spores, in external, egg-shaped, or globular conceptacles ; 

 2. Tetraspores immersed, without order, among the surface- 

 cells of the branches and branchlets. 



Genus XLIII. BONNEMAISONIA. 



TVond solid, flattened, much branched, beset with short, 

 slender, awl-shaped, alternate, cilia-like branchlets. Spores 

 pear-shaped, on simple threads, in egg-shaped conceptacles ; 

 tetraspores not known. — Boiwemaisonia, named in honour 

 of M. Bonnemaison, a Prench naturalist. 



The only described species of this genus is pretty 

 widely distributed along the shores of EuropCj from the 

 Mediterranean to the Baltic. 



Bonnemaisonia asparagoides. Asparagus-like 

 Bonnemaisonia. 



Boot a small disc. Fronds from a few inches to a foot 

 long, growing either singly or in tufts ; stem undivided ; 

 branches alternate, becoming gradually shorter towards the 

 top of the frond : branchlets alternate, awl-shaped, about a 

 quarter of an inch long, thickly studded over the whole 

 frond. Spores in ovate conceptacles, which are opposite to, 

 and alternate with, the branchlets. 



This beautiful plant has been found in many localities 

 on various parts of our coast. It is very distinct from 

 all other British Sea-weeds^ and may be readily recog- 

 nized, even when seen for the first time. The delicate, 

 cilia-like branchlets, which fringe every part with comb- 



