424 



NATURE 



Sept. 19, 1872 



whilst at the exterior tlie pyroxene was melted and the leucite 

 destroyed. 



Tlie author particularly pointed out that sodalite, which was 

 found sublimed in the interior of the block, is the silicate most 

 rich in sodium. This he contended was not an accidental cir- 

 cumstance, but resulted from the percolation of sea-water charged 

 with chloride of sodium. The author remarked that the 

 study of such matters is conducting us to the conclusion that the 

 quantities of water, hydrochloric, and sulphuric acid, &c , ex- 

 haled by craters and streams of lava, are not only an accompany- 

 ing phenomenon in the production of volcanic rocks and 

 mineral aggregates, but that they are essentially co-operating 

 at their origin. If once we succeed in proving and explaining 

 the origin ol minerals through vapours, or under the co-operation 

 of vapours, then the key to many problems relating to the plu- 

 tonic rocks and their minerals will be found. 



A fcio Remarks on Submarine Explorations, with Reference to 

 M. Delesse's work entitled " Lithoh^ic dii fond des mers," by J. 

 Gwyn Jeffreys, F. R. S. 



The lithology of the sea-bottom is not only a vast subject in 

 its various relations to natural history and physical science, but is 

 especixUy interesting in a geological point of view, because 

 every part of our globe has been at one period or another covered 

 by the sea. Mr. Jeffreys contended that it is almost impossible 

 t) ascertain with any degree of certainty what stratified forma- 

 tions are marine, unless we fuid in them such remains of marine 

 animals as were capable of being preserved. Exceptions doubt- 

 less occur, e.g. where the stratum had been subject to the action 

 of carbonic acid, produced by the subsequent passage of rain or 

 fresh water ; in which case all cretaceoui organisms might have 

 been dissolved before they became silicified or petritied. He 

 then gave a short account ol sabmarine explorations, from the 

 time when O. F. Muller first used a dredge for scientific pur- 

 poses (about 1772), to the present day ; and he summarised the 

 results of the ex[)editions conducted by his colleagues and him- 

 self on board H. M.S. Porcupine, under the auspices of the Royal 

 Society in 1S69 and 1870. liat next to nothing is known of the 

 enormous tracts of sea-bed which uu ierlie the depths of the 

 ocean in bjth heuiis|.iheres. He attributed the diffusion and 

 geographical distribution of the marine inver.ebrate fauna to the 

 action of currents;, and not to volun.ary migration. 



M. Delesse's work vvjs recently published at Paris, and con- 

 sists of two octavo volume^, besides an atlas of charts and maps. 

 The precise date of publicition docs not appear ; the dedicat.on 

 ii dated December I, 1871. It forms part of a series called 

 " Publications scieiidh(|ucs iudus'iiclles," and purports to have 

 been published wilii tlie s.inction of the JVIinistcra of Marine and 

 Minister of Public Works. 



While giving M. Delesse full credit for the laborious and con- 

 scientious manner in which he has evidently performed his gieat 

 task, Mr. Jeffreys regretted that he had omitted to notice the 

 reports on deep-sea explorations published by the Royal Society 

 in 1869 and 1S70, or the Address of Mr. Prestwich (the late 

 President of the CJeological Society), which was published in 

 May 1S71, and particularly treated of those reports. M. Dclcsse 

 is a foreign member of the Geological Society. By consulting 

 what had been published on tlie subject, M. Deltsse would have 

 been able not only to give fuller information, but to correct 

 errors which unavoidably occur in an extensive compilation. For 

 instance, his map of France during the leitiary epoch docs nut 

 show the communical ion which has been proved by natural is s 

 and geologists to have then existed betwten ihe Bay 01 Biscay 

 and the Gulf of Lyons. According to M. Delissj, there has 

 been no communication since the Liassic period between the 

 Atlantic and the Mediterranean north of the Pyrenees. His 

 division of the French marine fauna inio three provinces (Celtic, 

 Lusitanian, and Medilerr.inean) does noi agree with modern ob- 

 servations. Zoopnagoui moilusca do not, as stated by him, live 

 on those which are phytophagous ; pebbks {" gjlcts") are not 

 everywhere unfavourable to moUusca, even on coasts e.xposed to 

 a stormy sea ; and foraminifera never crawl at the bottom ol the 

 sea. But it is to be hoped that these omissions and erio;s will 

 be rectified in another edition of a work so desirable and im- 

 jiortant to scientific inquirers. 



Mr. W. Boyd Dawkins, F.R S., then read his paper On ihe 

 Physical Geography of the Mediterranean during the Pleistocene 

 Age. The author showed from the researches of M. Gaudry 

 that daring the late Miocene period it is probable that there was 

 some communication between Attica and Africa. During the 

 I'lioc.n; period a simd.;r com.nunicaticn must have existed at 



some part or parts of the Mediterranean area. The object ol 

 this paper was to show that a like union existed during the 

 Pleistocene age. The pakxontological evidence was first gone 

 over. It was shown that African mammalia are found at Gib- 

 raltar, in river gravels near Madrid, in Sicily, Malta, the Morea, 

 and in Candia ; particular reference was made to the occurrence 

 of a small species of Hippopotamus (//. Pentlandi) in these 

 localities, and it was contended that there must have been com- 

 munication between them and with Africa. 



An examination of the soundings makes this probable. It is 

 found thrt the Mediterranean consists of two deep basins, sepa- 

 rated from each other by comparatively shallow water, one 

 barrier extending from Africa, past the Straits of Gibraltar to 

 Cadiz, and the other reaching from Tunis, past Sicily and Malta, 

 to j lin Italy. An elevation of 2,000 feet would effect this. It 

 was pointed out that the existence of such a mass of high land 

 in the south of Europe must have had an important effect upon 

 the climate of the period. 



Mr. Charles Moore's paper On the Presence of Naked Echino- 

 ilennata ( llolothnria) in Oolitic and Liassic Beds, was then read. 

 Soft-bodied animils, such as these, are rarely found in a fossil 

 state ; but the author had fortunately discovered .some minute 

 wheel-like plates, sonewhat resembling those of a recent Green- 

 land species, and which he referred to at least four different 

 species of Holothuria Some of these plates indicate structures 

 not hitherto seen in recent species. 



Mr. J. E. Lee read a Notice of Veins or Fissures in the Keuper 

 filled with Rhu-lic Bone-led, at Goldcliff m Monmouthshire. There 

 are exposed on a scar( of Keuper mirl, bare at low wate', a 

 number of rounded masses of irregular f)rm,but of great length, 

 consisting wholly of bone-bed. Tne author presumed that these 

 projections are the casts of fissures in the marl which were 

 afterwards filled up with bone-bed. Mr. C. Moore afterwards 

 m ide some remarks on the extraordinary richness of the bo.ie- 

 bed. 



Wednesday, August 21. — Mr. J. H. Judd communicated through 

 Mr. Hughes, a njte On the Discovery of Cretaceous Rocks in the 

 /stands of Mull and Inch Kenneth. In the former they are seen 

 a several places, and the author supposed that they would be found 

 underlying a great part of the volcanic area of this district. The 

 rocks are all of upper cretaceous age and lie unconformably upon 

 taejurrassic series and older rocks. Like all other rocks of thee 

 islands the cretaceous beds are penetrated by intrusive dykes and 

 sheets of trap. Mr. Judd observed, that this discovery gave great 

 Confirmation to Prof Geikie's views as to the Tertiary age of 

 the volcanic rocks of the Hebrides. 



Mr. T. A. Readwin's paper. On Ihe Coal and Iron Mines oj 

 the Arigna District of the Connaught Coal Measures, I1 eland, 

 was then read in abstract. 



The shales overlying the Upper Limestones of district were sur- 

 mised by ttie author to belong to the Voredale Series. Over these 

 there are grits and shales with three seams of coal which the auihor 

 referred to the Gannister Series, remarking that a bed of true 

 "gannister" occurred there. 



The coal field was divided into three districts, each of which 

 was described by the author. lie noticed at some length the 

 clay-ironstone bands and nodules which occur over a much 

 larger area than do the coals. The ironstone is richer and 

 purer than most of our English clay ironstone. The author 

 believed that the time had come for a vigorous and scientific ex- 

 ploration of tlie district, which he felt convinced would so.m 

 become, as Sir Robert Kane had long ago predicted, "an im- 

 portant centre of industry for the interior of the country." 



SECTION D.— Biology 



On Deep Sea Dredging round the Island of Anticosti in the Gulf 

 of St. Lawrence, by T. F. Whiteaves, F. G.S. 



Depths of fiom too to 250 fathoms were successfully explored 

 during July and August 1S71. The temperature of the deep sea 

 mud was found by using a common thermometer to be almost 

 invariably 37^ or 38^ F., About 100 species of Inveitebrala new 

 to the Gu.f of St. Lawrence weie collected. The-e includet a 

 remarkable loraminiier, Marginulina, with spinous processes 

 from the first chamber, Grantia ciluita, a new Pennatula, &c. 

 Two rare Echinoderms were collected — the well-known Schizaster 

 /ragilis, and the curious Calveria hystri.x of Wyville Thomson. 

 Ne.irly all the marine invertebrates of the northern part of the 

 Gulf of St. Lawrence are purely Arctic species. Three-fourths 



