BY D. MAWSON. 405 



many had to be passed by with no further examination than 

 could be prosecuted from the deck of the vessel. A detailed 

 report of observations made on the island of Efate and in South- 

 West Santo appears in a later part of this paper. 



The titles of references when previous observers are quoted 

 will be found in the bibliography (p. 479). 



Aneityum is the southernmost island of the New Hebrides 

 proper; it is almost circular in outline, with a diameter of about 

 7 miles and an area approximately 40 sq. miles. 



Our stay at Anelgauhat was so limited that it was possible 

 only to make a geological examination for some two miles inland. 

 A well developed fringing reef completely encircles the island at 

 a distance of about ^ mile from the shore, affording one of the 

 the best examples of growing coral reef-formation to be found 

 in the Group. Beach sand rock is well developed along most 

 parts of the coast visited, giving place above high-water mark to 

 a blown sand rock composed of the finer beach sand material 

 which has been piled up to a height of 10 ft. or so by the trade 

 wind, and there become loosely connected, forming a porous lime- 

 stone containing a large proportion of mineral fragments; this 

 rock is well shown in a cutting just behind Wilson's store. 



Inland from the Mission Station is an area of low-lying ground 

 about half a mile in diameter, evidently once a shallow lagoon, 

 but since reclaimed by the deposition of large quantities of 

 volcanic boulders and other finer material brought down by a 

 small river which empties into the sea a little to the south. 

 Beyond this depressed area the land gradually rises to the flanks 

 of the central range of hills, which attain a maximum height of 

 2788 ft. The rocks of this region are all eruptive, either dark 

 greenish-grey or light grey olivine basalt porphyrites (1, 2)- the 

 latter variety outcrops some distance inland, and is relatively 

 less abundant than the former. 



It is possible that remains of old coral reefs may exist at 

 higher altitudes, as is the case in most of the other islands; the 

 contour of the hills, however, does not suggest such to be the 

 case, nor were any boulders of coral seen in the river bed. 



