EAST COAST OF AFRICA. 247 



a considerable space, to be without reefs. My information, I 

 may observe, is derived from the survey by Captain Owen, 

 together with his Narrative ; and that by Lieut. Boteler. At 

 Mukdeesha (2° 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 a distance of a quarter of a mile from the 

 shore, and has within it from 6 to 10 feet of water : this then 

 is a fringing-reef and is coloured red. From Juba, a little S. 

 of the equator, to Lamoo (in 2° 20' S.) 'the coast and islands 

 are formed of madrepore' (Owen's Narrative, vol. i. p. 363). 

 The chart of this part (entitled Dundas Islands) presents an 

 extraordinary appearance ; the coast of the mainland is quite 

 straight, and is fronted at the average distance of two miles, 

 by exceedingly narrow, straight islets, fringed with reefs. 

 Within this chain of islets, there are extensive tidal flats and 

 muddy bays, into which many rivers enter : the depth of these 

 spaces varies from one to four fathoms — the latter depth not 

 being common, and about 12 feet the average. Outside 

 the chain of islets, the sea, at the distance of a mile, varies 

 in depth from 8 to 15 fathoms. Lieut. Boteler (Nar. 

 vol. i. p. 369) describes the muddy bay of Patta, which seems 

 to resemble other parts of the coast, as fronted by small, nar- 

 row, level islets formed of decomposing coral, the margin of 

 which is seldom of greater height than 12 feet, overhang- 

 ing the rocky surface from which the islets rise. Knowing 

 that the islets are formed of coral, it is I think scarcely possible 

 to view the coast, and not at once conclude that we here see a 

 fringing-reef, which has been upraised a few feet : the unusual 

 depth of from two to four fathoms within some of these islets, 

 is probably due to the mud of the rivers having prevented the 

 growth of coral near the shore. As several parts of this line 

 of coast are undoubtedly fringed by living reefs, I have 

 coloured it red. — Mcdeenda (3° 20' S.) : in the plan of the 

 harbour, the south headland appears fringed ; and in Owen's 

 chart on a larger scale, the reefs are seen to extend nearly 



