Only a very small proportion of the species of shells to be found on the shore of this bay have been enumerated. In a work of general character a complete commentary on any particular branch of natural science would be out of place, nor is it competent for one who has but a trifling knowledge of a special subject to deal with it in an enlightening manner. It would be highly interesting to ascertain by study and observation why the denizens of so many parts of the ocean meet in community in such a narrow space, though it may not be very difficult to present a fairly satisfactory theory for the continuous presence of many species by reference to existing features and prevalent conditions. Within the area of the bay the water varies in depth from a few feet to four fathoms, the rise and fall of the tide being about two fathoms. The fringing coral reef represents all stages of development and decay--live growth on the outer edge, ever encroaching on the deeper water, and comprising many varieties; dying masses on the shore-side, and a considerable extent of dead and denuded relics lying in mud. There are also weedy patches, bare sand-banks of limited extent, uncovered at low water, and muddy depressions both in the deep and shallow portions and clean sand. Strong currents race past the sand-spit and across the bay, carrying, no doubt, continual supplies of spat from elsewhere to settle in quiet places. No one who has lived on the margin of the tropic sea can be astounded at its prolific life, though it may be a matter of unceasing wonder that along a beach not more than four hundred yards in extent should be found shells representative of species existing in nearly all the warm waters of the world. And there are other isles with other beaches. One may present a narrow strip of soft sand, cringing and squeaking under foot, almost entirely composed of finely ground coral and shells, among which polished fragments of red coral are to the beach-comber as the “colours” the gold fossicker may find in his dish--prospective of reward. They reinspire the like fervour which leads to the discovery of mountains as well as microbes, for may they not signify the existence within the bounds of the Great Barrier Reef of the precious coral of the Mediterranean and the Red Sea? Above such hopeful sands lies a band formed of stag's-horn coral, bleached snow-white, each time lying at right angles to the sea, and higher up on the strand are blocks and lumps of weather-stained coral among which vegetation is springing. A few yards further back stands a group of Pandanus palms, the van of the dense and intricate jungle covering rock and ridge. The shore of the sister islet may at the moment be but series of steeply shelving banks of coral debris, to the base of the granite ramparts over which the luxuriant foliage falls.