of Edinburgh , Session 1885—86. 
869 
that skirt at intervals this coast belong to the fringing class. They 
are marked here and there by wooded islets, and in some parts 
they have experienced an upheaval of a few feet. They attain 
their greatest breadth of nearly a mile in the vicinity of Cape 
Surville and Star Harbour, but usually their breadth does not exceed 
a quarter of a mile. The 100 fathom line lies generally about 1200 
yards from the edge of the reef-flat, and from this fact the angle of 
the submarine slope may be computed to be about 10 degrees. 
Where the land rises precipitously from the sea, as on the east side 
of Cape Keibeck, there are scarcely any reefs. They are absent 
usually from the shores of the wide bays which receive the waters 
of the large streams : here the beaches are of dark sand, which is 
composed partly of volcanic and partly of calcareous materials. 
The north coast of the peninsula included between Star Harbour 
and Cape Surville is low, and fringed with mangroves ; and it is 
often a difficult matter to distinguish where the reef ends and the 
land-surface begins, since the mangroves push forward their lines 
on the flat whilst it is yet covered by the sea at high water. By 
the agency of these trees, unassisted by any elevation, much land is 
reclaimed from the waves. One may walk for a distance of 100 
yards from the margin of the vegetation on a recently formed 
wooded tract raised but a couple feet and less above the sea-level, 
which is composed almost entirely of coarse calcareous sand mixed 
with fragments of corals and shells belonging to familiar reef species 
of the genera Cyprcea, Strombus , Turbo , Trochus, Tellina , Tapes, 
Hemicardium , Cytlierea , &c. These shells have lost most of their 
colour and have an ancient appearance. A species of the 
Auriculidae, Pytliia scarabceus (Lin.), lives commonly on these 
recently formed tracts throughout these islands, and its empty shells 
occur mingled with those of the marine genera just mentioned. 
Pumice pebbles may usually be traced amongst the trees for some 
15 or 20 paces, and in some places they are very numerous. 
The north coast of St Christoval, to the west of Cape Keibeck, 
is often bordered by a recently elevated flat of coral rock, which, at 
the sea margin where it has been worn back by the waves into low 
cliffs, is raised from 4 to 6 feet above the high water level. These 
flats rise gradually, as one proceeds inland among the trees, to a 
height of from 12 to 15 feet. They are frequently traversed by 
