42 



they branch sparingly in a dichotomous manner. They are usually 

 constricted here and there, and proliferate from the constricted parts. 

 Proliferous segments also arise repeatedly from the margin, apex and 

 surfaces. And in some cases they grow up into a surculus, instead of 

 becoming a leafy frond. Fronds attain the length of 2-5 cm. with neither 

 constriction nor proliflcations, but reach the length of 8-10 cm. when the 

 prolifications are repeated. The apex is roundish, rarely bifid. The 

 margin is mostly entire, but sometimes crenulated. 



{the end.) 



EXPLANATION OF FIGURES IN PLATE. 



1. Prionitis elata; Sp. nov. Fig. 1-2. 



Fig. 1. Portion of frond bearing sporophylls ; nat. size. 

 Fig. 2. Portion of the cross-section of frond ; ^~ . 



2. Pronitis articulata ; Sp. nov. Fig. 3-4. 



Fig. 3. Portion of a sterile frond ; nat. size. 



Fig. 4. Portion of a branch bearing sporophylls ; nat. size. 



3. Gelidium repens; Sp. nov. Fig. 5-8. 



Fig. 5. Single frond in the natural state ; nat. size. 



Fig. 6. Portion of a sterile frond viewed from the under surface ; r, root ; moderately 



mag^. 

 Fig. 7. Portion of frond bearing cystocarps ; " . 

 Fig. 8. „ „ „ „ „ tetraspores ; ~ . 



4. Herposiphonia fissidentoides (Holmes). Fig. 9-11. 



Fig. 9. Cystocarp; a, the original apex of a "kurztrieb ; " b, the secondary prominence ; 



JLQ . 

 l 



Fig. 10. Tetraspores formed in " Kurztriebe ; " ™ . 



Fig. 11. "Kurztrieb" producing a procarp ; a, the original apex; ^~. 



5. Herposiphonia subdisticha ; Sp. nov. Fig. 12-14. 



Fig. 12. Plant in nat. size, detached from the substratum. 



Fig. 13. Portion of frond, bearing tetraspores ; b, b, " Langtriebe ; " ~ . 



Fig. 14. Portion of frond, showing the disposition of "Kurz— " and "Langtriebe." 



