REVIEWS. DEEP SEA EXPLORATIONS.-In the Report before us are given the preliminary proceedings and equipment, the narrative of the three cruises performed during 1869, the general results so far as they relate to Physics and Chemistry, and, in an appendix, a summary of the observations upon, and analysis of, samples of sea water and deep sea bottom collected during the cruise. Passing over the first portion for the sake of brevity, (though there is much, especially in the description of the equipment, to interest all naturalists), we learn that the Porcupine, with Mr. Jeffreys and Mr. W. B. Carpenter on board, left Woolwich, May 18th, and after coaling at Galway, on the west coast of Ireland, cruised, dredging at intervals, to the southward and westward. The greatest depth reached was 808 fathoms and an essentially northern fauna was discovered throughout. Among the collections, were Nucula pumila, Verticordia abyssicola, "Fusus" n.sp. like "F." Sabinii, Phakellia ventilabrum, Gonoplax rhomboides, Ebalia n.sp., Ethusa n.sp., Geryon tridens and many small crustaceans. The next dredgings were taken in a line eleven degrees of longitude due west from Galway, and reached a depth of 1230 fathoms. All the mollusca except Aporrhais Serresianus were northern (the temperature of the bottom being 37° 8' Fahr.); several new species and two new genera of the family Arcida were found, as well as Trochus minutissimus Mighels (which has two conspicuous eyes), a species of Ampelisca, an eyed crustacean, and numerous gigantic foraminifera. A third trip, from Killebegs to the Rockall Bank was then made, and dredgings as deep as 1476 fathoms succeeded in obtaining an abundance of life. Among the species were an imperforate brachiopod with a septum in the lower valve, which Mr. Jeffreys calls Atretia gnomon, Kelliella abyssicola Sars, Cumacea n.sp., several small new crustaceans; Pourtalesia, probably P. miranda, A. Ag. and many fine foraminifera, including an Orbitolites of the size of a sixpence. The vessel reached Belfast at the end of her cruise on the 13th of July, 1869. The second cruise, under Prof. Wyville Thompson and Mr. Hunter, was undertaken for the purpose of getting a haul of the dredge in 2500 fathoms of water and thus affording a reasonable ground for belief that, if life existed at that depth, it could have no bathymetrical limits. In Lat. 47° 38' north, and Lon. 12° 08′ W. Gr. a depth of 2435 fathoms was obtained, and a dredge weighing 225 lbs. was sent down with a heavy weight attached to the line five hundred fathoms from the dredge, in order to make it bite the bottom. This apparatus, attached to 3000 fathoms of line, was ten minutes in running out. Preliminary Report of the Scientific exploration of the Deep Sea in H. M. Surveying Vessel Porcupine, during the summer of 1869. Conducted by Dr. W. B. Carpenter, V.P.R.S., J. Gwyn Jeffreys, F.R.S., and Prof. Wyville Thompson, LL. D., F.R.S. (Proc. R. Soc. No. 121.) When hauled in, the dredge contained 150 lbs. of pale gray ooze, containing 23 per cent. of silica, 61 per cent. of carbonate of lime, with some alumina, carbonate of magnesium, and oxide of iron. The animals brought up were, among others, Dentalium n.sp. (large), Pecten fenestratus, Dacridium vitreum, Scrobicularia nitida, Neæra obesa, Anonyx Hölbollii Kroyer, Ampelisca æquicornis Bruzel., Munna n.sp., several annelids; Ophiocten Kroyeri Lütken, Echinocucumis typica, Sars; a stalked crinoid allied to Rhizocrinus; Salicornaria, n.sp., two fragments of a hydroid Zoöphyte; numerous foraminifera, with a branching flexible rhizopod having a chitinous cortex studded with Globigerina, enclosing a sarcodic medulla of olive green hue; several small sponges belonging to a new group, etc., etc. Another subsequent haul brought up a Pleurotoma n.sp., Dentalium n.sp., and Ophiocantha spinulosa, besides others previously mentioned. Many of the animals were brilliantly phosphorescent and the eyes in species of all classes were well developed, showing that in these abysses light of some kind must exist. The temperature at the bottom in this case was 36° 5' Fahr. against 65° 6' Fahr. at the surface. The third cruise in charge of Dr. W. B. Carpenter, Prof. Wyville Thompson and Mr. P. Herbert Carpenter, was devoted to the exploration of the warm and cold areas which had previously been shown to exist between the north of Scotland, the Hebrides, and the Faroe Islands. Space will not admit of even a condensed exhibit of the valuable results obtained on this cruise. The most important and valuable of the results of these dredgings, due to the great liberality of the British Government, may be succinctly stated as follows. 1. It has been practically proved that there is no limit to the existence of animal life as far as depth is concerned, and that the difference in the specific gravity of the water at the surface and at 2500 fathoms is less than that between salt and fresh water. 2. That there is a constant interchange between the carbonic acid gas from the bottom and the oxygen at the surface, by which the animals at great depths are provided with means of respiration. 3. An abundant supply of dilute protoplasm in the water serves as food for the protozoic inhabitants of the deep sea, upon which latter the higher animals subsist. 4. A glacial submarine climate may exist over any area, without reference to the terrestrial climate of that area. 5. Cold and warm areas may exist in close juxtaposition, at great depths, and at the same time present quite distinct faunal characters. 6. The bottom, as analyzed by David Forbes, F.R.S., differs essentially in composition from the chalk rock (cretaceous) of England, and no evidence whatever has accumulated to sustain the hypothesis of Dr. Carpenter that the Cretaceous period is at present progressing in the Atlantic sea bed; indeed, that gentleman, in a late letter in "Nature" has practically abandoned this theory. 7. Temperature is the great agent which determines the distribution of submarine animals; a view previously maintained by many eminent naturalists and now permanently established by these, and other dredgings in the Atlantic, and by the researches of American naturalists in the North Pacific. It is to be regretted that the views of Mr. Jeffreys in regard to the specific and generic limits of animals, differ so widely from those of the majority of modern naturalists. In the present report he unites animals belonging to different genera under the same specific name; e. g., Waldhei-mia septigera and Terebratella septata, and those who have had occasion to critically examine his British Conchology, find in it many similar cases. Such determinations, of course, will tend to invalidate any conclusions which may be drawn from his report, and will undoubtedly throw a certain amount of confusion upon the whole subject. - W. H. D. THE CLASSIFICATION OF WATER BIRDS. * — Although from the title of this paper one might reasonably expect to find the classification of the commonly so-called water birds in general treated of, the writer restricts himself in this able essay to the consideration of the "swimmers proper, as distinguished from aquatic, or even natatorial Gralle." The series of special papers on several of the principal groups of the swimming birds which Dr. Coues has published during the last few years t indicates sufficiently his familiarity with the subject he treats; and the scientific student will find himself warranted in the natural anticipation of finding the essay in question full of important and, in general, well considered data. Dr. Coues sets out with the assumption that it is demonstrable that the Natatores "are one of three primary divisions of birds, at least of carinate birds," which he regards, practically, at least, as subclasses. To prove that the Natatores are such a division, and to define the "orders and families" of this subclass, he states to be the object of his paper. I After alluding to the fact that a singular unanimity has prevailed in regard to the definition of the group of Natatores, and that in the main similar subdivisions have been recognized, though by different authors differently collocated and their rank differently estimated, he proceeds briefly to a consideration of four of the leading modern systems of ornithological classification. These are, to quote his own words, “(1) a *On the Classification of Water Birds. By Elliott Coues, A. M., M. D., Ph. D., etc. Proc. Phil. Acad. Nat. Sci., 1869, Vol. 1, pp. 193-218. December, 1869. (1.) Synopsis of the North American forms of Colymbidæ and Podicipida. Proc. Phil. Acad. Nat. Sci., 1862, pp. 226-233, April, 1862. (2.) Revision of the Gulls of North America. Ibid., pp. 291-312, June, 1862. (3.) A Review of the Terns of North America. Ibid., pp. 535-559, Dec. 1862. (4.) A Critical Review of the subfamily Lestridinæ. Ibid., 1863, pp. 121-138, May 1863. (5.) A Critical Review of the family Procellaridæ. Ibid., 1864, pp. 72-91, March, 1864; pp. 116-144, April, 1864; 1866, pp. 25-33, March, 1866; pp. 134-197, May, 1866. (6.) The Osteology of Colymbus torquatus; with notes on its Myology, Mem. Bost. Soc. Nat. Hist., I, pp. 131-172, April, 1866. (7.) A Monograph of the Alcidæ. Proc. Phil. Acad. Nat. Sci., January, 1868. In a foot-note (p. 209) he states subsequently that he uses the term "subclass" in a conventional sense only. dichotomous arrangement in two 'parallel series,' based upon one physiological character, — Bonaparte; (2) a trichotomous, founded upon very general considerations, Nitzsch, and after him Lilljeborg; (3) quinary, a modification of the second, by dividing two of the three divisions into two each, and with minor changes, Vigors, and many others; (4) another trichotomous, but from a totally different standpoint - recognition of birds as modified reptiles - and carried out with special reference to one anatomical character, afforded by certain cranial bones, — Huxley." Each of these systems is reviewed at some length, their general features succinctly presented, and many of their deficiencies pointed out. In his remarks upon the Bonapartean system, Dr. Coues objects to the comparison of the two groups of birds termed Altrices and Precoces to the primary divisions of mammalia, "the Placentalia and Monotremata"; an objection which appears to be well founded; for in the one case there are important, constant structural differences, whereas in the other no such differences exist. "If helplessness at birth compared with precocity," says Dr. Coues," means, among birds, 'high' as opposed to 'low' in the scale, then either the reverse is the case with mammals, or else we must compare altricial Incessores with Marsupials, and præcocial Natatores with the higher orders: a dilemma either horn of which is sufficiently difficult." With the radical differences that exist between the placental and implacental mammalia, and the almost entire homogeneousness of the whole bird type, it is evident that no primary divisions of the latter have yet been discovered that are coördinate with the placental and implacental divisions of the latter. Hence, doubtless, as Dr. Coues partially suggests, birds, in regard to the condition of the young at birth, should be compared with the Placentalia alone. The præcocial birds would then be comparable with the præcocial Placentals, (as the Herbivores,) and the altricial birds with the altricial or higher Placentals. The vast difference in the modes of generation between birds and mammals, and between the two subclasses of mammals, renders the resemblance, as primary groups, of Altrices and Præcoces to the Placentals and Marsupials one rather of remote analogy than of homology or true parallelism. So widely different, in fact, are the ornithic and mammalian modes of execution of the vertebrate plan, especially as regards the mode of reproduction, that it is difficult to conceive of the possibility of a division of birds into two groups which would be strictly comparable with the subclasses of mammals. It is nevertheless true that in the two great groups of birds first recognized by Oken- the Altrices and Præcoces — but afterwards so thoroughly elaborated by Bonaparte that the system, as all will admit, appropriately bears his name, there is something that forcibly recalls the two subclasses of mammals. This division, in the present writer's opinion, trenchantly separates birds into two highly natural, primary series, with, to a great extent, parallel or representative groups in each, and so distinct that no removal of any of the groups of the one series to the other can be made without bringing illy-asso |