200 A NATURALIST IN THE PACIFIC chap. 



are irregular lacunar spaces filled with calcite and lined by a 

 brown palagonite-like material. 



I ascended the second highest peak of the Ngalau-levu moun- 

 tain, which rises to a height of i,68o feet behind the town of Lea, 

 the highest summit lying to the eastward. Ngalau-lailai, which I 

 also ascended, is a lesser peak, 1,400 feet in height, situated yet 

 nearer to the town. Basic tuffs and agglomerates similar to those 

 exposed in the western spur of the bay occurred all the way up to 

 the bare rocky pinnacles forming the summits. The blocks in the 

 agglomerates are made up of a semi-vitreous augite-andesite, which 

 is sometimes scoriaceous or amygdaloidal, and at other times 

 pseudo-vesicular. Augite crystals, 5 or 6 millimetres in length, 

 are inclosed in the tuffs which contain palagonitised materials, but 

 apparently no organic remains. 



In the spur on the east side of Lea Bay occurs a light-coloured 

 altered hornblende andesite. The brown hornblende is mostly repre- 

 sented by black pseudomorphs. Such a rock appears in strange con- 

 trast with its basic surroundings. This is followed, as one proceeds 

 eastward along the coast, by basic tuffs and agglomerates. It 

 should have been before observed that blocks of a blackish-brown 

 olivine basalt (sp. gr. 2'Sg), referred to genus 13 of the olivine class, 

 occur at intervals on the coast between Viene and Ndreke ; but the 

 rock never presented itself in position. The tiny felspar-lathes 

 (•03 mm. long) are in flow arrangement ; but there is little or no 

 residual glass, and the augite granules (*oi mm.) occur in great 

 abundance. 



About two-thirds of the way between Lea and Ndreke-ni-wai 

 there lie close to the shore two islets, 20 to 25 feet high, of reef- 

 limestone, in which massive corals may be observed in their 

 position of growth. Further east, about half a mile west of Ndreke- 

 ni-wai, there is exposed at the coast a bedded light-coloured non- 

 calcareous compacted tuff-rock, dipping 12 to 15 to the southward. 

 It contains pebbles and blocks of acid and basic andesitic rocks, 

 and may be described as an altered hornblende-andesite tuff. 

 Basic agglomerates occur as one approaches Ndreke-ni-wai. This 

 town lies at the mouth of the river of that name, the first river that 

 one meets on the north side of this peninsula. There exist here 

 between the tide-marks some hot springs, to which reference is 

 made on page 34. 



When crossing the Natewa peninsula from Ndreke-ni-wai to 

 the head of Fawn Harbour, one reaches a height of 660 feet 

 above the sea. This ridge represents the " divide " between the 



