CONFERVACEjE. 269 



part of the year, and varies much in appearance at dif- 

 ferent seasons. When young the colour is a bright-green, 

 the texture is silky, and the plant adheres closely to 

 paper; when fully developed the colour becomes dull, 

 the texture coarse, and the adherent quality is lost. In 

 the latter state there is generally a growth of young 

 branches at the tips of the fronds, which forms a bright 

 margin to the tuft, and contrasts strikingly with the 

 duller colour of the remainder. 



Cladophora lanosa. The woolly Cladophora. 



Fronds about an inch long, growing in dense, sponge- 

 like, level-topped, globular tufts, very slender, interwoven ; 

 branches straight, rod-like, spreading, generally alternate, 

 furnished with root-like fibres ; branchlets few, scattered ; 

 axils acute ; all the divisions of the frond blunt at the tip ; 

 cells of the lower part of the frond two or three times, 

 those of the upper part about six times the leugth of their 

 diameter ; colour a pale yellow-green, which becomes 

 almost white when the plant is dry. 



This species grows on rocks, sea-weeds, and Zostera 

 at various depths, and is common in most localities, at- 

 taining the greatest luxuriance and abundance in cold 

 regions. It very closely resembles C. arcta, but is 

 smaller, more slender and less branched. Specimens 

 should be laid out in salt water, as the cells are liable 

 to burst and discharge their endochrome if the fronds 

 be placed in freshwater. For the same reason they 

 should not be subjected to very great pressure while 

 drying. They adhere to paper, but do not retain their 

 gloss. 



