142 SEA-WEEDS. 



succulent plant called the prickly pear or opuntia, 

 which swells out into oval leaflets, contracting at 

 each end. This is just the shape of our only 

 species of catenella, which is jointed so as to 

 remind one of a string of beads. It is to be found 

 on most of our rocky shores, growing in small 

 creeping tufts, densely matted and entangled, 

 scarcely ari inch high, but the frond branched with 

 erect branches. Its hue is not beautiful, as it is 

 of a dull purple, almost approaching in some indi- 

 viduals to black, but it is somewhat transparent ; 

 it turns black in drying. 



Another sea-weed which soon darkens when 

 removed from its native waters, and becomes so 

 black as to resemble a dried plant of the olive- 

 coloured fuci, is that frequent plant the much 

 branched Forked Furcellaria (Furcellaria fasti- 

 giata], which grows on rocks in the sea, and is 

 scattered most profusely after a storm on the 

 shore. It is of a pale pinkish purple, or purplish 

 brown colour, rather rigid, and becoming quite 

 crisp as it dries. It is well termed forked, as it 

 branches off in a number of divisions, each like a 

 two-pronged fork. During summer it is half 

 covered with a sand-coloured crust, which is in 

 fact a zoophyte, the crust being the home of many 

 minute polypes. 



Our tangled plants are often very interesting to 

 the marine botanist, on account of the number of 

 delicate sea-weeds which grow on them. Some 

 grow only on their stems, and many which are 

 sometimes attached to other algae are often found 

 especially crowding on this. This is the case with 

 that pretty, delicate, rose-coloured plant, the Dotted 



