186 REPORT OF COMMISSIONER OP FISH AND VISHERIES. 



Filaments without a gelatinous slieatli, spores next to the lietero- 

 cysts Sphccrozyga, 



12. Filaments with a gelatinous sheath 15 



Filaments without a gelatinous sheath 13 



13. Filaments spu-ally twisted Spirulina. 



Filaments not spirally twisted 14 



14. Cells bluish or purplish green Oscillaria. 



Cells colorless or containing opaque granules Beggiatoa. 



15. Filaments free Lynghya. 



Filaments adherent in meshes Symploca. 



Filaments united in bundles and surrounded by a general gelatinous 



sheath _ Microcoleiis. 



IG. Filaments free Calotlirix. 



Filaments imbedded in a dense mass of jelly 17 



17. Filaments nearly ijarallel, fronds forming a thin expansion. . .Isactis, 

 Filaments diverging from the base of the hemispherical or somewhat 



flattened fronds Bivularia. 



Filaments simple at the surface and forking in the interior of the 

 vesicular fronds Honnactis, 



18. Fronds unicellular 19 



Fronds multicellular 20 



19. Cells small, ovoidal, prolonged into a long, root-hke process at the 



base Codiolum. 



Cells large, filamentous, pinnately branching Bryopsis. 



Cells large, with few, erect, alternate branches, some of which swell 



at the end and bear numerous spores Berhcsia. 



Cells very long, cylindrical, with irregular or subdichotomous 



branches, spores large, solitary, in special lateral or terminal cells. 



Vaucheria. 



20. Fronds membranaceous , 21 



Fronds filamentous . 22 



21. Fronds formed of a single layer of cells Monostroma, 



Fronds comi:)osed of two layers of cells, which in some cases sepa- 

 rate so as to form tubular fronds Ulva. 



22. Filaments simple 23 



Filaments branching 24 



23. Small algae, filaments soft and flaccid Ulothrix. 



Bather coarse algae, filaments more or less rigid, often twisted to- 

 gether Chcctomorpha. 



24. Some of the cells bearing long, hyaline hairs Bulbocoleon, 



Hairs wanting 25 



25 Branches small and root- like EJdzoclonium. 



Branches distinct Cladophora. 



2G. Fronds irregularly globose, hollow, gelatinous . Leathesia, 



Fronds forming crusts or expanded pellicles 27 



