BY D. MAWSON. 425 



Valua is 6 miles long, and 7 sq. miles in area. Viewed 

 from the vicinity of Mota, we noted sharp outcrops of steeply 

 dipping rocks, forming the central range, with sufficient distinct- 

 ness as to be almost certain that they represent alternating beds 

 of solid lava and softer tuff. 



Pakea. — A small flat island situated at the southern entrance 

 to Port Patteson, and elevated only a few feet above sea-level, is 

 composed of tuflfaceous volcanic material which, near the shore, 

 has been cemented by calcareous orgianisms into more solid beds. 



The Reef Islands are about five permanently dry patches of 

 small dimensions, scattered along a semicircular coral reef, 5| 

 miles long, and IJ miles wide at the broadest part. 



In course of time the growing reef will probably complete the 

 ring, supplying a further example of coral atoll-development. 



Gaua is approximately 10 miles square. The area, 85 sq. miles, 

 is equal to that of Vanua Lava. Highest point, 2300 ft. 



Towards the eastern side, elevated a considerable height 

 above the sea, is an old crater lake two miles in diameter. 

 Good exposures of lavas, alternating with tuff beds, were noted 

 at several points along the sea-cliffs. At Lakona Bay, where a 

 landing was effected, a bed of lava 20 ft. thick was found over- 

 lying coarse tufts. In the same locality several different lava 

 streams were noted within a short distance along the coast 

 which, when traced inland, were found to alter very little in 

 character for a distance of upwards of two miles. The specimens 

 of lava collected were various types of basalts, in most of which 

 appeared phenocrysts of pyroxene and olivine. 



Ureparapara is oval in shape, 4J miles by 3^ miles; area 

 about 11 sq.miles. Highest point, 2440 ft. The island is an 

 extinct volcano, possessing a unique harbour in the old crater, 

 which has been invaded by the sea breaking through on the 

 eastern side. Anchored there in Dives Bay, a wonderful view is 

 presented all around in the steep slopes leading up to the crater 

 lip, over 2000 ft. above. 



