PACIFIC OCEAN. 201 



Eev. W. Ellis, that on the N.E, side of Huaheine there is a 

 bank of sand, about a quarter of a mile wide, extending 

 parallel to the shore, and separated from it by an extensive 

 and deep lagoon : this bank of sand rests on coral-rock, which 

 undoubtedly was once a living reef. North of Bolabola 

 lies the atoll of Toubai (Motou-iti of the CoquilWs atlas), 

 which is coloured dark blue ; all the islands which are sur- 

 rounded by barrier-reefs are coloured pale blue : three of 

 them are represented in figures 3, 4, and 5, in Plate I. There 

 are three low coral-groups lying a little W. of the Society 

 Archipelago, and almost forming part of it, namely, Belling- 

 hausen, which is said by Kotzebue (Second Voyage, vol. ii. p. 

 255) to be a lagoon-island; Mopeha, which from Cook's descrip- 

 tion (Second Voyage, book iii. chap, i.) no doubt is an atoll; 

 and the Stilly Islands, which are said by Wallis (Voyage, 

 chap, ix.) to form a group of low islets and shoals, and which, 

 therefore, probably compose an atoll : the two former have 

 been coloured blue, but not the latter. 



Mendana or Marquesas Group. — These islands are almost 

 entirely destitute of reefs, as may be seen in Krusenstern's 

 Atlas, making a remarkable contrast with the adjacent group 

 of' the Society's Islands. Mr. F. D. Bennett has given some 

 account of this group, in the seventh volume of the Geograph. 

 Journ. He informs me that all the islands have the same 

 genera] character, and that the water is very deep close to 

 their shores. He visited three of them, namely, Dominicana, 

 Christiana, and Roapoa, their beaches are strewed with 

 rcunded masses of coral, and although no regular reefs exist, 

 yet the shore is in many places lined by coral rock, so that a 

 boat grounds on this formation. Hence these islands ought 

 perhaps to come within the class of fringed islands and be 

 coloured red ; but as I am determined to err on the cautious 

 side, I have left them uncoloured. Dana infers (Corals and 

 Coral Islands, p. 325), from their steepness and deeply in- 

 dented outline, that they have subsided. 



