KE VISED LIST OF MARINE ALG/Tl. 



Ill 



8. Filaments provided with heterocysts 9 



Filaments destitute of heterocysts 10 



9. Filaments with a thni gelatinous sheath, spores 



not adjacent to the heterocysts ... Nodularia 

 Filaments without a sheath, spores next to the 

 heterocysts Anahccna 



10. Filaments with a gelatinous sheath 12 



Filaments without a gelatinous sheath 11 



11. Filaments spirally twisted Spirulina 



Filaments not spirally twisted OsciUaria 



12. Filaments free Lynghya 



Filaments adherent in meshes Symploca 



Filaments united into a membranous layer 



Fhormidium 

 Filaments united in bundles and surrounded by 

 a general gelatinous sheath ... Microcoleus 



13. Filamentsfree Calotlirix 



Filaments imbedded in a mass of jelly ... Bivularia 



14. Fronds unicellular 15 



Fronds multicellular 17 



15. Cells free 16 



Cells united into a branched spongy frond Codium 



16. Cells large, filamentous, pinnately branched Bryopsis 

 Cells very long, cylindrical with irregular or sub- 



dichotomous branches, spores large, solitary, 



in special lateral or terminal cells ... Vaucheria 



17. Minute endophytic algse, growing in the 



cell- walls of Fylaiella En toderma 



Algae not endophytic... 18 



18. Fronds tubular Enteromorplia 



Fronds membranaceous 19 



Fronds filamentous 21 



19. Fronds formed of a single layer of cells 20 



Fronds composed of two layers of cells ... Viva 



