AGASSIZ: FIJI ISLANDS AND CORAL EEEFS. 117 



and north again as far as Asawa i lau, both of which islands, as I am 

 informed by Dr. Corney, consist of elevated limestone (Plate 2). Viwa 

 is 100 feet in height.^ 



Plateau off Nandi and Yasawa. 



To the westward of Nandi waters (Plate 3), off the northwest coast 

 of Viti Leva, extends a wide plateau, the result of the denudation and 

 submarine erosion of that side of the island. The depth of this plateau 

 is most irregular, varying from ten to forty fathoms. The plateau is 

 studded with sunken patches, and with rocks and islets and islands. The 

 southwestern line of islands from the Mololo Islands to Mana is flanked 

 by an outer line of reef flats, which gradually become smaller and disap- 

 pear off Tartar Reef (Plate 3). From these the edge of the plateau 

 crosses toward the north, and the outer reefs reappear again to the 

 westward of the long chain of the Yasawa group. 



The Yiwa Island reef is separated by a narrow, deep channel, with 

 137 fathoms in mid-channel, from the western edge of the Yasawa 

 plateau. To the northwai'd of the Malolo Islands are scattered a few 

 islands, — Kandavu, Lovuka, Tavua, and Yomo. The last is of volcanic 



TOMO LAI LAI. 



origin, while Kandavu is flanked by beach rock, as is also Tavarua at the 

 entrance of Xavula Passage. All the islands which Captain Thomson 

 examined on his way from the Malolo Islands to Waia he found to 

 be of volcanic origin, — Mana, Tavua, Monu, and others. As I have 



1 The elevated limestone'patches vrliich begin at Singatoka extend to the patches 

 and reef flats north of Xavula Passage (Plates 2, 3). Captain Thomson collected 

 some pieces of a negro-head on the edge of the reef flat near Tavarua Island 

 which consisted of elevated limestone. 



