140 Couthouy on Coral Formations 



The island of Eimeo, lofty and broken like that of Tahiti, 

 from which it is distant between four and five leagues, is almost 

 entirely surrounded by a fringing reef, containing occasional 

 small lagoons inaccessible to any thing but a canoe, and often 

 having no entrance whatever. The same may be said of 

 several other islands in the Tahitian group. For these reefs 

 to have formed upon the shore and extended so far as in some 

 instances to be blended with the outer ones, there must as it 

 seems to me, have been a long period of rest between the 

 cessation of subsidence and the re-elevatory process, which it 

 is my belief has been for some time and is still going forward. 

 For this belief I now proceed to submit some of the reasons. 

 At almost every Paumotu visited, I found the shore of the 

 lagoon raised from eighteen to thirty inches, containing im- 

 bedded shells, and corals standing as they grew. 



At Clermont Tonnerre Island, on the North shore of the la- 

 goon, there is a reef two feet above sea level, literally paved 

 with the shells of Tridacnse, imbedded precisely as in the 

 adjacent submerged plateau, and in a state of perfect preser- 

 vation, even as to color. At Honden Island, some two hun- 

 dred and twenty miles north-west of this, a similar raised 

 ledge borders the lagoon. At Raraka, three hundred miles 

 further west, on the plain between the windward ridge and 

 lagoon, which had a very slight ascent inland, corals both 

 sessile and arborescent, were met with in a normal position, 

 half a mile from the sea, and at about the same height above 

 it as the shells at Clermont Tonnerre. At King's Island, in 

 crossing from the leeward beach to the lagoon, several large 

 tracts of reef-rock were observed, full of imbedded Tridacnae, 

 and corals occupying their original locality. Similar appear- 

 ances were presented by several other islands, to which I 

 cannot refer at present. 



The surface reef or upper terrace, every where bears evi- 

 dence of having been elevated higher than the natural growth 

 of the corals would raise it, in their scanty number and di- 

 minished size, and the calcareous incrustations now covering 

 the larger portion of the reef, to the extinction of the polypes. 

 At Waterland Island, the leeward reef is quite bare at low 



