1895.] C. F. Oldham —Physical Features of the Laccadives. 
7 
for collecting and washing up whatever may be floating in the neigh¬ 
bouring seas. 
This pumice was first noticed by the surveying officers during their 
visit in the autumn of 1892, and is mentioned by Dr. Alcock in 
in his Administration Report for that year. 
The south extreme of the island is a sandy point along which vege¬ 
tation is gradually creeping as the point extends. 
The fringe-reef which fronts the eastern edge of the island is 
narrow, and has growing coral on its edge, only the surface of the reef 
being encrusted with Nullipore, or cemented into a reef flat. 
The remaining part of the atoll, not occupied by the island, is a 
coral reef, awash at low water, the only openings being to the N.-E., and 
very narrow. In consequence, there is very little live coral within the 
lagoon, the most notable patches being in the neighbourhood of the 
entrance and towards the western side, opposite the centre of the is¬ 
land. The lagoon is from 2 to 6 feet deep. 
The soundings shew that the bottom slopes steeply on both the east 
and west sides of the atoll, from about 20 fathoms into deep water, but 
towards the N. N.-E. and S. S.-W., the direction in which the atoll 
soundings shew a much more moderate slope, there is a depth of 272 
fathoms at two-and-a-lialf miles from the north point, compared to 500 
fathoms at one-and-a-quarter mile from the east side, and 730 fathoms 
at one-and-three-quarter mile from the west side of the atoll. 
Petra Par. This is an atoll six miles north and south, and three 
miffis broad, with an islet on its north-east end, and two sand cays 
joined by patches of sand, on its eastern side. The islet is nothing but 
a sand cay, covered with coconuts, extending nearly half-a-mile along 
the reef. Its inner side, which is washed by the waters of the lagoon, is 
probably the oldest part, as it carries the tallest coconuts ; here the sea 
is encroaching, the roots of the trees are exposed, and several have 
fallen. The north-east side of the islet is formed by a shallow bay in 
which are several slabs of coral-sand rock, which jutting out beyond the 
line of the beach shew that that part of the beach has been washed away. 
The extremities of the island are increasing in the direction of its 
greatest length. 
The encircling reef dries nearly everywhere at its edge at low 
water springs ; it is broadest on the eastern and southern sides, and has 
only one opening through it, just south of the islet. 
I examined the northern and western sides of the reef, and the 
other surveying officers visited the other portions. The middle of 
the western side is about 250 yards broad, and on the extreme western 
