FIG. 24. Animals associated with Posidonia Oceania, a sea-grass. 

 Three pieces of leaf are shown. (After Issel.) A. 1 . A Hydroid, 

 Plumularia (Monotheca) obliqua. 2. An Isopod, Idothea 

 hectica, protectively coloured. 3. A Bryozoon, Membranipora 

 pilosa, and small patches of another, Microporella malusii. B. 



4. A small fish, Lepadogaster bimaculatus, protectively coloured. 



5. Growth of coralline, a calcareous Alga. C. 6. Membrani- 

 pora. 7. A Hydroid, Sertularia mediterranea. 



