240 APPENDIX, 



Bays (14 40') and the islands in front of Pa Jama 

 Harbour are represented in the plans as regularly fringed, 

 and have accordingly been coloured red. With respect 

 to the East coast of Madagascar, Dr. Allan informs me 

 in a letter, that the whole line of coast, from Tamatave, in 

 1 8° 12', to C. Amber, at the extreme northern point of the 

 island, is bordered by coral-reefs. The land is low, uneven, 

 and gradually rising from the coast. From Capt. Owen's 

 charts, also, the existence of these reefs, which evidently 

 belong to the fringing class, on some parts, namely, N. of 

 British Sound and near Ngoncy\ of the above line of coast 

 might have been inferred. Lieut. Boteler (vol. i. p. 155) 

 speaks of "the reef surrounding the island of St. Mary's at 

 a small distance from the shore." In a previous chapter I 

 have described, from the information of Dr. Allan, the 

 manner in which the reefs extend in N.E. lines from the 

 headlands on this coast, thus sometimes forming rather 

 deep channels within them ; this seems caused by the 

 action of the currents, and the reefs spring up from the 

 submarine prolongations of the sandy headlands. The 

 above specified portion of the coast is coloured red. The 

 remaining S.E. portions do not appear on any published 

 chart to possess reefs of any kind ; and the Rev. W. Ellis, 

 whose means of information regarding this side of Mada- 

 gascar have been extensive, informs me he believes there 

 are none. 



East Coast of Africa. — Proceeding from the northern 

 part, the coast appears, for a considerable space, without 

 reefs. My information, I may here observe, is derived from 

 the survey by Capt. Owen, together with his Narrative ; 

 and that by Lieut. Boteler. At Mukdeesha (io° 1' N.) there 

 is a coral-reef extending four or five miles along the shore 

 (Owen's Nar. } vol. i. p. 357) which in the chart lies at the 



