126 SEA-WEEDS. 



packthread, and equal in size throughout. It is 

 very common in summer time on rocks and stories 

 in the sea, and may be but a few inches long, 

 though sometimes found of the length of three 

 feet. It is a firm, dark olive sea-weed, and is 

 solid in its centre. When seen under water, it 

 appears to have a fine fringe of little colourless 

 fibres, which render it very slippery to the 

 fingers. 



Very common in the sea, both in summer and 

 winter, on rocks and stones, are the spongy 

 branches of the sponge-like Cladostephus (Cla- 

 dosteplius spongiosus). It is not a very pretty 

 sea-weed, for it has thick clumsy branches, of 

 about the size of a cord, and about three or four 

 inches high, densely crowded with little branch- 

 lets. It is a dirty brown or olive-green colour, 

 and so spongy in its nature as to be unlike most 

 other of our marine plants. A tuft of this weed 

 is often very useful to the naturalist, as it retains 

 a good quantity of sea-water, and therefore will 

 long preserve any living creature which he may 

 wish to convey home for examination. The 

 whorled Cladostephus is equally common, and is 

 a larger plant, much like this, but less spongy in 

 texture. 



With the description of one other of the olive- 

 green sea-weeds, we must close this short account 

 of them, leaving untold of many an interesting 

 plant on which the imagination loves to linger. 

 Some, whole families, parasitic on other plants, 

 seeming scarcely more than tufts of brownish or 

 greenish threads ; some with flat fronds like the 

 sea endive ; and others, whose crowded fronds form 

 a thick fringe on the leaves of large sea-weeds. 



