392 J. STANLEY GARDINER. 



The seaward reef to tlie S.E. of Furnadu, beyond the boulder-covered beach, is only about 

 30 yards broad, but towards the middle of the island reaches about twice tliis breadth. In its inner 

 part it is verj' rough, but with few loose masses of rock, giving place outside to an absolutely bare 

 reef flat with a well-marked edge which continues evenly against the sea with practically no fissure 

 formation. Tiie whole right up to the edge is scattered with pinnacles, masses of the elevated rock. 

 Many of these are of extraordinary size, and a considerable proportion attain a height of 7 — 10 feet 

 above the reef flat, about 2 — 5 feet above the high tide level. Most are undermined somewhat, 

 and the surfaces of all are much worn. They show their composition fairly well, but the force of 

 the sea is too great to allow many upstanding coral colonies to be worn out of the rock. At the 

 south end, on the inner side of Furnadu, at the base of the U a number of similar masses were 

 found, which in their corals clearly showed their origin to be due to a small elevation. 



While to the S. of Furnadu almost the whole seaward reef is covered with rock masses, to 

 the N. they become continuously fewer and more scattered. Beyond the island a few are found on 

 the boulder zone and inner part of tlie reef flat the whole way along to Farukolu, but they gradually 

 decrease in size further N. Opposite the centre of the shoal the E. reef is much broader, and has 

 the regular reef flat characteristic of seaward reefs, the edge however being more regular than 

 is usual. Lastly, off Farukolu the reef is about 60 yards broad, the outer 40 yards of which 

 form an almost bare and typical reef flat, while the umer 20 are covered with rock masses. 



The W. reef has outside an only moderately steep slope with a broad area of growing corals, 

 of which 20 — 30 yards of its inner edge reach the low tide level. Inside this lies the sand flat, 

 which against the land forms the boat channel, but between Farukolu and Furnadu, where the whole 

 reef narrows somewhat, continues as a great sand flat with nowhere more than 3 — 4 feet of water at 

 low tide. On it sedentary life of all sorts is singularly scanty, the whole being covered with loose 

 sand, which is washed up by the wind into temporary banks. The ordinary sand-living organisms 

 also, such as Sipuncubis, Ptijchodera, and Holothuria macidata, are curiously rare except within the 

 horns of the main islands. 



Ereadu (PL XX.) is a crescent-shaped island enclosing a velu or basin with 2| fathoms of water. 

 Round its outer shore lies a belt of stony land, varjang in breadth from 45 yards in the 

 middle of the E. side to 80 — 90 yards near the points. Outside this to the E. there is no reef 

 flat, the slope commencing from the base of the beach, which is 10 feet high. It is very 

 gradual for about 40 yards out, where the depth is only a fathom or so. N. and S. a flat 

 of about the same breadth at the low tide level is found. A singular point is the complete 

 absence of pinnacles and of any definite masses of coral rock. The whole stony belt is covered 

 with loose corals, but the latter are not rounded off in any way, as if thrown up by the sea. 

 This fact, together with the presence of a definite, high ridge behind the beach, makes it difficult 

 to suppose that the corals can have reached their present position save by elevation. Yet the 

 coral blocks looked singularly fresh, although the inner 20 yaids of the stony area were formed 

 mainly of Pontes arenosa colonies, many 7 — 8 feet across, a coral which does not grow to any 

 size on the seaward sides of reefs. Near the points the rocky belt stretches across the whole 

 island, and is formed of small fragments, etc., obviously piled up by the waves. The points 

 themselves show distinct outgrowths towards one another, which in time might close in the central 

 basin of the whole reef, turning it into a lake or kuli. 



The sandy area fringes the velu to the N., S., and E., and its shores are everywhere to 

 some extent washing away. Broad sand flats fringe the beach to the N. and S., but in the 

 centre of the E. side the shore slopes directly into the lagoon, a depth of 2 fathoms being 

 reached within about 20 yards. A reef joins the points of the island, rising generally to the 

 low tide level, but with two channels serving for small boats. It is mainly covered and 

 apparently formed in its upper few fathoms by massive colonies of Forites (including P. arenosa) 



