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C. CROSSLAND—RECENT HISTORY OF THE CORAL REEFS. 
PostscRIPt. 
As the theory of the Barrier Formations here advanced turns on the structure 
and topography of the coast hills, I give the information I have been able to 
collect. . 
The hills are not distinguishable on any map, indeed part of the country is, 
as yet, unsurveyed, and I have had few opportunities of travelling inland. 
My account is therefore incomplete, but enough has been done to justify the 
conclusions drawn. 
From seawards these hills are easily distinguished from the jagged hills of 
igneous origin by their cliffs being of a light yellow colour and by their flat 
tops; generally also by their position being nearer the sea than the lowest of 
the igneous hills, and even than the mounds of gravel which occur in places 
at the foot of the latter. 
Passing from South to North, the first range is met with a few miles 
north of Mersa Durur (see map p. 6) as a chain of low butts rising from 
the alluvial plain four or five miles inland. These become higher and more 
continuous as one passes northwards till they end in two considerable hills, 
of about the same height and area of base, the northern of which is marked 
on the charts, where it is called Table Mountain and given a height of 
1100 feet. 
At about five miles inland from Dongonab are one or two small hills standing 
alone, but further north is a range of higher hills lying inland from the 
middle of the North Bay and extending towards the Hamama range, from 
which it is only separated by an interval of a few miles. 
The Abu Hamama* range (which I so named from its most prominent 
though not highest peak, a famous landmark for sailors) extends from around 
the inner branches of Khor Shinab to some distance beyond Khor Abu 
Hamama, lying much nearer the sea than do the above. Its height is estimated 
by the Government Surveyor at from 500 to 700 feet. 
These ranges are wholly inland, rising abruptly from the maritime plain, 
which they divide longitudinally. J have not been able to see whether they 
are coral-capped, but have seen that their bases, at least, have the structure 
of the range next described. 
The hills of the Rawaya Peninsula and Jebel Makawa form an outer range 
parallel to the above, and are capped with a stratum of modern corals. They 
were once barrier reefs, growing upon sandstone foundations. 
The highest points of the Rawaya peninsula are near its north end, and 
eastwards from the salt-works in the south, the northern being an extensive 
plateau of a height of about 100 feet. the latter a hill of about twice this 
* This may |be translated “ Pigeon Hill,” and is so called from the curious shape of 
its summit. 
