374 THE MICROSCOPIST. 



1. Sub-tribe COCCOARPEJE. Frond solid, dense, cartilagi- 

 nous, or horny. Favellidia in semi-external tubercles or 

 swellings of frond. 



1. Grateloupia. Frond pinnate, flat, narrow, dense, 

 membrano-cartilaginous. Favellidia immersed in the 

 branches, communicating with the surface by a pore. 

 Tetraspores scattered. 



2. Gelidium. Frond pinnate, compressed, narrow, 

 horny. Favellidia immersed in swollen ramuli. Tetra- 

 spores forming subdefined sori in the ramuli. 



3. Gigartina. Frond cartilaginous, cylindric, or com- 

 pressed, its flesh composed of anastomosing filaments 

 lying apart in firm gelatin. Favellidia in external tuber- 

 cles. Tetraspores in dense sori sunk in the frond. 



2. Sub-tribe SPONGIOCARPE^I. 



4. Chondrus. Frond fan-shaped, dichotomously cleft, 

 cartilaginous, dense- Tetraspores in sori immersed in sub- 

 stance of frond. 



5. Phyllophora. Frond stalked, rigid, membranaceous, 

 proliferous from the disk, dense. Tetraspores in distinct 

 superficial sori or in special leafletlike lobes. 



6. Peyssonelia. Frond depressed, expanded, rooting by 

 the under surface, concentrically zoned, membranous or 

 leathery. Tetraspores in superficial warts. 



7. Gymnogongrus. Frond filiform, dichotomous, horny, 

 of dense structure. Tetraspores strung together, contained 

 in superficial wartlike sori. 



8. Polyides. Root scutate. Frond cylindric, dichoto- 

 mous, cartilaginous. Favellaz in spongy external warts. 

 Tetraspores scattered in peripheric stratum of frond, cru- 

 ciate. 



9. Furcellaria. Root branching. Frond cylindric, di- 

 chotomous, cartilaginous. Favellce. unknown. Tetraspores 

 imbedded among filaments of periphery, in swollen pod- 

 like upper branches of frond, transversely zoned. 



3. Sub-tribe GASTROCARPE^E. Frond gelatinously mem- 



