PLATE IV. 



Figs. 1, 2.^Plumularia stylifera. 

 Fig. 1. — Natural size. 

 Fig. 2. — Portion of a hj'clrocladium with gonangium ; magnified. 



Figs. 3, 4. — Plumularia armata. 

 Fig. 3. — Natural size. 

 Fig. 4. — Portion of stem with hydrocladia and male and female gonangia ; magnified. 



Figs. 5, 6. — Antennularia fasciculari^. 

 Fig. 5. — Natural size. 

 Fig. 6. — Portion of stem with hydrocladia and gonangium ; magnified. 



Figs. 7, 8. — Polyplumaria pumila. 



Fig. 7. — Natural size. 



Fig. 8. — Portion of main stem, wdth two primary pinn^ and hydrocladia ; magnified. One 

 of the primary pinnsB carries a gonangium, and every hydrocladium bears 

 an accessory ramulus. 



