242 BRITISH SEA-WEEDS. 



when closely examined by the aid of a microscope, will 

 be found to be similar. 



Genus CIV. CODIUM. 



Frond sponge-like, globular, cylindrical or flat, simple 

 or branched, composed of interwoven, one-celled, branching 

 threads, filled with green endochrome. fructification, mul- 

 titudes of minute zoospores contained in sporangia at- 

 tached to the sides of the surface fibres of the frond. — 

 CoDiUM, from the Grreek Jcodion, a hide. 



This genus includes several species, some of which 

 are very widely distributed, both in high and low lati- 

 tudes in either hemisphere. • 



Codium bursa. The purse Codium. 



Fronds spherical, hollow, composed wholly of slender 

 threads closely interwoven, from the size of a pea to six or 

 eight inches in diameter, growing several together, attached 

 to the rock by matted fibres. 



Only two or three English habitats, chiefly on the 

 south coast, are recorded for this species. Curiously 

 enough, the principal of these is Brighton, a locality not 

 otherwise prolific of marine plants. I will not say it is 

 abundant there, but I know that a magnificent specimen, 

 six or eight inches in diameter, was recently obtained 

 from thence. On the. coast of Jersey many very fine 

 specimens occur. They grow chiefly on rocks a little 

 beyond the ordinary low-water mark, where they are 

 unapproachable, except at the lowest spring-tides, and I 

 have never had the good fortune to be in the island at 

 that season. The plant is not, however, confined to these 



