RHODOPHYCE, OR FLORIDEX 239 
proceeding from the carpogonium successively ferti- 
lises a number of auxiliary cells, each produced on its 
own branch. After the conjugation of the ooblastema 
filaments and auxiliary cells, the gonimoblast that 
results is usually developed in the form of more or 
less definite gonimolobes, almost all the cells of which 
give rise to carpospores. The gonimoblast is in all 
cases within the thallus tissue. The geographical 
Fic. 81 —a, fertilise carpogonium of Dudresnaya purpurifera ; b, ooblas- 
tema filament attached to auxiliary cell in passage (D. coccinea) highly mag- 
nified. (After Schmitz.) 
distribution is fairly general, and the British genera 
are Glotosiphonia (Gloiosiphonice); Halymenia and 
Grateloupia (Grateloupice); Dumontia, Dudresnaya, 
and Dulsca (Dumontiew); and Calosiphonia, Schizy- 
menia, and Furcellaria (Nemastomec). 
Rhizophyllidece. 
This family, also a small one of fairly general 
distribution, is represented in British seas by only 
one genus, Polyides. The essential process of fertili- 
