160 



HYDROGRAPHY. 



tant from it. It is a high, square-topped, rugged island, with an 

 extensive reef surrounding it, affording no entrance or protection for 

 vessels or boats. The island is 3 miles in length, north and south, 

 by 2 wide. With Chichia and Mango it forms an equilateral triangle. 



YTHATA. 



Ythata lies 8 miles north of Vaturera. It is a high island, with a 

 bill-shaped peak; its length is 2 1 miles, east and west, and but one 

 mile wide ; to the east of it and within the same reef are two small 

 low islets. The low grounds of Ythata are covered with extensive 

 cocoanut groves, but it has not more than 20 inhabitants. No water 

 except that procured from wells. There are several boat-entrances 

 through the reef. Ythata is one of the islands that form the boun- 

 dary of the Nanuku Passage. 



NUGUTOBE ISLETS. 



The Nugutobe Islets are three in number ; they lie west-south- 

 west of Ythata, the two westernmost being joined by the same reef. 

 They trend west-by-south and east-by-north, and are separated by a 

 channel from Ythata of a mile in width : there is also a passage 

 between the eastern and western islets. Two of the islets are com- 

 posed of white sand and coral, but the other is black lava and stones. 

 The reef is of small extent, and there is a passage through it on the 

 north side. On these islets are some pandanus trees, but they offer 

 little or nothing else. 



EXPLORING ISLES. 



The Exploring Isles are surrounded by an extensive reef, of a trian- 

 gular shape ; it has many breaks and irregularities in its sides, 

 which are upwards of 20 miles in length. The isles are seven in 

 number, besides many islets ; the most important are Vanua Valavo, 

 Malata, Susui, Munia, Ticumbia, Avia, and Osubu. There are six 

 openings through the reef, two on each side, which lead to safe and 

 convenient harbors. The island of Vanua Valavo is serpentine in 

 its form, 14 miles in length, but very irregular in width, being not 

 over li miles at its greatest breadth. Besides its irregularity in form, 



