BY W. G. WOOLNOUGH. 437 



could not obtain specimens, but judging from appearances it 

 consists of the ordinary reef material ; it was situated at a depth 

 of about three feet below low-water mark. This point is about 

 three miles from the present edge of the mud flat and dve miles 



Fig.l. — Index Map of Viti Le%-u showing the relative positions, but not 

 the absolute boundaries of the districts discussed in this paper. i.The Rewa 

 Area, ii.The Medrausucu Eange, iii. Upper Waidina and Waimanu Valleys, 

 iv.Wainivalau Valley, v.Waiqa Valley, vi.Navua-Wainikoroiluva Valley, 

 vii.Wainimala Valley, viii. Wailoa-Xadarivatu District, ix.Muanivatu 

 District, ix.Navosa Plateau. 



from the existing reef of Xukulau Passage. Its presence proves 

 that there has been a considerable seaward advance of the river 

 sediments, and that, for a long time, present conditions of level 

 have not been altered to any great extent, a fact borne out by an 

 examination of river history in the upper portions of the valley. 

 The high level soapstone near Xaduruloulou noted before* 

 proves to be of great interest and importance. There is evidence 

 that there formerly extended over the whole of the area now 

 occupied by the upper portion of the delta a continuous sheet of 

 estuarine deposits wiih lignitic bands. These are now represented 

 by isolated hills about Nausori, and more continuous areas higher 

 up in the neighbourhood of Xaduruloulou. They rise to a 

 height of about 100 feet above the surface of the present river 

 flat-s, indicating an elevation of this portion of the island since 

 the beds were deposited. Passing northwards and westwards 



* Loc. cit. p. 464. 



