RED AND GREEN SEA-WEEDS. . 145 



Cladophora rupestris or arcta, Bryopsis plumosa, Grif" 

 fithsia setacea, Corallina officinalis, Enteromorpha in- 

 testinalis, Ceramium rubrnm, Rhodymenia palmata, 

 Delesseria sanguinea, Padina pavonia, Plocamium 

 coccineum, &c. Corallina requires a good deal of 

 lime, for it will cover the rock on which it is growing 



Fig. 104. 



Padina pavonia. 



with a film of pinkish-white limey matter. If the 

 tanks be large enough the small wrack (Fucns canali- 

 culatus) and the carageen or " Irish moss " (Chondrus 

 crispus) may be grown. The latter takes to its ground 

 very readily, and is really a very pretty plant, liable 

 to assume different tints according to its surroundings. 

 The fructification of the small wrack is a very interest- 

 ing performance, and may be studied in the aquarium 

 if this species can be induced to grow. We have seen 



L 



