PlATE 16. 



Fort Jefferson, Tortugas. Florida. 



Fig. a. Wharf. Many corals are growing ou the peripheral piers. 



B. The moat and sallyport. Corals of lagoon facies live in the moat. 



C. Outside of the moat wall and the flood-gate, the northwest side of the 



fort. Many corals were planted near the wall, north of the flood- 

 gate. 



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