(**Footnote. This has for several years been under construction; its importance will appear more evident, when it is considered that a large vessel in the Australian colonies requiring repairs, which cannot be effected by the process of heaving down, will find no suitable place nearer than Bombay.) In compliance with a requisition from Sir Charles Fitzroy, the Governor of New South Wales, Captain Stanley, in the Bramble, paid a visit to Twofold Bay, 200 miles to the southward of Sydney, a place of rising importance as a harbour, also in connection with whaling establishments, and the extensive adjoining pastoral district of Maneroo. The bay was resurveyed, with a view to test the comparative merits of the two townships there--one founded by government, the other by private enterprise. After all, I believe, the advantages afforded by each of the rival establishments are so equally divided, that the question still remains an open one. SAIL UPON FIRST NORTHERN CRUISE. October 11th. After a protracted stay in Sydney of very nearly three months, we were at length enabled to start upon our first cruise to the northward, the object of which was to make a survey of Port Curtis and part of the Inshore Passage leading up to Torres Strait. The Rattlesnake and tender got under weigh soon after daybreak and ran out of Port Jackson to the northward with a fine South-east wind. In the evening the Bramble parted company, her present destination being Port Stephens, for the purpose of running a meridian distance, and ours Moreton Bay. One day, while off Cape Byron, an interesting addition to zoology was made in a small floating shellfish, which has since proved to constitute a new genus,* throwing light, I am informed, upon many fossil univalves in the older formations; and a rare bird of the noddy kind (Anous leucocapillus) perched on the rigging towards evening, and was added to the collection; for even the beauty and innocence of a tired wanderer like it was insufficient to save it from the scalpel. (*Footnote. This mollusc, allied to Litiopa, Professor E. Forbes has done me the honour to publish in the Appendix as Macgillivrayia pelagica.) ARRIVE AT MORETON BAY. On October 18th we anchored in Yule's Roads, Moreton Bay in 12 fathoms, sand, about a mile off shore, and remained there for sixteen days. During our stay, some additions were made to render more complete the former survey of this important sheet of water. Buoys were laid down to mark the intricate channels of the north entrance, now preferred for its greater safety to the south entrance, although lengthening by about 50 miles the passage to or from Sydney. The wreck of a steamer, and loss of most of those on board, had not long before caused a great sensation, and forcibly attracted attention to the dangers of the southern entrance.