RHODOPHYCEA, OR FLORIDEA 221 
viz. Cystocloniwm, Catenclla, Huthora,and Rhodophyllis, 
but a considerable number of exotic types, such as 
Solieria, Rhabdonia, Eucheuma, Erythroclonium, and 
Thysanocladia, exhibiting among them the most 
diverse forms of thallus. In Catenella a large com- 
pound fruit is formed by many procarpia, each with 
Fic. 69.—Catenella opuntia. a, section of fertile part of thallus showing 
Cater arvee Gitar. b, carpogonium with trichogyne highly magnified. 
its trichogyne, most of which are fertilised. The 
gonimoblast forms chains of carpospores which 
escape, since there is no ostiole, after rupture of the 
cortex “already weakened by the numerous aper- 
tures occurring in it through which the trichogynia 
pass to the exterior,’ as Prof. Harvey Gibson has 
described. 
