THE MANGROVE SWAMP 107 



was our chief luxury, and we willingly paid for it at the 

 somewhat exorbitant price of four fathoms of calico a bunch. 

 Farther on beyond the plantation the depression 

 becomes still wider, forming an extensive flat, partly 

 margined by mangrove-trees and Hibiscus ; this was 

 known to us as the mangrove swamp (Fig. 29). It is 

 an interesting corner of the island. The floor represents 





i'lG. 29. Heliopora in the foreground, Porites beyond; the Mangrove 

 Swamp, Funafuti. 



the upper surface of a dead coral reef, composed partly of 

 great masses of Porites ; their flattened summits, standing 

 some 8 or 10 inches above the floor, give them the 

 appearance of a row of stepping-stones, and mark what 

 was the level of low tide at the time the reef was living. * 



* The last episode in the history of the island appears to have 

 been a slight elevation of some 4 or 5 feet : at least, I was led 



