220 



SEAWEEDS 



closely allied genus Colacolepis is epiphytic on Phyl- 

 lophora nervosa and Ph. rubens. It forms a small 

 crust-like growth on the surface of its host, and is 

 closely attached to its epidermal layer. It also is 

 reproduced only by its tetraspores, so far as is 

 known. 



The family of Rhodopliyllidece is distinguished by 



FIG. 68. Eucheuma gpinosum reduced. 



the gonimoblast being divided into a number of 

 gonimolobes which radiate from the auxiliary cell in 

 all directions. These gonimolobes stretch out separ- 

 ately into the surrounding tissue of the thallus and 

 their terminal cells, or in other cases the upper cells 

 as well, form the carpospores. The auxiliary cell is 

 frequently very large, and it forms the central cell of 

 the whole fruit body. 



There are only four British genera of this family, 



