238 APPENDIX. 



it in the plan, in La Peyrouse's Atlas ; but in the account of 

 the voyage it is not stated to be of coral ; uncoloured. — Loo 

 Choo : the greater part of the coast of this moderately hilly 

 island is skirted by reefs, which do not extend far from the 

 shore, and which do not leave a channel of deep water within 

 them, as may be seen in the charts accompanying Captain B. 

 Hall's Voyage to Loo Choo (see also remarks in Appendix, 

 p. xxi. and xxv.) There are, however, some ports with deep 

 water, formed by reefs in front of the valleys, in the same 

 manner as happens at Mauritius. Captain Bcechey, in a letter 

 to me, compares these reefs with those encircling the Society 

 Islands ; but there appears to be a marked difference between 

 them, in the less distance at which the Loo Choo reefs lie from 

 the land with relation to the probable submarine inclination 

 of the land, and in the absence of an interior deep-water 

 channel. Hence I have classed these reefs with fringing-reefs, 

 and coloured them red. — Pescadores (west of Formosa) : 

 Dampier (vol. i. p. 416) has compared the appearance of 

 these islands to the southern parts of England ; they are inter- 

 laced with coral-reefs ; but as the water is very shoal, and as 

 spits of sand and gravel (Horsburgh, vol. ii. p. 450) extend far 

 out from them, it is impossible to decide whether the reefs are 

 of coral. 



China Sea. — Proceeding from north to south, we first 

 meet the Pratas Shoal (lat. 20° N.), which, according to Hors- 

 burgh (vol. ii. p. 335), is composed of coral, is of a circular 

 form, and has a low islet on it. The reef is on a level with 

 the water's edge, and when the sea runs high, there are 

 breakers nearly all round ; ' the water within seems pretty 

 deep in some places ; although steep in most parts outside, 

 there appear to be several parts where a ship might find 

 anchorage outside the breakers ; ' coloured blue. — The Para- 

 cells have been accurately surveyed by Captain D. Ross, and 

 charts on a large scale published : only a few low islets have 

 been formed on these shoals, and this seems to be a general 



