THIS is another important instalment of the published results of the deep-water dredgings made by our Transatlantic cousins and friends in the Gulf of Mexico. The first was issued in 1869, and consisted of a Preliminary Report on the Echini and Starfishes, by Prof. Alexander Agassiz. A report by Dr. Stimpson on the Crustacea procured in the same expedition is announced as nearly ready; and that distinguished zoologist has also undertaken the still greater charge of a report on the Moliusca. It is impossible to over-rate the impulse which will be every where given by such explorations to the study of marine Natural History. We are now entering on quite a new phase of research, and commencing a survey of the hitherto unknown world beneath the waters. Regarded not merely in a biological, geological, or physical aspect, but also as a basis of sound education, these investigations ought not to be neglected by any civilised nation, especially by Great Britain, which, it is hoped, will never cede her well-earned maritime prestige, and her laudable ambition of discovery. This has been forcibly urged as a duty on the Government in an admirable article which appeared in the Spectator of the 22nd of July. In the pages of NATURE (meaning, of course, the present periodical, and not the mythical book to which fanciful writers are wont to allude), some of the results obtained in our deep-sea explorations of the North Atlantic and Mediterranean have been already noticed; and next year will in all probability inaugurate an expedition on a more extensive scale, and worthy of this rich and intellectual country. Sweden has performed her part most nobly, by sending out, in 1869, the Josephine frigate for the exploration of the sea-bed lying between the coast of Portugal and the Azores, and this year a corvette and tender to Baffin's Bay and Davis's Straits. Russia despatched, last year, a frigate to New Guinea for a similar purpose, under the scientific charge of an experienced naturalist, Mr.N. M. v. Maclay. We are now informed on good authority that Drs. Noll and Grenadier, two German naturalists, are projecting a dredging expedition along the coasts of Portugal and Morocco to the Canaries. Even France, in the midst of her troubles, devoted some of her energy and vast resources to the peaceful object of dredging in the lower part of the Bay of Biscay, under the personal superintendence of the Marquis de Folin, the Commandant at Bayonne. In Canada a Government schooner has been lately placed at the disposal of the Natural History Society of Montreal for dredging the deeper part of the Gulf of St. Lawrence. But the United States, not content with the laurels she had gained in the Gulf of Mexico, has this year promoted two separate expeditions; one, under the charge of the veteran and celebrated Professor Louis Agassiz, and Count Pourtales, to proceed along the south-eastern coasts of the Atlantic from Bermuda, through the Straits of Magellan to the Galapagos and San Francisco, dredging all the way; and the other, under the charge of Mr. Dall, the author of the Report above cited, has already gone from California to the Aleutian Islands. Report on the Brachiopoda obtained by the United States Coast Survey Expedition, in charge of L. F. de Pourtales, with a Revision of the Craniidæ and Discinidæ. By W. H. Dall. (Bulletin of the Museum of Comparative Zoology, at Harvard College, Cambridge, Mass.) With two plates. (Cambridge, U.S., 1871, 8vo.)