Sect. T. DISTRIBUTION OR CORAL-REEFS. 
83 
In the last chapter I stated that the bottom of the 
sea round some islands is thickly coated with living 
corals, v hich nevertheless do not form reefs, either 
from insufficient growth, or from the species not being 
adapted to contend with the breaking waves. 
I have been assured by several navigators that 
there are no coral-reefs on the west coast of Africa, 1 or 
round the islands in the Gulf of Guinea. This perhaps 
may be attributed to the sediment brought down by 
the many rivers debouching on that coast, and to the 
extensive mud-banks which line great part of it. But 
the islands of St. Helena, Ascension, the Cape Verdes, 
St. Paul’s, and Fernando Noronha, are, also, entirely 
destitute of reefs, although they lie far out at sea, are 
composed of the same ancient volcanic rocks, and have 
the same general form with those islands in the Pacific, 
the shores of which are surrounded by gigantic walls of 
coral-rock. With the exception of Bermuda, there is 
not a single coral-reef in the central expanse of the 
Atlantic ocean. It will, perhaps, be suggested that 
the quantity of carbonate of lime in different parts of 
the sea may regulate the presence of reefs. But this 
cannot be the case, for at Ascension, the waves, charged 
to excess, precipitate a thick layer of calcareous matter 
Mr. Whitmee’s statement as to the upheaval of the above-mentioned 
part of Savaii. (From materials collected by Mr. Danvin.)] 
1 It might be concluded, from a paper by Captain Owen (Geo- 
graph. Journ., vol. ii. p. 89), that the reefs off Cape St. Anne and the 
Sherboro’ Islands were of coral, although the author states that they 
are not purely coralline. But I have been assured by Lieut. Hol- 
land, R.N., that these reefs are not of coral, or at least that they do 
cot at all resemble those in the West Indies. 
