382 J. STANLEY GARDINER. 



the gradual slope of their lagoon ends, the depth at about 40 yards from the reef edge in 

 this position being only about five fathoms, whereas off the reefs in the interior of the bank 

 and off the rim reefs in the channels, the general depth in the vicinity — 20/. or more — 

 is usually reached in considerably less than the same distance. Further out off the lagoon 

 ends of Mahrus and others of the encircling line of reefs I found no marked steep, and the 

 bottom, so far as I could see, was covered with growing corals and other organisms. The 

 character in these positions was that of a growing reef, and it is this outgrowth, which has 

 built the foundations, on which the islands have become elongated transversely to the line 

 of the edge of our bank. The singularly little growth of these rim reefs to seaward and 

 against the passages is peculiarly interesting, and not easily explicable. 



Turadu island (PI. XIX.) is of especial interest, lying as it does on the south-west corner of 

 the bank, where the greatest force of the S. W. monsoon would necessarily be felt. The island 

 lies about 400 yards back from the seaward edge of its reef, and is entirely of sand formation 

 with no trace of coral rock on any of its reefs. The seaward reef has a well-defined edge, reef 

 flat of 40 — 50 yards, boulder zone of 20 — 30 yards, and sandy boat channel with 1 — 2i feet of 

 water, which continues round the other sides of the island in a sandy flat. The latter, however, 

 at the extreme north point is scarcely existent, the shore sloping evenly to three fathoms in about 

 50 yards. 



The island has in recent years been struck by two cyclones, " at the commencement of the 

 S. W. monsoon'" of 1896, and in August, 1898. The former is said to have swept down along 

 the island from the N. W., while the greatest force of the latter was experienced at high spring 

 tide from the S. W. The combined result of the two has been to reduce the island by more than 

 the half of its former size. Yet, it is quite evident that destructive forces were at work long 

 antecedent to these gales, a few odd sandstone rocks on the reef to the south indicating that Turadu 

 and Warufinur were once nearly or quite connected. 



The chief characteristics of the island may best be seen in the accompanying Chart (PI. XIX.). 

 It now nowhere attains a greater height than 4i feet above the high tide level, and shows loss 

 on every side except perhaps at the N. W. point, and for about 150 yards down the W. side. The 

 sandstone rock to the N.E. exhibits nine terraces (sections A and B), while on the beach behind a 

 tenth is forming between the low and high tide limits. The layers have evidently been much worn 

 down, and are hollowed out underneath ; the lower ones are markedly less consolidated than the upper, 

 and serve to fully confirm the account of the rock given in Appendix A. The different lines of 

 this rock in the boat channel on the south side are separated by about two feet of water at low 

 tide, and serve admirably to show tlie former contour of the land. The outer line a has traces 

 of five terraces, but b of only two ; the average height of each above low tide is about 15 inches, 

 but a has a single undermined mass in the centre, which stands up for 3 ft. 5 in. and is about 

 8 sq. yds. in extent, c is the continuation of a firmly consolidated line of sandstone on the beach 

 to the north of the last, which formerly extended between the low and high tide levels. The sand 

 on the beach above it was scooped out for 8 — 10 yds. in one of the recent cyclones, but has filled 

 in again, c? is a breakwater piled up on the top of a more recent and less consolidated line of 

 sandstone. Its position represents the direction of the beach before the cyclone of 1896 (?1898), 

 and behind it in the small bay is an incipient formation of rock. 



The S.E. half of the island runs out into a point, beyond which a sand bank shows clearly 

 the direction of the island for a further 193 yards. It has along the middle of its south side 

 a line of sandstone, which runs as if to join d; it evidently belongs to the same formation as d, 

 and the complete line shows on this side of the island the destructive action of tlie two cyclones. 



1 The description given by the natives. 



