Ch. VI. DISTRIBUTION OF CORAL-REEFS. 181 



says that the modern beds attain a height of only 30 to 

 40 feet, Mr. Burton 1 found a deposit replete with existing 

 species of shells, at the height of 200 feet. In an admirable 

 series of drawings by Captain Moresby, I could see how continu- 

 ously the cliff-bounded, low, tertiary plains extended with a 

 nearly equable height, both on the eastern and western shores. 

 The southern coast of Arabia seems to have been subjected to 

 the same elevatory movement, for Dr. Malcolmson found at 

 Sahar low cliffs containing shells and corals apparently of 

 recent species. 



The Persian Gulf abounds with coral-reefs; but as in 

 this shallow sea it is difficult to distinguish reefs from sand- 

 banks, I have coloured only some near the mouth. Towards 

 the head of the gulf Mr. Ainsworth 2 says that the land is 

 worn into terraces, and that the strata contain organic remains 

 of existing forms. 



The West Indian Archipelago of 'fringed islands' alone 

 remains to be mentioned : evidence of an elevation within a 

 late tertiary epoch of nearly the whole of this great area, may 

 be found in the works of almost all the geologists who have 

 visited it. I will give some of the principal references in a 

 note. 3 



1 Lyell's Principles of Geology, 5th edition, vol. iv. p. 25. 



2 Ainsworth's Assyria and .Babylon, p. 217. 



3 These references only relate to works published before 1842, the 

 date of the first edition of this book. On Florida and the north shores 

 of the Gulf of Mexico, Eogers' Eeport to Brit. Assoc, vol. iii. p. 14. — 

 On the shores of Mexico, Humboldt, Polit. Essay on New Spain, vol. i. 

 p. 62. (I have, also some corroborative facts with respect to the shores 

 of Mexico.) — Honduras and the Antilles, Lyell's Principles, 5th ed. 

 vol. iv. p. 22. — Santa Cruz and Barbadoes, Prof. Hovey, Silliman's Journ. 

 vol. xxxv. p. 74. — St. Domingo, Courrojolles Jour, de Phys. torn. liv. 

 p. 106. — Bahamas United Service Journ. No. lxxi. pp. 218 and 224. — ■ 

 Jamaica, De laBeche, Geol. Man. p. 142. — Cuba, Taylor in Loncl. and 

 Edin. Phil. Mag. vol. xi. p. 17. Dr. Daubeney also at a meeting of the 

 Geolog. Soc. orally described some very modern beds lying on the N.W. 

 parts of Cuba. I might have added many other less important 

 references. 



