In passing from island to island we had many opportunities of observing the different formation and shape of several species of coral; some stood in masses of the brain-stone and cockscomb coral, some like petrified sponge, some like fans, some again of the branch-coral interlaced and intertwined in every direction; again, some broad flat masses lying layer over layer, like huge sea-lichens, again many presented the appearance of a fungus or great sea-mushroom, with a broad-spreading head springing from a small thick base. It is not a little singular that many of the growing islets which are nearly level with the surface of the water have a similar form, not rising from the bottom with a perpendicular side, but with broad overhanging heads resting upon a small base. In many places we passed over some of these isolated sea-mushrooms, upon which there was barely water for a small boat, where one step over the ledge would be in the deep sea, and you might see the hollows underneath as if looking under an umbrella. Birds were abundant on most of the isles, and on two of them were hawks' nests, raised to the height of four feet by an accumulation of sticks, stones, and shells. This day there was but little breeze; the thermometer ranged from 76 to 86 degrees. COAST UNDER THE MENAI HILLS. Saturday morning January 25. Stood in close along the shore opposite to the Table Hill and the Menai Hills, and examined the coast from the rigging. There are two openings of rivers laid down in the chart, that to the south being the larger, and both nearly abreast of Table Hill and only a few miles distant from one another; and besides these Captain Grey had marked down in another chart a considerable river, with a large estuary, close to the north of the Menai Hills, which he had called the Hutt River. As we were just on that part of the coast where all these are laid down we were the more anxious and eager. We saw three openings on the west range, but in truth very small, and after anchoring nearly opposite to the northern one we went in the boat directly for it. There was a continuous sandy beach the whole way across it, and the surf was running high, so that it was not very easy to land. LAND ON THE COAST.