116 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY. 



edged with a fringing reef, or we may find the remnants of the elevated 

 coralliferous limestone, which is less easily eroded than the volcanic mud 

 strata, as in the elevated reef in a valley to the north of Suva. This 

 reef rises to a height of 120 feet above high water mark, and is fully 

 fifty feet thicli (Plate 31). Its extension can be traced in outliers on 

 the north shore of Suva Harbor and on islands composed of elevated 

 limestone at the mouth of the inner harbor of Suva, — islands which 

 are from sixty to ninety feet in height, and rest directly upon beds of 

 stratified volcanic mud and capped by similar strata. On the northwest 

 shore of the inner harbor there is a bluff of the same elevated limestone 

 rising to about sixty feet. The continuation of the reef can be traced 

 inland and along the shore for a considerable distance. 



The character of the islands within the barrier reef patches of Xamuka 

 and of Serua indicate that the corals growing upon the flats rest upon 

 beds of stratified volcanic mud (Plate 5). Here and there we find a 

 negro-head of the harder volcanic rock upon which the volcanic muds 

 rest. From Serua westward the fringing reef varies in width from a mile 

 to a mere narrow fringe of corals close to the shore (Plate 42). Negro- 

 heads of volcanic rock stud the reef flats, which are here and there 

 hollowed out into small boat harbors (Plate 6). At the Singatoka 

 Eiver the fringing reef has disappeared (Plate 6), and the heavy 

 breakers roll upon a coral sand beach for a distance of about three 

 miles. Immediately behind the beach rises a line of huge coral sand 

 dunes, one of which attains a height of 190 feet (Plate 44). At this 

 point the character of the fringing reef changes again. It is built upon 

 the remnants of the ancient elevated limestone reef (Plate 43), small 

 bluffs of which occur all the way between the Singatoka Ptiver and 

 Xandronga Harbor (Plate 45). Some of the bluffs on the shore 

 attain a height of more than seventy feet. Negro-heads consisting 

 of elevated limestone fragments now abound upon the whole line of 

 the fringing reef, and the two islands which protect the harbor of 

 Nandronga on the east, and on the west are outliers of the ancient 

 elevated reef (Plate 45). The height (thickness) of that reef must 

 have been very considerable, judging from the height of an extensive 

 bluff, consisting of limestone to the north of the sand dunes at the mouth 

 of the Singatoka, which must be fully 250 feet. The fringing reef 

 extends to the west of Nandronga as far as Likuri Harbor, where it 

 gradually passes again into a barrier reef with a gradually widening 

 shore passage (Plate 6) as we approach the Nandi waters. 



The elevated limestone reef must have extended west as far as Viwa, 



