146 MARINE AQUARIA FOR ROOMS 



another not uncommon sea-weed (Halidrys siliquosa) 

 grown in tolerably large marine tanks, and looking 

 both healthy and attractive. The Zostera marina 

 a true flowering plant, and not a sea-weedmay even 

 be grown where the tank is large enough. This is 

 undoubtedly a most useful plant for giving off oxygen. 

 Mr. Shirley Hibberd recommends Codium tomentosum> 



Fig. 106. 



Fig. 105. 



Corallina officinalis 



Plocamium coccineum. 



not only on account of its growing easily, but because 

 it is a favourite food-plant for many mollusca, &c. 

 For it should be remembered that if certain animals, 

 hereafter to be mentioned, are introduced, they will 

 feed on many of the sea-weeds ; so that the latter 

 have to serve the double purpose of aeration and 



