238 
appendix. 
and gently sloping land. In the Bay of Bonin, between 
the two southern arms of Celebes, there are numerous coral- 
reefs ; but none of them seem to have an atoll-like structure. 
I have, therefore, not coloured any of the islands in this 
part of the sea ; I think it, however, exceedingly probable 
that some of them ought to be blue. I may add that there 
is a harbour on the S.E. coast of Bouton, which, according 
to an old chart, is formed by a reef, parallel to the shore, 
with deep water within ; and in the Voyage of the Coquille, 
some neighbouring islands are represented with distant 
reefs, hut I do not know whether with deep water within. 
I have not thought the evidence sufficient to permit me to 
colour them. 
Sumatra. — Commencing with the west coast and out- 
lying islands ; Engano Island is represented in the published 
chart as surrounded by a narrow reef, and Napier, in his 
Sailing Directions, speaks of the reef being of coral (also 
Horsburgh, vol. ii. p. 115) ; coloured red. Rat Island (3° 
51' S.) is surrounded by reefs of coral, partly dry at low 
water (Horsburgh, vol. ii. p. 96). — Trieste Island (4° 2' S.) : 
the shore is represented, in a chart which I saw at the India 
House, as fringed in such a manner, that I feel sure the 
fringe consists of coral ; but as the island is so low that the 
sea sometimes flows quite over it (Dampier, Voyage, vol. i. 
p. 474) I have not coloured it. — Pulo Dooa (lat. 3°) : it is 
said in an old chart that there are chasms in the reef round 
the island, admitting boats to the watering-place, and that 
the southern islet consists of a mass of sand and coral. — 
Pulo Pisang : Horsburgh (vol. ii. p. 86) says that the rocky 
coral-bank, which stretches about 40 yards from the shore, 
is steep all round : in a chart, also, which I have seen, the 
island is represented as regularly fringed. — Pulo Mintao is 
lined with reefs on its west side (Horsburgh, vol. ii. p. 107). 
— PuloBaniak : the same authority (vol. ii. p. 105), speaking 
of a part, says it is faced with coral-rocks. — Minguin (3° 
