128 THE GREAT BARRIER REEF. 



as Wreck Bay. The depth in this bay was found by the Fly to be very great, no bottom 

 being reached except close to the reefs. South of Raine Island Passage, the Osprey reef, with 

 soundings around it of 1,300 and 1,400 fathoms, lies a little over seventy miles off the Barrier 

 border, its southern edge being intersected by the parallel of 14° S. The Bougainville, 

 Holmes, and Flora reefs, all of which include small areas that dry more or less at low tide — 

 and a sand cay on Holmes reef, which is permanently elevated to a height of six feet, — are 

 all located some eighty miles to sea, approximately, opposite the Trinity Opening. The Flinders' 

 reefs, a scattered patch thirty-five miles long and fifteen broad, enclosing an irregular lagoon- 

 shaped area with soundings of from twenty-six to thirty-three fathoms, with a sandy bottom, is 

 situated fifty miles south-east of the Holmes reefs, and at about sixty miles distance from the 

 Barrier's edge. 



Several reefs occur further seawards, occupying parallels of latitude that roughly corres- 

 pond with those of the Holmes and Flinders' reefs, — i.e., 16° to 18° S. They include 

 the Willis group, Coringa Island, the Magdelaine and Herald Cays, Tregrosse and Diamond 

 Islets, and Lihou reef and cays. The last-named group of combined reefs and sand cays 

 forms an elongate atoll-shaped chain, sixty-five miles long by about twelve in width, its 

 long axis having a north-east and south-west direction. Its nearest distance from the Barrier 

 margin is as much as one hundred and forty miles. The latitude of 19° S. intersects the 

 northern edge of Marion reef, having a pear-shaped contour, and a length of about twenty-five 

 miles, with its wider, obtuse, end directed north-east by east ; its distance from the Barrier 

 margin is about eighty-five miles. Along the Barrier farther south, no other independent 

 group of reefs occurs within a moderate distance of its outer edge until the latitude of the 

 inner Barrier (Swain reefs) series is arrived at, m about 22° S. Here the detached series of 

 reefs and cays collectively known by the title of Saumarez reef occur at a distance of eighteen 

 miles only from the outer border of the Barrier. Like the Marion reef, it is pyriform 

 in contour and twentj'-five miles in length, but with its broadest end directed towards the 

 Barrier. It has a well-defined lagoon, with depths of from fourteen to twenty-seven fathoms, 

 while immediately outside its rim the shallowest soundings are from 150 to 190 fathoms, but 

 more often charted with no bottom at 200 fathoms. In addition to the detached reefs now 

 enumerated, which occupy a position sufficiently near to the Great Barrier to be incorporated 

 within its geographical radius, there are a few others, more notably opposite its southern 

 moiety, that, standing out farther seawards, form, as it were, points of connection with New 

 Caledonia and the more remote islands of the Pacific. Notably mention may be made of 

 the Avon Islands, in latitude 20° S., 350 miles distant from the Great Barrier, and but 300 

 from the north end of New Caledonia. Farther south, the groups of the Mellish, Frederick, 

 Wreck, and Bellona reefs occupy similarly isolated positions at varying distances, ranging 

 from two to four hundred miles from the Great Barrier's edge. 



