474 



NA TURE 



\_Scpt. 15, 1 88 1 



sources of eiror, through admixture of foreign materials, and he 

 was led to think ihat the organisms belonged to the rocks. 



The Siibjcxt- mailer of Geology and its Classijicalion. — Prof. W. 

 J. Sollas, ^I. A., slated his object was to remove certain prevailing 

 misconceptions as to the aim and scope of geology ._ The accepted 

 definition of geology as "the history of the earth's crust and the 

 fossils it contains," was considered to be both too wide and too 

 narrow ; the former since it includes pala;ontology, which, so far 

 as it is a study of forms of life, belongs to biology ; and too 

 narrow, since the science of the whole, necessarily embraces 

 much more than a stuiiy of its crust. Geology is one of the group 

 of concrete sciences which include astronomy, geology, and 

 biology. The scope of geology, or the science of the earth, is fo 

 wide, that a fresh classification of its subject-matter is required, 

 and the author proposes Morpkologieal Geology : — embracing 

 geography, petrology, lithology, and mineralogy cprresponding 

 to anatomy and histology in biology; minerals, rocks, rod; 

 masses, constituting the earth's crust as cells, tissues, organs 

 constituting living organisms, while paleontology is a study of 

 successive morphological states, corresponding to embryology 

 or development. Physiolos^ieal Geology, considering the move- 

 ment of the earth as a whole, and of all activities produced 

 upon it, by extrinsic and intrinsic forces, acting singly or in 

 combination ; it rightly includes meteorology, hydro-geology, as 

 well as the physiology of the earth's crust. Distributional Geo- 

 logy seeks to determine the distribution of the earth in time and 

 space, and Otiological Geology corresponds roughly to what is 

 known as cosmogony. 



Exploration of a Fissure in the Mountain Limestone at Ray^ill, 

 by James W. Davis, F.G.S. — Attention was first called to this 

 fissure by Mr. Tiddeman about eight years ago. It occurs in a 

 quarry in Lothersdale, about five miles fiom Skipton. The 

 mouth of the cavern is blocked with glacial drift ; under this 

 occurs a finely laminated clay, beneath v\ hich is a brown sandy 

 clay with well-worn boulders. The fis;ure, when excavated, 

 proved to be forty feet in length, horizontal, with a second 

 branch, both of which are abraded and smoothened by the 

 action of running water. Contains bones of Elephas, teeth of 

 Hippopotamus, Rhinoceros leptorhinus, remains of the roe- 

 buck and hyaena, and one or two teeth of lion, and a single 

 tooth of bear. 



On the Zoological Position cf the Genus Petalo-rhynchus, Ag., a 

 Fossil Fish from the Mountain Limeitone, by J. W. Davis. — The 

 species described resemble genera Janassa, Munst., and with it 

 appear to occupy an intermediate po.ition between the genera 

 Myliobatis and Cestraciontes. 



On DioJontopsodiis, Davis, a Nev) Genus of Fossil Fishes from 

 the Mountain Limestone at Richmond in Yorkshire, by James 

 W. Davis, F.G.S. — These teeth resemble those of the modern 

 fish Diodon. 



Frelintinaiy Remarks on the Microscopic Structure of Coal 

 from East i>cotland and South Wales, by Prof. Williamson, 

 F.R.S., Owens College.— This subject will not be worked 

 out until ten year--, but he described layers of vascular tissue 

 which can be separated la)er by layer, while in other cases 

 the charcoal layer on the surface of the coal and the organic 

 structure is not capable of separation, and he stated that 

 charcoal contains a tubular structure, like tissues of ordinary 

 lark. The association of tissues resembles that of Cycadian 

 plants ; and referred to the genus Cordailes having been 

 proved to belong to this group by M. Ren:.ult ; the author has 

 made nearly a thousand distinct observations on the structure of 

 coal. Separates ordinary coal with large quantities of mineral 

 charcoal, with macrospores of Lepidendroid plants filled up w i:h 

 myriads of microspores which were certainly not floated to the 

 spots, from the partffitie coals wdiich do not contain these large 

 macrospores. lie divides coals into " Iso-sporous " coals and 

 " Heterosporous " coals ; loth alound in Cordaites, which form 

 the mineral charcoal. 



On an International Scale of Colon rs for Geological Maps, by 

 W. Topley, Geological Sm-vey of England. — The author de- 

 scribed the oljects of the International Geological Congress 

 which is to meet at Bologna this month. Three main subjects 

 are there to be discussed, (a) coLurs and signs for geological 

 maps, ((5) nomenclature of rocks and formations, (<r) nomen- 

 clature of species. This paper is concerned only with the first 

 of these questions, and especially with the resolutions passed by 

 the English Map Committee, of which Prof. Ranisay is pre- 

 sident, a. d the author secretary. At present all countries and 

 many map-makers in each country have different systems of 



colouring maps, and it is necessary carefully to study the index, 

 or scale of col .ur- u-ed, before the map can be at all understood. 

 The Congress pr*.;p.ses to frame some scheme of colouring which 

 can be u,-ed and readily under.-tood by all nations. It may not 

 be possible, at least for seme time to come, to obtain any altera- 

 tion in national surveys in progress. But it is to be hoped that 

 in new smaII-^cale maps the scheme to lie decided on will be 

 adopted. One important point which the Congress proposes is 

 the preparation and publication of a general map ov atlas of 

 Europe, compiled under the authority of the Congress, from 

 the various national ^urveys and the work, of independent 

 observers. The scheme of colouring proi ed is one based 

 on the order of colours in the sular spectrum, violet denoting 

 the older r^cks. Bright reds are re eived for igne us rocks; 

 metamorphic roeks will be shown by dark bands of colour 

 over the colour denoting the age ; to these will be added 

 bands of colour showing the period at which metamorphism 

 has taken place, when such fact is clearly established : thus, 

 Silurian rocks metamorphosed in Cretaceous time would be 

 shown by violet striped with alternate lines of dark violet and 

 green. The sub-divisions of a formation will be show n by shades 

 of the body colour, the darkest shade denoting the oldest sub- 

 division. The lett r denoting the formation will be the capital 

 initial letter of the name of the formation ; with very small 

 arrangements one system of lettering can be made to apply to all 

 Countries. It has been found impossible to adhere strictly to the 

 order of colours of the spectrum, and an interpolation has been 

 made of Irowns and gr^ys for the series of beds be'.ween the 

 Silurian and the Lias. Examples of maps and tables of strata 

 coloured according to the plan adopted were exhibited, as were 

 also a series of Indexes of Colours issued at various dates by the 

 Geological Survey, commencing with one in MS. by Sir H. de 

 la ileche in the year 1832, The author al o drew attention to a 

 proposal made by Mr. J. W. Salter befere this A;sociaticn in 

 1847, and again at the International Exhibition in 1862, to 

 colour geological maps in the order e^f col/urs of the solar spec- 

 trum. The plan recommended by the English committee differs 

 con-iderably in detail from that of Mr. Salter. 



On the Rhxtics of Notts, by E. Wilson, F.G.S.— The author 

 gave a summarised account of the Khatic series in Nettingham- 

 shire. The Rleetic sections of this district already known to 

 geologists comprise those at Gainsboro', Newark, and Elton. 

 The author detcribed several additional new sections in the 

 Rhaetics of the county- — viz. at Cotham and Kilvington betw een 

 Newark and Bottesford ; at Barnstone, between Bingham and 

 Stahern ; the boring for coal at Owthorpe, near Colston Bassett; 

 and the section at Slanton-on-the- Wolds, between Nottin.;ham 

 and Melton Mowbray. A lift of the Khtetic fo-sils of Notts 

 was given, and the presence of bone-beds noticed. The author 

 could not agree with certain geologists that the green marls 

 which are found beneath the Paper shales in Notts (nor probably 

 also the "Tea green marls" of the West of England) belong to 

 the Rh^tic series, but took them to be Upper Keuper marl?, 

 once red in c <le ur, which had become discoloured by some de- 

 oxidising agent, probably carbonic acid evolved during the 

 decomposition of the organic matters of the fossils of the Paper 

 shales. For, in lithological character the green mails agreed 

 w ith underlying beds in the Keuper, but differed markedly from 

 the ovei lying Rha:tics; then there was every arpearance of a 

 passage letwern the green marls and ihe underlying red and 

 green marls of the Keuper ; and, la-tly, the green u.arls, like 

 the rest of the Keuper marls, were practically unfossilifercu'^, 

 while with the commencement of ihe Paper shales we get the 

 remains of an abundant and distinctly marine fauna, in part 

 Lias sic. 



Notes on the Cheshire Salt-Field, by C. E. De Ranee, F.G.S., 

 of H.M.'s Geological Survey. — The author c^escribed the brine- 

 springs of the Keuper marls in Cheshire and part of Shropshire 

 as havmg been derived from rainfall absorbed at the line of the 

 original outcrop of the beds of thick n ck-:alt, which is repre- 

 sented by a porous bed. These waters flow out by pressure in 

 various natural springs, and are bored into by the w ells or ai te- 

 sian shafts of the 1 rine-puuiper^. The natural solution of the 

 rock-salt has caused the characteristic subsidences th:it occur in 

 the district. Norshwich subsidences, however, have been chiefly 

 caused by bad mining. 



On the Strata bet-djeen the Chillesford Beds and the Lower Boulder 

 Clay. " The Mundesley and Westleton Beds," by J. Prest- 

 wich, M.A., F.R.S., Professor of Geology in the University of 

 Oxford.— The beds between the Chillesford Clay and the Lower 



