4S C01I1I0X SEAWEEDS. 



found parasitic on Algce in the tide-pools, and is an 

 annual. Common on the south coast and in the 

 Channel Islands. 



Ceramium Acanthonotum (Spined Ceramium). 

 — This weed grows in dense dark purple tufts, from 

 two to six inches in length ; the filaments are as fine 

 as human hair, excessively branched, so as to be all of 

 a tangle, and difficult to float out clearly. The joints 

 beautifully transparent, with richly-coloured interme- 

 diate parts; and the distinctive mark is a strong, 

 single, but three-jointed spine on the outside of every 

 filament. The forked tips curve inward most deci- 

 dedly; the fruit is either the usual whorl of tetra- 

 spores (four seeds in a cluster), or a favellce — a cell 

 containing many spores, which, instead of nestling in 

 a tuft of branchlets like most other species, sit on 

 the curved arm of one protecting ramulus or short 

 branch. 



It is a common plant on the north coast of Britain, 

 on half-tide rocks covered with young mussels: it 

 seems to like to live amongst them. 



Ceramitjm Botryocakpum (Grape-fruited Cera- 

 mium) . — The distinguishing mark of this seaweed is 

 its fruit, which grows in clusters, with merely a few 

 short branches like a fine-rayed star beneath the 

 cluster. It is in perfection in June and July, but 

 disappears in September. This Ceramium is less 

 branched and the forks more indistinct than in other 

 species, neither do they curve inwards. It is very 



