150 Je STANLEY GARDINER. 
and Pitti also the coral is visible, and is building up circumscribing reefs. The natives do 
not visit the northern banks, and so less is known about them. If they were fairly level, 
they might conceivably be deemed to be washing away, but they vary in depth to such 
an extent (Munyal 14 in 34 fathoms), that there can be little reasonable doubt but that 
they too are in places being built up by corals and other organisms to the sea level. 
Growing coral is very seldom obtained by any sounding apparatus, while decaying coral 
(which abounds, wherever there is growing coral) is readily secured; hence no reliance can 
be placed on the recorded presence of the latter, as showing the real character of the 
bottom in any particular place. A further feature is the very marked steep round all these 
banks, seeming to be in many places absolutely precipitous. To a less extent the same is 
a feature of all the Laccadive banks, and is especially noticeable as the fall off some seems 
to extend from about 25 fathoms to 400 or 500 fathoms, or even more. 
Il. Tue Maupive ARCHIPELAGO. (Plates IX. and X.) 
In discussing the question of the formation of the Maldives it is necessary to consider 
the Archipelago in three main divisions, Addu, Suvadiva, and the main group. The two 
former differ so greatly both from one another and the remaining banks that they require 
separate consideration. They are divided by relatively broad channels both from one another 
and the rest of the group, so that their conditions of wind, rain, and currents are not the 
same. The changes going on in them differ materially as compared with the other banks, 
and indeed they would appear almost to have been formed quite independently of the more 
northern shoals. 
Addu (fig. 25) differs from all the other banks of the Maldives and Laccadives in its more 
perfectly-typical atoll-form. Being 10 
miles in maximum length east and 
west by 64 miles north and south, its 
encircling reefs are about 20 miles 
long, of which at least two-thirds are 
covered with land. The greatest length 
from reef to reef of the atoll is at 
the north end, and on this as_ base 
the reefs to the south form a rough 
semicircle. In this there are two 
passages to the south and south-east— 
both with shoals growing up—except 
for which practically the whole reef is 
crowned with land, only narrow gaps 
separating the different islets. To the Fic. 25. Addu Atoll (from the Admiralty Chart), 
Seale 4 miles to 1 inch. 

north the reef runs so as to form a 
bay, which has at its head two narrow passages; these seem to have been considerably 
filled up since the survey was made in 1835, and are never now used by the islanders 
for their vessels. The north reef itself is narrower and almost bare, two islets being found 
on the patch of reef between the passages, and a few others extending out along the reef 
for about a mile from Midu at the north-east. The chart has in the lagoon a patch of 
soundings of 34 to 39 fathoms, but our deepest sounding was only 31 fathoms, and soundings 
