76 FOYE. 



Vekai. 



The island of Vekai represents almost the final stage in the destruc- 

 tion of an elevated bank of coralliferous limestone by atmospheric 

 solution, the transformation of the resulting platform into an atoll by 

 submergence, and the upgrowth of corals about its edge. Vekai reef 

 is slightly over 2 miles in diameter. No portion of its rim has been 

 aggraded above sea-level. On its eastern edge three or four remnants 

 of a dismembered island of elevated limestone rise out of the ocean. 

 None of these remnants is over 15 or 16 feet in height and their com- 

 bined area is less than an acre. The limestone is so re-crystallized 

 that nearly all its original structure is lost. It is extremely brittle, 

 rings under the hammer and contains a considerable amount of mag- 

 nesia. The surface of the islets is so rough and jagged that walking 

 is dangerous. A few more centuries of undercutting and solution will 

 destroy them completely. 



Group III. Volcanic Islands. 



Introduclion. 



Between the large islands of Viti Levu and Vanua Levu, and the 

 Lau Islands on the east lies a group of purely volcanic islands, 

 namely, Koro, Mokongai, Wakaya, INIbatiki, Nairai, Ngau, INIoala, 

 Totoya arnl Matuku. None of these islands was visited. Koro was 

 seen from a distance and appeared to have certain resemblances to 

 Taviuni. Several of the islands of the Lau group are wholly volcanic. 

 The largest of these are Kanathea, Munia, Olorua, IMothe, and Komo. 

 Only Kanathea and Munia were visited. 



Of the islands more or less closely associated with ^^iti Levu and 

 Vanua Levu, Ovalau, Mbengha, Kandavu, and the Yasawa group are 

 mainly volcanic. Of the Yasawa group, Yasawa"-i-lau alone is com- 

 posed of elevated limestones. Though previously unknown, it was 

 found that the volcanic rocks of a part of Kandavu are underlain by 

 limestones. 



The stay on Ovalau was so brief that little geological work was pos- 

 sible. The island appeared to be a volcanic cone in a sub-mature 

 stage of erosion. 



The islands to be described are the following: — Munia, Kanathea, 

 Mbengha, and Kandavu. 



