ioo A NATURALIST IN THE PACIFIC chap. 



another group of hills, of which Ndrandramea (1,800 feet) is the 

 highest and best known. Associated with it are Kala-Kala (1,600 

 feet), Mako-mako, Thoka-singa (1,300 feet), Vatu Mata (1,050 feet), 

 and another unnamed peak (1,400 feet) lying west of Ndrandramea. 



The districts between and among the hills are much cut up into 

 lesser hills and ridges, the result of the very extensive denudation 

 to which this region has been subjected. The greater part of this 

 area is drained by the Tambu-lotu tributary of the Wainunu ; but 

 in the northern part we cross the watershed between the Wainunu 

 and Ndreketi basins, and to reach Navuningumu we cross the 

 valley of one of the tributaries of the Ndreketi. To the east ot 

 the Ndrandramea region extends a broken country, elevated rather 

 more than 1,000 feet above the sea, and from it there rise one or 

 two hills with bare cliff-faces, which are probably composed of 

 similar acid andesites. 



Although for the most part composed of these acid andesites, 

 each hill, as far as my observations show, has as a rule its own 

 type of the rock, differing from the others in specific weight, in the 

 texture of the groundmass, and in the relative proportion of the 

 porphyritic constituents. The petrological characters will be found 

 more fully discussed in Chapter XXI. ; and only some of the more 

 distinctive features will be noticed here in the following description 

 of the district. 



The Ngaingai Group of Hills. — Within a space less 

 than a mile square rise Ngaingai, Wawa Levu, and the other three 

 hills above named, so closely clustered together that the collective 

 name of " Hen and Chickens " might be aptly applied to the 

 group. 



The peculiar form of Ngaingai is shown in the accompanying 

 profile-sketch. It is the Nangorongoro of the Admiralty chart. 

 The height of the mountain from its base is 1,100 to 1,200 feet. 

 Its ascent, which is not difficult, may be made from the west side. 

 Above its wooded slopes rises its bare rocky peak, from which 

 a magnificent panoramic view of the western half of Vanua Levu 

 can be obtained. Characteristic dacites with porphyritic quartz 

 came under my notice all the way up from the foot to the summit, 

 being occasionally exposed in perpendicular cliff-faces. Specimens 

 taken from the upper and lower portions are uniform in character, 

 and have a specific gravity of 2*57. No other rocks were observed 

 on its slopes. The whole hill-mass is in great part if not entirely 

 formed of these acid andesites. 



The contrast between the narrow crested peak of Ngaingai and 



