i 9 8 A NATURALIST IN THE PACIFIC chap. 



The broken elevated district that extends eastward from the 

 Salt Lake to Fawn Harbour on the south coast, and to the 

 mouth of the Ndreke-ni-wai River on the north coast, is divided 

 into two principal masses, which are connected by a ridge or col 

 about 400 feet above the sea, which is situated a little east of Viene. 

 The western portion, which may be named the Viene sub- district, 

 attains a maximum height of 1,000 feet. The eastern portion 

 reaches in the peak of Ngalau-levu, a height of 1,960 feet, and may 

 be termed the Lea sub-district. 



The Viene Sub-District. — The cliffs on the north coast 

 between Muanaira and a little east of Viene are mainly formed of 

 basic tuffs, often calcareous. At a place about 1^ miles east of 

 Viene, these tuffs as exposed in a coast spur display large fiat 

 spiral tests of shallow-water foraminifera 4 or 5 millimetres across. 

 They may be described in this locality as palagonitic calcareous 

 tuff-sandstones, more or less compacted, and containing fragments 

 of palagonitised basic rocks. When crossing the col above referred 

 to one finds similar palagonitic calcareous sandstones and clays 

 exposed on its slopes up to its summit (400 feet). 



On the south side, in the vicinity of Vunilangi Inlet, foramini- 

 ferous clays and reef-limestones are displayed at the foot of the 

 slopes ; and the coast between this place and Tathelevu to the 

 westward is bordered by low cliffs of reef-limestone raised 6 to 

 8 feet above the high-water mark and displaying massive corals 

 in their position of growth. Near Tathelevu there occur raised 

 reefs 10 to 15 feet above the sea ; whilst the hills, 250 to 300 feet 

 in height, at the back of this place are composed of fine and coarse 

 tuffs and tuff-sandstones containing little or no lime, and apparently 

 no organic remains. They are sedimentary tuffs of mixed com- 

 position, made up of fragments of plagioclase, rhombic and mono- 

 clinic pyroxene, brown hornblende, portions of semi-vitreous basic 

 andesite, and palagonitic debris. In the lower levels they are fine 

 textured with a grain of - 2 to "3 mm. In the higher part their grain 

 is -5 to 1 mm., and they are more basic in character and come near 

 to the palagonite-tuffs. At an elevation of 200 feet they form 

 inland cliffs, 50 feet high, in which are imbedded blocks, 2 feet 

 across, of a blackish pyroxene-andesite with a specific gravity of 

 273, and belonging to the prismatic sub-order of the orthophyric 

 order of the hypersthene-augite andesites. It is remarkable for the 

 pyroxene prisms of the groundmass, and shows a little interstitial 

 glass. These cliffs are well displayed behind Navelatha, about 

 half a mile from Tathelevu. Between this locality and the Salt Lake 



