of Edinburgh, Session 1885 - 86 . 
875 
side this atoll were not sufficiently numerous to enable me to 
estimate the angle of the submarine slope. 
The largest of the three islets that have been formed on the reef 
is half a mile across, and rather more than a mile in length. In its 
interior, which is thickly wooded, the soil is made up in varying 
proportion of humus and calcareous sand. Numerous shells, 
belonging to familiar reef species, and large massive corals occur on 
the surface in the centre of the island and all over its area. Pumice 
pebbles are commonly found on the surface near the coast ; and 
they may he often seen to largely compose the miniature cliffs of 
sand which have been worn back into the beach by unusually 
high tides. This islet is elevated in its interior some 15 or 20 feet 
above the sea. On its south coast occur low cliffs of coral rock, 
4 to 5 feet in height, which betoken a recent elevation of a small 
amount. The other two islets are evidently of similar character, 
though of more modern formation. On the south coast of the 
larger islet occur a number of rounded blocks of volcanic rocks,* 
pebbles of which are to he found embedded in the rock of the reef- 
flat. The largest of these blocks must have weighed, according to 
its measurement, about 2 cwt. ; hut the majority of them were con- 
siderably less than 30 lbs. in weight. Some of them, which were 
raised 2 to 3 feet above high water mark, had apparently reached 
their present position before the last upheaval. All of them had 
evidently been transported by floating trees, which are very com- 
monly met with among these islands : they were probably originally 
derived from the adjacent portion of Guadalcanal I have frequently 
found blocks and pebbles of volcanic rocks in the roots of trees 
which have been thrown up on the reefs of this group. In some 
cases they were so firmly embedded that they could only have been 
set free by the final decay of the tree. 
Florida Islands . — Fringing reefs, varying in width from 150 to 
600 yards, skirt the coasts with which I am acquainted on the east 
and south sides of this sub-group. They present nothing of special 
interest. 
Eddy stone or Simbo Island . — This volcanic island originally 
existed as two distinct islands, which have become united by the 
* Dolerites and other dense basic rocks, all much altered and sometimes 
schistose. 
