21 



Series II. 



RPIODOSPERME.E. 



Plants in this series are rosy or purplish red. Fructification of 

 two kinds, formed on separate individuals; 1st, spores external or 

 immersed concepiicles, or dispersed in masses through the sub- 

 stance of the frond ; 2d, tetraspores not contained in proper concep- 

 tacles, either exiernal or immersed in the frond. Marine, except 

 two. This series contains seven orders, namely — 



1. RlIODOMELACEiE. 2»! 3. DeLESSERIACEjE. 



2. Laurenciacf^e. 4. RllODYMENIACEjE. 



3. CoRALLINACEJE. 6. CRYPTONEMlAGEiE. 



7. CERAMIACEiE. ' 



Order L— RHODOMELACEiE. 



Frond cellular, jointed or areolated. Spores external. Tetras- 

 pores in rows, immersed in the ramuli or in proper receptacles. 

 Contains five genera, namely — 



I. Khodomela, Ag. — '-Name, red and black. 

 II. Bostrychia, Mont. — Name, curled hair. 



III. Hytiphlsea, Ag. — Name, wrinkled bark. 



IV. Polysiphonia, Grev. — Name, many siphons. 

 V. Dasya, Ag. — Name, hairy. 



Genus I. — Rhodomela. Ag. 



Frond cylindrical, inarticulate, and opaque. Tetraspores con- 

 tained in a pod-like receptacle. 



R. svbfusca, Woodward ; New York Bay. 



U. gracilis, Kirby ; N. Y. Bay and L. I. Sound. 



R. Sp. ? or new ; Greenport 



II. — Bostrychia. Mont. 



Frond pinnatifid, cylindrical, dotted, not jointed. Tetraspores in 

 pod-like receptacles. 



B. Montagnei ; Key West. 



1 Sp. ? or new ; Key West. 



III. Rytipitl^a. Afj. 



Frond cylindrical, jointed ; branches transversely striate. Te- 

 traspores in pod-like receptacles. 



2 Sp. ? or new. 



IV. Polysiphonia. Grev. 

 Frond cylindrical, composed of many siphons, jointed ; branches 

 longitudinally striate. Tetraspores in swollen ramuli. 

 P. nigrescens, Hudson, tubes 20 ; N. Y. Bay, &c. 



