wee ~ iin whee wines mae SE a ere tangy) SE Te enpqanay ge Ot 1G ry tg, ee ee eee! ee ane 2 4 ye V7] ak ret eye) Hons fa ne, Ri, ea) (HG ars emer i 4 by % iy M sf Sa " BRNG +, . “ a a 4 pe} anes Loaf = eat ee - 220 2 ee Ps ip fer tt eP F TeR ROSH Sot. woe ey Mie fa tes! “te Fy iE Set ak eG a (i An! FS i. fy fecivott oy y f ah fin il’ fk i ae. ca ak Lb : ree THE AMERICAN JOURNAL OF SCIENCE. Epitorn: EDWARD S. DANA. ASSOCIATE EDITORS Proressors WILLIAM M. DAVIS anp REGINALD A. DALY, oF CAMBRIDGE, Proressors HORACE L. WELLS, CHARLES SCHUCHERT, HERBERT E. GREGORY, WESLEY R. COE anp FREDERICK E. BEACH, or New Haven, ProFessor EDWARD W. BERRY, or BAutTIMorg, Drs. FREDERICK L. RANSOME anp WILLIAM BOWIE, OF WASHINGTON. FIFTH SERIES VOL. IV—[WHOLE NUMBER CCIV]. WITH PLATE ONE fe ee Gye 6a 2 NEW HAVEN, CONNECTICUT" be sae {> THE TUTTLE, MOREHOUSE & TAYLOR CO., NEW HAVEN, CONN. CONTENTS TO VOLUME IV. Number 19. Page Arr. I.—The Melting of Potash Feldspar; by G. W. Morry apm eels @ NyeEUNGe hes is oes Ske a cel 6 slase boeee ss es 1 Art. IJ.—Triassic Reptilian Order Thecodontia, by F. TD) LSE se as tet Sco ee ee 22 Arr. III.—A Discussion of Triple Salts; by H. L. Wexis, 27 Arr. I1V.—Horned Eocene Ungulates; by E. L. Troxrny,.. 31 Arr. V.—The Genus Hyrachyus and its Subgroups; by E. Bee ienexcermy. (with ilateh)s iincdoe ips eiel Sj ilak ae dale 38 Arr. VI.—A New Occurrence of Ilsemannite; by C. W. Cook, 50 Arr. VII.—On the Zonal Division and Correlation of the Silurian of Bohemia; by J. PERNER, with the collaboration IE LL SUSI Bi geae oss u SR ke gece meee Rae ee ee dd SCIENTIFIC INTELLIGENCE. Chemistry and Physics.—A New Process for the Industrial Production of Barium Hydroxide for Treatment of Molassesin Sugar Refining, DEGUIDE and BoDE: Advanced Course of Instruction in Chemical Principles, A. A. Noyes and M. S. SHERRILL, 73.—Determination of Sulphur in Iron and Steel, H. B. PULSIFER: Organic Chemistry, V. v. RicutEerR, 74.—Friction and Lubri- cation, Harpy and DouBpLEeDAy, 75.—Power Alcohol, G. W. MonteR- WIxuiAmMs, 76.—The Journal of Scientific Instruments: La Théorie Ein- steinienne de la Gravitation, 77. Geology and Mineralogy.—Gravity Anomalies and their Geological Interpre- tation, 78.—Publivations of the United States Geological Survey, G. O. SmituH, 79.—Die Eruptivgesteine des Kristianiagebietes IV; Das Fengebiet in Telemark, Norwegen, W. C. BroOGGER, 80.—Mineral Resources of the Philippine Islands for 1919 and 1920, 82.—A List of new Crystal Forms of Minerals:. Handbook and Descriptive Catalogue of Gems and Precious Stones in the U. S. National Museum, G. P. MERRILL, etc.: Virginia Geo- Jogical Survey, T. L. Watson: The Topographic and Geological Survey of Pennsylvania, G. A. ASHLEY: Geology of Drumheller Coal Field, Alberta, J. A. ALLAN, 83.—Potash in a new area of Texas, 84. Natural History.—Arctic Alcyonaria and Actinaria, A. E. VERRILL: Genetics, An Introduction to the Study of Heredity, H. E. Water, 84.—A Natur- alist in the Great Lakes Region, E.R. Downine: La Constitution des plantes vasculaires révélée par leur Ontogénie, G. CHAUVEAUD, 85.—The Vegetation of New Zealand, L. CocayNe: Les Mouvements des Végétaux, R. Dutrrocuet: Die Pflanzenwelt Afrikas, insbesondere seiner tropischen Gebiete, A. EnGLEeR, 86.—Précis de Physiologie Végétale, L. MAQUENNE: The North American Slime-moulds, T. H. MacpripE, 87.—Soil Conditions and Plant Growth, E. J. Russert: A Handbook of the British Lichens, A. L. Smitg, 88. Miscellaneous Scientific Intelligence.—The Outline of Science, J. A. THOMPSON, $8.—Publications of the Smithsonian Institution, C. D. Watcorr, 89.— Banking, Principles and Practice, R. B. WeSTERFIELD: Civie Science in the Home. G. W. HuntTeER and W. G. Wuitrman, 90.—Memoirs of the Queensland Museum: United States Life Tables, J. W. GLover, 91.—Public Opinion, W. Lippmann, 92.—Publications of the Carnegie Foundation for the Advancement of Teaching, 93.—American Association for the Advance- ment of Science: Observatory Publications, 94. Obituary.—G. Smmonps: A. Bacot: L. A. RANviER: H. M. Howe, 94. GV: CONTENTS — Nuamber 20: : _ Page Arr. VIII.—Colloidsin Geologic Problems; byG.D.Huspparp, 94 Arr. [X.—Primitive Pecora in the Yale Museun ; by R.S. I ick 5 pate nerryas eee rps ares WE NG Sai es 8 Pee Arr. X.—A Critical Eyes in the aoe of Ammonites; by C. DIENER s 25). 0 Acs eh ae ee ee 120 Arr. XI.—Saccoglottis, Recent and Fossil; by E. W. Berry, 127 Arr. XII.—A Crossotheca from the Rhode Island Carbon- > pferous:;. by" Ei: WES dR OUND, . fen eh 131 Arr, XIII.—A Fossil Dogwood Flower; by F. H. Know roy, 136 Art. XITV.—Intrusive Rocks of the Portsmouth Basin, Maine and New, Hampshire; “by A...WANDKE, 2.1... (eee 139 Art. XV.—Babingtonite from the Contact’ Metamorphic Deposits of the Yakuki Mine, Province Iwaki, Japan; by2DL: WATANABE,” o>. . eetes Sum eo) ee 159 Arr. XVI.—A Tillite-like Conglomerate in the ‘‘HKocambrian”’ Sparagmite of Southern Norway; by O. Hotrrpant,... 160 SCIENTIFIC INT ERELGEIGENCE: Obituary.—A. G. Mayor, 173. CONTENTS Vv Number .-21. Page Arr. XVII.—The Determination of the Space Group of a Cubie-Crystal; by BR. W:.. G.csWYCKOFF, 0.20. 0205 oie. 175 Arr. XVIII.—The Symmetry and Crystal Structure of Zinc Bromate Hexahydrate, So bee Ye Gh OF hye: WEG. DURE IS ONE oe doe asc & ROR ci LEa ep ete ce RIS At INGE 188 Art. XIX.—On the Symmetry and Crystal Structure of Sodium Hydrogen Acetate, NaH(C,H,O,),; bots We G: WycKkorr, SE Gere a SS ae hE in 528s spon cage 193 Peieeso .._Ccone-in-Cone’; .by W. A. TARR... 5 oe 199 Art. XXI.—Notes on the Flora of the Payette Formation; Ryeeins VW SCH ANE onc 3 Ga Se Set ata Reis. gSReE Ae: 214 Art. XXII.—Notes on the Structure of the Triassic Rocks: in Southern Connecticut; by C. R. Lonewet1,........ 229 Art. XXIII.—Amphisymmetric Crystals; by E. T. Wuerry, 237 Art. XXIV.—A New Trilobite Appendage; by T. H. Crarm, 245 Art. XXV.—Cyprine and Associated Minerals from the Zinc Mine at Franklin, N. J.; by J. V. Lewisand L. H. Baver,. 249 SCIENTIFIC INFELLIGENCE. Miscellaneous Scientific Intelligence.—Stratigraphy of Northwest Greenland, L. Kocn, 261.— Revue de Géologie et des Sciences connexes: First Pan-Pacific Commercial Conference: First Congress of Industrial Chemistry, 252. Obituary.—A. G. BELL, 252. We CONTENTS Number 22. Page Art. XXVI.—Jones’s Criticism of Chamberlin’s Ground- work for the Study of Megadiastrophism; by T. C. . CoAMBERDIN, | oft). og ee © ee 253 Arr. XXVII.—Relation of Sea Water to Ground Water along Coasts; by J: S. BROWN, 2 .:..%.27.)00_ oe eee 274 Art. XXVIII.—A Petrologic Study of the Cape Neddick Gabbro by *A. WANDES,. 00. eink Gee 295 Arr. XXIX.—Fossils of the Olympic Peninsula; by W. H. Dyk sett So Seys Sete Se ag Atl, EOI crete Rome tee 30d Art. XXX.—A Mid-Devonian Callixylon; by C. J. Hy- LANDER, 05020 .0e conte. oye: Seber ee. hats ceed eae eee 315 SCIENTIFIC INTELLIGENCE. Chemistry and Physics.—A Revision of the Atomic Weight of Beryllium: The Analysis of Beryllium Chloride, O. Honiescumip and L. BIRLENBACEH: Experimental Attempts to Decompose Tungsten at High Temperatures, G. L. Wenpt and C. B. Iron, 322.—A Micro-Method for the Determina- tion of Molecular Weights ‘in a Melting-Point Apparatus, K. Rast: Women in Chemistry: A Study of Professional Opportunities, THE BUREAU oF VOCATIONAL INFORMATION, 328.—Spectrum of Aurora, 324.—Suspended Impurity in the Air, 325.—The Principles of Geometry, H. F. BAKER, 3826. Miscellaneous Scientific Intelligence.—Smell, Taste, and allied Senses in the Vertebrates, G. H. PARKER: Science and Human Affairs from the View- point of Biology, W. C. Curtis, 327.—The Biology of the Sea-Shore, F, W. Fuatteny and C. L. WALTON, 328.—New Meteoric Iron from Ken- tucky, G. P. MrerrRiuy, 329. Obituary.—R. D. Satispury: G. H. Cox, 329. ee ee Tr pe eee CONTENTS IVGEE Number 23. : : Page Arr. XXXI.—The Silicates of Strontium and Barium: by PSK OES bios iet es sae ev aR RSs Fae ee Se ick dal Arr. XXXII.—Sedimentation in Lake Louise, Alberta, etre ay Vert A OHNSEON Sci ago ute ee seek 376 Art. XXXIII.—Imbricated Structure in River-gravels; by DEP TOERN SHONE ap. chon os a De be ewes 387 Art. XXXIV.—Zircon as Criterion of Igneous or Sedimen- tary Metamorphics; by P. ArmsTrone, .............. oo Arr. XXXV.—The Minnesota Devonian and its Relationship to the General Devonian Problem of North America; by Rn SOA IGRI. Cah pois Sk So ae eee hele oe 2 396 SCIENTIFIC INTELLIGENCE. Chemistry and Physics.—A New Method of Separating Arsenic from All Other Metals, L. Moser and J. Emruicu: A New Volumetric Method as Applied to Certain Problems in Inorganic Chemistry, P. Durorr and E. GRoFET, 413.—Theories of Organic Chemistry, F. Henricn: The Chemistry of Combustion, J. N. Frrenp, 414—Petroleum, Where and How to Hind it, A. BLum: The Heavier Constituents of the Atmosphere, J. J. THomMson: The Corrosion of Iron and Steel, 415.—The Mathematical Theory of Prob- abilities, A. FIsHEer, 417. Geology.—The Paleontology of the Zorritos Formation of the North Peruvian Oil Field, H. M. Sprexker: The Recession of the last Ice Sheet in New England, E. AntEevs, 417.—A Section of the Paleozoic Formations of the Grand Canyon at the Bass Trail. L. F. NospLte: Essentials for the Micro- scopical Determination of Minerals and Rocks in Thin Sections, A. JOHANNSEN: The Rocks of Mount Everest, 419.—A Newly Found Tennes- see Meteoric Iron, G. P. MERRILL: Minor Faulting in the Cayuga Lake Region, E. T. Lone, Errata, 420. . Miscellaneous Scientific Intelligence.—Foundations of Biology, L. L. WoopRuFF: The Study of Living Things: A Course in Biology for Secondary Schools, W. 4H. D. Meier, 421.—Field Museum of Natural History, Annual Re- port for 1921: National Academy of Sciences, 422. Obituary —A. SmitH: F. T. TRouton: D. SHarp: W. KELLNER: A. L. KIMBALL: A. A. STURLEY, 428. VIII CONTENTS Number 24. Page Art. XXX VI.—John Day Felidee in the Marsh Collection; | by Groree F. Waton,. wees). eo eee ee 425 Art. XXX VII.—The Antimony Mines of Shiu Chow, —— by G-.D. HUBBARD, 2.\). <2) 9on. aot oe 453 Arr. XX XVIII.—A Tribolite retaining Colon Maing by PoE. RAYMOND yt 6. oh al: ee oe le 461 Art. XX XI X.—On the Occurrence of Richthofenia in Japan; by Te dTAVASAK A io 2 cele ee oe 465 Arr. XL.—On the Crystal Structure of Ammonium Chloride; bya. W... Gun WYCK OBR. 25. 22. cages Se 469 Arr. XLI.—The Alleged Variable Composition of Triple Chlorides Containing Silver and Gold; by H. L. Wetts, 476 Art. XLII.—The Structural and Stratigraphic Relations of the Great Triassic Fault of Southern Connecticut; by WoL. RUSS hE on aig cies ee 483 SCIENTIFIC INTELLIGENCE. Chemistry and Physics.—The Presence of Cobalt and Nickel in Vegetables, BERTRAND and MoxraGnatz: Standard Methods of Chemical Analysis, W. W. Scott, 498.—Outlines of Theoretical Chemistry, F. H. German: The Formation of Colloids, T. SvEDBERG: Physikalische Chemie der Zelle und der Gewebe, R. Héser, 499. ee Determination of Temperature, I. G. Priest: Vector Calculus, J. B. Saaw, 500.—The Origin of Spectra, P. D. Foors and F. L. Mouter, 02, Geology and Mineralogy.—Pottsville Fauna of Ohio, H. Morninestar, 502.— Earth and Star, an Hypothesis of Weather and Sunspots, EH. HUNTINGTON and 8.8. VisHz=R: Seventeenth Report of the Director of the New York State Museum and Science Department, 503.—Sveriges Olenidskiffer, A. H. WESTERGARD: The Geology of the Broken Hill District, E. G. ANDREWS, 504.—Eclogites of Norway, P. EskoLta, 505.—New Deposits of Radium in Afrika: United States Geological Survey, P. S. Smirx, 506. Miscellaneous Scientific Intelligence.—National Academy of Science, 506.— Nobel Prizes for 1921 and 1922, 507. Obituary.—J. WATERHOUSE: W. H. WesLeEy: OC. M. Suita: L. A. TCHUGAIEV: R. W. Wiuson: C. W. WAGGONER, 907. InpEx, 508. fey es | THE Z 4 AMERICAN ’ ie J OURNAL OF SCIENCE. Z 3 - Eprror: EDWARD S8. DANA, ed: ie ASSOCIATE EDITORS re PROFESSORS WILLIAM M. DAVIS anp REGINALD A. DALY, 4 eS ie oF CAMBRIDGE, | | Prorsssons HORACE Db, WELLS, CHARLES SCHUCHERT, _ || HERBERT E. GREGORY, WESLEY R. COE anp ‘| ~—__—s FREDERICK E. BEACH, or New Havsn, | Proressozs EDWARD W. BERRY, or Battimonz, | ae FREDERICK L. RANSOME ann WILLIAM BOWIE, | be oF WASHINGTON. a oo « Ws tae . “it ~ Bt oo Sia | FIFTH SERIES VOL. IV-[WHOLE NUMBER, CCIV}. st et ne -@ i< © mt, ig tere 2g Rs v h f A ‘a te ee > ) . ¥ fale 4 a Ae t : a * » ’ Lot 4 5 i « Te f No. 19—JULY, 1922. WITH PLATE ONE ee ee ee aN 1 Srey ao ae | ig ena ne { | NEW HAVEN, CONNECTICUT. | pee 5 ok mee | E TUTTLE, MOREHOUSE & TAYLOR CO., PRINTERS, 128 TEMPLE STREET. 7 whip “Six dollars per year, in advance. $6.40 to countries in the 5% 6.25 to Canada. Single numbers 50 cents; No, 271, one dollar. ) 1d-class. matter at the Post Pp at New Haven, Conn. ., under the Act ANNOUNCING | - Huntington & Williams’ BUSINESS GEOGRAPHY By Ellsworth Huntington Research Associate in Geography, Yale University, and Frank E. Williams Professor of Geography and Industry, Wharton School of Business, Uni- versity of Pennsylvania. With the co-operation of Robert M. Brown, Professor of Geography, Rhode Island College or Education, and ; Miss Lenox E. Chase, Teacher of Geography, Mount Vernon (N. 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And A New Pdition The Second—of HUNTINGTON & CUSHING’S PRINCIPLES OF HUMAN GEOGRAPHY This epoch-making book, which marked a new era in the teaching of Geography, has been carefully revised and now appears in materially improved form, It is used in about 150 schools, colleges and normal schools. - A380 pages. 6bhy 9. Illustrated with photographs and maps. Cloth, $3.50 postpaid. JOHN WILEY & SONS, Ine. 432 Fourth Avenue New York London : _. Montreal, Quebec CHAPMAN & HALL, Ltd. Renouf Publishing Company : ais 6.22 THE AMERICAN JOURNAL OF SCIENCE BOLE dS E.R LS: | poe Arr. I1—The Melting of Potash Feldspar; by G. W. Morey and N. L. Bowen. Introduction. While studying systems of the alkaline oxides with silica, alumina, and water, the one of us (Morey) carrying on the thermal and chemical work and the other (Bowen) the optical examination, we succeeded in crystallizing some pure artificial orthoclase in a bomb with no flux other than water. Crystalline orthoclase, as hitherto pre- pared artificially, has been contaminated somewhat by the flux used in preparing it, and for this reason natural erystals have always been used in determining the melting point of orthoclase. The natural crystals never have the theoretical composition KAISi,O, but always contain a considerable amount of albite and sometimes other mole- cules. We concluded, therefore, that the pure crystals we had prepared would furnish good material for the redetermination of the melting-point of orthoclase, a point of much importance in the system under investi- gation. The melting-point of orthoclase, as determined on natural crystals, has been found to be in the neighborhood of 1200°C. It has been found by Day and Allen to melt very sluggishly... We expected, therefore, that long exposure to a given temperature would be necessary, before assurance of the attainment of equilibrium might be had. For such long exposures we have had the inesti- mable advantage of the use of a furnace-temperature regulator designed by our colleague, Mr. H. 8S. Roberts.? By means of this regulator we were enabled to maintain * The isomorphism and thermal properties of the feldspars, Carnegie Insti- tution of Washington, Pub. No. 31, pp. 51-53. * J. Wash. Acad. Sci., 11, 401-409. 1921. AM. Jour. Sci.—FirtH Series, Voit. IV. No. 19.—Juty, 1922. 1 2 Morey ¢& Bowen—Melting Potash Feldspar. a constant temperature (varying less than one degree) in our furnace day and night, for a week or more. Preliminary Results. When we heated our artificial orthoclase for a week at the temperature noted above (1200°) we obtained a product with the appearance of a glass when examined megascopically, and with the low refractive index (about 1.485) and the isotropic character of orthoclase glass when examined under the microscope. However, under a high power (600 diameters) and with the cone of light cut down to a small angle, this ‘‘glass”’ is found to show a sort of structure, visible only when it is immersed in a liquid that matches it very closely in refractive index. This structure can be described only as a sort of fine cross-lining, usually rectangular and giving therefore a grating effect. Day and Allen have suggested that.orthoclase, on melting, loses the ordered arrangement characteristic of the crystalline form only very slowly. Thinking, therefore, that this observed structure was inherited from the crystalline material by the extremely viscous liquid, we held it at a somewhat higher temperature (1225°), where the hquid would be more mobile, with the expectation that the structure would disappear. Instead of this we found that it became more distinct. Ata still higher temperature (1250°) it became apparent that the material was not a homogeneous glass but was made up of two phases, the one occurring as skeleton crystals in widely extended, branching forms of rectangular pattern, and the other, of somewhat lower refractive index, acting as a matrix for these. This latter was subsequently shown to be glass, but under crossed nicols the whole mass appears to be doubly refracting with a grating structure recalling that of microcline. Ata still higher temperature (1300°), where the crystals are present in smaller amount, they grow as more discrete grains, though retaining skeletal ten- dencies and appearing usually as rectangular crosses. Finally, when formed at a temperature of 1400° or higher the crystals assume definite rounded to polyhedral (icosi- tetrahedral) forms, with indistinet patchy birefringence, * Op. cit., p. 54. . oe P “ i “ a a eS Morey € Bowen—Melting Potash Feldspar. 3 with a refractive index only a little higher than that of the glass in which they are embedded, which is about 1.49, with regularly arranged inclusions of glass; in fact, with all the characters of leucite crystals. The series of forms assumed by the leucite with increasing freedom of growth (increasing temperature) is shown in fig. 1. This series is strikingly similar to that observed by Pirsson in the small leucite crystals in the groundmass of rocks from the Bearpaw Mountains.t| The more primitive skeletal forms are not shown in Pirsson’s series. TBE “Le a, OO. Fic. 1.—Grains of glass containing leucite. Showing increasing perfec- tion of form, with increasing temperature, of leucite crystals as grown ina mixture of composition KA1Si,QOg. The rounded leucite crystals, obtained at higher temper- atures, may have a diameter as great as 0.025 mm. and are surrounded by a rim of strained glass which is observed as a birefracting halo under crossed nicols. In fact the birefringence shown by the glass immediately adjacent to the crystals is decidedly greater than that of the crystals themselves. The birefringence of the glass fades out as the distance from a crystal increases, and when the crystals are not numerous there are areas of ordinary isotropic glass. When the crystals are closely spaced, however, all of the interstitial glass is birefrac- ting, which accounts for the fact that, when the crystals grow as ramifying skeletal forms, the whole mass is bire- fracting, with the cross-grating effect analogous to that in microcline. In the birefracting halo about the crystals y is radially disposed, which shows that the glass is subjected to radial tension. This tension is no doubt caused by the abrupt contraction of the leucite crystals in cooling through their *L. V. Pirsson, this Journal, 2, 145-146, 1896. Figured also by Iddings in Rock Minerals, p. 249 (2d ed., 1911). 4 Morey & Bowen—Melting Potash Feldspar. inversion point in the neighborhood of 700°, where they experience a volume change of more than ) per cent.? This may seem a small change, but it is twice as great as the whole change between 585° and room temperature. Detailed Results with Artificial and Natural Feldspars. The above observations showed very clearly that potash feldspar has no true melting-point, that the point in the neighborhood of 1200°, which has hitherto been regarded as its melting-point, is really the temperature at which it breaks up into liquid and leucite or, as it is commonly stated, it melts incongruently. It is perhaps not sur- prising that the existence of leucite in the material obtained near the decomposition-point has not been detected hitherto. Megascopically the ‘‘glass’’ has all the appearance of an ordinary glass; it is perfectly trans- parent, with only a faint suggestion of a bluish opales- cence, the leucite crystallites being too minute and too closely matched in refraction by the medium in which they are embedded to cause a scattering of light. Even under the microscope the leucite appears, as we have seen, merely as an indefinite crosslining of the ‘‘glass’’ and only when the temperature was raised, to see if this structure would disappear, did the structure assume more definite form and finally become identifiable leucite erystals. After obtaining these results we then proceeded to determine the temperature of incongruent melting more accurately and also to fix the temperature at which the leucite crystals disappear and the mass is entirely liquid. While carrying out these determinations we studied the similar changes as displayed by natural potash feldspars in as pure a state as we could obtain them. For this - purpose we made use of three analyzed feldspars, micro- cline from Mitchell County, North Carolina, sanidine from Laacher See and adularia from St. Gotthard, the last being the nearest to pure potash feldspar, though even it °So far as we are aware the volume change has not been measured, but it may be estimated from the change of refractive index between 585° and 750° as observed by Rinne and Kolb, Neues Jahrb. 2, 157. 1910. Morey & Bowen—Metiing Potash Feldspayr. d contains about 10 per cent albite. The composition of these minerals is shown in Table I. The last two analy- ses were made by Dr. H. EK. Merwin in connection with an investigation he has not yet published. The results of his analyses, together with some of the material, he has kindly turned over to us. TasLeE I.—Analyses of natural feldspars. I 1GE III Microcline Sanidine Adularia (Mitchell County, (Laacher See, (St. Gotthard, North Carolina, U.S. A.) Rhineland) Switzerland ) SO). rn 65.83 64.21 64.24 Oi es 18-07 19.10 19.21 7. ee 36 arr oe i ee eee 42 24 none Meee, Sueeeiae 2.30 1.76 1.45 2.0 | ae eats 13.02 14.60 14.90 100.00 Oo eoile 99.80 I. E. T. Allen analyst. Recaleulated to anhydrous basis. Day and Allen, op. cit. p. 48. The microscope shows that a very little of the albite is present as perthitic stripes. Iland III. H. EH. Merwin analyst. The details of the experiments on these three natural feldspars and our artificial material are given in Table II. It may be noted here that all four show the breaking up of the feldspar into liquid and leucite. The temperature at which this occurs is not greatly different in the differ- ent feldspars, being lowered only a little by the presence of albite. The evidence points to about 1170° as the proper temperature for pure potash feldspar. There is moreover no appreciable difference of behavior connected with the difference in form of orthoclase and microcline. All of the feldspars show a very large temperature interval in which the mass consists of leucite and liquid. A full discussion of the change of habit of the leucite with increase of temperature has already been given for the pure artificial material. Natural crystals usually give more perfect leucite forms than the pure material when exposed to a given temperature for an 6 Morey & Bowen—Melting Potash Feldspar. TasuE Il.—Results of heating experiments on potash feldspars. Microcline. Tempera- Time of ture °C. exposure. Result. 1140 8 days Little change except formation of rare stripes of glass corresponding with original stripes of albite. ILLES 8 days About half unchanged microcline; other half glass showing cross-lining (leu- cite). 1204 8 days All changed to glass showing cross-lin- ing (leucite). PZa2, ) days All changed to glass and definite skele- tal forms of leucite. 1307 3 days Glass and definite skeletal leucites, often as rectangular crosses. 1400 3 days Glass and rounded to subhedral leucites (0.02 mm. diameter) with regularly arranged inclusions of glass. 1435 3 days Glass and rare subhedral leucites. 1452 3 days All glass. Sanidine and Adularia.* 1140 8 days Mostly unchanged. Small percentage olass showing cross-lining (leucite). Lg 8 days About one quarter unchanged feldspar; rest glass showing cross-lining (len- cite). 1204 8 days All changed to glass showing cross-lin- ing (leucite). 1252 oO days All changed to glass and definite skele: tal forms of leucite. | 1400 3 days Glass and minute rounded leucites. 1452 3 days Glass and very rare minute leucites. 1465 2 days Glass only. a The results obtained with these are practically identical and can be given together as above. Morey & Bowen—Melting Potash Feldspar. T Pure synthetic potash feldspar (initially crystalline). 1140 8 days No change. 1179 8 days About half changed to glass showmeg eross-lining (leucite.) 1204 8 days All changed to glass showing cross-lin- ing (leucite). 1252 > days Glass and definite skeletal forms of leu- cite. 1400 3 days Glass and definite leucites, principally : rectangular crosses. 1510 2 hrs. Glass and minute rounded leucites. 1510 20 hrs. Glass and rounded leucites (0.02 mm. diameter ). 25 20 hrs. Glass and rare leucites. 1535 Qaes: Glass only. Pure synthetic KAISi,0, (initially glass). 1252 5 days Glass and definite skeletal forms of leu- cite. 1400 3 days Glass and definite leucites, principally rectangular crosses. 1510 2 ES. Glass and minute rounded leucites. _ 110 20 hrs. Glass and rounded to subhedral leucites. equal period. The foreign matter apparently lowers the viscosity of the liquid appreciably. Notably typical leucite crystals were obtained by holding the North Caro- lina microcline at 1400° for 3 days. The upper limit of temperature at which leucite crystals are obtained varies greatly in the different feldspars. As is to be expected, the presence of other compounds lowers the temperature of complete melting. Thus the Carolina microcline is all liquid at about 1440°, the sani- dine and adularia at about 1460°, but the pure potash feldspar is not completely liquid until a temperature of about 1530° is reached. Therefore, between the temper- - atures 1170° and 1530°, an interval of 360°, a mass of the composition of pure potash feldspar, KAISi,O,, con- sists, at equilibrium, of leucite crystals and liquid. That we have obtained equilibrium is unquestionable, for we were able to approach it from opposite directions. Whether we started with crystalline potash feldspar or with a glass of that composition we always obtained 8 Morey & Bowen—Melling Potash Feldspar. leucite crystals and glass in this 360° temperature-inter- val. When held at 1510° for 2 hours glass and small crystals of leucite were obtained. When the heating was continued at this temperature for 20 hours the leucite crystals became larger and less numerous. They evi- dently grew freely in equilibrium with the liquid. On the other hand when the same material was held at 1535° for only 2 hours the crystals completely disappeared. There can, therefore, be no question that the persistence of erystals at 1510° for 20 hours is the result of the fact that they are in equilibrium with the liquid. Incidentally it may be noted, too, that, for the attainment of equi- librium, prolonged heating is unnecessary at the higher temperatures (in the neighborhood of 1500°). Incongruent Melting. Definite crystalline compounds may melt in one of two different ways. A compound of one class melts com- pletely at a definite temperature, giving a liquid of the same composition as the crystals, for which reason it is said to melt congruently. The temperature at which this occurs is a true melting point. A compound of the other class forms, at a definite temperature, a liquid of different | composition from its own and at the same time one or more new crystalline compounds. Such a compound is said to melt incongruently or, sometimes, to melt with decomposition. The temperature at which this occurs is ” not a true melting point. Thus the compound CaAl,8i,O0, (anorthite) has a true or congruent melting point at 1550°. At that temperature crystals of the composition CaAl,Si,O, are in equilibrium with a liquid of the same composition. It constitutes, by itself, a one-component system. The compound MgSi0, is a familiar example of a com- pound of the other class. At 1557° the crystalline clino- enstatite'(MgSi0,) melts incongruently or breaks up into liquid and another crystalline compound Mg,SiO, (for- sterite). There is no temperature at which clinoenstatite is in stable equilibrium with a liquid of its own composi- tion. It, therefore, has no true melting point. ‘The com- pound MegSi0, does not constitute, by itself, a one-compo- nent system but can be treated only as a part of a eee ee reer Morey & Bowen—Melting Potash Feldspar. 9 two-component system. In order to represent its behav- ior graphically one must construct a two-component diagram. ‘Thus fig. 2 represents equilibrium in mixtures of Mg,SiO, and SiO, and shows MgSi0, as a compound of these with an incongruent melting point at 1557°. From the diagram we may read off that MgSiO, breaks up at 1557° into Mg,SiO, and liquid somewhat more sili- ceous than MgSiO;. Above 1557° a mass of the compo- sition MgSiO, is made up of crystals of Mg,Si0, (forsterite) and liquid, the forsterite gradually dissolv- Fic. 2. 1860. FORSTERITE CLINO-ENSTATITE & CRISTOBALITE CLINO-ENSTATITE Mg,S10, 20 MgsSi0, 40 WT PER CENT conv: S10, Fic. 2.—Equilibrium diagram of the system Mg.SiO,—Si0.. ing as the temperature is raised, until at 1577° the for- sterite completely disappears and only then is a liquid of the composition MgSi0, obtained.® A compound of three oxides may melt acon pe tently in such a way that it breaks up into a liquid and two new crystalline compounds. Monticellite (CaMgSi0,) shows this behavior. At 1498° it breaks up into Ca,Si0,, MgO, and liquid. It can be treated only as a part of a three-component system.‘ However, a compound of three oxides, which melts incongruently, does not neces- sarily break up in such a way that it must be treated as a three-component system. It may form liquid and only ° For a full discussion see Bowen and Andersen, this Journal, 37, 487-500. 1914. ‘Ferguson and Merwin, this Journal, 48, 116. 1919. 10 Morey & Bowen—Melting Potash Feldspar. one new crystal phase, in which case it can be treated as a two-component system with relations in every respect analogous to those of the binary compound MgSi0,. ENG oe Or. « S10, KA.S0;49 KA\S.0.30 40 50 60 70 80 90 SO, WT.PER CENT Fie. 3.—Diagram illustrating the melting of orthoclase. The compound, KA1Si,0,, with which we are here con-* cerned, breaks up in this latter manner. At 1170° it forms leucite, K AlSi,O,, and liquid, and its behavior can be completely described in terms of a diagram in which KAISi1,0, and SiO, are taken as components, when KAISi,0, (orthoclase) becomes a binary compound of these. In fig. 3 the general form which this diagram must assume is shown. We have accurately determined the temperatures on this diagram only at the composition KAISi1,0,;. Work is now being carried out on the whole Morey & Bowen—Melting Potash Feldspar. itl system, but it presents many difficulties. On the leucite side of orthoclase the temperatures are very high, on the silica side the mixtures react very sluggishly and require excessively long heating. In the meantime we have thought it well to place on record our results on orthoclase. The point E (fig. 3) is accurately fixed as is also the temperature of the line AB. The composition of the liquid B, which is in equilibrium with both orthoclase and leucite, we have not yet fixed accurately. The proportion of leucite in a mixture of composition KAISi,0,, held at about 1250°, is very difficult to estimate, but appears to be about 20 per cent. We have placed the point B in accordance with this estimate. The melting point of leucite we know to be very high, above that of platinum (1755°).8 The melting point of SiO, (cristobalite) has been fixed at 1710°.° Of the temperature and composi- tion of the indicated eutectic between orthoclase and Si0, we know nothing. Except at the composition KAIS1,0, we wish to stress only the general form of the diagram, not its details. That it must assume this general form eannot be doubted. PETROGENIC SIGNIFICANCE OF THE INCONGRUENT MELTING OF OrTHOCLASE; by N. L. Bowen. The discovery of the fact that orthoclase melts with decomposition into leucite and liquid is of great signifi- eance to petrogenic theory. It is the first definite exper- imental demonstration of a genetic relation between a mass consisting of feldspar and feldspathoid and a mass consisting of feldspar and free silica, in other words, between what may be termed an alkaline and a sub-alka- line mass. Moreover, it shows plainly the nature of this relation as a fractional crystallization phenomenon. © Before going into this matter more specifically it is desirable to discuss the course of crystallization in mix- tures of various compositions shown in fig. 3. Reference to that diagram shows that crystallization of a liquid of composition KAISi,O, takes place under equi- * Leucite crystals were prepared by one of us some years ago when investi- gating kaliophilite. To melt the leucite it was found necessary to use an iridium container (N. L. Bowen, this Journal, 43, 117. 1917). ° Ferguson and Merwin, this Journal, 46, 424. 1918. 12 Morey & Bowen—Melting Potash Feldspar. librium. conditions in the followimg manner. At 1530° (E) leucite begins to crystallize and it increases in amount as the temperature falls, until at 1170° orthoclase begins to separate and leucite to redissolve, or, stated better, perhaps, the liquid reacts with the leucite, transforming it into orthoclase. This continues at constant tempera- . ture until the liquid and leucite are entirely used up and the mass consists entirely of orthoclase. A mixture lying on the leucite side of KAISi,O, begins to crystallize at a temperature higher than that of the point EK. In this case when the temperature 1170° is reached the reaction between liquid and leucite proceeds as before, but all the liquid is used up while still some leucite remains and the completely crystalline mass con- sists of orthoclase and leucite. A mixture on the silica side of orthoclase, if not richer in silica than that represented by the point B (probably corresponding to about 10 per cent free silica), also begins to crystallize with separation of leucite but at a temperature lower than that of the point E. At 1170° the reaction is completed as a result of the disappearance of leucite and the mass now consists of orthoclase and lhquid of composition B. The liquid then proceeds to crystallize along the curve BC, with separation of ortho- clase, until at C free silica separates as well and the whole mass is now solidified as a mixture of orthoclase and free Si0,. The exact temperatures and compositions are in these parts quite unknown. Only in mixtures with a greater excess of free silica than that represented by the point B does the early separation of leucite fail. Such is the behavior of the various liquids when perfect equilibrium obtains. Now in any of these mixtures leucite might fail to react completely with the liquid at the reaction point (1170°) as a result of the formation of an armor of orthoclase about it. The consequence of this would be that some liquid of the composition B would be left over in all of the mixtures above discussed, even that on the leucite side of orthoclase, and this liquid would then form orthoclase and free silica. Or if leucite crystals were locally segregated that part of the mass from which they were removed would crystallize as ortho- clase and free silica, even though the composition of the original liquid were on the leucite side of orthoclase. Conversely, too, even though the composition of the original liquid were a moderate distance on the silica side Morey & Bowen—Melting Potash Feldspar. 13 of orthoclase, the early formed leucite crystals might collect locally and if so they would not be completely used up by reaction with the liquid and a localized leucite- bearing mass would result. Now this early separation of leucite from a mixture of the composition of orthoclase cannot be immediately neg- atived by the addition of other components. Excess silica rapidly neutralizes the tendency, of course, but other sub- stances cannot have a comparable effect. Our microcline from North Carolina shows that 25 per cent foreign material (mainly albite) is insufficient to neutralize this tendency, in fact the interval in which leucite appears is ‘as much as 270°, so that it would plainly require a con- siderably larger amount of albite to bring about the dis- appearance of the leucite field. Therefore, in magmas rich in orthoclase, and even in those containing much albite as well, if at the same time they contain not more than a small excess of free silica, it is to be expected that this early separation of leucite may occur. The leucite erystals should disappear with falling temperature but the two factors noted in the foregoing may intervene to bring about their persistence. The factors are the armor- ing of the leucite crystals or their local collection, or indeed both. Evidence of the Existence of Similar Relations in Natural Leucite Rocks. Certain described rocks give evidence of the occurrence, under natural conditions, of the phenomena noted. Hussak describes a rock from Brazil consisting of pheno- erysts of leucite (now pseudoleucite) in a groundmass of quartz and feldspar, which rock he terms a leucite granite porphyry. Evidently strongly influenced by the dictum of Rosenbusch and Zirkel that leucite and quartz cannot occur together, Hussak suggests the possibility that the leucites are remnants of fragments of a foreign rock, caught up by the granitic dike. ~ In his final conclusions, however, he inclines towards the opinion that it is an ordinary igneous rock from which the mineral combina- tion quartz-leucite-orthoclase has crystallized1® Our results show plainly that such a mineral combination is possible, particularly with the relations he notes, namely, phenocrysts of leucite in a groundmass of quartz and feld- * E. Hussak, Neues Jahrb., 1, 27. 1900. 14 Morey & Bowen—Melting Potash Feldspar. spar. To be sure, if perfect opportunity for reaction were presented, either quartz or leucite should be absent, but it is easy to conceive of conditions under which such opportunity would fail. Cross describes a rock from Wyoming which contains leucite. Bulk analysis of this rock shows, however, that the silica present is entirely adequate to have formed orthoclase with the potash and alumina present. It seems necessary, therefore, to assume that the glassy eroundmass is highly siliceous.t Such an assumption would be entirely justified in the light of our results. There is one occurrence that appears to illustrate in a convincing manner the separation of leucite under the - influence of gravity and the consequent formation of a quartzose differentiate in those parts from which the leucite has moved. Near Loch Borolan in Scotland there is a differentiated laccolith which is described by Shand as being made up of the following in stratiform arrange- ment, as stated below, and shown in fig. 4:1? I. Quartz syenites (nordmarkite with 12 per cent. quartz and other more quartzose types). II. Transition zone of quartz-free syenites. Til. Feldspathoid-bearing syenites. IV. Probable ultra-basic zone (noted in one locality). The syenites of [iI are in part demonstrably pseudo- leucite bearing. If it can be imagined that the laccolithie chamber was filled with a magma very rich in alkaline feldspars, and with not more than a moderate excess of free silica, this magma might, as our results show, begin to crystallize with separation of leucite. The actual pro- portions of the various rock types in the composite mass (see fig. 4) show that the general liquid would be very rich in feldspar, principally orthoclase, and excessively poor in the molecules that go to make up the heavy minerals. The density of such a liquid as a glass at ordinary temperatures would probably be not far from that of rhyolitic obsidian (2.37).12 The density of leucite 1 'W. Cross, this Journal, 4, 122 and 132. 1897. “8. J: Shand, Trans. Edin. Geol. Soc., 9, pt. III, p. 202, 1909, and pt. V, p. 376, 1910. See also Horne and Teall, Trans. Roy. Soc. Edin., 37 pt. 1, p. 163, 1892. ** H. S. Washington, Rhyolites of Lipari, this Journal, 50, 449. 1920. Pas. Pilih 2, Morey & Bowen—Melting Potash Feldspar. 15 Pig. -4. w £ = ca OS peers SS Pt @ YIFSOIUSY JOASS — t = eo = S es Sa = S Ss = = o = > — “ a ~~ — peel ey iseeaees pace ein teste ti ak UD JDAY4W TD 4207 47704 43A1y baqpes = — wn — a2 FS = woryeas 24 fo aury re Pat OY y20b)vadnuy y = = = = — > = — 5 om D — Ss inet aes o ot A3Aiy atoupay o ~Y Y (uorgpas put fo 2u'}) asiD]W2Y 4 Dupo = 4PIPSUUE 3 I11Y autoug ou Jou ea iis 2 yn n RS a = > Eee ea ery es Oo — o o So = a s a & ~~ Fy S ce 6 _— = ce a a 5 agpa7y ~n = 2) Gay) Ssr vo 9g so — Pa SG S28 Oe Bee ers S ££ SSS Fe s ee ote! (ot conus Ae x = a = ce 3 BY = = o E Fig. 4.—Sections of the laccolith at Loch.Borolan, Scotland (after Shand). 16 Morey & Bowen—Melting Potash Feldspar. at ordinary temperatures is 2.46. At higher tempera- tures, then, there would probably be a definite though small margin of density in favor of leucite crystals, — especially since the Hquid would, no doubt, contain a considerable amount of volatile substances, whereas the obsidian noted above is nearly free from these. Presum- ably the leucite crystals could settle under the influence of gravity; indeed, the general arrangement of zones ean scarcely leave room for doubt that they did and gave a lower zone (III) much enriched in that mineral. When the time of reaction of the leucite with hquid arrived there would be an amount of leucite above that requisite for the reaction and some would be left in excess. The excess leucite was, during the further crystallization of the mass, transformed into pseudo-leucite (orthoclase + nephelite) which is the normal fate of natural leucites when cooled slowly under deep-seated conditions. On the other hand, in the zone from which the leucites were entirely removed (I) there were no crystals to react with the liquid (which would be the natural analogue of our liquid B, fig. 3) and it crystallized appropriately with an excess of free silica. | We are thus able not merely to accept Shand’s inter- pretation of the differentiation as gravitative, but we may oo further and connect the differentiation with the course of crystallization; in short, we may state that the differ- entiation was due to fractional crystallization under the influence of gravity. One may still accept the possibility that the magma was affected by absorption of limestone, but the formation of both a quartzose and a feldspathoid- bearing portion from a homogeneous mass shows plainly that desilication of feldspar molecules by limestone was not essential to the production of feldspathoids. The fact that leucite can exist under certain conditions in equi- hbrium with a hquid containing exeess silica is the secret of the coexistence of two such differentiates. Bearing of the Results on the Origin of Nephelite Syenites. Now the rocks of zone III, while undoubtedly at one time leucite rocks, in part, at least, are now simply nephelite syenites. This is the result of the usual change of the leucite to orthoclase and nephelite, already noted. Morey & Bowen—Melting Potash Feldspar. tz Plainly, then, in the early separation of leucite, itself a consequence of the incongruent melting of orthoclase, lies the key to the origin of these nephelite syenites. This conclusion opens up the whole question as to whether many other nephelite syenites may not have been formed in a similar way. Leucite may have formed at a certain stage and the evidence of its formation, after its breakdown into orthoclase and nephelite, may not always have been preserved in the form of the pseudo- leucite structures. Even in the example described by Shand the nephelite of the pseudo-leucites has suffered a further change to muscovite and a zeolite. Through such further changes, not necessarily exactly of this kind, the evidence of the former existence of leucite may fre- quently, perhaps, have been entirely destroyed. More- over, upon the change of leucite into orthoclase and nephelite the course of crystallization will follow lines upon which our work throws no hght and it may be possible that even the more common, highly sodic, nephelite syenites could form as further differentiates. Hxamining nephelite syenites and their associates with these considerations in mind, we find a considerable amount of evidence that the formation of leucite may have occurred as an intermediate step in their genesis. The flimausak batholith in Greenland is stratified in a manner closely related to that shown by the Loch Borolan mass. At the top is a quartzose phase, arfved- sonite granite, which passes downward into quartz-free syenite and finally into sodalite and nephelite syenites of great variety.'* In one of these, the so-called lujavrites, which are the lowest exposed rocks of the mass, there are large crystals of analcite which Ussing presents reasons for believing were formerly leucite.> The nature of the stratification and the existence of these pseudo-leucites (?) is so strikingly similar to the condi- tions at Loch Borolan that one must consider the possi- bility that the early separation of leucite has been a ee controlling the differentiation of the mass (see =; 5): “N. V. Ussing, Geology of the Country around Julianehaab, Greenland, Med. om Groénland, vol. 28, p. 322, fig. 29, 1911. » Op. cit. pp. 164, 165. Am. Jour. Sci.—FirtH Series, Vou. IV, No. 19. D) a” JULY, 1922. 18 Morey & Bowen—Melting Potash Feldspar. The igneous massif of Bezavona in Madagasear, as described by Lacroix, consists of quartz syenites, nephe- lite syenites, monzonites, and other types, including vari- ous dike and flow rocks. In the coarse granular rocks there is apparently nothing suggesting the formation of leucite, but in quickly chilled facies, which may be regarded as quenched, leucite appears. Thus there are microsyenites with leucite and also leucite phonolites.*® These facts again suggest the possibility that the forma- tion of leucite may have been an intermediate step in the genesis of the nephelite rocks. Fig. 5. Me Sa CC) Mi hee Be geet mt os Sodalite - foyaile Naujaite Fig. 5.—Section of the Ilimausak mass, Greenland (afer Ussing). Still less definite as evidence, and yet worthy of consid- eration, are certain structures observed in nephelite rocks that suggest the former presence of leucite. In some members of the Ice River complex of British Columbia there are spots of a ‘‘finger-print-like’’ intergrowth’’ of orthoclase and nephelite that is practically identical with the ‘‘dactylotype’’ intergrowth of these minerals when they form pseudo-leucites. Structures that are perhaps of similar origin are described by Lacroix from the nephe- lite syenites of the Los Archipelago'® and by Brouwer in rocks from the Transvaal.'° ** A. Lacroix, Les Roches Alealines d’Ampasindava, Nouv. arch. du muséum, Paris. Série 4, 5, 197 and 207, 1903. “J. A. Allan, Geology of the Field Map-area, B. C. and Alberta. Geol. Surv. Can., Mem. 55, p. 133 and p. 285, 1914, Plate XVIIB. * A. Lacroix, Les syénites népheliniques de 1’archipel de Los. Nouy. arch. du muséum, Série 5, 3, p. 53, 1911. * H. A. Brouwer, Transvaal Nephelien-Syenieten. p. 40, Pl. I, Fig. 1. Morey & Bowen—Melting Potash Feldspar. 19 An intimate relation between leucite and nephelite rocks is observed in many fields. A striking example is shown by the Magnet Cove complex. In particular it is noteworthy that a leucite porphyry and a foyaite, asso- ciated there, have nearly identical chemical composition, at least in some specimens. Washington has called atten- tion, also, to a similar relationship of a leucite-rich rock (leucite phonolite) of the Sabatinian district, Italy, with a nephelite syenite of Beemerville, N. J.”° In voleanic fields the frequent intimate association ae trachyte, leucite-trachyte and phonolite is suggestive im this connection. We may mention only the Laacher See area from which region came one of the feldspars (sani- dine) which we used in our investigation and which shows in a typical way the decomposition into leucite and hquid. On the whole, then, there is a considerable body of evi- dence pointing to the importance of the incongruezit melt- ing of orthoclase as a factor not merely in the formation of leucite rocks but of other feldspathoid-bearing rocks as well. It is not intended here to set this up as the sole factor involved in the formation of feldspathoid rocks. There are many indications that some leucitic rocks are formed as a result of differentiation along lines which produce a liquid rich in mica molecules and that then the extrusion of the liquid places it in surroundings where it is unable to retain the water necessary for the forma- tion of mica, with the result that leucite is formed just as it is when mica is melted in an open crucible.2t. The more basic leucite rocks, leucite basalts, ete. may perhaps have formed in some such way. In former papers the writer has presented reasons for believing that in the reactions which are revealed by the presence, side by side in a rock, of alkaline feldspar, mica, and quartz, there is evidence of the breakdown of the: polysilicate (feldspar) molecules into less siliceous (feldspathoid) molecules and free silica.- This was believed to be due to the hydrolyzing action of water in the magma.” It was not then anticipated that it would be found that potash feldspar breaks down in a similar * H. S. Washington, Igneous complex of Magnet Cove, Arkansas, Bull. Geol. Soc. Amer. i: 399, 1900; and Roman Comagmatic ‘Region, Carnegie Institution of Washington, Pub. No. 57, 1906, p. 47. *“ H. 8S. Washington, The formation of leucite in igneous rocks. J. Geol., 15, 379, 1907; and N. L. Bowen, The later stages of the evolution of the igneous rocks, J. Geol. Suppl. to vol. 23, 60, 1915. 20 Morey & Bowen—Melting Potash Feldspar. way even in the dry melt. The discovery of this fact should not, however, lead us to reject the effects of water as important in promoting such behavior of the polysil- eates.2? Nor need we abandon the suggestion that in the preparation in the liquid of feldspathoid molecules, under the influence of water, there enters the possibility, with appropriate fractional crystallization, of the formation of feldspathoid-bearing rocks. However, these reactions represent, as the writer has always admitted,”* a consid- erable extrapolation from any facts that have yet received laboratory demonstration. It is with considerable satis- faction, therefore, that we announce a laboratory demon- stration of the fact that a mass consisting in one part of feldspar and quartz and in another of feldspar and feld- spathoid can form from a single homogeneous liquid. The method of formation of these contrasted parts, which may be referred to as subalKaline and alkaline, respec- tively, is the method of fractional crystallization, which has also been shown fairly definitely to be adequate for the production of all varieties of subalkaline rocks from one liquid.”° Summary. A pure synthetic orthoclase was prepared by erystal- lizing glass of the composition KA1Si,O0, in a bomb with water vapor. This material is particularly suitable for the determination of the melting-point of pure orthoclase and was used for that purpose. The temperature ordi- narily given as the melting-point of orthoclase is about 1200° and has been determined on natural crystals. When our artificial crystals were held at 1200° for a week they gave a product which had the appearance of a glass, megascopically, but which, examined under the micro- scope, showed a structure described as a very fine cross- lining. At higher temperatures this structure became more distinct, taking the successive forms shown in fig. 1 “ N. L. Bowen, The later stages of the evolution of the igneous rocks, J. Saul , Suppl. to vol. 23, 60. 1915. 2 Tn dry melts albite shows no tendency to decompose in a manner analo- gous to that shown by orthoclase. * N. L. Bowen, Crystallization-differentiation in magmas, J. Geol. 27, 395. OMS: * N. L. Bowen, The later stages of the evolution of the igneous rocks, J. Geol., Suppl. to vol. 23. 1915. Morey & Bowen—Melting Potash Feldspar. 21 and finally becoming typical leucite crystals. The point at about 1200° is therefore not the true melting-point of orthoclase but is the temperature at which it melts incon- eruently, breaking up into liquid and leucite. The exact temperature of this decomposition we have determined as somewhat lower than 1200°, namely, about 1170°. The temperature of final disappearance of leucite is about 1530°, so that the interval of incongruent melting 1s remarkably large, viz., 360°. Three natural potash feld- spars, microcline from North Carolina, sanidine from Laacher See, and adularia from St. Gotthard show the same kind of behavior, though in these the upper limit of melting (disappearance of leucite) is lowered some- what through the presence of foreign matter. This incongruent melting of orthoclase is of particular importance in petrogenic theory because it shows plainly how, by fractional crystallization, a homogeneous liquid eould form a differentiated mass consisting of orthoclase and leucite in one part and of orthoclase and free silica in another. It shows, too, that leucite can form from a liquid containing an adequate amount of silica to form orthoclase and that a mass may have leucite as early crystals (phenocrysts) together with free silica as late erystals (groundmass). These considerations explain the occurrence of such a rock as the leucite granite por- phyry of Brazil and such a differentiated mass as the syenite laccolith at Loch Borolan, Scotland. It is to be noted that both these occurrences show pseudo-leucites, formed secondarily after leucite, and consisting, as do the leucites of intrusive rocks in general, of an inter- growth of orthoclase and nephelite (or secondary products after nephelite). This regular behavior of leu- cite in breaking up into orthoclase and nephelite suggests that the early separation of leucite, with a subsequent change of that nature, may afford a key to the origin of many nephelite rocks as well as leucite rocks. Geophysical Laboratory, Carnegie Institution of Washington, Washington, D. C., Mareh, 1922. 292 F.. von Huene—Order Thecodontia. ART. aa —The Triassic Reptian Order Thecodontia; De F. von HvueEne. During the last several years the writer has been much occupied with reptiles of the order Thecodontia (see Nos. 10-20 of the literature list at the end of this paper) and allied groups. In the present paper I am going to give briefly the results as regards classification and relation- ship. The latest literature is given at the end, and all other papers will be found quoted in these. The order Thecodontia (R. Owen 1859) consists of three suborders: Pseudosuchia (Zittel 1889), Parasuchia (Huxley 1875) and Pelycosimia (Huene 1911). The animals constituting these three suborders are of very dissimilar form and size, but are anatomically very nearly related. The Pseudosuchia form the radicle stock of the whole group. Both of the other suborders spring from early Pseudosuchians, but have no descendants them- selves; the Pseudosuchians give rise probably to all Archosauria. The Pseudosuchia I propose to classify as follows: | Proterosuchus fergust Dyoplax arenaceus |Erpetosuchus granti Sphenosuchide ............... Sphenosuchus acutus | Ornithosuchus woodwardi Proverosuchidaet es tia. Aaa Ormthosuchus taylors Saltoposuchus connectens | Saltoposuchus longipes |Pedeticossaurus leviseurt Scleromochlids 3 san yee Scleromochlus taylori {\Euparkeria capensis Ormthosuchds "a6 a Biuparkeriidee (25 2 tna penne | Beommielta ates Wetosauride =. 22a eo. Pee. ferratus '"""lAétosaurus crassicauda mbecomosuchids (444. 4. ee Stegomosuchus longipes With regard to the last of these forms, it was first described as Stegomus longipes by Hmerson and Loomis.® Then the writer re-investigated it at Amherst in 1911 and published his results in 1914.18 The skull now agreed with some of the other Pseudosuchians, but extremities and dermal plates were different. It has a long skull and less than half of its length is preserved. This form can- F. von Huene—Order Thecodontia. 23 not go generically with the older animal described by Marsh as Stegomus arcuatus (see also 1), which I now take for a primitive Parasuchian. Therefore I propose to call the former Stegomosuchus (n. gen.) longipes and its Pseudosuchian family Stegomosuchide (n. fam.). - The elassification of the Parasuchia is mostly based upon features of the skull. The essential points are: relative length of the base of the skull, relative length of the snout, position of the narial openings, condition of the supratemporal opening, and palate. The posterior part of the skull (beginning in front with the anterior margin of the nares) in different genera has a relative length of from 48 to 33.3 per cent of the whole skull. In some very primitive genera, however, it cannot yet be measured as the tip of the snout is missing in the known specimens. The Parasuchia may be classified in the following manner : Desmatosuchids Stagonolepide Phytosauridex Desmatosuchus (Mesorhinus a tagonolepis 2Stegomus (arcuatus) Phytosaurus ~ Angistorhinus Paleorhinus Macheroprosopus Rutiodon 2? piscoposaurus ?Parasuchus | Rileya eae n. gen. Mystriosuchus Mystriosuchide The Desmatosuchide and the Stagonolepide I regard as the most primitive families, of not later than Middle Triassic age. The Huropean ? Phytosaurus I take as a persistently primitive form retaining an early stage of Parasuchian evolution in the very long posterior part of the skull and the dermal armature. But the shifting backward of the supratemporal groove and the short base of the skull nevertheless indicate a terminal member of this branch of the Parasuchia. The Mystriosuchide are a big group which probably in the future will be divided into at least two families, as their feet show very different 24. F. von Huene—Order Thecodontia. structures, but the evidence is not yet complete enough to do this. Further, it might be noted that ‘‘Rutiodon”’ manhattanensis probably does not belong to this genus but to another. In a paper still in press?® an extensive discussion is given of the history of the Parasuchia, and in another a general view of the Thecodontia. The writer holds'? that the Pseudosuchia give rise to the Archosauria. The reasons for this need not be repeated here. From forms probably nearly related to the Ornithosuchide, the Ornithischia and the Aves prob- ably arose through adaptations and the Pterosauria not very far from them. The Crocodilia also probably came from that part of the stem. But the Saurischia the writer takes to be an offshoot of the very earliest Pseudo- suchians in the most ancient Triassic time. Capto- rhirnidae -In 1920'* the writer expressed the opinion that the Rhynchocephalia (with the taxonomic rank of an order) are descendants of the same root as the Thecodontia. If that is true, it would be easy to understand why so many characters are common to both phyla. From this viewpoint, the Gnathodontide (Howesia, Mesosuchus, Brachyrhinodon, Polysphenodon and probably Eifelosau- rus) would form the most primitive family of the Rhyn- chocephalia. The contemporaneous family Rhyncho- sauride (Rhynchosaurus, Hyperodapedon and Sten- ometopon) is little more specialized. The stem of the Rhynchocephalia is represented in later times by the Acrosauride in the Upper Jurassic and by the Tertiary and present Sphenodontide. In the Upper Jurassic the Shai RRP NE bo Or F. von Huene—Order Thecodontia. Sauranodontide, and in the uppermost Cretaceous the Champsosauride, branched off from the main line. - As an Upper Permian Thecodont Broom has described? the genus Youngina. But this form seems to the writer very nearly related to Broomia Watson.** Watson has pointed out that Broomia is nearly related to Heleosaurus and Heleophilus. They are also allied with Adelosaurus, Aphelosaurus and even with the much more specialized Protorosaurus, further with ““Hosuchus’’ (Watson = Noteosuchus Broom). All of these genera should appar- ently be united in a single inclusive group, the Protoro- sauria. Watson has pointed out’ that Broomia possibly might be related to the Lower Permian Captorhinide, and through these to the more typical Cotylosaurians. If this chain of connections be true, the Protorosauria would form an intermediate link between a group of the primitive Cotylosaurians and the Thecodonts, or, in gen- eral, the Archosauria. Tubingen, 7. January 1922. LITERATURE. * Broom, R.: On a new reptile (Proterosuchus fergusi) from the Karroo beds of Tarkastad. Ann. 8S. Afr. Mus., 4, 1904, 159-163, pl. 19. * Broom, R.: The South African diaptosaurian reptile Howesia. Proc. Zool. Soe. London, 1906, 591-600, pls. 40-41. * Broom, R.: On the South African Pseudosuchian Huparkeria and allied genera. Ibid., 1913, 619-633, pls. 75-79. * Broom, R.: A new Thecodont reptile. Ibid., 1914, 1072-1077, 38 figs. ° Case, E. C.: Preliminary description of a new suborder of Phytosaurian reptiles, with a description of a new species of Phytosaurus. Journ. of Geol., 28, 1920, 524-535. * Emerson, B. K. and Loomis, F. B.; Stegomus longipes, a new reptile from the Triassic sandstones of the Connecticut Valley. This Journal (4), 17, 1904, 377-380, pl. 22. "Haughton, S. H.: A new Thecodont from the Stormberg beds. Ann. S. Afr. Mus., 12, 1915, 98-105, 3 figs. * Haughton, S. H.: On the reptilian genera Huparkeria Broom and Meso- suchus Watson. Trans. R. Soc. S. Afr., 10, 2, 1921, 81-88, pls. 2-3. ° Hoepen, E. C. N. van: A new Pseudosuchian from the Stormberg beds. Ann. 8S. Afr. Mus., 5, 1915, 83-87, pls. 13-14. ** Huene, F. v.: Ueber eimen echten Rhynchocephalen aus der Trias von Elgin, Brachyrhinodon taylori. N. Jahrb. f. Min., ete., 1910, 2, 29-62. “ Huene, F. v.: Ueber Hrythrosuchus, Vertreter der neuen Reptil-Ordnung Pelycosimia. Geol. u. Pal. Abh., 10, 1, 1911. 1-60. Tf. Y-11. * Huene, F. v.: Beitrage zur Kenntnis u. Beurteilung der Parasuchier. ibid, 10, 1) 19115 Gl=122, Tt. 12-17. *% Huene, F. v.: Beitrage zur Geschichte der Archosaurier. Ibid., 13, 1, 1914, 1-53, Tf. 1-7. 26 F, von Huene—Order Thecodontia. “ Huene, F. y.: On reptiles of the New Mexican Trias in the Cope Collec- tion. Bull. Amer. Mus. Nat. Hist., 34, 1915, 485-507, 64 figs. * Huene, F. v.: Bemerkungen zur Systematik u. Stammesgeschichte ~ einiger Reptilien. Zeitschr. f. indukt. Abstammungs- u. Vererbungslehre, 22, 3, 1920, 209-212. Huene, F. v.: Ergebnisse eiiger stammesgeschichtlicher Untersuchun- gen an fossilen Reptilien. Ibid., 24, 1920, 160-163, Tf. 7 ™ Huene, F. v.: Die Osteologie von Aétosaurus ferratus. Acta Zoologica, 1, 1920, 465-491. . i Huene, F. y.: Ein Parasuchier im oberen Muschelkalk von Bayreuth. Senckenbergiana, 2, 5, 1920, 143-145, 2 figs. * Huene, F. v.: Neue Pseudosuchier u. Celurosaurier aus dem Wiurttem- bergischen Keuper. Acta Zoologica, 2, 1921, 329-403, 4 Tf. 7 Huene, F. v.: Neue Beitrage zur Kenntnis der Parasuchier. Abh. Preuss. Geol. Landesanst. (Still in press.) *1 Jaekel, O.: Ueber einen neuen Belodonten aus dem Buntsandstein von Bernburg. Sitz. ber. Ges. nat. Freunde, Berlin, 1910, 197-229. » Lees, J. H.: The skull of Paleorhinus. Journ. of Geol., 15, 1907, 121- ois Lull, R. S.: Triassic ife of the Connecticut Valley. Conn. Geol. and Nat. Hist. Surv., Bull. 24, 1915. ** MacGregor, J. H.: The Phytosauria, with especial reference to Mystrio- suchus and Rhytidodon. Mem. Amer. Mus. Nat. Hist., 9, 1906, 29-101, pls. 6-11. 2 Neh lai: Ge ep hie 22 HEP SEITE of the Trias. Journ. of Geol., 23, 1915, 129-165. - 20 figs. *° Mehl, M. G.: The Triassic fossil bearing horizons near Wingate, New Mexico, with a description of Acompsosaurus wingatensis. Bull. Univ. Okla- homa, Studies, 5, 1916, 29-39, 1 pl. 27 Watson, D. M. S8.: Broomia perplexa gen. et sp. nov., a fossil reptile from South Africa. Proc. Zool. Soe. London, 1914, 995-1010, pl. 6. ‘ s } > | = ‘| % ad x H. L. Wells—Discussion of Triple Salts. 27 Art. HI—A Discussion of Triple Salts; by Horace L. WELLS. [Contribution from the Sheffield Chemical Laboratory of Yale University. | The object of this article is to present a few points in regard to triple salts, particularly in connection with the regularity and irregularity of their types, without attempting to give a complete list of those that are known, or to discuss them fully. There are many instances where analogous triple salts are known, and in some eases these occur in rather exten- sive series, but there are a great many cases where anal- ogy is lacking between salts of analogous metals, so that there appear to be no definite laws, based upon the valency or other characters of the constituent salts, according to which they appear to be formed. A similar conclusion was reached by the writer! in connection with a discussion of double halogen salts, To give examples, the triple chlorides recently described by the writer,? Cs,Ag,Au.Cl,,, Cs,Au’,Au’”.CL,, Cs,ZnAu,Cl,,, Cs,HgAu,Cl,,, Cs,CuAu,Cl,., | show analogous formulas and isomorphism, even where two atoms of a univalent element and one of a bivalent element replace each other, but Pollard’s salt,? (NH,),Ag> Au;Cl,;, fails to agree with them, as do also two triple bromides, KFe’Fe”.Br,.3H,O and RbFe’Fe’”,Br,.3H,0, described in this laboratory by Professor P. T. Walden,‘ although, in this case, there are agreements in the valen- cies of the metals. Among the considerable number of triple thiocyanates described by the writer and his associates,® many analo- gous salts were found, but the number of types that * Amer. Chem. Jour., 26, 389. * This Journal, May, 1922. * This Journal, April, 1922. * This Journal, 48, 283, 1894. °H. L. Wells, O. G. Hupfel, H. F. Merriam, C. S. Leavenworth, R. T. Roberts, Amer. Chem. Jour., 28, 245; F. L. Shinn and H. L. Wells, Ibid., 29, 474; H. L. Wells, I[bid., 30, 144. ] 28 H. L. Wells—Discussion of Triple Salts. occurred with metals of corresponding valency is remark- able. A lst of these thiocyanates, according to their types, is as follows: eee 2 Sallis: Cs sMeAg, (SCN), .2H,O Cs,CaAg, (SCN) ..2H,O Cs,MnAg, (SCN) ,.2H,O Cs,NiAg, (SCN) ,.2H.O Cs,CoAg, (SCN) ,.2H,O° Cs,NiCu’, (SCN) ,.2H,0 Cs,CdAg, (SCN) ,.2H,O Rb,BaAg, (SCN),.2H,0 Os,Cd Ag, (SCN), Oi Wee Sallis Cs,SrAg, (SCN), Cs,.BaAg, (SCN), Os,8r0u', (SCN). Cs,BaCu’,(SCN), A> 1-2 salts: | K,BaAg, (SCN) ..H,O Rb,BaAg, (SCN ),.H.O 1 eal : 2:1:1 salt. CsZnAg(SCN),.H,0 Cs,ZnAg(SCN),. jee Ibs op ceybee 1-22 Ss salt: CsCdAg, (SCN) ,.2H,O° CsZn,Ag,(SCN)., 2:1:4 salt. 1:2:4 salt. Cs,CdAg, (SCN) ..2H,O CsZn,Ag,(SCN), In most cases only a single triple salt could be pre- pared from the same three simple thiocyanates, but Rb, Ba,Ag gave two of them, one of which is analogous to the K,Ba,Ag salt, while neither of them corresponds to the single Cs,Ba,Ag compound. With Cs,Zn,Ag and Cs, Cd,Ag four different salts were prepared in each ease, but there is no correspondence between these compounds of such closely related metals as zine and cadmium. It is a curious circumstance also that while two of the cad- mium salts, as hydrous — anhydrous forms, belong to the most common, 2:1:2, type, the other two cadmium compounds and all four OF the zine salts are unique in type, and thus comprise six out of the nine kinds of formulas shown in the above table. A series of analogous triple nitrites was described in this laboratory by Professor George 8S. Jamieson.’ Their formulas are as follows: * Described as Cs,Cd,;Ag,.(SCN) ».6H,O, which varies but little from the simpler formula given here. "Amer. Chem. Jour., 38, 614. H. L. Wells—Discussion of Triple Salts. 29 Cs,BaAg(NO,) ..2H,O Cs,PbAg (NO, ) ..2H,O Cs,SrAg (NO, )..2H,O K,PbAg(NO,),.2H,0 It is to be observed that the compounds in the first column contain the same metals as two of the triple thio- eyanates, but the formulas do not correspond, nor was the 3:1:1 ratio, which these nitrites show, found at all among the triple thiocyanates. Triple nitrites appear to be formed with particular facility, and a few others will be mentioned here to show their types. The salt K,CaNi(NO,), was described by Birdman’ and the analogous strontium and barium compounds are known also. The compound K,NaCo’’(NO,), is well known as the precipitate obtained in a qualitative test for potassium, while the analogous salts (NH,),NaBi (NO,),, Rb,.NaBi(NO,), and Cs,NaBi(NO,), have been described by Ball.® A triple chloride described by Bonsdorff'® a very long time ago is worth mentioning on account of its irregular, complex formula, K,CuHg,Cl,,.2H,O. Its composition was confirmed in this laboratory by H. F. Merriam," who prepared and partially analyzed it. Triple cyanides are known, such as the precipitate, Kk,Cake(CN),.3H,0, obtained with potassium ferrocy- anide in Baubigny’s test for calcium. Of course this may be called a double ferrocyanide. The following are examples of triple salts that occur as minerals: Pachnolite, NaCaAlF,.H,O Polyhalite, K,Ca,Me (SO,) 4. 2H,O Thaumasite, CaCO,.CaSi0,.CaSO,.15H,0 Sulphohalite, 2Na,SO, NaCl. NaF. Hanksite, INa,SO,.2Na,CO,.KCl Kainite, K. »»O0,.MeSO, Mel, .6H,O Northuptite, MeCO, Na,CO, NaCl. The first two of these show that fluorides and suiphates are capable of forming triple salts, the next two are triple SJ. prakt. Chem., 97, 395. * J. Chem. Soc., 87, 761; 95, 2126. To the cesium salt, which is obtained as a precipitate in Ball’s test for sodium, the formula Cs,Na,Bi,(NO.);. was ascribed, but the simpler formula, differing but slightly from it and analo- gous to the others, appears preferable after a careful consideration of the original description. Pogg-. Ann., 33, 81, 1834. % Amer. Chem. Jour., 28, 256 (1902). 30 H. L. Wells—Discussion of Triple Salts. salts of single metals with three acids, while the last three show combinations with two metals and three acids, and with two of each. Enough examples have been given to show that triple salts of analogous metals may have corresponding formu- las in some eases, but that there are many irregularities, leading to a large variety of formulas. Some of the variations depend, as is the case with the Cs-Zn-Ag and Cs-Cd-Ag thiocyanates, upon the proportions of the three simple salts in the solutions from which they are depos- ited, but this appears to be exceptional, since in most cases only a single triple salt can be obtained under such variations. A great many of the triple salts show simple numerical ratios in their formulas, but a few of them have undoubt- edly complex compositions. The frequent occurrence in the formulas of 6 and 12 negative atoms or radicals seems worthy of mention as suggesting related molecular struc- tures in such compounds, but there are many varieties of formulas not corresponding to these numbers. New Haven, Conn., March, 1922. E. L. Troxell—Horned Eocene Ungulates. 3d Art. 1V.—Horned Eocene Ungulates; by Epwarp L. TROXELL. [Contributions from the Othniel Charles Marsh Publication Fund, Peabody Museum, Yale University, New Haven, Conn. | In the Hocene period two distinct forms of rhinoceros- like animals are found to have rugose and thickened nasal bones which appear to be the beginning of horn supports analogous to those of our modern rhinoceros. The first of these is the well known Colonoceras agrestis Marsh; the second is Metahyrachyus bicornutus, new genus and species. j In Oligocene time we see nothing again of horned rhinoceroses until late in the period, when the dicera- theres come in, and one concludes therefore that we either have no record of the intervening members of one single, great, and continuous race, or that the earlier braneh was cut off and that nature wrought the later forms from another, a hornless group leading through Trigomas Lucas and Cenopus Cope. Colonoceras agrestis Marsh. (Fies. 1-3.) Holotype, Cat. No. 11082, Y. P.M. Eocene (Bridger), near Fort Bridger, Wyoming. By CS 11082 Yeo PeVE Fic. 1.—Colonoceras agrestis Marsh. A small specimen closely related to Hyrachyus, but having rugosities on the nasals. Eocene (Bridger). <%. The original description of this species is as follows 31 *O. C. Marsh, This Journal (3), 5, 407, 1873. 32 E. L. Troxell—Horned Eocene Ungulates. ‘In its cranial characters and dentition, this genus resembles most nearly Hyrachyus Leidy, and Helaletes Marsh. It differs especially from these genera, so far as they are known, in the presence of a pair of dermal horns on the nasal bones, which were strengthened to support them. These horns were placed opposite each other, and their position, in a nearly perfect skull in the Yale Museum, is indicated by two rugosities, which have their surfaces marked by radiating lines. In the present species, © which was about as large as a sheep, the horns were widely divergent. WL OSA INANE Fie. 2—Colonoceras agrestis Marsh. <%. Measurements. mm Space occupied by seven teeth in upper molar series........ 77 Nxtent of three: trite amohar sre. ko oe Fe ee 41 Distance between: orbits, son. oss oe ee 62 Distance between apices of horn rugosities...............-.- 27 Lieneth of frontals. on=median=sutune -..245... .5. ee 62 Hxpanse of occipital -comdyles EVPE ES se . A\ id Ail! / De 7a LS iM me NY a S Ml : gre : — =x ‘ & ( \ SS RAG = ; Hh , ie => Zins ey i = ~~ S\ ~~ C i WN Zs ‘ZS \ Fic. 3.—Colonoceras agrestis Marsh. «4. As compared with the more complete skull of H. affinis gracilis nobis, Cat. No. 11170, Y. P. M., one sees these differences: C. agrestis has more slender condyles, broader frontals, especially between the orbits, and finally has the incipient horn rugosities as the generic name implies. Except for the presence of horns, none of these features separates C. agrestis widely from H. affins, and only in a most rigid splitting of groups can the two be distin- guished generically. It has been suggested that the horns of the early rhinoceroses indicate sex distinctions, and this may be true in the present ease. Metahyrachyus bicornutus, gen. et sp. nov. (Fies: 4, 5.) Holotype, Cat. No. 10258, Y. P. M. Eocene (Bridger), Millersville, near Fort Bridger, Wyoming. One of the rarer skulls of early rhinoceroides in the collection is this specimen found by R. E. Son in 1873. Am. Jour. Sci.—FirtuH SErizs, Vou. 1V, No. 19.—Juny, 1922. 3 ; 34 E. L. Troxell—Horned Eocene Ungulates. The first incisor is absent, otherwise every tooth of the superior series is represented. The lower jaws are not present. 3 In two important respects this specimen is different from any Hyrachyus. It has the double internal cone on the third and fourth premolars, and has incipient horn rugosities on the nasals. 10258 DPE Vivi es AG Sp Li SS i ait Le Fic. 4.—Metahyrachyus bicornutus, gen. et sp. nov. Top view of skull showing what appears to be the beginning of the horn supports in the great family of the rhinoceroses. «1%. The first feature, the separation of the tetartocone from the deuterocone, at. once reminds us of many species of the later rhinoceroses, in which there is a tendency for the premolars to become molariform. Because the metaloph is so abbreviated, we find its nearest comparison with Cenopus (see C. platycephalus (Osborn and Wortman) ). The second important feature, the appearance of horn rugosities on the nasals of this species, is a matter of great significance; for some such race must have given rise to Diceratherwwm armatum Marsh and to Menoceras cooki (Peterson) in the later Oligocene and Miocene periods, in which we see the same transverse arrange- ment of the two elements. This may mark the beginning E. L. Troxell—Horned Eocene Ungulates. 35 of the horn-supports seen in the modern rhinoceroses, but here the horns, when there are two of them, are placed one in front of the other. It is well known that Colonoceras agrestis had similar thickenings of the nasal bones, even more rugose; they probably had a common ancestry, but that species is far separated from the present one in other respects: C. agrestis is about two thirds the size; the premolars have the simple internal cone; the strong transverse ridge on P? is anterior and not medial in position; and finally the rugose areas are midway on the nasals and not posterior ‘as in the new species. Detailed Morphology of M. bicornutus——The upper incisors increase in size from front to rear, and there is a progressively larger space between each and between the last incisor and the canine. The third incisor is subeaniniform, being rather long and slightly recurved, but it is narrow transversely. The canine is only moderately long; it is compressed and recurved and . therefore bears no resemblance to those of the later rhinoceroses except Hyracodon Leidy. ; The first premolar, although elongated fore and aft, is much broader than that in Hyrachyus. This tooth has the one main protocone and on the inner side an inci- pient deuterocone with minor ridges. ._The second pre- molar is nearly circular in form, consisting mostly of the large strong outer cone (protocone), with a small tritocone behind it, and of one prominent inner cone, the deuterocone. A thin ridge runs from the latter to the middle of the ectoloph and divides the tooth equally; this is a distinctive feature of the genus. Undoubtedly the most important feature of the skull is the double inner cone on each of the larger premolars. It shows the beginning of the separation of the tetarto- cone from the deuterocone, and a first. step toward the assumption of the molariform condition which was actually realized both in Hyracodon cf. H. leidyanus, and in Cenopus ef. C. tridactylus metalophus. This partial separation is brought about by a vertical groove on the inner side of each tooth which, theoretically, is the predecessor of the normal, transverse, median valley. There is a small internal basal cingulum cutting across the base of this groove on P*. 36 E. L. Troxell—Horned Eocene Ungulates. The protoloph, the anterior cross ridge, on P** is patterned after the molars; but the metaloph is extremely small and irregular. It consists of a small tubercle situated between two folds of enamel extending inward from the proto- and tritocones, and is distinctly separated at the ends from both the ecto- and protolophs From the drawings it may be seen that the main valleys of the premolars open backward instead of inward and in this respect are like those of Cenopus platy- — cephalus nanolophus. -_- DZ Fiore AAS Vi PM: Ca S Fig. 5.—Metahyrachyus bicornutus, gen. et sp. nov. Crown view of upper teeth and part of skull. The diastema between the canine and molar is reduced to half its normal length of 25 mm. by the distortion of the skull. The chief distinguishing features are found in the unusual premolars. «W%. Of the teeth of the cheek series the second molar is largest; it approaches in size that of Hyrachyus princeps Marsh. The third molar is relatively small and its outer and posterior sides form a fairly smooth curve, with the ectoloph extending slightly beyond its edge. On this third molar the posterior cingulum is conspicuous; a small overlapping cingulum across the median valley corresponds to the small cusp which les on the base of the © protocone of M?. The inner side of the ectoloph of M® is nearly straight in this specimen. Back of the point of union of the metaloph, only, does it curve outward and away from the straight line, where it forms a thin, prominent edge. The small crista is far back on the paracone and les low on its base. On M?* it is higher and farther forward. On all the molars, the parastyle, antero-exterior corner, is rather small and is not set off from the adjacent proto- loph by such sharp grooves as one sees in Hyrachyus princeps. E. L. Troxell—Horned Eocene Ungulates. 37 The posterior extension of the ectoloph on M?, the form of the slender premaxillaries and of the nasals, the presence of erect canines, the deep posterior nares, all remind one of Amynodon erectus nobis, and it seems that there must have been a rather near relationship. The notches on the anterior ends of the nasals are found also in Cenopus allus nobis. | The following are important measur ements of Metahy- rachyus bicor nutus: mm. Molar-premolar lenoth <0. os 2 leet: Moka series leniot . as sak oe 64.5 JES VU TECIUEL sips aaa ele an aon Re oe SR Piles Fearne RLM SBP eae pepsi ha are 16.5 Monnaie b Me. A te as ee 26.3 SUMMARY. Two HKocene specimens are figured and described here which are unusual in having on the nasals slight thicken- ings, or centers of ossification, which resemble the horn supports in later rhinoceroses. One is the type of the well known Colonoceras agrestis Marsh and the other the type of Metahyrachyus bicornutus, gen. et sp. nov. The latter may be distinguished by the caniniform I’, the large P', the median cross ridge on P?, and the odd forms of P?4 with their strong development of the tetar- tocone and much reduced metaloph. 38 Troxell—Hyrachyus and its Subgroups. Arr. V.—The Genus Hyrachyus and its Subgroups; by EKpwarp L. Troxenn. (With Plate IL) [Contributions from the Othniel Charles Marsh Publication Fund, Peabody Museum, Yale University, New Haven, Conn. | CONTENTS. Introduction. Definition of the genus. Subdivisions of Hyrachyus. Hyrachyus agrestis group. H. agrestis Leidy. H, bairdianus (Marsh). Hyrachyus affinis group. H. affinis affinis (Marsh). H. implicatus Cope. _ H. intermedius, crassidens, and paradoxus Osborn, Scott and Speir. H. affinis gracilis, subsp. nov. ? H. modestus (Leidy). Hyrachyus princeps group. H. princeps Marsh. A. eximius Leidy. H. imperialis Osborn, Scott and Speir. Summary. Measurements. References. INTRODUCTION. As early as the Eocene period in America we find representatives of the great group of animals called the rhinoceros. With them, and not far removed, we see also the ancestors of the horse and of the tapir, and still other closely related forms which were early blotted out, and whose line has been discarded from the material of the great evolutionary structure. Within the great family Rhinocerotide, there was already a differentiation in the Middle Eocene which gave rise to later subdivisions: (1) Amynodon, leading to the Amynodontide, extinct with the Middle Oligocene; (2) Metahyrachyus nobis, a possible progenitor of the true rhinoceros through Trigonias and Cenopus; and (38) Hyrachyus, giving rise to the Hyracodontide, which existed throughout the Oligocene. The present study deals with the last of these three groups, the cursorial hyracodonts, and with the single genus Hyrachyus Leidy. As to what constitutes Hyrachyus there need be little doubt; there are about one half dozen valid species which SAD. ail a aae'e Troxell—H yrachyus and tts Subgroups. 39 may be combined into a harmonious genus with certain well defined features and yet with certain individuali- ties which indicate a rather wide variation. As to what constitutes the type of the genus, there has been much misunderstanding. Through a passive tolerance, authors have come to accept H. agrarius Leidy as the type, following Leidy, who himself chose to eliminate H. agrestis, a species founded upon the lower jaw of a young animal with milk teeth. Although Leidy stated specifically in his first deserip- tion of the genus (1871 A, p. 357) that Hyrachyus ‘‘an extinet genus, allied to H yracodon, is founded on a frag- ment of a lower jaw of a. young animal,’’ yet in a later paper (1873, p. 60) he figures this jaw but says that he regards it as the same species as H. agrartus, and sub- stitutes the latter as the genoholotype. This has been followed in the literature with only one or two excep- tions. It is of no great moment which of these species represents the genus, but the rules of nomenclature demand that we adhere strictly to the original type in spite of the desires of later writers, including the nomen- clator himself, and so H. agrarius must give place to Hf. agrestis. This species is reinstated as the genoholotype with greater confidence because of the following statement from Doctor O. P. Hay, who has recently looked into this question and says in a letter dated June 18, 1921, “Tt is evident that Leidy meant to base his genus on H. agrestis.’’ Neither the holotype of H. agrestis nor that of H. agrarius 1s specifically determinable. The first is based on a lower jaw fragment containing the first and fourth deciduous premolars, the roots of the intervening two, and also the first molar of the permanent series; the second type is founded upon a lower jaw without the crowns of any teeth. Definition of the Genus. —Hyrachyus Leidy may be distinguished as having smooth nasals without horn rugosities ; diastemata separating the canines and premolars; canines moderately long, pointed, and only shghtly fattened ; premolars with cross crests not parallel but forming a loop, the metaloph encircled by the protoloph; molars with strong parastyles consti- 40 Troxel—H yrachyus and tts Subgroups. tuting isolated cones, with median valleys open, meta- cones receded, with parallel cross ridges leading from points anterior to the two main outer cones respectively, and finally with a strong posterior extension of the ecio- loph on the last upper molar; dental formula 3. 1.4.5. — All the species of the genus are from the Bridger beds of the Middle Hocene. THE SUBDIVISIONS OF HYRACHYUS. Hyrachyus agrestis Group. Hyrachyus agrestis Leidy 1871, genoholotype. Hyrachyus agrarwus Leidy 1871, synonym. Hyrachyus bairdianus (Marsh) 1871. This group, besides the two species of Leidy already discussed, includes also H. bairdianus Marsh, probably a subspecies under 7. agrestis. 3 Leidy’s types, inadequate for accurate specific deter- mination, serve only to define the genus. Marsh’s type, .although also far from being complete, offers some dis- tinguishing characters and is here redescribed along with a nearly complete skull and jaws in the Yale collection (Cat. No. 11081, Y. P. M., apotype). Hyrachyus bairdianus (Marsh). (Fies. 1, 2.) Cotypes, Cat. Nos. 11035 and 11057, Y. P. M. Eocene (Bridger), near Fort Bridger, Wyoming. The first type consists of a portion of the left maxil- lary with the three molars (fig. 1), of which M* and M? are so worn and broken that one gets little character of the species from their study. M? shows a strong internal cingulum across the transverse valley. The third molar is, however, well preserved, and shows certain important specific features. The tooth is wide on the inner side, narrow on the outer; thus the ectoloph is short, and its posterior end, making up the metacone and style, does not extend beyond the bulging posterior cingulum. The posterior fossette cuts deeply, forming a sharp angle between the ectoloph and metaloph. Hortons) WS Bur. Mant ae allel del ssl sa OilG: C. W. Cook—New Occurrence of Ilsemanmite. 51 broken rock. It would seem, therefore, that the altera- tion of the molybdenite to ilsemannite had been relatively rapid. ee to different authorities, ilsemannite has been formed in different ways. Cahen and Wooten® state that it is formed by the alteration of jordisite; Dana’ says | that ilsemannite is ‘‘a product of the decomposition of metallic molybdates’’; while Lindgren and Ransome® indicate their belief that at Cripple Creek it has been formed by the direct oxidation of molybdenite. The exact composition of ilsemannite is hkewise sub- ject to discussion. Dana® gives the formula (MoQ,. -4MoO,); Schaller’® has proposed the formula (MoQ,. SO,.3H,O); while Yancey! believes that Guichard’s formula for the synthetic blue oxide (MoO,.4Mo0,.6H.O) most closely, although not exactly, expresses the compo- sition of the blue of ilsemannite and for the present prefers to consider it is a chemical mixture of molyb- denum dioxide with relatively larger amounts of the tri- oxide. In support of the latter supposition, the writer wishes to advance some observational evidence which may also shed some light on the nature of the alteration process in the case of molybdenite. On the crystal and cleavage faces of the molybdenite in specimens from Gibson, a phenomenon has been observed which the writer has not seen on specimens from any other locality, namely a tarnish or iridescence which immediately reminds one of the ‘‘peacock colors’’ on bornite. A closer examination shows the color to vary from a bronze-brown to a violet brown to blue. Appar- ently the product is identical with that obtained near the assay on charcoal when molybdenite is subjected to the action of the oxidizing flame. Also the writer has produced this tarnish artificially by gently touching crystals and cleavage faces of molybdenite with an oxi- dizing flame. Guichard'? has shown that the true color of molybdenum dioxide is brown or violet brown although this color is easily obscured by the blue of the mixed oxides. It, therefore, seems to the writer quite probable that this bronze.to violet brown coating on the molyb- * The Mineralogy of the Rare Metals. 1912, p. 51. “System of Mineralogy. 6th edition, p. 202. © 1g0¢.. eits abioc cit » Wash. Acad. Sci., vol. 7, p. 417, 1917. * Chem. and Met. Engr., vol. 19, p. 189, 1918. “ Compt. Reud., vol. 129, p. 722, 1899. 52 C. W. Cook—New Occurrence of Ilsemanmte. denite from Gibson is molybdenum dioxide. All material so far examined indicates a thickness for the coating no ereater than that of one of the cleavage lamine of the molybdenite. Hence, the definite determination of its composition or of its properties other than color and luster, the latter being metallic, has been impossible. One other observed phenomenon should: also be men- _ tioned since it may have a direct bearing not only upon the composition of both the coating and ilsemannite but also upon the nature of the decomposition process. In some instances the blue colored material which has been designated as ilsemannite does not appear to be water soluble. This might be expected if the following stages were passed through in the alteration of molybdenite to molybdite. If the molybdenite was first altered by the oxidation of the sulphur, molybdenum dioxide, a brown substance insoluble in water (Muthmann),'? would result. This would represent the tarnish stage mentioned above. The subsequent oxidation of a small portion of the molyb- denum to the hexavalent form would result in a change of color from brown to blue although the compound would still remain insoluble in water, and would correspond to the substance referred to in the preceding paragraph. The existence of such an insoluble blue compound might be expected from the fact that for many years after its original preparation, the color of molybdenum dioxide was thought to be blue. Further oxidation, with an increase 1n the relative amount of the trioxide, and hydra- tion would then transform this insoluble blue compound into the soluble blue compound, ilsemannite. Finally, complete oxidation to the trioxide, on combination with iron, would yield the yellow compound, molybdite. The above interpretation of the observed facts would seem to indicate the composition proposed for the coating and also to support Yancey’s suggestion regarding the composition of ilsemannite. Further, it has a direct bearing upon the question of the secondary enrichment of molybdenite, a subject now under investigation by the writer. University of Michigan, Ann Arbor, Mich., February 14, 1922. * The process of Ullik described by Muthmann (Liebigs Annalen vol. 238, p. 114, 1887) involves purification with hydrochloric acid and potassium hydroxide so that it seems probable that it is insoluble in water. Perner & Kodym—-Silurvan of Bohemia. ae Arr. VII.—On the Zonal Division and Correlation of the Silurian of Bohemia; by J. Perner, with the collabora- tion of O. Kopym. The Silurian formation in central Bohemia (== Upper Silurian in the sense of Kuropean geologists) 1s repre- sented by three ‘‘bandes,’’ designated by Barrande as H,, E,, and F,. The boundaries of these beds were orig- inally not sufficiently defined, and especially that between the most important beds, EH, and H., which was somewhat arbitrary owing to the gradual passage of one into the other; there has also been a change of opinion as to where and how the boundary line should be drawn between HK, and K,. No attempts have been made to divide all these beds, formed chiefly of very fossiliferous shales and lime- stones and attaining at several localities a thickness of at least 500 feet, into minor divisions or zones, as has been very successfully done in other countries. However, Marr’ and Tullberg,? in- discussing Barrande’s theory of the so-called ‘‘ecolonies,’’ have ascertained the existence of several graptolitic zones in EK, similar or analogous to those in England and Sweden. Wenzel,®? on the contrary, comparing the Lower Paleozoic deposits of Bohemia with those of Great Britain, endeavored to prove that the geological distribution of graptolites in Bohemia is quite different, and quoted associations of graptolites in H, (on the same slab) which in other countries appear sep- arately in altogether different horizons, and declared that the fauna in the Silurian’ basin of Bohemia was so con- centrated that no such zones could be distinguished. In order to get a reliable basis for a more detailed divi- sion of our Silurian and a closer comparison with that in other countries, I undertook a revision of the Bohemian graptolites,* which had been neglected from the paleonto- logical standpoint since 1850.° J found in many cases that Barrande had included more than one species under a single specific name, and in some instances had even * Quart. Jour. Geol. Soc., London, 1880. * Sveriges geolog. Undersdkning, Ser. C, No. 50, 1882; Zeits. deut. geol. Gesell, 1883, 2. * Jahrb. d. geol. Reichsanstalt, Wien, 41, 1, 1891. “Etudes sur les graptolites de Bohéme, I, II, IIIa, b, with 17 plates. Prague, 1894-1899. *J. Barrande, Graptolites de Bohéme, with 4 plates, Prague, 1850; a streoe Ueber bohmische Graptoliten. Haidiger’s naturwiss. Abhandl., , 1851. 54 Perner & Kodym—Zonal Diwision and included three species confined to different, vertically widely separated horizons. Consequently correct identifi- cations could not be made until such a revision had been finished, and this explains not only the quite erroneous. assertions of Wenzel as to the non-existence of zones in the Silurian of Bohemia, but also the incongruous views on graptolitic zones in Bohemia held by other authors. In addition, a more detailed division and comparison of Bohemian strata could not be systematically worked out until this revision of species had been made. After redefining the world-widely distributed species of Bar- rande in accordance with his type specimens, I was able to ascertain in the Silurian beds H,, K,, and ', many new species, and to note the presence of forty forms heretofore known only from Great Britain and Seandinavia. Addi- tional studies regarding the vertical distribution of other fossils and different facies in the beds named above have led to results here communicated.°® The limit between the Upper Ordovician (Barrande’s Bande D;) and the Lowest Silurian beds in central Bohemia is a very sharp one, both from the petrographic and the paleontologic standpoint. The lowest Silurian beds, black graptolitic shales of K,, rest at some rare local- ities with a slight unconformity on the soft yellow or olive-green, sometimes argillaceous, shales of D,;, which are interstratified, especially toward the top, with quartz- ites, gritty shales, and graywackes. The fauna of D, is also completely different from that in Ki, having no species in common, and being characterized by Trinucleus, Remo- pleurides, Carmon, Dindymene, Homalonotus, Avglina, Asaphus, Agnostus, Areia, and Dicellograptus, as against the 1, shales bearing Diplograptus, Rastrites, and Mono- graptus, so that a hiatus seems to be evident between the Ordovician and Silurian in Bohemia. * It was my intention immediately after the completion of my paleontolog- ical studies on Bohemian graptolites to publish as their final part a paper dealing with the zonal division of the graptolitic rocks of Bohemia. But my official duties connected with the Bohemian Museum and with working out the Gastropoda of Barrande prevented my doing this befcre the outbreak of the Great War. During the past few years I have been greatly aided by my pupil, Mr. Od. Kodym, with whose collaboration a preliminary report on this subject was published in the Journal of the Bohemian Museum for 1919 (in the Czech language). In the present English communication I hope to enable foreign workers to get the review and comparison of the Bohemian Silurian beds before the more detailed paper on this subject appears, since I have no idea when this latter can be accomplished, because of the desolate situa- tion of the scientific institutions of Czekoslovalia. Correlation of the Silurvan of Bohemia. 55 Bande H, is composed chiefly of black graptolitic shales, but becomes calcareous toward the top, passing into the limestones of H.. This passage is marked by the appear- ance of caleareous coneretions (anthracolites) and thin seams of bituminous limestones in the higher graptolitif- erous Shales. These intercalations become more numerous toward the top of E,, until the shales gradually dis- appear and limestone-beds prevail, followed by thickly bedded compact or crystalline limestones. The boundary between EH, and E., formerly uncertain, was proposed by J. Jahn’ almost wholly on the basis of petrography, and the horizon of shales with coneretions and limestone inter- ealations was classed as H,. I myself defined the same boundary paleontologically,$ taking the zone with Mono- graptus colonus, M. dubwus and M. roemeri as the highest horizon of K,. This limit agrees in many localities with the petrographic one of Jahn, and I compiled at the same time a list of 230 more common molluses, brachiopods, and crustaceans, indicating their true horizon, EH, or EK,, based on the new material collected from the chief expo- sures zone by zone; this will, I hope, aid in correcting the designations in many collections abroad (see pp. 64-66). BanveE K&,. H,, as now limited, can be divided into three chief subdi- visions, which in general correspond to three ‘‘zones’’ recognized by Marr, and for which I propose accordingly (as in use for other Lower Paleozoic rocks of Bohemia) the following designations: K,e = Diplograptus beds. E,8 = Priodon beds. Hy = Dubius beds. About thirty years ago Jahn (1. ce.) proposed to desig- nate as K,o the graptolitic shales in which the calcareous concretions are absent, and the upper part of E, (shales with concretions and limestone interealations) as H,8. I could not accept this purely lithological division, as it is imaccurate and unreliable. As the far more reliable graptolite fauna demonstrates in many sections, there are shales containing Monograptus priodon, M. vomerinus, Stomatograptus grandis, Cyrtograptus murchisoni, and ‘ Jahrb. d. geolog. Reichsanstalt, Wien, 42, 3, 1892. *Bohemian Acad. Sci., Jubileum Memoirs, XX, 1915. 56 Perner & Kodym—Zonal Division and Retiolites gemmtzianus in some localities without nodules and limestone intercalations; in others, however, they are crowded with them, although they both correspond to Marr’s ‘‘priodon zone.’’ The same thing occurs in some upper zones. The division into three parts is, | am con- vineed, more appropriate to the three distinct graptolitice faunas existing in KH, and in general fits to the facts known from other countries. E,a—Diplograptus Beds. Hie or the Diplograptus beds is characterized by the frequent occurrence of many species of Diplograptus and other genera of the Diprionide, which are all absent in the upper beds. It contains four zones, as follows: a. Lone of Diplograptus vesiculosus Nich.—Soft, light yellow or brown, lilac-shaded shales, known only from Bélec* and Libomysl. Aside from D. vesiculosus and an undeterminable Climacograptus, no other graptolites are known from this zone, demonstrating that in Bohemia, beds of Lower Llandovery age are also represented. In the other localities this zone can not be ascertained, as for instance, in the vicinity of Tman, where similar shales resting directly on D,; (Ordovician) have so far yielded no graptolites. At Korno and elsewhere black shales lying on D; are metamorphosed by diabase intru- sions into hard hornstone-like shales without a trace of graptolites. At several localities this zone is certainly absent (for instance, at Zadni T'reban), because the black shales lying directly on D,; belong already to the next higher zone (Rastrites peregronus). It seems that the transgression which began after the close of Ordovician time gradually reached different places in the ‘‘Silurian basin’’ of Barrande. b. Zone of Rastrites peregrinus Barr.—This zone also contains shales but of different petrographical characters, and is developed in the entire area of the Silurian. For example, at Treban, Motoly,.and colony ‘‘Haidinger’” between Radotin and Kuchelbad, the zone consists chiefly of soft micaceous, somewhat arenaceous, black or gray shales; in the vicinity of Tman, of yellow or grayish, llac- - *Jn this and other cases beyond, the accent is from necessity omitted. °The names of Barrande’s colonies are used here only as designations of localities. ) Correlation of the Silurian of Bohemia. 57 shaded, non-micaceous, fine shales; in most localities, however, are found hard, gritty, hornstone-like, black shales, especially in the neighborhood of diabases (IXarlik, Reporyje). Faunistically, this zone is the richest one, and it is relatively thick enough to be divided into subzones. Besides Rastrites peregrinus, which is everywhere the most common species, the following forms occur: Diplo- graptus modestus Lapw., D. (Glyptograptus) sinuatus Nich., D. (G.) bellulus Torng., Climacograptus scalaris Lin. (auct.), Cephalograptus folium His., C. cometa Gein., Retiolites (Gladiograptus) perlatus Nich., Monograptus lobiferus M’Coy, M. commums Lapw., M. fimbriatus Nich., M. leptotheca Lapw., M. convolutus His., M. tri- angulatus Harkn., M. distans Portl., and Corynoides sp. None of these species appears in the next higher zone. c. Zone of Rastrites linnér Barr.—Very fine-grained, fissile shales, almost without mica, mostly of gray-green- ish color; the graptolites in them have a bright silver-like luster; the best locality is at Zelkovice, where occur: Diplograptus palmeus Barr., D. ovatus Barr., Monograp- tus beck: Barr., M. clingan Carr. var. hopkinsom Per., M. halli Barr., M. holm Per., M. marri Per., M. jaculum Lapw. var. variabilis Per., M. planus Barr., M. proteus Barr., M. runcinatus Lapw., M. turriculatus Barr. var. minor, and Rastrites inner Barr. d. Zone with Monograptus turriculatus Barr.—Sim- ilar hard dark shales, in some localities ciayish and of dark brown color. Characteristic graptolites are: Monograptus palmeus Barr. var. tenuis Barr., M. turri- culatus Barr. (typical large form), M. jaculwm Lapw., and Retiolites (Plegmatograptus) obesus Lapw. Some grap- tolites of the preceding zone occur sporadically here also, as WM. proteus, M. runcinatus and M. marrt. E,8—Priodon Beds. The commonest fossils in these beds are Monograpti of the group of M/. priodon Bronn; for the first time appear here the genera Cyrtograptus and Stomatograptus; totally absent are Rastrites, Diplograptus, and Climaco- graptius. In this horizon we find already in the grap- tolitic shales calcareous concretions (nodules of ellipsoidal 58 Perner &€ Kodym—Zonal Dwision and shape, 2-15 inches in diameter), often forming almost con- tinuous beds; thin beds of shaly lhmestone and compact or crystalline hmestone often alternating with shales are also a common feature in many localities. Some- times these calcareous intercalations contain trilobites, brachiopods, various molluses, ete., and graptolites in them are often preserved ‘‘en relief.’’ As already suggested, these intercalations do not occupy a definite horizon; in some sections they are not to be met with until the much higher beds. Some of these lmestones are very similar to those from Barrande’s Bande EK., and many fossils which are confined to these Hi, limestones have indeed been erroneously cited as occurring in H,. Three zones ean be distinguished in Ep: a. Zone with Monogr aptus spiralis Gem. var. subconi- cus Torng.—Dark brown fissile shales, or grayish and dark flagstones; no caleareous nodules present. Char- acteristic graptolites are: Monograptus priodon Brn., M. vomerinus Nich., M. spiralis Gein. var. subconicus Torng., M. griestonensis Lapw., M. sacculiferus n. sp.,*° and Retiolites geamtzianus Barr. b. Zone with Cyrtograptus murchisoni Carr.—Shales of similar lithological character to those in the former zone. First appearance (in the same localities) of eal- careous nodules. In the western part of Barrande’s ‘‘Silurian basin’’? these shales alternate with dark com- pact limestones or hght crystalline limestone; the latter occurrence seems to be in connection with the nearby coral reef, forming an almost continuous seam between 'T'ach- lovice and Tetin, and reaching vertically into higher zones (see section on the coral-reef facies). The shales of this zone ylelded: Monograptus priodon Brn., M. vomerius Nich., M. latus M’Coy, M. kettnert n. sp., M. remotus See Cyrtograptus murchison Carr., M. purkynéi n. sp., M. centrifugus n. sp., M. insectus n. sp., M. evolvens n. sp., Retiolites gewmtzianus Barr., and Stomatograptus gr andis (Suess). In the limestone ‘and calcareous shales and mudstones at Lodénice I have found, in association 10 Tn recent years many new graptolites have been found in E,, descriptions of which are being prepared by my pupil and collaborator, O. Kodym. 1 R. Kettner has proposed and is using the term ‘‘Barrandien’’ for the area in Bohemia in which are developed the Paleozoic rocks included in Barrande’s old and inappropriate term, ‘‘bassin Silurien du centre de la Bohéme,’’ viz., his Etages A-H (Algonkian to Devoniar). Correlation of the Silurian of Bohenua. 59 with MW. priodon, M. vomerimus, Cyrtograptus murchisoni, and Retiolites geimtzianus, the trilobites Arethusina kon- mck, Barr., Acidaspis mora Barr., A. prévost. Barr., A. roemer Barr., and Bronteus planus Corda, which have been many times quoted as EK, fossils, although they are confined to E,. With them are associated a few brachio- pods, as Leptena transversalis and Atrypa sappho, which are also met with in H,; and several cephalopods extend- ing into higher zones occur here. c. Zone with Monograptus riccartonensis Lapw.— Chiefly brown or dark fissile calcareous shales with nodules and intercalations of dark compact limestones. Best localities: Lodénice, Vyskocilka, colony ‘‘Krejei,”’’ Konéprusy. Here have been found: M. riccartonensis | Lapw.,'? M. vomerinus Nich., M. dubws Suess var. proeva, M. solitarus n. sp., M. validus Per., and M. prio- don Brn. Associated are: Slava bohemica Barr., Apty- chopsis prima Barr., and Arethusina konincki Barr. E,y—Dubius Beds. These are characterized by the occurrence of Mono- grapti of the type of MW. dubius Suess, and allied forms, such as JM. colonus Barr., ete? The shales of these beds very often alternate with seams of caleareous nodules and limestones, in which, besides the rarer graptolites, some- times occur brachiopods, various molluses, and erinoidal remains. In the northwestern region ot Barrande’s ‘‘Silurian basin’’ these beds are developed as coral-reef limestones (see section beyond). Two zones can be distinguished : a. Zone with Monograptus testis Barrande—Brown or grayish yellow, argillaceous, slightly calcareous shales without concretions or nodules (Barek), or dark shales with concretions and limestone intercalations (Dvorcee, * Most of the specimens of this species I formerly considered to belong to M. flemingi Salter and allied forms. The admirable monographs of British graptolites by G. HE. Elles and E. M. R. Wood (Mrs. Shakespear) in Paleon- togr. Soc. London 1901-1913 now enable me to undertake a revision of all the British species formerly recorded in my ‘‘Etudes,’’ and to correct some previous determinations. 18 The original designation, Marr’s ‘‘colonus zone’’, i think should be changed to ‘‘dubius beds’’ since M. dubius occurs in the whole of E,y, while W. colonus is absent in the lower part. 60 Perner € Kodym—Zonal Division and Kozel). This zone yielded: Monograptus testis Barr., M. bohenucus Barr., M. flemingi Salt., M. nilsson Barr., M. dubwus Suess, Cyrtograptus lundgrent Tullb., and Retiolites (Gothograptus) nassa Holm. In addition have been found associated: Ampyx rouaulti Barr., Dalman- ites orba Barr., Proétus (Phetonellus) dentatulus Novak, Discina unguis Barr., D. nana Barr., Orthis honorata Barr., and Orthotheca fragilis Nov. . b. Zone with Monograptus colonus Barrande.—Lith- ological character nearly the same, brown, somewhat argillaceous shales prevailing, concretions frequent; the alternating lmestones here more frequent, dark, non- erystalline, compact (in contrast to the majority of the very similar KH, limestones), sometimes with numerous cephalopods or erinoid fragments. Associated occur here: Monograptus colonus Barr., M. nilsson Barr., M. bohenucus Barr., M. roemer Barr., M. gotlandicus Per., and M. unguiferus Per. Inthe same zone, the concretions and limestones yield, sometimes in association with the graptolites named above: Cyrtoceras vestitum, Gompho- ceras clava, Ophidioceras proxvmum, Orthoceras epulans, O. socum, O. alludens, O. pleurotomum, O. styloideum, Ascoceras cf. murchisom, Cirropsis spp., Cyrtolites eximius, Huryzone tuboides, Orthonychia ampla, O. ele- gans, Platyceras longipes, Polytropis (Poleumita) potens, Spirina patula, S. tubicna, Avicula glabra, Slava bohemica, Cromus beawmonti, Cyphaspis, and Illenus . bouchardi. The shales of H,y also sometimes contain Orthoceras, some Acephala, and brachiopods, but these are mostly undeterminable. REEF-FACIES IN BARRANDE’S ETAGE E. The upper EK, beds in the northwestern Silurian region are developed as coral-reef facies, with coarse crystalline limestones of gray or brown color (never white as in F,), sometimes indistinctly stratified, or nodular. The lowest part of these limestones must be attributed to Hi, beds, as their base is formed by the zone of Cyrtograptus murchi- sont (H,8). They extend up from H,y to the highest H, beds, and it is most probable that they existed in some localities without a noteworthy interruption until the mid- dle part of Barrande’s Bande G,, which 1s. of Lower Devonian age. Correlation of the Silurian of Bohemia. 61 A boundary between EK, and EK, can not easily be drawn in these limestones, as their lithological character is the same through the whole thickness of these deposits. Graptolites are almost absent and the fauna bearing a decided coral-reef character is for the greater part unknown from the other ‘‘normal’’ parts of HE, or EK,. From the rich characteristic coral fauna, which occurs chiefly at Kozel and Tachlovice, may be named: Halysites catenularia, Favosites asper, F. tachlovicensis, Cyatho- phyllum prosperum, Cystiphyllum bohemicum, and Om- phyma grande. Besides these corals, there frequently occur in these deposits: Orthoceras caduceum, O. endy- ~mion, O. pedum, O. valens, O. currens, Modiolopsis pupa, Spanila cardiopsis, Cardiola persignata, Conocardiwm dorsatum, Atrypa obolina, A. melegans, A. reticularis, A. squamma, A. dormitzert, Rhynchonella niobe, R. nympha, and Rk. princeps. The greater part of the Mol- lusea and Brachiopoda mentioned above are apparently confined to these coral limestones.+ In the immediate neighborhood of these coral reefs there seems to be a peculiar trilobite fauna, represented by Bronteus planus, Cheirurus msignis, Spherexochus mirus, Deiphon forbesi, Lichas, ete., the true horizon of which belongs to E,, as | have found them in the mud- stones and limestones associated with Retiolites geimitzi- anus, Cyrtograptus murclhisom, Monograptus priodon, and M. vomerimus. BAanveE E,. As already stated, the boundary between E, and KE, was proposed by me on a paleontological basis, taking the horizon characterized by Monograptus dubius, M. colonus and M. roemeri as the highest in H,. As in K,, there are to be distinguished in EK, two different developments of deposits or facies: (a) normal, stratified limestones with intercalated shales and mudstones; (b) reef facies, with nodular, indistinctly or irregularly stratified coral lime- stones, a direct continuation of the reef facies mentioned above in E,, and not divisible into zones, the faunal char- acter remaining the same. * Atrypa reticularis, Rhynchonella nympha, and R. princeps occur also in the coral limestones of the Devonian stage F, and extend to G,. 62 Perner & K odym—Zonal Division and In the normal EK, there are three chief horizons which are recognizable in the entire Silurian area, as follows: 1. Cephalopod horizon."® 2. Brachiopod horizon. 3. Crinoid horizon. Between them can be distinguished several subordinate zones, which in one locality, where the exposure can be described in detail, can be characterized by their fauna; but in another, not far distant, can not be demonstrated. A majority of the EK, fossils occur in all the EK, beds; some species, however, very characteristic for one limited locality, are totally ‘unknown in others. A detailed scheme of sequence applicable to the whole horizontal extent of IH, can not be given at present, but I hope future detailed comparative studies of numerous exposures, like those of Kiaer made in Norway’s Silurian, will throw more hght on this subject. Cephalopod Limestones. : ‘These are usually grayish or bluish, compact imestones, in thick beds, that in some localities have intercalations of brown shales and shaly limestones. Abundant species are: Orthoceras nobile, O.bohemicum, O. janus, O. explana- tum, Cyrtoceras murchisom, C. vernum, Gomphoceras cylindricum, and Lituites (Ophidioceras) sumplex. This horizon is also the chief source of other well known fossils at Dlouha Hora and Hopanina, among them being Cromus beaumonti, Calymene bayler, Harpes ungula, Cyphaspis burmeisteri, C. depressa, Cheirurus wmsigus, Proétus striatus, Ly ytospira subuloidea, Murchsonia latona, Lox- onema beraunense, Cardiola bohemia, C. mterrupta, C. grandis, Dualina excisa, and Atrypa sappho. A charac- teristic graptolite is the rare Monograptus transgrediens Per. Brachiopod Horizon. White-gray limestones without shaly intercalations (Dlouha Hora), or dark, thinly bedded limestones alter- These designations do not mean that, for instance, cephalopods in EH, are confined to the lowest beds; they are intended only to indicate the sudden and striking appearance of the three groups of animals, so that the sequence named above would mean rather a sequence of different bionomic conditions. Correlation of the Silurian of Bohemia. 63 nating with shales (Lochkov). The majority of the . limestones are finely crystallized. In certain localities, some of the limestone beds consist almost exclusively of the shells of Atrypa linguata, in other horizons this species is rare. Very common are Pentamerus, Cyrtia, Merista, and Rhynchonella. Graptolites are represented by Monograptus ultumus Per., which, however, continues up to the highest’ EH, beds. Records of the occurrence of M. priodon or M. colonus in Ki, are quite erroneous. Crinoid Horizon. Dark bituminous limestones in thick and thin beds with numerous crinoid remains (chiefly stem fragments, often even loboliths or Camarocrinus), forming locally true erinoid limestones.1®° They are followed by brown or gray, sometimes nodular limestones, alternating with brown shales or shaly limestones, with flat caleareous con- eretions. In this horizon occurs Monograptus ultunus Per., associated with Cardiola wterrupta, cephalopods, dendroids (Dictyonema, Callograptus, Desmograptus, Rhodonograptus), and Gigantostraca. Some of the limestone beds yield gigantic Orthocerata, as O. neptuni- cum, O. severum, O. potens, O. pelagicum, O. temperans, O. extenuatum, O. socum, and O. rivale. In general, the E, beds with their frequent alternations of limestones with shales and mudstones, and their changing fauna seem to suggest that they are deposits of a shallow sea-basin, not distant from islands or coral reefs, where the bionomic conditions changed rapidly. DISTRIBUTION OF F'ossmus IN H, AND H,. As already mentioned, many fossils have been described by Barrande and others as occurring in K, although they are confined to E, or at least are common to both levels; this is true chiefly of Mollusca and Crustacea in the lime- stones. These errors have been due not only to the uncer- 7 These limestones are often very similar to those in E,y (zone with - Monograptus colonus), which also bear in many OES numerous crinoid fragments (stems, Joboliths, rarely cups). 64 Perner & Kodym—Zonal Dwision and _ tainty in delimitation of K,, but also to the similar aspect of the limestones occurring both in KE, and in E,.17 After collecting at the chief localities with due regard to the present boundaries between Hi, and H., and com- paring with Barrande’s material, | was able to compile the following list of the more important fossils found in EK, and E,, indicating their true range. Graptolites which - have been treated more in detail in describing the H, zones are omitted here, but special attention is given to other fossils which have not been known at all from H, or not with certainty, and which occur in the lmestones. The fauna of H,, as it is now delimited, therefore appears much richer than has hitherto been supposed. CrPHALOPODA: Cyrtoceras abstimens (H,)**, formidandum (1-2), lepidum (1-2), mgrum (1-2), phillipss(1), plutos (1-2), potens(1), serratum(1), superbum(1-2), vestitwm(1), victor(1) ; Gompho- ceras agassizi(1-2), amygdala(1-2), atrophum(1-2), billings (1-2), bohenicum (1-2), clava(1-2), contrarrwm (1-2), halla(1-2), umperiale (1-2), mumia(1-2), nuciforme(1-2), ovum(1-2), rigt- dum (1-2), spherosoma(1-2), vespa(1-2); Ophidioceras amissus (1), proximus(1), rudens (1-2), tener(1-2) ; Orthoceras equabile (1), annulatum Sow.(1-2), bohemicum(1-2), compulsum (1-2), currens (1-2), decurtatum (1-2), docens (1-2), duponti (1-2), egre- gium (1-2), endymion (1-2), epulans(1), extensum(1), germanum (1-2), «dludens(1), wchoatum(1-2), imnotatum(1-2), jucun- dum (1-2), magister (1-2), manus (1-2), murchisom (1-2), particeps (1-2), pectinatum(1), poculuwm(1-2), pseudocaiamiteum (1-2), simois(1), soctum(1-2), stexmngeri(1-2), tenwmcrnctum(1), tran- stens(1-2), trecentesimum(1); Phragmoceras callistoma(1-2), imbricatum (1), panderi(1), perversum(1) ; Trochoceras amicum (1), nodosum (1-2), placidum (1-2), pulchrum(1-2?). Gastropopa: Cirropsis bohemica Per. (1-2), C. disjuwncta Per. (1-2), C. prestans Per. (1-2), Conotoma eximia(1), Con- radella wmopinata(1), Cyrtolites erenita(1), C. eximius(1), C. tuboides(1), Dyeria carens(1), Epiptychia dush Per. (1), Euryzone tuboides Per.(1), Holopea twrregularis(1), Naticopsis “Tn the latter period of his paleontological activity, Barrande used to refer the majority of the Silurian fossils imbedded in limestone to H,, although his collectors, workers in quarries, who brought the fossils to Prague, were getting them chiefly from E, limestones, which on the old weathered exposures yielded the fine, entire specimens with well preserved sculpture, such as are now seen in the Bohemian Museum. Many such rich localities have disappeared or become nearly inaccessible; others yield from the fresh exposures chiefly fragments, hardly determinable, so that it is now a difficult task to ascertain the true horizon of all Barrande’s species. 18 The author is Barrande, unless otherwise stated. To save further space, E, and E, are hereafter written simply 1 and 2. . ine = sie ala on eke tet cantonal Sapte wins Correlation of the Silurian of Bohemia. 65 imsculpta(1), Orthonychia ampla(1-2), O. cuneus(1), O. elegans (1-2), O. nobilis (1-2), O. togata(1), Platyceras wsopus (1-2), P. complanatum (1-2), P. concors(1-2), P. conviva(1-2), P. exsur- gens (1-2), P. formosum (1-2), P. forte(1-2), P. inchoans (1-2), P. longipes(1),.P. edematosum (1-2), P. sanum(1-2), P. subcarina- tum(1), P. vexatum(1-2), Polytropis dives(1), P. potens(1), P. pulchra(1), P. robusta(1), P. ventricosa(1), Spirina patula(1-2), S. tubicina (1-2). AcCEPHALA: Astarte minuscula(1), Aviculopecten cybele(1), Avicula glabra(1), A. manulia(1), Cardiola expectans (1-22), C. fortis(1-2), C. gibbosa(1-2), C. intermittens (1-2), C. inter- rupta(1-2), C. mgrans(1-2), C. petasina(1-2), C. pulchella (1), C. radiata(1-2), Dualina bella(1-2), D. branikensis(1), a exiracia(i-2).~ DD. fidelis(-2), Dv humilis (1-2), .D. meongruens (1-2), D. nympharum(1-2), D. secunda(1-2), Gonophora phrygia(1-2), Grammysia precox(1-2), Maminka comata(1-2), M. tenax(1-2), Mila consangws (1-2), M. onsolrta (1-2), Modiolopsis imvoluta(1-2), M. pupa(1), M. rebellis (1-2), Panenka capitata(1-2), P. gyrans (1-2), P. insocialis (1-2), P. vendita(1), Paracardium complicatum (1-2), P. delicatum (1-2), P. fisferum(1-2), P. incipiens(1-2), P. mundum(1-2), P. rarissimum(1), Posidonomya eugyra(1-2), Precardium adolescens(1-2), P. bohemicum(1-2), P. complacens(1), P. fidens (1-2), P. ministrans(1), P. promulum (1-2), P. quadrans (1-2), Slava aberrans(1), S. bohenica(1-2). ~ BracHiopopa: Atrypa wnsolita(1-2), A. sappho(1-2), A. squamma (1-2), A. thetis(1-2), Crama(?) bohemica(1), Discina nana(1), D. propinqua(1-2), D. ungwis(1), D. truncata(1-2), D. vexata(1-2?), Hichwaldia bohemica(1), Lnngula albicans (1-2), L. comes(1-2), L. dilatata(1), L. mgricans(1-2), Orthis cognata(1), O. honorata(1), O. venustula(1), Pentamerus per- ditus(1), Rhynchonella mobe (1-2), Strophomena bracteola(1-2). TRILOBITA: Acidaspis dufrénoi(1-2?), A. mira(1), A. preé- vosti(1), A. rara(1), A. roemeri(1), Ampyx rouaulti(1), Are- thusina komncki(1), Bronteus partschi(1-2), B. planus Cda.(1), Cheirurus insigms Beyr. (1-2), Cromus beaumonti (1-2), Cyphas- pis burmeisteri(1-2), C. depressa(1-2?), Dalmamtes orba(1), Deiphon forbesi(1-2?), Harpes nawmanni(1-2?), Illenus bou- chardi (1-2), Lichas scabra Beyr. (1-2), L. palmata(1-2), Phacops glockeri(1-2), Proétus decorus(1-2?), P. dentatulus Nov. (1), P. nasutus Nov.(1), Staurocephalus murchisoni(1-2). CRUSTACEA DIVERSA: Aptychopsis prima(1-2), Ceratiocaris beraunensis(1-2), C. bohemica(1-2), C. decipiens(1), C. grata (1), C. nequalis (1-2), C. leptoglypha N. (1), Cryptocaris pul- chra(1), Discinocaris dusliana N.(1), EHurypterus acrocephalus S.(1), Holocaris univalvis N.(1), Plumulites mimmus(1), P. squamatula(1), Pterygotus beraunensis 8.(1-2), P. barrande: N. (1), P. eyrtochela(1), P. hellicht N. (1). Am. Jour. Sct.—Firta Serizs, Vou. IV, No. 19.—Juxy, 1922. 5) 66 — Perner & Kodym—Zonal Division and Diversa: Scyphocrinus decoratus W. & J.(1), 8S. excavatus (Sehl.) (1), 8S. subornatus(1), Bohemicocrinus pulverens (1-2), Aulopora disjecta Poé.(1), Desmograptus plexus Poé.(1-2?), D. giganteus Jahn(1), Dictyonema bohemicum (1-2), D. confertum Poé.(1-2?), D. grande (1-22), D. graptolithorum Poé.(1), Inocau- his attrita Poeé.(1). - Banpe F,. The highest member of the Silurian series in Bohemia is the dark limestones which have been referred by Bar- rande to his Ktage F and designated as F,. Their litho- logic and faunistic characters place them much nearer to the E, beds than to the F’, limestones, which are undoubt- edly of Lower Devonian age.'® In addition, a faunistic hiatus between F, and F’,, signifying the boundary line between the Silurian and Devonian in Bohemia, together with the decidedly Silurian aspect of the F', fauna, points out the closer connection of F', with K,. The boundary line between HK, and F', is marked by the occurrence of hornstones in the limestone, and by a change of fauna. As in H, and K,, there are two facies developed in F,. The reef facies, which in F, has a far ereater extension, 1s formed of limestones with very sub- ordinate shales. The limestones in the lower part of F, | are dark, nearly black, fine-grained or compact, thickly bedded, and contain dark hornstones of irregular shape; shaly reddish interealations occur only in the lowest beds. In the upper part the lmestones are lighter, gray or whitish, thinly bedded, finely or coarsely grained, resem- bling the white limestones of F’,, but contain yellowish or reddish hornstones. Opposite Tetin this facies is fossil- iferous, bearing almost the same coral fauna as in H,. The other, ‘‘normal’’ facies is more shaly, and is lim- ited chiefly to a seam between Prague and Kosor (valley of Radotin). Characteristic are dark fine-grained lime- stones, splitting into flat plates and alternating many times with dark or brown shales; hornstones are rare or completely missing. As for the fauna, it is quite different from the contem- poraneous coral fauna, and differs also from thé ‘‘nor- 7 It would perhaps be more appropriate to call the F, beds E;, so that the Silurian of Bohemia would correspond to Barrande’s Etage E, and the letters F, G and H could be reserved for the Devonian. Some Bohemian geologists have already accepted this proposition. Correlation of the Silurian of Bohemia. 67 mal’’ K, fauna; a considerable part is, however, common to E,and F,. It is characterized by numerous species of Hercynella, which are regarded by some paleontologists as pelagic Pulmonata.2? Moreover, cephalopods (40 species, badly preserved, enumerated by Barrande and Novak), large lamellibranchs (Panenka, Prelucina, Modi- olopsis, Dalila, Cypricardima, Hemicardium, Avicula), gastropods (Strophostylus, Rotellomphalus, Stylonema), Conularia, and Tentaculites, are other prominent groups; a noteworthy feature is the thin shell of the molluscs men- tioned. Graptolites are represented by two last species, Monograptus hercynicus and M. kayseri Per. Concerning the more detailed division of these F', beds, I must content myself with giving a brief recapitulation . of results published elsewhere,*! and adding some further remarks. In the ‘‘normal’’ F’, can be distinguished three horizons, which are not sharply delimited, as follows: 1. The lowest consists of dark or black thick lime- stones, alternating with thick beds of shales; it contains rare fish remains (Macheracanthus, and some new genera resembling Ateleaspis, Aspidichthys, Cyathaspis, Dinich- thys, Macropetalichthys, and Mylostoma). Other fossils are also rare. 2. Fine-grained limestones, thinly bedded, alternating with shales. The greater part of the EF, fossils occur here. Characteristic ones are: Hercynella nobilis, H. radians, H. bohemica, H. paraturgescens, Rotellomphalus tardus, Strophostylus gregarws var. proéva, Stylonema solvens, Dalila obtusa, D. resecta, Lunulicardium analo- gum, L. evolvens, Panenka amena, P. grata, Ceratiocaris, Aristozoe, Pygocaris, and Gigantostraca. 3. Shaly limestones and shales (black, brown or gray), with Monograptus hercyncus and M. kaysert. Spirifer inchoans is very abundant, and the following species are common: S. neret, Atrypa canaliculata, Pentamerus janus, P. lingufer, Cyrtia trapezoidalis, Avicula nugrans, A. pusilla, and Conocardwm aptychoides. In the upper part of this horizon also appear trilobites. Common among them and very characteristic (confined to F',) is * These are wanting in the reef limestone of F, (Konéprusy) and reappear in the shaly limestones of G,. 1 Centralblatt f. Min. u. Geol., 19-20, 318-322, 1918. 68 . Perner & Kodym—Zonal Dwision and Bronteus umbellifer; others are rare and mostly frag- - mentary. Their geological distribution in other Silurian and Devonian beds of Bohemia is very interesting and important, as may be seen from the following table: KH, F, F, G, G, A Cid adspIS VESICULOST, Cyt. eee ee Xk Bronteus, Unnvelli ier Oy ae site es ee eee X Crotalocephalus gibbus (Beyr.) ............ x, ees Crotalocephalus sternbergi (Boeck) ......... x ke Gow Cyphaspis hydrocephala A. Roem. .......... Sere ae . EHarpes microporus Novdken sto. oe ee x Harpes venulosus Corday xe. oa eee ones 5 Phacops mseri Barta. ee eee x Protiusheteroebyils Date oo, ee x ~ Protiws Lepid ts Bar nte ste ee ea ee ee x, POCEUS MCKOPY CUSAC ON GA =. Hehe eae Xpiok We see that besides five species confined to F,, there are five which pass into the Lower Devonian (F,); they are very rare in F',, but common in the reef limestone of F, (IKonéprusy). It may be that the uppermost trilobite- bearing beds of this horizon belong already to the Lower Devonian. ‘This possibility is also indicated by other cir- cumstances, such as the absence of the reef limestones of I’, above the true F, beds, which are in turn succeeded directly in many places by the upper division of F, beds. It would thus seem that these uppermost trilobite-bearing I’, beds are merely ‘‘normal’’ shaly deposits, contem- poraneous with the Lower Devonian white reef limestones of F’,, a theory which might also explain the other great differences between upper F,, and F,.** | ™ Without dwelling longer on the Hercynian question in Bohemia, I will restrict myself here to the following remarks: (1) O. Novak (Sitz. d. kgl. bohm. Ges. d. Wissensch., 1886) endeavored to prove that all of F, is equiva- lent to F, and therefore of Devonian age, a view which can no longer be sus- tained; (2) the F, fauna exhibits a Silurian aspect (many species common to E,, frequent graptolites, absence of goniatites, see the faunal list given by Novak and additions to it by Zelizko (Verh. geol. Reichsanst., Wien., 9-10, 1898)); (3) the different opinions on F, and F, contained in the papers of Kayser, Holzapfel, Katzer, Frech, Seeman, etc., are to be corrected in accord- ance with the researches of Kodym (Bohem. Acad. Sci., 1918), which prove that F.a (white reef limestone of Konéprusy) is a distinct lower horizon, succeeded by F.8 (red marbles of Slivenec), the latter being identical with. Kayser’s and Holzapfel’s ‘‘Ménaner-Facies’’ of F, (erinoidal limestones). The surprising results of Barrois and Pruvost on the passage beds and boundary between Silurian and Devonian in the Calais coal basin, accepted by Stamp for Shropshire and southern Wales, became known to me too late to be taken into consideration in discussing and correlating the F, beds in the present paper. Correlation of the Silurian of Bohemia. 69 CORRELATION OF BOHEMIAN STRATA. A detailed and definite parallelization of Silurian strata in Bohemia with those in foreign countries can not yet be made, therefore only a scheme of approximate correlation is inserted here, based chiefly on the geological distribu- tion of graptolitic and other faunas and on the zones con- nected therewith. Further investigations in Barrande’s area will surely reveal many important details and solve questions either merely mentioned or omitted in the pres- ent communication; moreover, future progress in zonal division and correlation in other countries will also modify the scheme here given. Because of limited space, two or three smaller districts of the chief countries are combined in single columns. The greatest changes will probably take place when future investigations are made with due regard to the principles, facts, and views dis- cussed in Ulrich’s ‘‘ Revision of the Paleozoic systems.’’?? To the scheme above, in which only the ‘‘normal’’ shaly facies and not the aberrant reef deposits are con- cerned, a few remarks can now be added. There is in the main divisions and succession of faunas in Bohemia a general harmony with those of other countries; in par- ticular, E,a, H,@, and H,y correspond well enough with the Rastrites-, Cyrtograptus-, and colonus-shales in Sweden. But in the subordinate zones, there are consider- able differences in their vertical limits, a feature not sur- prising when we consider the great geographic separation of the Bohemian basin and the varied development of its deposits (see for instance, the relative frequency of grap- tolites in limestones in association with various molluses and brachiopods). The higher the zones, the greater the differences; this seems to be partly due to the fact, observed in graptolitic faunas in Great Britain by Miss HK. M. R. Wood, that graptolites of the highest Silurian zones show an extended vertical range and limited geo- graphic distribution. There seem to be considerable dif- ferences in the association of some graptolites in the higher Bohemian zones, as compared with those of Wen- * Bull. Geol. Soc. America, 22, 1911. I confess freely that Ulrich’s work made so strong an impression upon me that I hesitated to publish the present communication and was about to review all my former studies from the standpoints of that work. This would, however, cause another considerable delay, so that I preferred to print the present article (cf. footnote 6), the purpose of which is to offer at once a general orientation to foreign students. 70 Silurian oii Ordovician Perner & Kodym—Zonal Diwision and CORRELATION TABLE OF England and Scotland (Lapworth) (Elles, Wood, Lake) Bohemia Downtonian Monosraptus ?Temeshill hercynicus : Upper Ludlow Crinoid 2 zone 8 M.lLeintwardin- ~~ A ensis "Brachiopod | 3 elles oe ee aes = ‘ M. tumescens Cephalopod M.scanicus i: 4 °o 3 M.nilsoni Monograptus i | a ee colonus o M.vulgaris —_—_—— | OD M t ieoaser = M.testis C.lundgreni testis pe C.rigidus Monosraptus 8 | C.linnarsoni riccartonensis a _C.symmetricus _ ti: => C.nurchisoni Cyrtosraptus : eae ete ie igs Se C.murchisoni Ta aa C. Srayae Monosraptrs spiralis subbonicus Bala-Tarannon Monosgraptus turriculatus E M.exisuus Rastrites <> 2-71) eee linnei Up. Llandovery Rastrites. =)" 2c ee eee peresgrinus _ Mespiniserus _ M.gresgarius Diplodraptus.."1. fone ee a ane D. vesiculosus Low. Llandovery Biatus a Dicellosraptus aeons Up. Bala-Caradoc 5 | anceps : (Onny,Trinucleus sh.) Up. Hartfell Correlation of the Silurian of Bohemia. EUROPEAN SILURIAN See France 1°) > Sweden, Skane, Gotland = 3 (Bergeron, Barrois, 2X Kerforne) Sheand qu. of Plougastel - Ascoceras beds (Possid.eugyra ‘3 Megalomus and _ 9(Ling. lewisii = Trimerella = (Goniop. reluctans E Pine okegerety a KRY ? 2 Tlionia er (M.clavulus & Spongiostroma {| # | 8(Card.interrupta o Sphaerocodiun A (Slava bohemica “Ele ailg Phe ig aa RI a sa eee pe ame = 3S Oolite 4 (M. salweyi = Sphaerocodium 3 | 7(Bolbozoe bohemica c (B.anomala as M.sothlandicus g(M-colonus, M.nil- M.dubius ( soni, By. simplex C. carruthersi (M. dabius, M.prio- o | Metestis ( don,C.rigidus - 60 o = = pees M.riccartonen- 2 : ; M. riccartonen- : = 4(M.riccartonensis 2 : sis Pe 2! sis I S : C.murchisoni - & | C.murchisoni 5 apagaes - - = 2 : ic} a (Me jaekeli 5 M.spiralis M. spiralis G (Ret.geinitzianus © ? (M.exiguus 2(M.densus (D. palmeus M.exiguus M.turriculatus M.runcinatus dovery = Up. Llan- Etasge 7 2 i en < M.sedgwicki aie enas a |Ceph.cometa___|C.cometa (M.lobiferus 2) Ceph.folian _ 1(R. peresrinus %|M.triangulatus [M.gregarius = (Clim. scalaris = Morevolutas §(|M.cyphus === @ a s D. vesiculosus eee 3 Brachiopod shales Upper Ordovician and D.anceps beds (Orthis actoniae, Trin. pongerardi) Etage 5 | RathLand (Schmidt) id 72 Perner & Kodym—Silurian of Bohemia. lock or Lower Ludlow age in Great Britain, or in cor- responding strata in different Scandinavian districts; but as the limits of higher zones in all countries are not as sharp as those of the lower ones, and hence the range of many of the youngest graptolites is not everywhere coin- cident, it would exceed the scope of the present communi- cation to dwell longer on the particulars. Interesting data along this line may be found in papers by J. Marr,”* Lake,?> KE. M. R. Wood,” and G. Elles,?7 as regards the British Silurian, and in the papers of Tuilberg (1. ¢.), Munthe, Warburg, Hedstrom, Wiman, Moberg,?® and Kiaer?® for Scandinavian districts. In spite of this, however, the graptolites are, generally speaking, more reliable zonal guides than other groups in these beds. Thus, for instance, the world-wide Cardiola nterrupta appears already in H,6 and survives until the highest E, beds, while in other countries it is recorded up to much higher beds than those of H,8, and has a more limited range. Further discussion on the correlation of Bohemian beds will be deferred until more facts shall have been gathered by new investigations. Prague, Czekoslovakia, July, 1921. 4 Geol. Mag, 534, 1892. °° Quart. Jour. Geol. Soe. , London, 51, 22, 1895. ° Tbid., 56, 415, 1900. * Thid., 56, 370, 1900. 23 For the five preceding authors see Guides for Excursions, XIth Internat. Geol. Cong., Stockholm, 19-22, 40, 1910. * Videnskabs-selsk. skrifter, 2, Kristiania, 1908. Chemistry and Physics. 73 SCIENTIFIC INTELLIGENCE I Cuemistry anp Puysics. 1. A New Process for the Industrial Production of Barium Hydroxide for the Treatment of Molasses in Sugar Refining.— Since the discovery of the sparingly soluble barium sucrate by Péligot in 1838 many attempts have been made to extract the cane sugar from molasses by the precipitation of this compound, but up to the present time the cost of converting the barium car- bonate produced in the process into the hydroxide has been too great to render the operation remunerative, although it is stated that in the Freneh beet-sugar industry about 15% of the sugar fails to erystallize directly. DrcuIpE and BopE have now found a promising method for carrying out this process. They ignite the barium carbonate with an addition of silica in the proper pro- portion to yield 3BaO.Si0,. This mixture does not fuse at the temperature of about 1300° C. necessary for the transformation, and when the product is treated with water a very large propor- tion of the barium goes into solution as barium hydroxide. The process has been tried on a rather large scale, but has not yet been put into commercial operation. The authors state that the mother-liquors from the filter-presses containing barium sucrate allow the recovery of nitrogen and potassium taken from the soil, representing 1% and 6%, respectively, of the molasses employed. Comptes Rendus, 174, 1177. H. L. W. 2. An Advanced Course of Instruction in Chemical Princi- ples; by ArtHuR A. Noyses and Mines 8. SHERRILL. 8vo, pp. 310. New York, 1922 (The Macmillan Company).—This is a very notable and unusual textbook of advanced physical chemis- try. Instead of presenting the subject in the usual descriptive manner, the course is so planned as to give an intensive training in the application of the principles of the science to concrete problems. The text is interspersed with numerous problems, which generally require clear, logical thinking and a thorough understanding of the principles for their solution. These prob- lems are the important feature in the course of instruction. The subjects treated in the course have been selected on account of their fundamental and practical importance to chem- ists. For certain reasons, chiefly to avoid making the course of study too long, some topics such as radiation, atomic structure, colloidal solutions, etc., have not been included. The course of study laid out is evidently not an easy one for the student, but it should be of much value in developing his reasoning-power as well as in equipping him for a career in educational, research, or industrial chemistry in which the principles of physical chem- istry may be applied. It is the opinion of the authors that 120- 74 Scientific Intelligence. 150 exercises are required for covering satisfactorily the whole course as presented, but a provision is made for employing the book for a shorter course by the omission of certain designated articles and problems that are less important or more difficult than the others. H. L. W. - 3. The Determination of Sulphur in Iron and Steel; by H. B. PuLSIFER. 8vo, pp. 160. Easton, Pa., 1922 (The Chemieal Publishing Company).—The determination discussed in this book is an exceedingly important one, since sulphur has a delete- rious effect upon the metals even in small amounts, and small variations in the amounts present may have important effects upon quality. As the total amount of sulphur present, except in certain crude pig-irons, is usually less than 0.100%, and often below 0.010%, the analytical problem is a delicate and difficult one. A vast amount of research has been devoted to methods of making this determination, and an excellent feature of the book under consideration is an extensive and evidently very com- plete bibliography of the subject, with many interesting com- ments and citations of results. The bibliography covers prac- tically the whole period of modern chemistry, as it begins with the year 1797. It takes up about two-thirds of the book, and it is not only interesting historically, but it should be of great value to future workers on this problem. The author has made and records here a very large number of sulphur determinations by several methods, and he recommends the use of an ‘‘evolution’’ method, where the sulphur is first converted into hydrogen sulphide by the action of concentrated hydrochloric acid upon the metal in an apparatus of his own modification, then the hydrogen sulphide is absorbed in an ammoniacal solution of cadmium chloride, and after acidifying the latter the sulphur is determined by titration with iodine solu- tion. It does not appear to the reviewer that the author has definitely shown that his preferred method is the most reliable one, and it must be admitted that his results by different methods show unexpectedly wide variations. EH ay: 4. Organc Chenistry; by Victor von RicHtrer. Vol. II. Chemistry of the Carbocyclic Compounds. Translated from the 11th German edition by E. EK. Fournrrr D’AuBE. 8vo, pp. 760. Philadelphia, 1922 (P. Blakiston’s Son & Co.)—This transla- tion appears ten years later than the corresponding German edition, but it is to be heartily weleomed as a work of much importance to Eneglish-readine students of organic chemistry. For many years the various editions of Richter’s Organic Chem- istry have been very valuable sources of study and reference to advanced students in the subject, as they have given excellent presentations of the theories, as well as descriptions of very large numbers of compounds. Our older chemists will remember that Chemistry and Physics. io the earlier English translations of the work were made in a very satisfactory way by Dr. Edgar F. Smith of the University of Pennsylvania. At present the work appears in two volumes, the first of which deals with the aliphatic compounds. The recent German edi- tions have been ‘prepared under the direction of Dr. Richard Anschutz of Bonn. H. L. W. 5. Friction and Lubrication.—In discussing lubrication two cases are to be distinguished: (1) When two surfaces are floated apart by a lubricant, static friction is absent and the resistance to motion varies directly as the viscosity of the lubricant. (2) Where two solid surfaces are near enough together so that the friction depends not only upon the lubricant but also upon the chemical nature of the surfaces, the resistance varies as some inverse func- tion of the viscosity of the lubricant. This second case is termed boundary lubrication. It has recently been studied by Harpy and DovuBLEDAY using polished surfaces of steel, glass, and bis- muth lubricated with liquids of the paraffine series. To assure definiteness of contact area, one of the surfaces was made of spherical form, and the other a plane. The coefficients of friction were first determined for the ‘‘clean’’ state where all possibly removable impurities had been abstracted. This is to be judged from the fact that the friction has a high and constant value. The variables studied were (a) the weight of the slider, (b) the curvature, (c) the thickness of the layer of the lubricant, (d) the chemical nature of the lubricant and the solids respectively. The authors find that the friction is strictly proportional to the weight or that the coefficient of friction is (a) independent of the weight and (b) of the curvature. In studying (c) three methods of lubrication were adopted: (1) the flooded state, where the slider stood in a pool of the fluid; (2) the primary film. When a drop of lubricant with sensible vapor pressure is placed on a clean plate, although the drop to all appearance remains where placed without change, an invisible film nevertheless spreads so as to cover the whole plate as is evidenced by the fall in friction ; (3) lubrication by deposit from the saturated vapor alone. The results showed that the friction was independent of the quantity of lubricant present provided there was enough to cover the surfaces with the invisible primary film. Where the amount was less than this critical value the fall of friction was propor- tional to the concentration of the molecules in the gaseous phase, indicating that each molecule exerts the same influence as every other. The influence of chemical constitution (d) was found to be unexpectedly simple. If » denote the coefficient of friction and M the molecular weight, their relation is given by »—b—aM where a and b are parameters. The parameter a is independent 76 Scientific Intelligence. of the nature of the solid faces and depends only on the chemical type of the lubricant, varying from one chemical series to another. The parameter 6b however depends both upon the chemical series and the nature of the solid face. The interpreta- tion of these results is difficult. The authors do not accept the current view that friction is due to interlocking asperities of molar dimensions but rather depends upon molecular attraction across an interface. If asperities are to be considered they must be the atoms and the molecules of the substances. The effect of a tangential force is not merely to move the atoms and molecules in the tangential plane but also to rotate them. The mental picture which the authors offer is that the primary film of lubricant. consists of a single layer of molecules which have been oriented by the attractive fields of the solids so that their long axes are perpendicular to the solid faces. When two such surfaces are brought together the friction represents the maximum tangential stress which can be supported at some median plane of slip which is an imaginary surface parallel to the surface of the solid. This resistance is obviously conditioned by the attractive field of the solids which must vary rapidly along the normal, and also by the nature of the molecular chain of the lubricant used.—Proc. Roy. Soc. 100, 550, 1922. FB B. 6. Power Alcohol; by G. W. Monigr-Winuiams. Pp. xu, 328. London, 1922 (Henry Frowde and Hodder & Stoughton).—In view of the possible insufficiency of the world’s petroleum reserves the investigation of alternative motor fuels is an important subject which is very fully examined in this book. The first chapter passes in review the questions of the supply, the production and the economy of the various motor fuels, and reaches the conclusion that there is strong probability that before many years the supply of gasolene will be permanently unequal to the demand, and that power alcohol has an undoubted future before it as a supplementary if not as a competitive fuel. Chap- ter 2 discusses the way in which various organic constituents of plants are elaborated, and the chemical processes by which sugars are converted into alcohol by the yeasts. Chapter 3 treats of the raw materials from which fermentation alcohol is produced, namely, plants supplying starch, plants containing ready formed sugars, and cellulose, and also of the commercial processes of mashing, saccharification, fermentation and distillation. Chap: ter 4 surveys the more important starch or sugar-bearing raw materials from the point of view of yield, availability and related economy of alcohol production. Chapter 5 is devoted to the commercial treatment of cellulose materials for the production of alcohol. Chapter 6 explains the ways of making synthetic alco- hol and its production on a commercial scale. Chapter 7 reviews the methods of denaturation and various Chemistry and Physics. fl matters in connection with excise supervision in Great Britain. Chapter 8 discusses the principles of the internal combustion engine and its efficiency. In Chapter 9 the chemical and physi- cal properties of alcohol are presented in full detail both by tables and by diagrams. Chapter 10 summarizes with considerable detail the results of alcohol-engine tests with regard to per- formance and efficiency. These compare very favorably with gasolene-engine tests except in the matter of fuel consumption. Apparently the price of alcohol will have to fall considerably below that of gasolene before it can be regarded as a commercial competitor. Another and more promising line of attack on the motor fuel problem is in the direction of mixtures of alcohol with other easily volatile substances such as ether or benzoi, or even with gases such as acetylene. The final chapter (11) discusses various proposals of this nature but the subject is too extensive to receive adequate treat- ment in a book of this character. Appended to each chapter will be found a useful and numerous list of references to the particu- lar topics which have been under discussion. F. E. B. 7. The Journal of Scientific Instruments.—The Institute of Physics (England) in connection with the National Physical Laboratory proposes to publish a journal devoted to the theory, construction and use of instruments as an aid to research in all branches of science and industry. The preliminary number appeared in May. To assure its continued existence a subscrip- tion list of about 3,000 is desired. F. E. B. 8. La Théorie Einsternienne de la Gravitation; by GUSTAVE Mig, translated from the German by J. Rossignou. Pp. xi, 118. Paris, 1922 (J. Hermann).—This little volume contains a clear and readable exposition of the relativity theory and Hinstein’s theory of gravitation couched in simple language and free from mathematical symbols. It should appeal to the reader who has a knowledge of the principles and laws underlying the subject of physics, but who is not conversant with the somewhat compli- cated differential geometry involved in a detailed presentation of the general relativity. The author’s emphasis on the philosophi- cal aspects of the subject should make the book particularly interesting to those philosophers who are looking for a clear and simple account of the revolutionary changes in our concepts of space and time which the relativity principle has occasioned. A short mathematical appendix (11 pages) added by the trans- lator presents in condensed form the author’s derivation of Einstein’s law of gravitation. Ty Ps 78 Scientific Intelligence. Il. Grotogy anp MINERALOGY. 1. Gravity Anomalies and their Geological Interpretation* — This article is in part a condensation of a more detailed paper by the same author entitled ‘‘Die mediterranen Kettengebirge in ihrer Beziehung zum Gleichgewichtszustande der Erdrinde.’’ '(Abh. Sachs. Akad. d. Wiss., Bd. 38, 2. Leipzig, 1020.) The article opens with some general explanations of the formulas for theoretical gravity and of the methods for reducing gravity observations for topography. This opening section contains two or three statements not strictly correct, but these concern mat- ters not generally understood except by specialists in gravity work or in the theory of the figure of the Earth, and do not essentially affect the conclusions reached. The Bouguer anomaly is used throughout the article as a measure of the compensation. A single Bouguer anomaly meas- ures, of course, merely the net effect of the compensation and of the distant topography and affords no clue to the mass of the compensation nor to its situation. Thus no allowance is made by this method for the effect of nearness to the continental shelf, but for nearly all of Europe this effect is practically negligible. The advantages of using Bouguer anomalies are the ease with which they are computed and the fact that they imply no par- ticular depth or distribution of compensation, and that, when gravity stations are sufficiently dense, they lend themselves, according to Prof. Kossmat, to geological interpretation better than the anomalies computed by the isostatic method. The article summarizes the results of Prof. Kossmat’s examina- tion of known gravity anomalies in Europe, Asia, Africa and North America. For the last-named the war has evidently pre- vented him from receiving the more recent publications on the subject. He maintains that mountain chains are not caused by a swelling of the crust in their vicinity but by the folding under tangential pressure of certain weaker portions of the crust. Such a chain is not compensated by itself but only in connection with the neighboring piedmont regions. The additional matter imposed upon a given area by the folding may be partly com- pensated by the sinking of that area under the additional load. This sinking the author conceives as partly elastic rather than entirely flotational, the substratum being bent under the load. The result is that the compensation is regional rather than local. In regard to the evidence on this subject offered by the 124 sta- tions in the United States, the number treated in U. S. Coast and Geodetic Survey Special Publication No. 12, which evidently * Die Beziehungen zwischen Schweranomalien und Bau der Hrdrinde, by Franz Kossmat. Geologische Rundschau, vol. 12, pp. 165-189. 1921. Geology and Mineralogy. 79 was the latest publication available to him, Prof. Kossmat is non- committal. In accepting the existence of large tangential forces he does not accept Wegener’s ideas as to the crustal movements produced by them. At the close of the article there is a useful bibliography. Geologists have been rather slow to utilize the evidence avail- able from gravity observations in regard to the distribution of density in the Earth’s crust, evidence which began accumulating when Bouguer from 1736 to 1740 made pendulum observations in what is now HKeuador. One reason for the neglect of this accumulating geodetic evidence has doubtless been the difficulty of finding an unequivocal interpretation, but as gravity stations and stations where the deflection of the plumb line is known become more numerous and more densely distributed over a given area, the practical range of our interpretations of this evidence in terms of density, if not the range of purely specula- tive mathematical possibilities, becomes more and more restricted and the evidence of more real service to the geologist. Articles like the present are a welcome sign that geologists are beginning to realize that geodesy has evidence of value to them and that compensation for every topographic feature exists in some degree and must be explained by the adopted hypotheses of dynamic geology. Both geologists and geodesists will find the article profitable reading even though they may not accept all of the author’s conclusions. W. D. LAMBERT. 2. Publications of the Umted States Geological Survey, GEORGE OTIs SmitH, Director.—Recent publications of the U. S. Geological Survey are noted below: (See earlier, 3, 97-98, Jan., SPD.) ANNUAL ReEportT :—Forty-second Report of the Director for the year ending June 30, 1921. Pp. 108, 1 plate—This publica- tion gives in detail the work carried through by the Survey dur- ing the year noted. The Director dwells in particular upon the economy attained through a higher degree of efficiency. The end sought for is one greatly to be desired in all departments of the Government, but, unfortunately not often attained. In the case of the Survey the efficiency striven for is much limited by con- ditions which have already existed too long. These include inadequate office quarters, restriction in the selection of person- nel, small salaries and reduced appropriations for printing. The total funds available for 1920-21 were $405,575. The authorized expenditures were distributed as follows: For economic geology of metalliferous deposits, $50,000; of non-metalliferous deposits, $23,575; of oil, gas, coal, $110,000. Scientifie researches not directly economic were allotted $117,000; while administration, salaries, etc., received $105,000. Of the total sum available for geologic work, $122,000 was used for field expenses (including 80 Scientific Intelligence. search for potash) ; of this 75 per cent was expended west of the one-hundreth meridian. Other publications are: - PROFESSIONAL Papurs, No. 123.—A Superpower system for the region between Boston and Washington; by W. S. Murray and others. Pp. 261, 11 pls., 61 text figures. This is the report of a special investigation of the possible economy of fuel, labor, and materials resulting from the use in the industrial region named of a comprehensive system for the generation and distribution of electricity to transportation lines and industries. The investiga- tion was made by a staff of engineers under the administrative supervision of the Geological Survey The annual net saving, after fixed charges are deducted, if the energy required in this region in 1930 were supplied by a co-ordinated power system, as described, is estimated at $429,000,000; the annual return on the investment would be 33 per cent. Of the 36,000 miles of railroad in this region it is estimated that 19,000 miles can be profitably electrified, so as to yield by 1930 an annual saving of $81,000,000 as compared with the cost of operation by steam. The coal saved . annually under the superpower system would amount to 50,000,- 000 tons. The system contemplates interconnection of existing planis and systems and construction of new steam-electric and hydroelectric plants at the most favorable locations. This ‘‘superpower zone’’ embraces one-fourth of the population of the United States, with a corresponding importance in railroads, industrial plants, ete. se No: 129.< Bartse@sto ut. TopoGRAPHic ATLAS :—Forty-three sheets. . GroLocic Fouto, No. 218. New Athens-Okawville, Tiare by EK. W.SuHaw. 12 pages of folio text, 4 maps, 6 text figures. BULLETINS :—Several parts, separately issued, of Nos. 722, 725, 726, 730, 735. Part B of No. 735 by L. F. Nosuz describes the colemanite of Clark County, Nevada. This occurs in fairly extensive deposits of economic importance. WATER SuPPLY PApER:—No. 500, C. Some characteristics of Run-off in the Rocky Mountain Region; by Ropert FouLANSBEE. 17 pages, 10 text figures, and in MINERAL REsouRcES.—Numerous advance chapters. 3. Die Eruptwegesteine des Kristianiagebietes IV. Das Fen- gebiet in Telemark, Norwegen; by W. C. Bréccur. Videnskap. Skrifter. I. Mat.-naturw. Klasse 1920, no. 9. 408 pages, with 2 geologic maps, 30 plates, and 46 text figures. Christiania, 1921. —It is nearly a quarter of a century since the third volume of the epoch-making series ‘‘Die Eruptivgesteine des Kristianiage- bietes’’ appeared. During this interval detailed mapping of the region has been in progress, and a vast amount of material Geology and Mineralogy. 81 has been accumulated—about 15,000 hand specimens, 6,000 thin sections, and 300 chemical analyses. The results of this work were to have been embodied in volume IV, but the discovery of a remarkable series of alkali rocks in the Fen district by Professor Brogeger’s colleague, Professor V. M. Goldschmidt, m 1918 made it imperative to study this district at once, because it differs so strongly from the Christiania district. It is the results of this study, this interim investigation as it were, that are presented in this superb monograph. It need hardly be said that it represents a very notable achievement, but coming as it does at the time of Professor Brégger’s seventieth birthday, the remarkableness of the achievement is enhanced many fold. The outstanding feature of the Fen area is the occurrence of large intrusive masses of limestone and dolomite in association with ijolitic rocks that range from highly leucocratice to highly melanocratic. The Fen area, lying 115 km. southwest of Christiania, is 4.2 square kilometers in extent, and is surrounded on ail sides by Pre-Cambrian granite. A little less than half of the area con- sists of intrusive limestone, termed sdvite. The predominant rocks consist of a series of plutonic pyroxene-nephelite rocks. In composition they range from hypermelanocratic members— jacupiraneite—through members in which pyroxene predom- nates (melanocratic rocks here named melteigite), through members in which nephelite predominates (the leucocratic rock ijolite), finally to the hyperleucocratic end member of the series —urtite. All these rocks carry more or less primary calcite. In connection with the systematic description of this series, the occurrence of all ijolitic rocks the world over is reviewed and critically discussed, and melteigite is shown to occur in various alkalic provinces. At Fen melteigite predominates. The melteigite magma exerted a truly remarkable and profound contact metasomatism on the Pre-Cambrian granite, the result of this action being to transform the bordering zone into a wide band of aegirite syenite, or fenite. Fenite has also been formed by the assimilation of the granite by the melteigite magma. Chemically and texturally the pyrogenetic fenite often cannot be distinguished from the fenite of metasomatic origin. Countless dikes of calcite (sdvite) and a lesser number of dolomite (rauhaugite) cut the melteigite, ijolite, and fenite. Their occurrence in the fenite of metasomatic origin rules out the possibility that the dikes may in reality be roof-pendants. Professor Brogger is emphatic that the carbonate rocks are truly igneous and leaves us in no doubt as to what he means by a dike, namely that a dike consists of material that was injected as a homogeneous fluid mass during one pulse, filling the fissure and Am. Jour. Scl.—FirtTa Series, Vou. IV, No. 19.—Jcry, 1922. 6 82 7 Scientific Intelligence. subsequently consolidating there. The dikes are described. as streaky (schlierig) and as unusually rich in apatite, containing as much as 8 per cent, fluidally arranged. These tluxional struc- tures would appear to be the strongest evidence in support of the igneous origin of the carbonate dikes. Further evidence is afforded by the complete series of transitional rocks from pure silicate rocks (ijolites) to pure carbonate rocks. Many of these intermediate rocks have excellent ‘‘eutectic’’ structure, which is regarded as sure proof of their igneous origin, but in view of the fact that in recent years many of the so-called eutectic inter- erowths have been shown to be due to replacement, this criterion has not the absolute value that the author attaches to it. From the petrographic resemblance of the central mass of limestone of the Fen area to the sdvite dikes, it also is interpreted as of igneous origin. ‘The possible length of the limestone area is 2 km. and its width is 1 km. The intrusive carbonatites and older rocks are cut by alnoitic dikes, and all are intruded by diabase dikes, but these last injections are not believed to have any genetic relation with the Fen magma and its consanguineous rocks. Daly’s hypothesis for the origin of alkaline rocks is appre- clatively considered, but it is believed that at Fen the parent magma was essexitic rather than basaltic. Igneous activity began at Fen by the formation of a volcanic conduit by a gigantic explosion. The essexite magma dissolved at great depth large quantities of limestone, thereby producing the melteigite magma, which by gravity differentiation eventually yielded urtite. After differentiation the carbonate magma swam on top of the heavier silicate magma and finally solidified in the throat of the voleano. Subsequently the voleano has been very deeply eroded, and to this great denudation is ascribed the marked difference between the igneous phenomena revealed at Fen and those in the Christiania region: at Fen the phenomena are those due to deep- seated igneous activity, whereas in the Christiania region they are those produced in the comparatively shallow depths of the earth’s crust. ADOLPH KNOPF. 4. Mineral Resources of the Philippine Islands for 1919 and 1920. Pp. 70, with 4 plates and 4 text figures. Manila, 1922.— The mineral production of the Philippines has increased from 234,000 pesos in 1907 to 7,611,000 pesos in 1920. In money value: gold is much the most important, namely 3,000,000 pesos (1916), 2,620,000 (1919), 2,425,000 (1920.) Coal increased from nearly 400,000 pesos (1918) to over 800,000 (1919) and 1,452,000 (1920). Salt, sulphur, stone and sand, with other products, are also important. Iron ore exists though not yet developed and the existence of a high grade of petroleum is believed to be assured when active work of prospecting can go on. D Geology and Mineralogy. 3 5. A List of new Crystal Forms of Minerals; by HrsBert P. Wuirtock. Bull. Amer. Museum Nat. History, voi. 46, pp. 89-278.—Dr. Whitlock in 1910 published a lst of new crystal forms in the School of Mines Quarterly (81, p. 320, 32, p. 51) ; this included forms deseribed subsequent to Goldschmidt’s Index (1891). The same author has now in this pamphiet of about 190 pages covered the entire period from 1891 to 1920, and his ardu- ous labors will be highly appreciated by all interested in this: subject, one that no work on mineralogy, however comprehensive, can expect to cope with. The accepted letter, the Goldschmidt and Miller symbols, locality, and original reference are all given. 6. Handbook and Descriptive Catalogue of Gems and Precious Stones in the U. 8S. National Museum; by G&rorGE P. Merriuu, assisted by Marcaret W. Mooprty and Enpe@ar T. WuHerry. Pp. 225, with 14 plates, 26 text figures. (Bulletin 118, U.S. National Museum.)—Dr. Merrill’s contribution will be welcomed by all interested in precious stones, particularly those of American origin. The collection, even if ‘‘ poorly balanced,’’ is large and worthy of careful study. The ‘‘Isaac Lea Collec- ‘tion’’ forms a very important part; this originated with the bequest of Mrs. Frances Lea Chamberlain of the collection of her father, Dr. Isaac Lea. This has been made more valuable by the further gift from Dr. L. T. Chamberlain of numerous specimens and (on his decease) a bequest for the increase of this collection. 7. Virgina Geological Survey; THomas L. Watson, Director. Bulletin XVII. The Geology and Coal Resources of Russell County; by CHESTER K. WENTWORTH, with a chapter on the For- ests of Russell County by J. W. O’Byrng. Pp. X, 179; 28 plates (3 in pocket), 16 figures. Charlottesville, 1922.—-Russell County is in the southwestern part of the State and the part here described is a belt, 3 to 5 miles wide, alone the northwestern border. Its resources are estimated at 706,000,000 tons of recov- erable coal; in 1918 the output was very nearly 2,000,000 tons, having a value of over $5,000,000. 8. The Topographic and Geological Survey of Pennsylvania; Grorce H. AsHury, State Geologist —Bulletins 5, 9, 38-42 have been received (mimeographed). No. 40, by F. B. Beck, is on the white clay deposits at Saylorsburg, Monroe Co.; the others (see 3, 305, 384) deal with various aspects of the coal situation. 9. Geology of Drumheller Coal Field, Alberta; by JoHN A. ALLAN. Pp. 72 with index; 17 plates including a large colored geological map of the Drumheller district in pockét.—This dis- trict is the largest producer of coal in Alberta. Within the 75 square miles mapped there are 28 mines and the annual output is over one million tons. The coal seams and associated sedimen- tary beds belong to the Edmonton formation, the uppermost member of the Upper Cretaceous. The area is 85 miles east- 84 Scientific Intelligence. northeast from Calgary and 185 miles south of Hdmonton. It is assumed that in the Red Deer and tributary vaileys within the area mapped there is an aggregate of ten feet of workable coal over at least 6,000 acres; this is figured as meaning a reserve of over one hundred million tons. 10. Potash in anew area of Texas, deposit aE penne found at several levels in a well in Reagan County, Texas—The dis- covery of potash in notable amounts in a new area in Texas is announced by the U. S. Geological Survey. This has been brought to ight through the analysis by the Survey of drill cut- tines collected from the Santa Rita No. 1 weli, drilled by the Texon Oil and Land Co., in the southwest corner of Reagan County. Most of the samples contained no potash worth noting, but the samples which were taken from bailings at depths of 1150 to 1325 feet showed from 2.05 to 8.29 p. ec. K,O. The richest of the samples indicates 10.78 per cent of K,O in the soluble salts when one gram of the dry rock is dissolved in 100 ce. of water. Ill, Natorac History. 1. Arctic Alcyonaria and Actinaria; I, II, The Alcyonarva of the Canadian Arctic Expedition, 1913- 1918, with a revision of some other Canadian genera and species; Ti. The Actinaria of the Canadian Arctic Expeditions, with notes on interesting species from Hudson Bay and other Canadian localities; by A. E. Verrimu. Pp. 164, with 31 plates. Ottawa, 1922—These papers from volume VII of the Report of the Canadian Arctic Expedition, 1913-1918, contain a full systematic revision, with specific deseriptions and illustrations, of all the species of these eroups known from Arctic North American waters, including some of the more characteristic forms from the Grand Banks. Several new genera and species-are included, and the previously perplexing confusion in synonymy is eliminated. Zoologists will long be indebted to Professor Verrill for brine- ing together in this monographic form the accumulated results of his studies for more than half a century on these orouees Regs 2. Genetics: An Introduction to the Study of ia by Herpert EvGENE Wauter. . Revised edition; pp. xvi, 354. New York, 1922 (The Macmillan Company ).—In the ten years that have passed since the first edition of this widely used text-book was issued discoveries of such profound significance have been made as to necessitate extensive revision and the rewriting of a large portion of the work. Several new chapters have been added and a number of cleverly elucidative diagrams incorpo- rated. The first edition was recognized as one of the most suc- cessful elementary treatises of the subject of genetics that have Natural History. 85 been written since the discovery of the Mendelian principles. Its usefulness is attested not only by its wide adoption as a text- book in English-speaking countries but also by its translation into other languages. The present revision will restore the book to its former pres- tige. In it both the student and the general reader may find the essential facts of the rapidly advancing science of heredity pre- sented in a most orderly, intelligible, and discriminating manner. We Re, Os 3. A Naturalist in the Great Lakes Region; by Evuior Row- LAND Downinc. Pp. xxv, 328, with 452 illustrations. Chicago, 1922 (The University of Chicago Press).—The object of this book is to place in the hands of school children an intelligible and inspiring story of the natural world about them. The first chapter shows them the unfinished world at their-feet, with the elements ever at work changing the topography of hill and valley —filling up the ponds and eroding the mountains. They next read about the world in the making and the story told by the rocks and by the boulders in the fields as to the changes which have taken place on the surface of the earth in its past history. Then the living world is surveyed and the adjustment among the different groups of organisms is pointed out. This is followed by visits to the dunes, the ponds, the swamps, forest, prairie, ravine, brook, and river. In each of these pleasant and instruc- tive excursions the reader makes the personal acquaintance of the more interesting plant and animal inhabitants of the regions and learns the reasons why each has become settled in its particular environment. Although the modern name for this method of studying nature may be ecology, it is, nevertheless, good old- fashioned natural history. The book is most attractively bound in flexible covers and will 20 easily into a coat pocket, and it should be carried afield not only by the pupil in nature study courses, but also by grown-ups whenever they are fortunate enough to have an hour to spend with nature. | WeBeC. 4. La Constitution des plantes vasculaires révélée par leur Ontogéme; by GUSTAVE CHAUVEAUD. Pp. xiii, 155, with 54 text- figures. Paris, 1921 (Payot & Cie.).—In this interesting pamphlet. the author explains and defends his theory of the ‘“phylorhiza,’’ according to which the fundamental unit of the vascular plants is neither the stem nor the leaf but a composite organ composed of a leaf-like part united to a root-like part. In certain aquatic pteridophytes these units are clearly shown by young embryos; the first phyllorhiza gives rise to a second by means of a vegetative point arising laterally, the second gives rise to a third, and so on. At first the successive phyllorhizas remain distinct but, as development goes on, they become more 86 Scientific Intelligence. crowded and, where they are joined together, a stem gradually makes its appearance upon which the leaves seem to arise second- arily. Although the described conditions are clear in these lower aquatic types, the development in spermatophytes and especially in those of terrestrial habit is so condensed that the phylorhizas can be demonstrated only with difficulty. In support of his theory Chauveaud secures evidence from the gross morphology of the plants discussed and also from their minute anatomy. A. W. E. dD. The Vegetation of New Zealand (Engler und Drude’s ‘“ Vegetation der Erde,’’ vol. 14); -by lL. CockaAYNE, 2p. xocme 364, ‘with 65 plates, 13 text-figures and 2 maps. Leipzig, 1921 (Wilhelm Ene igatl Zea- land date back to 1769 and the unique characteristics of the flora of this island have been made known through a long series of works by many authors. Most of these investigations, however, have been along taxonomic lines and it is only within the last twenty years that serious attention has been given to the study of vegetation—of plants considered en masse rather than as indi- viduals or species. With studies along this line is inseparably linked the name of Cockayne, and the present voiume (in Eng- lish) embodies a clear and comprehensive summary of the work carried on by this author and his colleagues since about 1900, together with that contained in the scattered contributions of earher writers. The greater part of the book is devoted to the ‘“Vegetation of primitive New Zealand,’’ but there are also sections on the physical geography and climate, the flora and its distribution, and the history of the flora. G. E. NICHOLS. 6. Les Mouvements des Végétaux—Du réveil et du sommiel des plantes; by Ren& DutTrRocHET. Pp. vu, 121, with 21 text-fie- ures. Paris, 1921 (Gautier- Villars et Cie., Editeurs ) —Dutrochet’s essays on plant movements, which are here reprinted, were pub- lished in 1837 and exerted a profound influence on the develop- ment of plant physiology. The author was able to demonstrate the fact that many of these movements could be explained from a mechanical point of view and emphasized the important part played by osmotic phenomena in bringing them about. The present volume is the first botanical number of a series entitled, ‘‘Les Maitres de la Pensée Scientifique.”’ A. W. E. 7. Die Pflanzenwelt Afrikas, insbesondere seiner tropischen Gebiete: Die dicotyledonen Angiospermen (Engler & Drude’s ‘“Vegetation der Erde,’’ vol. 9);. by A. ENeumr. Pp. vii, 878, with 338 text-figures. Leipzig, 1921 (Wilhelm Engelmann ).— In this second part of the third volume of the Vegetation of Africa (the ninth of the series of plant geographical monographs edited by Engler and Drude) Professor Engler continues the discussion of the families of African plants commenced in Vol- Natural History. 87 ume 2. The present volume completes the dicotyledonous Angio- sperms, extending from the Euphorbiaceae through the Corna- eeae. Engler was assisted in the preparation of this work by several of his friends and students, notably. Dr. Pax of Breslau, who is responsible for the exhaustive treatment of the EKuphor- biaceae. Other collaborators include Drs. Brehmer, Brandt, Burret, Diehls, Gilg, Harms, Krause, Loesener, Mildbraed, Radl- kofer and Ulbrich. The method of treatment follows that of the earlier volumes and is essentially similar to that of the familiar Pflanzenreich. The discussion of the families is followed by a summary of the geographical relations of the African flora with examples of the various floristic elements of which it is com- posed; and also by an account of the morphology, taxonomy, dis- tribution and origin of the characteristic xerophytes of the country. eggs Maa S00) By 8. Précis de Physiologie Végétale; by L. MAQuENNE. Pp. 175, with 4 text-figures. Paris, 1922 (Payot & Cie.) —Professor Maquenne’s work gives in condensed form the essentials of plant physiology. It represents a resumé of a course of lectures given for many years at the Natural History Museum in Paris. The first chapter deals with certain physical and chemical phenomena which have an immediate bearing on the plant’s activities. In the second chapter germination is discussed; in the third, fourth and fifth, the anabolic processes of the plant; _ in the sixth, the respiratory processes; and in the seventh and eighth, the movements of water and other substances in the plant, together with the changes associated with maturity. The ninth and last chapter discusses the more important chemical sub- stances found in plants. Aa W. EB: 9. The North American Slime-moulds: A descriptive list of all species of Myxomycetes hitherto reported from the continent of North America with notes on some extra-limital species; new and revised edition; by THomas H. Macsripz. Pp. xvii, 299, with 23 plates. New York, 1922 (The Macmillan Company) .— The first edition of this valuable manual was published in 1899 and contained 231 pages and 18 plates. The increase in size is largely due to the addition of 53 species to the flora of North America, including 12 proposed as new. The extra-limital species described number 13 and occur in various parts of the world. The most important change in the systematic portion of the work is the recognition of both orders and families, these eroups being designated by the usual suffixes. In the first edition the orders had the family suffix while the families had the tribal suffix. The first 18 plates in the new edition are in large part redrawn from those in the first edition, while the additional plates illustrate the species since accredited to our flora. A com- parison of the two editions demonstrates the continued activity of 88 Scientific Intelligence. North American students of the sliime-moulds and the important results achieved during the last twenty-five years. A. W. E. 10. Soil Conditions and Plant Growth; by EH. J. RussEuu. Pp. xii, 405, with 32 text-figures. Fourth edition. London, 1921 (Longmans, Green & Co.).—Originally pubiished as one of a series of monographs on biochemistry, this book in its present form appears as the first of the *‘Rothamsted monographs on agricultural science.’’ Presenting as it does a comprehensive survey of the physical, biological and chemical conditions of the soil as related to plant growth, a survey which three thorough revisions have kept well abreast with advances in scientific knowl- edge in this complex field, its value to students both in this and in related fields has been recognized from the outset. The fourth edition, more than half as large again as the first, retains the eveneral character of the earlier editions, dealing broadly with the whole subject. G. E. NICHOLS. 11. A Handbook of the British Iichens; by ANNIE LORRAIN SmirH. Pp. 158, with 90 text figures. London, 1921 (British Museum ).—This Handbook is based on the author’s recent Mono- graph of the British Lichens, a much more extensive work in two volumes published by the British Museum. After a brief intro- duction in which the morphology of lichens is described, together with notes on their physiology, ecology, economic uses and phylo- gveny, the author gives full descriptions of the families and genera of British Lichens, and makes it possible to determine the species by means of keys. Characteristic species of the more important genera are illustrated. Since many of the British species occur also in North America the Handbook ought to prove serviceable to students of the lichens on both sides of the Atlantic. A. W. 5. IV. Miscetztangous Scientiric INTELLIGENCE. 1. The Outline of Science: A plain story simply told; edited by J. ArTHUR THOMPSON. Four volumes, with 40 colored plates and 800 other illustrations. New York and London, 1922 (G. P. Putnam’s Sons).—With the high degree of specialization that has taken place in recent years among the workers in the various fields of science there are now but very few who have been able to keep in touch with the marvelous discoveries of recent years and with the modern points of view in all these branches. Conse- quently there are but few whose knowledge of science is so far-reaching as to give them a broad view of the interrelations of the entire field; and only those could hope to succeed in present- ing to the general reader a comprehensive story of science. The editor of these volumes stands pre-eminent in this class. The first volume, which is the only one of the series which has Miscellaneous Scientific Intelligence. 89 yet appeared, gives bright promise of the phenomenal success of the whole. It consists of eight chapters, covering 296 pages, with more than two hundred illustrations and ten colored plates. The book begins with a survey of the universe, with a simply- stated but thrilling ‘‘romanee of the heavens.’’ Then follows the story of evolution, with an account of the evolution of the earth, the hypothetical origin of life, the beginnings of life, and its evolution through the ages. The reader is next shown the mar- velous adaptations of organisms to their environment, the endless struggle for existence, followed by the ascent of man. Now comes an analysis of the evolutionary changes taking place in man and other organisms at the present day and the wonderful progress which may result from man’s intelligent propagation of desirable types selected from the multitude of new forms which nature is constantly producing. The dawn of mind is next taken up for discussion and the reader is led from the simple reaction systems of the lower forms of life to the eventual devel- opment of intelligence and reason. With the completion of the story of evolutionary biology the reader’s attention is directed to that .most fascinating and speculative subject, the foundations of the universe. In this final chapter of the book the atom is analyzed in terms that any one may understand, the electron is pictured, and the inferences as to the relation of matter and enerey are pointed out. At the end of each article is a short list of the books in which _ the reader can follow the subject to which the chapter has been SO auspicious an introduction. It will be readily admitted that the aim of the book ‘‘to give the reader a clear and concise view of the essentials of present- day science’’ will be fully realized if the remaining volumes are of the character of the first We. R..,C: 2. Publications of the Smithsonian Institution, Washington, D. C.; Cuartes D. Watcort, Secretary.—The Annual Report for 1920 has been recently received. This is a volume of over 700 pages, containing the Secretary’s report already noticed (vol. 1, pp. 95, 96) ; also the General Appendix (pp. 145-690) embrac- ing twenty-seven papers of wide interest all illustrated by excel- lent plates. Explorations and Field Work in 1921. Pp. 128—The paper (pp. 1-22) by the Secretary, giving a Summary of his continued work in the Canadian Rockies for 1921, opens this pamphlet and aside from its scientific value will charm the réader by the repro- ductions of the beautiful photographs taken by Dr. and Mrs. Walcott in the region studied to the northwest of the Lake Louise Station. Other papers, by various authors in different regions, deal with paleontological, astrophysical, botanical, entomological and 90 Scientific Intellagence. archeological field work. The admirable character of the illus- trations leaves nothing to be desired. 3. Banking, Principles and Practice; by Ray B. WESTER- FIELD.—An important and comprehensive work in five volumes on the historical, legal, practical arid theoretical aspects of bank- ing has recently been published by the Ronald Press Company (New York City). The author, R. B. Westerfield, is assistant professor of political economy at Yale University and secretary- treasurer of the American Economic Association. Prof. Wester- field writes authoritatively from long experience and exhaustive study, and although the work is thoroughly up-to-date, embrac- ing the most recent developments, a conservative approach to the issues in discussion has been preserved throughout. The exposi- tion of the subject matter is admirably clear, and the various phases of banking are presented with as much conciseness as their numerous ramifications allow. The author has apparently spared no pains or caution in makine the work completely reliable, so that it constitutes a valuable and accurate symposium for refer- ence study. The careful and orderly arrangement of chapter headings and subjects is well adapted to convenience and handy use. The first volume (pp. 207) deals with the fundamental princi- ples of money, credit and banking; the second (pp. 208-507) with the banking system of the United States, including full dis- eussion, historical and descriptive, of the Federal Reserve and the Federal Farm Loan systems; the third (pp. 511-809) with domestic banking, covering cash and deposit operations, bank management, administration of departments, and other import- ant branches of the subject. The fourth volume (pp. 810-1080) continues the discussion of domestic banking with complete information concerning earning assets, and the fifth (pp. 1081- 1370) gives all the details of the foreign division, comprising foreign exchange, the handling of foreign operations, collections, letters of credit, and miscellaneous departments. The book admirably fills the needs of more than one class of people; First, the student who wishes to know what banking is and how it is done; second, the employe who desires to perfect himself in his subject and secure promotion; third, the banker of experience who will use the book for reference and latest methods; fourth, the teacher who could find no better text book in so wide a field; fifth, every inquiring mind. ‘“Bankinge, Principles and Practice’’ provides a compendium of practical information which unites in a single work the many phases of an entire subject. As such, it fills a definite need and does so in a comprehensive and authoritative manner. DEAN B. LYMAN. 4. Cuwic Science in the Home. Pp. 416. Civic Science in the Miscellaneous Scientific Intelligence. 91 Community. Pp. 480; by Grorece W. Hunter and WALTER G. Wuitman. New York, 1921 (Amer. Book Company ).—These books cannot be criticized for narrow specialism. They compass the whole wide domain of General Science, and attempt to relate this science to citizenship. The books are intended for public elementary school use and their scope is defined by their authors in the following statement: ‘‘In short, Civic Science plans to lead the child in a manner which is both logical and psychologi- eal from the simple factors which make up his environment as a living thing to the complex combinations and interactions which have arisen through what we eall civilization.’’ — Consequently the chapters range from flies, foods, and pests to street lighting, automobiles, plumbing, eugenics and euthenics. The task of organizing such eclectic material into pedagogical units is, of course, a difficult one. The authors have depended on the problem setting or project method to accomplish such unifica- tion. They have also made very free use of the blank score card as a teaching device. Thus we have score cards for the ‘‘home,’’ ‘“the natural resources of my environment,’’ ‘‘water In my home,’’ ‘‘foods in my home,’’ ‘‘removal of wastes from my home,’’ ete. The volumes are attractively printed, crowded with pictures and diagrams and references and, therefore, constitute a useful source book for the teacher. The proper teaching of elementary school science unfortunately depends to a very sheht degree upon textbooks; but, even without a good teacher, these books will awaken a popular interest in science and an appreciation of its everyday importance, thus anticipating In a way the ‘‘Science Service’’ of the American Association for the Advancement of Science. ARNOLD GESELL. ). Memoirs of the Queensland Museum, vol. VII, parts II and III; edited by the Director, HEBER A. Lonaman.—Part II (pp. 65-80, with 4 plates) contains an account by the Director of a new venus of fossil marsupials, Huryzygoma. This was obtained from the Post-Tertiary deposits in the Darling Downs. It is described as a remarkably bizarre monster of the Nototherium gvroup (Huryzygoma dunense) with a skull, the width of which exceeds the length by 46 mm. Part III (pp. 81-240, plates VIII to XII) contains an article by T. D. A. Cockerell of Colorado on Australian bees, with a catalogue by Henry Hacker; also the second of the papers on Queensland fishes by A. R. McCulloch; a new Nyctimene by H. A. Longman and on Coleoptera, mostly from Queensland, by A. M. Lea. : 6. Umited States Life Tables, 1890, 1901, 1910 and 1901-1910; prepared by JAMES W. Guover. Pp. 496, quarto. Washington, 1921. (Bureau of the Census, Samven L. Rogers, Director.)— 92 Scientific Intelligence. This volume, in addition to the full explanatory text, mathemati- eal theory, computations, graphs and original statistics, gives also tables of United States life annuities, life tables for foreign coun- tries and mortality tables of life insurance companies. The scope of the work is, therefore, as wide as the subject itself; Mr. Glover, who has had charge of it, is not only the expert special agent of the Census Bureau but also professor of mathe- matics and insurance in the University of Michigan. The tables show the rates of mortality and expectation of life for all classes of people residing in the country. It is interesting to note that the two decades from 1890 to 1910 show an improve- ment in mortality conditions for men and women under 50 years, while above that age conditions were stationary. Hurther women rank much higher than men, persons living in the country higher than those residing in cities, whites than negroes, and for most ages the native born than those of foreign birth. The work is divided into eight parts, the first five being designed for the general public, the remainder for the specialist. Part I (pp. 23-49) carefully read will give the average reader all the information ordinarily required, and enable him to con- sult the many tables with intelligence. . 4. Public Opinion; by WaLtTER LipPMANN. Pp. x, 427. New York, 1922 (Harcourt, Brace & Howe).—Mr. Lippmann’s book falls into two parts, nearly equal-in size. The first part is mainly a study in psychology, as is indicated by its headings: The world outside and the pictures in our heads, approaches to the world outside, stereotypes, interests. The author, who was eraduated from Harvard in 1910, has kept alive the interests developed under William James and others there, and applies his analysis to the conditions, both individual and social, underlying the formation of public opinion. In the latter part of the book he follows his subject into the field of polities, taking as his main topics: The making of a common will, The image of democracy, Newspapers, Organized intelligence. The author has observed the action of the modern political sys- tem, both from the outside as journalist, and from the inside as a worker in practical politics, and, during the latter part of the war, in the service of the government. He illustrates his mean- ing with concrete examples from recent history, and so does much to help the reader over the hard places in doctrine. The book is interesting. It is, furthermore, important. The author makes a determined effort to see things as they are, not as they have been supposed to be. If he has not the experience of political sages like Morley and Bryce he has a freedom from tradition, a fresh- ness of imagination, and a vigor of attack which make his analy- sis of present conditions well worth attention. He does not offer a panacea for the ills of the time, but in his concluding chapters he discusses in a sober and practical way some measures of reform. His proposal, in brief, looks to a system in which Miscellaneous Scientific Intelligence. 93 experts, trained and organized for the purpose, shall be set to ascertain facts of public interest, and so provide at least a firm basis for public opinion. CLIVE DAY. 8. Publications of the Carnegie Foundation for the Advance- ment of Teaching (522 Fifth Avenue, New York City)—The following publications of the Carnegie Institution have been recently issued. (See earlier, vol. 3, pp. 157, 307.) BuuLuEetin XVI. Education in the Maritime Provinces of Canada. Pp. vil, 50, with a map (frontispiece).—Dr. W. 8S. Learned of the Carnegie Foundation and Dr. KENNETH C. M. Simus of Bowdoin College have prepared this study of the present provincial situa- tion in higher education in Nova Scotia and New Brunswick, discussing also the elementary and secondary school conditions. The conclusion reached is the desirability of the union of six small universities in the Canadian provinces of Nova Scotia and New Brunswick to make one strong university at Halifax. The institutions concerned are King’s College at Windsor, N. 8., Dal- housie University at Halifax, Acadia University at Wolfville, N. S., Mt. Allison University at Sackville, N. B., St. Francis Xavier’s University at Antigonish, N. S., and the University of New Brunswick at Fredericton, N. B. It is proposed to raise $4.500,000 to accomplish the purpose proposed. The plan suggested is an adaptation of English collegiate organization. Each college would maintain its own student resi- dence, class-rooms, chapel, etc., where most of the freshman and sophomore work would be conducted, while advanced courses, all honor courses, and the expensive laboratory sciences would be taught in a central university controlled by a joint board and sup- ported in part by the provinces. This arrangement would make possible the equipment of a first-class university, while sacrificing few or none of the advantages of the small colleges. It would permit the denominational college with small endowment to com- mand the most extensive university privileges and at the same time retain and strengthen its denominational character. An attractive feature of the scheme from an American point of view is the method suggested for the better organization of large bodies of students—an acute problem in American colleges. Other publications are: No. 215-A. History of Domestic and Foreign Commerce of the United States; by E. R. Jonnson, T. W. Van Metre, G. G. Hvesner, and D. 8S. Hancuert, with an introductory note by H. W. Farnam. Pp. xxiv, 761, 10 maps. ee S. Lull—Primitive Pecora m Yale Museum. Hypertragulus calcaratus Cope. The original description of the genus is brief, and two species, H. calcaratus and H. tr icostatus, are mentioned without definition, the first adequate description appear- ing in Paleontological Bulletin No. 16, p. 7, under the genus Leptauchema. In this description Cope mentions several characters which are really of generic value, the real specific distinctions of H. calcaratus being apparently as follows: Molars bear a slight external cingulum which has a small cusp between the two outer crescents, representing either an incipient or vestigial mesostyle. M?® relatively somewhat smaller in H. calcaratus, and the metastyle, while variable, never as pronounced as in the John Day form. In general, the teeth are somewhat smaller than in the John Day jaws, and in one instance where P, is preserved, it is markedly smaller. Interrupted cingula are present in all the Hypertragulus jaws before me, although omitted from every published figure. Cope’s measurements are: mm. Length o£ tive molares ses ae ee 26 Length of three true molaxss....22 2... a bPAS, Length of Wash reine lies en eee 8 Wrdth ‘ot last trie molar =e... 7 This species is smaller than the smallest of the genus yet described (Cope). Of the Yale material, assuming Cope’s fone to be correct, but one specimen agrees exactly with the type in the combined length of the five teeth, and even in this specimen M?* is only seven-eighths as long. The third molar, however, has been shown to be variable and the degree of wear also affects its dimensions. I find no evidence in the Yale Great Plains material of even sub- specific departure from H. calcaratus. Hypertragulus tricostatus Cope. Cope thought he recognized a second species about the size of H. calcaratus but distinguished therefrom by the presence of but three ribs on the outer side of the third R. 8S. Lull—Primitive Pecora in Yale Museum. 118 molar, the characteristic heel being absent. This molar also lacked the posterior cingulum. H. tricostatus is considered a synonym of H. calcaratus by Hay, and with this the present writer agrees, for out of twenty-four individuals in the Yale Collection represented by the upper molar teeth, the metastyle of M* varies from good development to marked reduction in at least four speci- mens, but is never entirely absent. The degree of devel- opment of the posterior cingulum is also variable to total obsolescence. As tricostatus is founded upon a single specimen, it seems to represent merely the extreme of a variational series of which the means were still extant and therefore not a separate species but a varietal ten- dency. Cope himself says in 1884 (p. 24): ‘‘I know but the one species, the H. calcaratus Cope,’’ a statement which, as Matthew rightly says, invalidates H. tricostatus. MATERIAL FROM THE JOHN DAY FORMATION. — Hypertragulus hesperius Hay. Both Cope and Leidy have discussed hypertragulids from the John Day Basin of Oregon, but have referred them either to H. calcaratus or to Leptomeryx evansi without further attempt at specific differentiation. Scott has also figured John Day material belonging to this genus under the name H. calcaratus. Hay, however, in his catalogue, p. 675, gives the new name H. hesperius to the John Day hypertragulids, with neither definition, indi- cation of type, nor restriction to any one level. Doctor Matthew informs me (personal communication) that Cat. No. 7918, A. M. N. H., the specimen figured by Cope and later by Scott, is to be regarded as the type. It consists — of the skull and jaws and a few fragments of the skeleton. The matrix is ‘‘greenish tinged with buff and rather hard’’ but there is no record of its exact level or locality, save that it is from the John Day. The matrix color, judging from the known distribution of the large amount of John Day material in the Yale Collection, would indi- cate middle John Day as the horizon of this type. Cope’s description of H. hesperws gives no specific characters other than that the size is the same as H. cal- caratus, sometimes distinctly larger; later (1884, p. 25) 114 R. 8. Lull—Primitive Pecora m Yale Museum. che says ‘‘I can not distinguish the John Day species from the H. calcaratus, although the size is generally distinctly larger.’’ He does, however, use the John Day material | for his description of the morphology of the feet of the genus, but this part of his description is generic and not specific. The type skull is fairly complete, except that it is injured in the pterygoid region, and represents a fully mature animal in which the tooth pattern of M* is entirely obliterated. Anteriorly, a portion of the large canine alveolus is present, but no trace of the premaxillaries is preserved. ‘There is no jugal process, but the postorbital process of the frontal forms about half the posterior margin of the orbit. Scott’s figure, which was drawn by Mr. R. Weber, is the more accurate of the two except for the restoration of the superior canine behind the canini- form P,, which the author evidently mistook for the true lower canine tooth. Scott further restores the orbit as though it were closed behind, for which there is no evidence. Allomeryx planiceps Sinclair. This form agrees with Hypertragulus in the absence of the mesostyle on the molars and in the development of the metastyle on M*. It is distinguished by the closure of the orbit behind by the frontal and jugal processes which overlap but are not completely fused. The bulle are small and separated from the basi-occipital by an outgrowth of the petrosal. The brain-case is shorter than in Hypertraguius, and the interorbital tract and sagittal crest lie in one plane. Merriam and Sinclair in a later paper (1907) doubt the generic rank of these several characters. The closure of the orbit, however, is an evolutionary advance which is significant, especially as in the known species of Hyper- tragulus the jugal process is undeveloped. An imperfect skull, No. 10227, Y. P. M., shows Allo- meryx characters in so far as preserved, especially those noted in the basicranial region. It also possesses an ample brain-case. Unfortunately the postorbital region is not preserved. The Yale skull is from the upper John Day beds. © : | R. 8S. Lull—Priumitive Pecora in Yale Museum. 115 Hypertragulus ordinatus Matthew. This species is based on a complete lower jaw (No. 13011, A. M. N. H.) from the lower Rosebud beds on Poreupine Creek, South Dakota. It is larger than the type species of the genus, H. calcaratus, and about equal to H. hesperius. It may be distinguished from either by the following characters: Closing of diastema between P, and P,, and great reduction of diastema between C, and P,; increased length of diastema between caniniform P, and P,, so that general proportions of jaw are about the same; molar crowns more hypsodont than in H. hes- perius, about as in H. calcaratus; P, and P, shorter and proportionately higher than in the John Day species but less reduced than in that from the White River. In the upper Rosebud this species is replaced by Blastomeryz. Hypertragulus minutus, sp. nov. Holotype, Cat. No. 10545, Y. P. M. Upper Oligocene (upper John Day), Oregon. Fragments of upper and lower jaws and teeth. A very small form, apparently Hypertragulus. Dis- tinguishable from H. hesperiuws mainly by its small size. Cingula well developed, but metastyle of M?® much reduced, not forming the conspicuous ‘‘heel’’ of hes- perius. Its measurements are, compared with those of hesperwus: H. minutus H. hesperius Yale spm. mm. mm. ene che? tosMet ee 3 14 | 20: reroll Me ate. ie: 8.5 Notch ee WES ar, St aa 5 8.5 Leptomeryx obliquidens, sp. nov. Holotype, Cat. No. 10541, Y. P. M. Oligocene (Protoceras beds), Her- mosa, South Dakota. Poorly preserved skull and jaws, with entire series. of cheek teeth. Distingmshing characters—Large size; superior molars obliquely set; temporal ridges meeting at a wide angle to form the sagittal crest which is sharp and thin throughout its preserved length; bulle laterally com- pressed, elongated oval in shape. LEG RAS: Lull—Primitwe Pecora in Yale Museum. This form is distinguished from L. evansi of the Oreo- don beds, aside from its geological level, by being about one fourth larger, and by the great obliquity of the molars. The bulle in all specimens of L. evansz before me are more inflated. The type is an aged animal, hence in their present state of wear there is little that is dis- tinctive about the teeth. The general shape of the man- dible and the position of the mental foramina, of which there are two, are about the same in both species. Cingula are absent and the external basal pillars are feebly developed, as in evansi. Measurements are as follows: L. evansi L. obliqumdens Cat. No. 10542 — Holotype Ratio ¥7 Poe mm. mm. Length, tooth-row, P? to M® (left).. 48 1.23 39 Bene tho to, Men. ea ae 26 1.24 21 Tiseraortla, ANIC ee eee V2 Se keer geet 9 1.20 7.0 WW bla SVS eet See eget reer 12 1.54 CA. Walt: PP cs ais came earnia eee pec eee D 1.25 4. Length, tooth-row; P10, DE 2. O17 1.21 42.5 lueme th, Whe to Trois ee. ee es eee ol 1.26 23.0 Levee thn. WE eno ce eee eee 14 se) 10.8 Waihi, MD cee. Sh wea etc ee eae: th 1.40 a Nanotragulus loomst, gen. et sp. nov. CHres1.) Holotype, Cat. No. 10330, Y. P. M. Collected by R. S. Lull in 1908 at Castle Butte, Big Muddy River, near Spanish Mines, Wyo. Miocene (lower Harrison). Palate with upper cheek teeth complete, right lower jaw fairly complete, with six teeth, left with series of four teeth. Detached premolar. Imperfect petrosal? Mstinguishing characters: Upper dentition.—Teeth subhypsodont; P?-M® a compact series without diaste- mata; mesostyle lacking on molars; no trace of molar cingula nor of internal basal pillars; molars simple, of four crescents each; M* with four external pillars; meta- style enlarged toward base of tooth. Premolars three only, preserved in situ; P? trenchant, single-cusped, two- rooted, slightly grooved on outer face. P? also trenchant, of greater antero-posterior diameter than P?, apparently three-rooted, with postero-internal cingulum but no internal cusp (deuterocone), and with two faint external R. S. Lull—Proumitive Pecora m Yale Museum. 117 ridges. P* a unique tooth, triangular in section, with outer crescent not fully evolved, flanked by three faint ridges on its outer face; postero-internal cingulum form- ing a sharp, straight ridge abutting against the well devel- oped deuterocone but distinct therefrom in the unworn tooth. Measurements: | mm. en ouheeS tOn MS Feo sate ea Py oo hee he 27 emote ME hore ke oss eee aie os Sa Pee aaah ale STE RAR TD ll SE eRe ne et dae ar ene a 7 Width, M*, at base of ant. crescent........ D Lower dentition.—P,-M, a continuous series. Prob- ‘ably shght diastema separating P, and P., but condition of specimen renders this uncertain. Molars simple, with Fie. 1—Nanotragulus loomisi, gen. et sp. nov. Holotype. A, left upper dentition. B, right lower dentition. >» a little more than 3. shghtly developed cingula on anterior face. No acces- sory pillars. Posterior column of M, as in Hypertrag- ulus, with outer and inner lobes opposite and not separated posteriorly by a cleft as in Leptomeryx. Py, a simple, compressed cone, two-rooted, slightly recurved. P, high-crowned, but not so much so as in Hypertragulus, hardly rising above P,, with a main anterior cusp and rather prominent heel. P, the most complex, laterally compressed, high protoconid, and pronounced heel. Antero-internal cusp well developed. Protoconid flanked on inner side by a second cone which is confluent with it, 118 R. S. Lull—Primitive Pecora in Yale Museum. while a third bears the same relation to the heel. Thus there are three internal buttresses separated by valleys. No traces of cingula on premolars. Measurements: heneth, Po it0. We ee eee ee Beneth Vito ME Aes ee ee Dencthy, Mo ie ce a eee ee Wadi, Mie + Sina Be eee Penton *Slightly elongated by fracture between P, and P;. A detached small, slender, two-rooted premolar is present. It probably represents P, of the left ramus and is not distinguishable from that already described. . Relationships—tThis is the smallest artiodactyl thus far described from the Lower Miocene. In this respect it is suggestive of the Oligocene Hypisodus, with which it also agrees in hypsodonty and in the absence of the mesostyle. They differ, however, in the absence of a buttress on the posterior external crescent of M'-? and in the character of the premolar teeth. The inner anterior crescent of M* is markedly different. The form under discussion differs from Leptomerysx in the absence of mesostyles, character of heel of poste- rior lower molar and of the premolars, and in size. With Hypertragulus it agrees in the absence of mesostyle and the character of the heel of M,, but differs again in its much smaller size and the character of its premolars. Nanotragulus differs markedly from Merycodus in size and geologic level, also morphologically in the absence in the former of the mesostyle, in the convergence of the molar crowns, and in the character of the premolar teeth. They agree mainly in hypsodonty. From its contemporary, Stenomylus, the new genus also differs very markedly in size and in the character of the premolars. The two genera agree, however, in hypsodonty, and in the absence of mesostyle, though the latter is indicated on M?* of Stenomylus. In Stenomylus, moreover, the external face is relatively smooth except for parastyle and metastyle. In the lower dentition of Stenomylus there is greater simplicity, especially in P,, which in no way resembles that of Nanotragulus. In other words, Nanotragulus is deer-like, not camel-like as is Stenomylus. Bess: Lull—Primitive Pecora in Yale Museum. 119 I can not at present place the new genus elsewhere than in the Hypertragulide, but it is not clearly derivable from any known Oligocene form except possibly Hypisodus. The generic name Nanotragulus refers toe its dwarfed size, while the species is named for Professor F. B. Loomis of Amherst College, leader of the joint Amherst- Yale expedition of 1908 during which the type was col- lected, and the first to recognize its unique character. REFERENCES. Cope, E. D. 18753A. [On Menotherium lemurinum, ete.| Proce. Acad. Nat. Sci., Philadelphia, 25, 419-420. —1873B. Third notice of extinct Vertebrata from the Tertiary of the Plains. Pal. Bull. 16. —1884. On the structure of the feet in the extinct Artiodactyla of North America. Proc. Amer. Philos. Soc., 22, 21-27. —1889. The Artiodactyla. Amer. Nat., 23, 111-136. Leidy, Joseph. . 1873. Contributions to the extinct vertebrate fauna of the Western Territories. Rept. U. S. Geol. Survey Terr., 1, 14-358. Matthew, W. D. 1907. A Lower Miocene fauna from South Dakota. Bull. Amer. Mus. Nat. Hist., vol. 23, 169-219. Merriam, J. C. and Sinclair, W. J. 1907. Tertiary faunas of the John Day region. Univ. Calif., Bull. Dept. Geology, vol. 5, 171-205, Scott, W. B. 1899. The selenodont artiodactyls of the Uinta Eocene. Trans. Wagner Free Inst.. Sci., Philadelphia, 6, 1-121. Sinclair, W. J. 1905. New or imperfectly known rodents and ungulates from the John Day series. Univ. Calif., Bull. Dept. Geology, vol. 4, 145-161. 120 Diener—Critical Phase in History of Ammonites. Art. X.—A Critical Phase in the History of Ammonites; by C. Dinner. The extinction of ammonites, those masters of the Mesozoic seas, near the close of the Cretaceous period is a fact well known to all students of paleontology. The number of their families and genera is diminishing gradually during the Senonian epoch. Five species only reach into the stage of the Mestrichtian. Not one passes the fatal border of the Danian. It is, however, less known, that the existence of ammon- ites was threatened by a similar crisis at a considerably - earlier period of the Mesozoic era. They passed through a very critical phase at the boundary of the Rhetic and Liassic stages. All but one phylum of Triassic ammon- ites became extinct at the close of the Rhetic epoch. By the survival of this single phylum, which in the Lower Lias gave rise to the development of a new and rich fauna, the ammonites were saved from complete extermination. | KH. v. Mojsisovics was the first to notice this remarkable erisis in the history of Triassic ammonites. For fuller details the reader is referred to J. F. Pompeckj, ‘‘ Am- moniten des Rhet’’ (Neues Jahrb. f. Muineral., ete., 1895/11, pp. 1-46) and to some of my own memoirs. The Upper Triassic deposits of Tethys are divided generally into three subdivisions, the Carnic, Noric and Rheetic stages. KH. v. Mojsisovies divided both the Carnie and Norie stages into three substages, thus imparting to the Rhetic stage a taxonomic value inferior to that of the two preceding ones. Many genera belonging to all the known familes of Upper Triassic ammonites reach the acme of their development in the Carnic stage. Although a considerable number of older genera are found for the last time at this level, the ammonite fauna of the Noric stage is a continuation and evolution of the Carnic fauna in every branch of life. The last life phase of the Noric stage seems to be the first which is distin- guished from the preceding by the apparent extinction of numerous wide-spread and important genera and by the absence of any new elements either of foreign origin ~ or derived from endemic forms. Nevertheless it is doubt- ful whether a single family of lower Noric ammonites becomes really extinct. Diener—Critical Phase in History of Ammonites. 121 This decay is completed in the Noric epoch. From this stage eleven forms of ammonites only have been enumer- ated by Pompeckj, all of them of decidedly Triassic affinities. Five belong to the Norie genus Choristoceras and its subgenus Peripleurites, a phylogerontic descen- dant of the Ceratitide, whose last whorl became gradually uncoiled. Arcestes, the true leading genus of the Hall- statt limestone, is still represented by two species. ‘To these are added one species of Monophyllites (Mojsvar- ites), of Megaphyllites, and a specifically undeterminablé representative of Cladiscites, all genera of considerable vertical range. A single newcomer is indicated by Hes- perites, a genus still imperfectly known, which is probably allied to the family of Trachyceratide. It is noteworthy that not a single ancestral represen- tative of Liassic ammonites is recognized in this assem- blage. The discovery of one other genus is to be expected beds of Rhetic age. Thisis Phylloceras or, more exactly, with certainty, although it has as yet not been found in Rhacophyllites, if this subgeneric designation is extended to all widely umbilicated species of Phylloceras. Rhaco- phyllites debilis Hau. and R. neojuwrensis Quenst. are among the most common leading fossils of the upper Noric substage. In the Lower Lias, Phylloceras, Rhaco- phyllites and Euphyllites are remarkable for their rich- ness and variety. The apparent intermittence of Phyl- loceras- in the Rhetic is therefore purely accidental. It is in reality the only genus surviving the general exter- mination of Triassic ammonites. | The importance of the gradual decline of Triassic ammonites during the Rhetie epoch is evident from a comparison with the number of genera in the Carnic and Noric faune. Those faune do not contain less than 146 genera and subgenera of ammonites, which were reduced to six in the Rhetic stage. Hyatt was certainly right in speaking of a ‘‘culmination of ammonites in the Upper Trias after a period of uninterrupted progressive evolu- - tion from the early Devonian.’’ Both the Carnic and Noric ammonites were highly varied, including forms with long and short body-chambers, with few and simple clydonitic sutures (Lobites) and with a very large number of the most complicated sutural elements (Pinacoceras) ; smooth, globose shells with serial lobes (Arcestes) and 122 Diener—Critical Phase in History of Ammonites. extremely flattened shapes (Pompeckjites); shells exhausting almost every possible combination of sculp- ture from the most graceful ornamentation (Acanthin- ites) to stout ribs (Heraclites) and profusely tuberculated costations (Trachyceras). The close of the Rhetic epoch is marked by the final disappearance of all Triassic types, excepting Phyl- loceras. Primitive and highly specialized forms were equally subjected to this general extermination. In the eastern Alps the beds of the lowest Lias follow above those containing a Rhetic fauna without any uncon- formity. There is no trace of a hiatus nor of any diastrophic movement between the two groups. Never- theless the ammonite fauna of the lowest zone of the Mediterranean Lias is entirely different from that of the Upper Trias. The first impression of this Liassic fauna is the sudden introduction of a large number of types which are only a httle less manifold and diversified than those of the Upper Noric, but do not exhibit any phylo- genetic affinities with them. We are indebted to F. Waehner for their careful and detailed examination. There is httle doubt that the extinction of the different phyla of Triassic ammonites prepared the way for the evolution of a new and vigorous stock, which originated from the genus Phylloceras, the only one which connects the faune of the Triassic and Liassic periods. Phyl- loceras 1s the ancestor of the two leading families of the lowest Lias, the Arietitide and Lytoceratide. Waehner and Pompeck]j have demonstrated their intimate relation- ship with Psiloceras, the most primitive element of the Arietitide. Together with Psiloceras, more specialized types of the Arietitide: A goceras, Schlotheima, Ariet- ates, make their appearance in the deepest zone of the Lias. But they are comparatively rare, Psiloceras remaining the predominant genus in this and the follow- ing life-phase. All these genera are linked together most closely with the ancestral Psiloceras. Of equal moment is the sudden appearance of the Lyto- ceratide in the Lower Lias, where they are represented by the genera Lytoceras, Ectocentrites and Pleuracanthites. Forms transitional between Pleuracanthites and Psilo- ceras have been described by Waehner. Thus Phyl- Diener—Critical Phase in History of Ammonites. 123 loceras was destined to give rise to all Lower Triassic ammonites by the interv ention of Psiloceras. Thus an aspect quite different from that of the Upper Trias is given to the ammonite fauna of the Lower Lias. Not one of the numerous and diversified eenera of world- wide distribution, belonging to the families of Arcestide, Cladiscitide, Pinacocer atide, Haloritide, Tropitide, Didymitide, Ceratitide, Tir olitide, and Trachyceratide i 1s repr esented i in the latter. Their place has been taken by Arietitide and Lytoceratide. Phylloceras, which never played an important part in the fauna of the Upper Trias, was the only survival and was destined to become the ancestor of all Liassic ammonites. In direct opposition to these facts, Steinmann denied the extermination of Triassic ammonites at the close of the Rhetic epoch. His reconstruction of a phyletic tree, in which Macrocephalites is branching off from Juvavites, Spheroceras from Halorites, Harpoceras from Disco- tropites, Desmoceras from Arcestes, Pachydiscus from Cladiscites, need not be discussed here. It means toying with possibilities, the reality of which can never be proved. One of his eritical arguments, however, deserves consideration. He believes the paleontological record not to be sufficiently perfect to prove a real decline of the Triassic ammonites during the Rhetic epoch. It is true that cephalopod-bearing strata of Rhetic age have scarcely been discovered up to now outside the north- eastern Alps. But here they are as rich in ammonites as *In connecting Psiloceras with Phylloceras (Rhacophyllites) I am fol- lowing J. F. Pompeckj’s view, which has been set forth by this author in his memoirs, ‘‘ Note sur les Oxynoticeras du Sinémurien du Portugal, ete.’’ (Comm. serv. géol. Portugal, VI, 1906-1907, p. 332) and ‘‘Zur Rassenper- sistenz der Ammoniten’’ (3. Jahresber. d. niedersachs. Geol. Ver. Hanno- ver, 1910, p. 82). E. v. Mojsisovies prefers to consider a specialised type of Monophyllites (Mojsvarites planorboides Winkler) as the ancestor of Psiloceras. Winkler’s description and illustration, on which this suggestion has been based, are not absolutely reliable, and the type-specimen itself has, unfortunately, been lost. It makes, however, little difference, whether the one or the other view is adopted, Mojsvarites itself being closely related to the Phylloceratide. According to Pompeckj, one genus only, Phylloceras, persists throughout the Triassic and Jurassic periods. In following E. v. Mojsisovics we have to record, simultaneously with the decline of Monophyilites, the first appearance of a new and transitional form, connecting this genus with Psiloceras, the undoubted ancestor of all Arietitide. 2 Its only advocate is O. Wilckens (Naturwiss. Wochenschrift, N. F., X., No. 45, Jena, 1914, p. 20). 124 Diener—Critical Phase in History of Ammonites. many beds of the Ladinic or Noric stages. Our knowl- edge of Rhetic ammonites is certainly not more limited than that of Permian ammonites after the discovery of the Artinsk and Sosio fauna. There is, consequently, as much evidence of a decline of the group during the Rhetie, as there is of a decline of the trilobites during the Car- — boniferous and Permian. Such are the facts. They show us a great dying-out of ammonites towards the close of the Triassic and a rebirth, as it were, of a new fauna in the early Liassie, giving rise to the great wealth of Jurassic ammonite evolution. In entering into a discussion of the probable causes of this remarkable event in the life history of ammonites, we have to face the grave problem of the repeated extinction of large and flourishing groups of organisms. ‘That this extinction has been partial only, affecting all but one stock of Triassic ammonites, marks the special case of our problem. If we reflect on the multitude, the variety, and the complexity of the facts to be explained, and the seantiness of our information regarding them, we shall be ready to acknowledge that a full and satisfactory solution of so profound a problem is hardly to be hoped for, and that the most we can do in the present state of our knowledge is to hazard a more or less plausible conjecture. In discussing the possible causes of the decay and final extermination of Upper Triassic ammonites, it will be best to follow the lines which have been traced by H. F. Osborn in his memoir on the causes of extinction of Mammalia (Amer. Naturalist, XL, 1906, p. 769). Changes of Geographical Conditions—The Triassic was on the whole a geocratic (land) period. A transgres- sion of marine Rhetic beds is confined to the coasts of western Kurope. It is counterbalanced by a regression of the sea in southern China, Japan, North and South _ America, where the Rhetic stage is represented by deposits of terrestrial and lacustrine origin only. There is but a small change in the distribution of land and sea during the Lower Lias, which in some regions of the ancient geosynclines is marked by a transgression of a rather limited range. The extinction of Triassic ammon- ites consequently does not admit of an explanation by changes of geographical conditions. Changes of Climate.—The importance of this factor has Diener—Critical Phase in History of Ammonites. 125 been advocated very strongly by C. Schuchert,’ who insists on a general lowering of the temperature during the Liassic period, chiefly on the strength of the argu- ments of Handlirsch. I am happy to agree with this learned author in the opinion that the facts which prove the influence of climatic changes are many and weighty, but I think that the extinction of Triassic ammonites at the close of the Rhetic does not admit of this explanation. It can hardly be too often repeated that the decay of ammonites, near the close of both the Triassic and Creta- ceous periods, was gradual, that in the first instance it clearly began in the Upper Noric and continued through- out the Rhetie. Now, we are well informed about the climatic conditions of Upper Noriec time, due to the dis- ~ eovery of rich faune of reef-building corals in this sub- stage. Such faune are known to us from the Austrian Alps, from Timor, Nevada, Oregon and Alaska. J. Per- rin Smith demonstrated the identity of nearly all his Alaskan species with types from the Upper Norie Zlam- bach beds of the Salzkammergut. The presence of this fauna under the 60th degree of north latitude is contra- dictory to the suggestion of a lowering of temperature in the Upper Norie seas. It may be equally well to call attention to the wide distribution of several species of ammonites and bivalves (Pseudomonotis ochotica) throughout the Pacific Ocean and into the arctic region (New Siberia), which is in favor of a comparatively equable but not of a low temperature. Nor does the flora of the Rhetic stage exhibit any traces of increasing cold. It is of a remarkable uniformity in North America, England, Sweden, Germany, eastern Greenland, Spitzbergen, Persia, India, Japan, China, New South Wales, New Zealand, South Africa, Argentina, Chile and Honduras, and seems to prove a climate more uniform and milder in the polar regions than that of the present day. If a period of cooling set in at the close of the Rhetic epoch—and I do not dissent from Professor Schuchert’s opinion in this respect—it came too late to influence the extermination of Triassic ammonites, for this had been heralded long before by their gradual decay. *Ch. Schuchert, Climates of geologic time, Carnegie Inst. Washington, Publ. No. 192, p. 284. 126 Diener—Critical Phase in History of Ammonites. Lack of Internal Adaptation and Inadaptability.— Arcestes is one of the most persistent ammonite genera, ranging from the Anisic into the Rhetic stage, without undergoing any modifications of its characters. Thus its inadaptability can scarcely have been the primary cause of its extinction. : In the family of Ceratitide Hyatt signalized the first symptoms of general regression by the appearance of uncoiled and turriliticonic genera in the Noric stage. The development of uncoiled shells, which reaches its climax in the lower and middle Cretaceous, is considered as a sign of degeneration by many paleontologists. To this view I cannot assent. ‘The best instance of this mode of development is Lytoceras. It is one of the most con- servative types from the Lias up to the Neocomian, when suddenly a large number of uncoiled, straight, hook- shaped and even turriliticonic genera branch off from the old stem. All this stock flourishes for a considerable time. This does not mean degeneration, but adaptation to new and different forms of marine life, from a ben- thonic swimming to a chiefly creeping or even sessile mode of living. Still less can Lytoceras be stigmatized as degenerating, if we take into consideration the fact that it survives all its uncoiled offspring and persists into the Senonian stage. I consequently find in the devel- opment of uncoiled shapes in the family Ceratitide, which begins with Choristoceras in the upper Carnic and reaches its climax in the lower Noric substage, a sign of increased adaptability to new modes of life, not of degeneration. Peculhiarities of Constitution.—It is only touching the fringe of a great subject, if I venture to call attention to Brocchi’s hypothesis, that the gradual and successive disappearance of species might be regulated by a constant law, that their death, like that of individuals, might depend on certain peculiarities of constitution. In our special case, as in many others, the extermination of a large and flourishing group of animals can be explained satisfactorily neither by external nor by such internal causes as are accessible to examination. Jn such eases Brocchi’s hypothesis, although dealing with powers and influences of a still hitherto obscure nature, may yet serve its purpose as a first attempt to approach the solution of a hitherto unexplained problem. - University of Vienna. Berry—Saccoglottis, Recent and Fossil. 127 Art. XI.—Saccoglottis, Recent and Fossu; by Epwarp W. Berry. One of the most interesting of the romantic assemblages of fruits and seeds that constitute the sea drift, typically developed in the tropics, is Saccoglottis amazonca. Although the plant itself was described by Martius from the lower Amazon, its strange fruits had been known in Europe for over two centuries before their identity became known. They were figured by Clusius in 1605 and mentioned by Sloane in 1696 but it was not until 1889 that their botanical identification was accomplished, the details of this story having been told by both Morris! and Guppy.” The latter author deals very fully with this species, whose fruits are widely distributed in the Antillean sea drift, and are occasionally washed ashore in Europe. The fruits possess great buoyancy because of the hgneous pericarp and the numerous large resin cysts which it contains. Although the fruits are such ideal ocean travellers there is no evidence that they have established themselves on any of the Antilles where they are habit- ually washed ashore, unless the few plants in southern Trinidad have been introduced in this way through the agency of the Orinoco drift. According to Guppy this species is an inhabitant of the estuarine forests of the great rivers of Brazil, the Guianas, and Venezuela. As far as I know it has never been recorded from Colombia or Central America or anywhere on the Pacific coast. Great interest, therefore, attaches to my finding the fruits in 1919 near Old Panama in the sea drift of Panama Bay. Obviously the parent plant must grow somewhere on the Pacific watershed of Central or Northern South America. Two of these fruits from Panama Bay are shown in the accompanying figures. One with the warty sarcotesta intact and indicative of the fruit not having been in the water a long time, and the other with the outer coat worn away thus exposing the resin cavities and representing the usual form of preser- vation of these fruits in the Antillean sea drift. * Morris, D., Nature, Jan. 31, 1889; Nov. 21, 1895. *Guppy, H. B.; Plants, Seeds and Currents in the West Indies and Azores, pp. 133-137, 1917. Am. Jour. Sc1.—FirtTH Series, Vou. LV, No. 20.—Avcust, 1922. 128 Berry—Saccoglottis, Recent and Fossil. The genus Saccoglottis consists of about ten existing species found in the region from Brazil to Venezuela, and is a member of the restricted family Humiriacee of the order Geraniales. The family is usually divided into the three genera Humiria, Vantanea, and Saccoglottis, and all of the known species are dwellers in the wet forests Joe, obs d EXPLANATION OF Fig. 1. a. Saccoglottis tertiaria Berry. Side view of a prolate form. b. End view of same showing the 5 seeds. c. A single seed of same. d. Saccoglottis amazonica Martius from Panama Bay. e. End view of a worn fruit of this species showing seeds. f. Same in side view. of Brazil, the Guianas, Venezuela and eastern Peru, except for the single species Saccoglottis or Humiria gabonensis Urban which is sometimes considered the type of a fourth genus—Aubrya. The presence of Saccoglottis on the Pacific coast would suggest that the genus was an inhabitant of this general Berry—Saccoglottis, Recent and Fossil. 129 region before the Isthmus of Panama was closed, and the presence of a well marked fossil species, to be described presently, suggests an American origin for the family, and suggests further, that the smgle west African coastal species reached that continent either by means of an equatorial counter current, or before the continental out- lines had assumed their modern form. As I have pointed out on a former occasion, there are a number of facts which suggest that Guppy, in his admirable studies on distribution, has underestimated the possibilities in this direction. Although the main equatorial currents might be expected to carry coastal types with seaworthy fruits from the Old to the New World, I see sheht evidence of this ever having taken place, and there is a considerable body of evidence of dispersal in the opposite direction. If the present currents in the equatorial Atlantic pre- elude effective dispersal from west to east then we are forced to assume that the Tertiary oceanic circulation in this region differed from its present arrangement, and this could readily be brought about by changed conti- nental outlines, even though we are not in a position to predict at the present time just what these outlines were. One of the most interesting localities that I visited in 1919 was a place called Pisllypampa in the mountains north of Cochabamba, Bolivia. Here on a bleak and treeless pampa at an elevation of 11,800 feet I found a rich tropical flora of Pliocene age preserved in beds of tuff. This flora will be described in full in the Hopkins Studies in Geology. One of the most abundant elements in this Pliocene flora were the fruits of a species of Sac- coglottis, which may be described as follows: Saccogloitis tertiaria Berry, n. sp. Fruits relatively small, varying from globular to pro- late spheroidal in form, sometimes somewhat flattened by pressure during fossilization. Drupaceous in character, the thin outer flesh (sarcotesta or epicarp) being pre- served as a carbonaceous incrustation in several speci- mens. The bulk of the fruit consisting of a woody stone or pericarp. The surface is slightly irregularly mam- niilated or warty, and thickly impregnated with resinous cysts, whose cavities conspicuously and thickly pit the surface of the woody stone with depressions from 1 to 2 130 Berry—Saccoglottis, Recent and Fossil. millimeters in diameter. The stone has imbedded in it five large seeds, arranged symmetrically around the central axis, and these appear to break away tardily on drying’ as in Saccoglottis amazonica Martius, since several are found as fossils in a detached state. These seeds are narrowly elliptical in surface outhne, about 2 centimeters long and 7 millimeters wide; the inner margins are trun- cated to a central, nearly straight, gable-like keel; the thickness of the seed, i.e., measured radially with respect to the fruit as a whole, being about 6 millimeters. There is some slight inequality in the development of the indi- vidual seeds, but generally all five seeds are nearly equally developed. The total dimensions of the fruit are from 2 to 2.25 centimeters in length and from 1.6 to 1.9 centi- meters in diameter. No leaves that could be correlated with these fruits were found in the deposits. No plant family except the Humiriacee has the features shown by these fruits—thin flesh, woody stone with numerous resin cysts, and 5 radially symmetrically arranged large seeds.. I am unable to state the nearest hving relative of these fruits, bemg much hampered by the lack of comparative material in the larger herbaria, and this is well illustrated by the number of years that elapsed before the botanists at IkKew succeeded in deter- mining the fruits of Saccoglottis amazonica. The fossil fruits, as may be seen in the accompanying illustrations, are in a good state of preservation. They are certainly referable to the Humiriacee and are strikingly like those of Saccoglottis amazonica, but as just stated, I have not seen the fruits of the majority of the Humiriacee. I have ventured to refer the fossil to Saccoglottis which it so much resembles, and in any event it affords a striking ghmpse into the past history of a family which is other- wise scarcely known in the geological record. Round—Crossotheca from R. I. Carboniferous, 131 Arr. XII.—d4 Crossotheca from the Rhode Island Car- bomferous; by Epa M. Rounp. The presence of any form of fruiting body in the Penn- sylvanian is of interest, especially if it sheds hght upon the evolution of seed plants. Among fossils of this class from the Rhode Island coal basin have been found speci- mens of a new species of Crossotheca named from its diminutive size nana and described as follows: Crossotheca nana, n. sp.—Stirps 5 mm. latus, paniculi laxi racemorum fructuum sustinere videtur. Paniculi for minimum 5-6 em. longi vel longiores probabiliter; secundariz divisiones ovatas fusiformas fruges sustinent, unaquaque 3-4 mm. longa, 1-114 mm. lataque est. Fruges maturiores inclives sunt arcuta- tim paullum esse, ex raceme axe super quem sustinentur. Fruges longitudinales in partes tres dividuntur. Partes ulteriores novi- ter divisae sunt et compositae oblongarum antheridium quae separatae vel ex parte conjuncte centrali parti videtur esse Smuas timbris, (Kigs. 1, 2.) Stem 5 mm. wide, bearing loose panicles of ciustered fruits. Panicles at least 5-6 em. long, probably longer; secondary divi- sions bearing oval fusiform fruits each 3-4 mm. long by 1-114 mm. in diameter, in more mature forms inclined to be slightly arcuate, the more convex side being farthest from the axis of the raceme on which they are borne. The fruits appear to be divided longi- tudinally into three parts. The outer portions, which are again divided, are composed of oblong antheridia which are either separate or partly attached to the central part like fringe. In seeking for evidences of the presence of Crossotheca nana in other parts of the world, sketches by Gutbier of specimens! from the Zwickau coal basin of Saxony may be cited. The raceme figured by him (see fig. 3) is sug- gestive of the general appearance of the Rhode Island fossil when viewed under low magnification. Gutbier, however, makes no reference to his figures but in another text speaks of them as Sphenopteris allosaurioides,? a name which gives an interesting sidelight upon his inter- pretation of the fossil and shows that he regarded it as the fertile portion of a fern closely allied to the modern cliff brake. *Gutbier, A. von: Abdriicke u. Verstein. Zwickauer, Atlas, Pl. 10, figs. 4-4b, 1836. * Reichenbach, Ludwig: in Gaea von Sachsen (Verst. Uebersachsen) 1843. 132 Round—Crossotheca from R. I. Carbomferous. Game Fic. 1.—Crossotheca nana Round, nat. size, Pawtucket, R. I. (No. 1012 Roger Williams Park eollection, Prov., R. I.) IGS 2. FG. 2.—Crossotheca nana; detail, X 5. Round—Crossotheca from R. I. Carboniferous, 13838 According to Kidston,’ Crossotheea fruits are not, as formerly supposed, the exannulate fertile pinne of Pter- idophytes allied to the Marattiaceae but represent micro- sporangiate parts of a Pteridosperm, the sterile forms of which are of the Sphenopterid or Pecopterid type. Fig. 3.—Showing specimen as figured by Gutbier. Three typical Crossotheea species from the HKuropean coal flora show noteworthy differences from the American form. Crossotheca schatzlarensis Sturt consists of a more complex panicle than the Rhode Island specimen, the units of which are divided into four to eight antheridia as contrasted with fifteen to twenty in Crossotheca nana. The size of each unit, however, is about the same as that of the Rhode Island form although the proportions are very different, being loose where Crossotheca nana is compact. Sphenopteris (Crossotheca) Crepini Zeiller? is about the size of the Rhode Island species but more stout in form and simple in details. Sphenopteris (Cros- * Kidston, R.: Phil. Trans. Roy. Soce., vol. 198B, pp. 413-445, Pls. 25-28, 1908. Les vegetaux houillers recueillis dans le Hainaut belge, p. 41, 1909. * Kidston, R.: Proc. Roy. Phys.-Soc., vol. 9, Pl. 21, figs. 1-6, 1888. ° Zeiller, R.: Bassin houiller de Valenciennes, Pl. 13, figs. 1-3, 1886. 134 Round—Crossotheca from R. I. Carboniferous. ‘puvBIs], opoyy é [80D 9TPPTIN ‘OOUBIT ‘SOUUITOUITL A. ‘uvrpeydyso ‘IOUBIY ‘SOUUITOUITE A ‘uerpeydyse A ‘oun “OITYSYLO A [80D eTPPHAL “UOTP BULLO HL “VIpPLIoyyUe FO WPI = + |S co Cai IL ‘QOL-0L ‘Sey “8p ‘Id “prqt “xbsery ‘snznq.1bn8 SNPDIIOLOY “FO 4 OSST “46-6 ‘Soy ‘8h ‘Id “uuad “AING [OOH PZ ‘O10, [VoD “xbsary ‘saprosaysy snpw}I0LOK) “TO » CHU WEG RB Bie 1 oGF poaoo.rs BG ‘ds -u ‘nupu “f a LS, He OG Bie g oGP poyeLtys ba\ Wiens. Gee cheat jihvjnog °¢ Ajouy. Bie eR Oye? ge Gy Lt BL 609 poyeLtys Cea) a Seer es midalg °% Me 6-F Ce. 8 Cpa Wh MOVES ic OS poaoois Car Teas gSISUIMDIZIDYIS *T “UU ‘ULUT *ULUL «= * “UL ‘Ul) “UD Ss = TN Seaton ee Be aS B =| Ie = Fp ct Sy IE 5 = oa © Stes ga = + 7 Wa gg et ie 5 a 09 + Hb © > fan fart lel Ge Pm & ‘ = oct =r oR 5 » oo = ° Sen ° fo) 2 = ‘a ro) ot 4. ° Pata oe oe MAS oa eo. |e oe: “BdOYJOSS oe ag Oy ts MGR Wiks toqe & fehls ee MA OEE O40) = 2 fa>) ¢ hs a Big) 2 fe ae » ct & Le = ard ot ee © oO ie) e Bo ang Pees 99 © B st | @ (qe) ion |= 5 — : (a) 4 mR D a mR Fs 5 By my 2. ar a © ° ® =e Ds Cl s ® Ey Round—Crossotheca from R. I. Carboniferous. 135 sotheca) Boulayt Zeiller,® however, has about the same proportions as Crossotheca nana but is about four times larger. Details of comparison of all these species are shown in the accompanying table. Specimens of Crossotheca nana have been found in the Pawtucket and Portsmouth sections of Rhode Island, an indication that the species was somewhat widespread in the Narragansett Basin during the Carboniferous. Paleontological Laboratory, Brown University. °Tbid., Pl. 4, fig. 4. 136 )6F.. H. Knowlton—Fossil Dogwood Flower. Arr. XIII—A Fossi Dogwood Flower; ~ by “Poe KNOWLTON. Fossil flowers are of such rare occurrence in this coun- try that when one comes to light it seems to merit an early description. In working up some material from the Fort Union formation (Kocene) in the Glenrock coal field, Con- verse County, Wyoming, I found the specimen here deseribed, which is so obviously a dogwood ‘‘flower’’ that there is no hesitation in referring it to Cornus. It may be named Cornus speciosissima and described as follows: Involueral bracts 4, closely sessile, elliptical or elliptical- obovate in shape, rather obtuse at the apex where the tip is thick- ened. The bracts appear to have been rather thick and have the veins strong and all converging in the thickened tip. The length of the bracts is 18 or 20 millimeters and their greatest width 12 or 13 millimeters. The spread of the perfect ‘‘flower’’ must have been nearly 4 centimeters. Although no evidence of the peduncle can now be detected it is clearly the under side of the whorl of invo- lueral bracts that is exposed. At the base of the best preserved one of the four bracts the surface is seen to be’ finely striate and somewhat wrinkled, and showing through are five or six dark circles which undoubtedly represent a part of the cluster of fiowers on the upper side. This completes the evidence necessary for its reference to Cornus. Cornus has some forty or fifty lving species widely distributed over the three continents of the northern hemisphere, with a single species crossing the equator and reaching Peru. The genus is sharply separated into several groups which have sometimes been given separate generic rank, but it seems to me that they are all best retained under Cornus. In one group which embraces the majority of the species the flowers are cymose and not involucrate, while in another group the flowers are capitate with an involucre of large usually white bracts. Cornus speciosissuma belongs, of course, to the invo- lucrate group and as nearly as can be made out seems to be most like Cornus canadensis Linné, the dwarf cornel or buneh-berry, which ranges from Newfoundland to FPF. H. Knowlton—Fossil Dogwood Flower. 187 Alaska and south to New Jersey, Ohio, Colorado, and California. This species is herbaceous above and woody at the base, with a whorl! of leaves at the top, and long- stalked flowers. The fossil species under discussion is shghtly larger than C. canadensis, has the bracts more nearly elliptical than obovate, and seemingly thicker in texture. No leaves of Cornus were found in direct asso- ciation with this specimen, but the collection was a small one and so such leaves might have escaped observation. FIGURE 1.—Cornus speciosissima, new species, showing the four involucral tracts. FicurE 2.—Bract showing thickened tip. There are, however, two well-defined species in the Fort Union, based on leaves, namely Cornus newberryt Hollick and Cornus fostert Ward. Judging from the size and texture of the leaves of these forms they were shrubby species and not of the herbaceous type of Cornus cana- densis. Without being in any way positive about it, it seems probable that Cor nus Speciosissuma Was borne on a plant of the shrubby type, and not by one of the herba- ceous type, although its flowers do resemble that nies (Oi: canadensis. 1388 F. H. Knowlton—Fossil Dogwood Flower. Over twenty fossil species of Cornus have been described from North America, all based on leaves. These range in age from Middle Cretaceous to Pleisto- cene. In the Old World over forty fossil species have been named, two of which—both from the Miocene of Switzerland—are founded on the involucral bracts. Of these, Cornus buchu Heer has the bracts oblong in shape but not conspicuously thickened at the tip, and C. apicu- lata Heer,” with a long, slender evidently hardened point. Both these species are based on small detached bracts, and while C. speciosissima agrees closest in shape with C. buchu, they are distinct. Cornus apiculata is wholly unlike C. speciosissima. The exact locality whence Cornus speciosissima came is the west bank of Cole Creek, about 1 mile east of Big Muddy, Converse County, Wyo. (Sec. 36, T. 33 N., R. (7 W.). Collected by John B. Reeside, Jr., September 5, 1913. The types are preserved in the United States National Museum, Nos. 36616, 36617. U. S. Geological Survey, Washington, D. C. * Flora fossilis helvetiz, vol. 2, p. 27, pl. CV, figs. 6, 7, 1859. elideman- 28-n plen@ Vestios a alO ia lele A. Wandke—Intrusive Rocks. 139 Art. XIV.—Intrusive Rocks of the Portsmouth Basin, Maine and New Hampshire; by ALFRED WANDKE, Foxcroft House, Cambridge, Mass. INTRODUCTION. Location —The portion of the Portsmouth Basin to be treated in this paper includes 500 square miles of terri- tory that lies partly in the southwestern corner of Maine, and partly in the southeastern corner of New Hampshire. The area under consideration is easily accessible by rail being served by the Hastern and Western Divisions of the Boston and Maine Railroad. The Atlantic Shore Street Railway passes through much of the country not touched by the steam road and thus but little remains that is not easy of access. The portion of this area in Maine, except for the imme- diate vicinity of the shore where a thriving business is done entertaining summer visitors, is sparsely settled; that in New Hampshire, traversed by several rivers upon which manufacturing industries have been established, although not densely populated, contains a number of prosperous communities. Field Work.—This paper is based upon field work done during the years 1915, 1916 and 1917. During this time members of the United States Geological Survey were conducting an investigation of the geology of southwestern Maine and conferences with Dr. L. Laforge of the Survey aided greatly in deciphering the obscure geology. Previous Work.—Kxcept for the work of Jackson! of the Maine Survey in 18389, and of Hitchcock? of the New Hampshire Survey in 1868, but little had been done in this field. At various intervals since the publication of the reconnaissances of these two men, notes mention- ing the area have appeared in several publications: the clays of South Berwick, Maine, which contain Pleistocene fossils, have been cited in papers dealing with the elevation of the coast of Maine; Kemp? in 1890 described some of the dikes at Kennebunkport and Bald Head Cliffs, *Geology of Maine, Augusta, Maine, 1839. * Geology of New Hampshire, Concord, New Hampshire, 1878. * Amer. Geologist, vol. 5, 1890. 140 ~ A. Wandke—Intruswe Rocks of Maine, and mentioned similar occurrences at Portsmouth, New Hampshire; G. P. Merrill noted the Durham granite in his ‘‘Building Stones’’; Dale’ briefly referred to the Berwick ‘‘black granite’’; Powers® in 1914 had occasion to visit Bald Head Cliffs while collecting material for his paper on the inclusions in dikes. Recently the U. 8S. Geological Survey began a systematic study of this region and two papers’ relating to the geology have appeared. : Acknowledgments.—In connection with this paper acknowledgments are due to Professor R. A. Daly of Harvard University under whose guidance the area was studied; to Professors John EK. Wolff and Charles Palache, both of Harvard, for helpful aid in the micro- scopic investigation; to Dr. L. Laforge and Dr. Frank Katz of the U. 8. Geological Survey for suggestions regarding the characteristics of the formations. TOPOGRAPHY. The Portsmouth Basin lies within the tilted and dis- sected Cretaceous peneplain of the Northern Appala- chian Geological Province. The portion of this pene- plain near the shore, spoken of as the coastal lowland, to which the area under consideration properly belongs, is a land surface of low relief and slight diversity. It rises gently toward the interior and its few hills, either monadnocks or morainal material left by the Pleistocene glaciers, rarely attain an elevation of more than 300 feet above sea level. Its valleys, except for those of the short coastal streams, are relatively broad and shallow depressions whose courses, determined largely during post-Cretaceous time, were but slightly affected by the glaciers of the Pleistocene period. The shore line is marked by a succession of bold rocky head- lands between which are marshes fronted by excellent sand beaches. Wherever rivers enter the ocean they generally afford good harbors, this being one result of a recent drowning of the shore. *G. P. Merrill, Stones for Building, 1897. ° 'T. N. Dale, U. 8S. Geol. Survey, Bull. 313, 1907. °S. Powers, Jour. of Geol., vol. 23, 1915. "U.S. Geol. Survey, Prof. Paper 108, 1917. Portsmouth Basin, Me. and N. H. 141 AREAL GEOLOGY. General Statement.—The Portsmouth Basin resembles in many respects the other fragmentary geological basins which have been recognized in the as yet imperfectly known area of the Northern Appalachians. The rocks consist of fine-grained steeply inclined sediments supposed to be of Upper Carboniferous age, of both intru- sive and effusive igneous rocks, and of some thoroughly metamorphosed rocks of doubtful origi and unknown age which have been classified as gneisses and schists. The sediments and the metamorphic rocks have a general strike of N 45° KE, but local departures from this general direction are numerous; the dikes of the region follow a northeasterly trend; and the batholiths are elongated in the same direction. The dip of the stratification of the sediments and of the schistosity of the metamorphics is, on the whole, to the northwest, but frequent departures from this direction indicate, perhaps, local folds and erumplhngs. The gneisses and schists occur both to the northwest and to the southeast of the sediments of Upper Carboniferous age, and since the highly metamorphosed rocks almost close in on the sediments to the southwest, a basin-like arrangement results. Sedimentary Rocks. General Statement.—Hitcheock® in his survey made no attempt to separate the rocks of the Portsmouth Basin into groups or formations, as is indicated by the following quotation: ‘‘This name (Merrimack Group) was infor- mally applied by my father to the mica schists, slates, and quartzites contained in the Merrimack River, in Massa- chusetts. They skirt the Exeter sienites in New Hamp- shire, lying in troughs in an anticlinal. They probably belong to the earliest Silurian.’’ On purely lithologic grounds it seems possible to separate this Merrimack group of Hitcheock’s into two groups. The first contains three formations which have been called the Gonie schist’, the Berwick gneiss’, and the Rye gneiss*; the second con- “Geology of New Hampshire, Concord, New Hampshire, p- 27, 1878. a Correlated by Katz, as a part of the Eliot formation but lithologically different. b Is the same as the Berwick gneiss of Katz. cIs the Algonkian complex of Katz. 142 A. Wandke—Intrusiwe Rocks of sists of two formations, the Kittery quartzite’ and the Eliot phyllites. No definite age has been assigned to the first group nor can correlations be made between the different members; the second group, it seems, can be traced to Worcester, Massachusetts, where fossil-bearing rocks,® Upper Carboniferous in age, have been found. The writer, however, has been able to trace the Kittery formation only as far as Lowell, Mass. From there on to Worcester, Mass., a distance of 30 miles, glacial material makes it difficult to follow the strata. The rocks at Worcester from which the fossils have been reported are lithologically unlike those of the Portsmouth Basin. In the hand specimen the typical Kittery quartz- ite is almost identical in appearance with the Isleboro!® formation of Rockland, Maine, perhaps of Cambrian age. It would seem, therefore, that until fossils are found within the Kittery formation its age must remain a matter of inference. The Kittery and Eliot formations are however provisionally dated as Carboniferous, follow- ing the lead of the U. 8. Geological Survey. Metamorphic Rocks of Unknown Age. General Statement——This classification imeludes the Gonic schist and the Berwick gneiss which form the north- western boundary of the basin, and the Rye gneiss on the southeastern side. Limits have been assigned to the extent of these formations with the understanding that they are not to be regarded as fixed. Gonic Schist—The Gonic schist has been named from the typical exposures occurring in the falls of the Cocheco River at Gonic, New Hampshire. The rock is a biotite- garnet schist evidently produced by dynamic and contact metamorphism of argillaceous and arenaceous sediments. Cutting across the schistosity of the forma- tion, although occasionally paralleling the same, are a great many stringers of coarse pegmatite and veins of quartz. It is entirely probable that these stringers and veins are genetically related to the intrusive pegmatitic d The same as the Katz’s Kittery quartzite. els the Eliot slate of Katz. ° David White, Jour. Wash. Acad. Sci., p. 115, 1914. U.S. Geol. Survey, Folio 158, 1908. Portsmouth Basin, Me. and N. H. 143 eranite which outcrops less than 2000 feet distant from the exposures of Gonic schist. The formation has, in general, a gentle northwesterly dip, but departures from the normal dip and strike are abundant. The thickness of the formation is unknown. Berwick Gneiss.—This formation is typically devel- oped at the falls of the Salmon Falls River in Berwick, Maine. Dynamic and static metamorphism have entirely obseured the original texture and composition of the rocks which now consist of thin bands of mica schist alternating with well banded paragneiss. The formation appears to-have been derived from an argillaceous sand- stone or a graywacke. Because of metamorphism some of the bands are now. characterized by glaucophane. Associated with the amphibole are feldspar, quartz, biotite, chlorite, pyrite, and titanite. Quartz veins vary- ing in width from mere stringers up to masses two feet in thickness frequently cut the formation. Although some of the veins are developed parallel to the foliation of the gneiss, the general tendency is for them to occur ‘im cross-cutting relationships. The thickness could not be determined. Departures from the general north- westerly dip of the foliation, which in rather limited areas may undergo wide variations, suggest that the formation 1s compressed into several tight folds which have been overturned to the southeast. Little can be said of the position of this formation in relation to its neighbors. Rye Gneiss—The Rye gneiss has been so called from the typical exposures that occur along the Rye coast of New Hampshire. The most northerly outcrops of rock belonging to this formation are found on Gerrish’s Island, Kittery, Maine. From this locality the rocks have been traced south and southwest into Portsmouth, Rye, North Hampton and Hampton, New Hampshire. At Hampton Falls the country becomes drift-covered and for a space of six miles westward across the towns of Kensington and Kast Kensington no outcrops are to be seen. Tn the town of Kingston eneisses outcrop at Rock Rimmon Hill. _ At the type-locality the gneiss is well banded, consist- ing of alternations of light feldspathic layers, which become pegmatitic with dark- fine biotite-rich bands that Am. Jour. Sci.—FirtH Series, Vou. IV, No. 20.—Avausr, 1922. 10 144. A. Wandke—Intrusive Rocks of are schistose. On Gerrish’s Island the rock is fine- orained, the banding characteristic of the typical gneiss being absent. As narrow stringers of feldspathic mate- rial penetrate the rock it loses its sedimentary habit. The feldspathic stringers may increase in size until they attain a width of fifteen feet. The entire occur- rence is suggestive of the feldspathization described by Wherry"! in the pre-Cambrian highlands of eastern Pennsylvania. On Newcastle Island the process of feldspathization is well marked, and the gneisses become distinctly granitized. 3 : A number of dikes cut the gneisses, but in not a single instance in the good exposures along the coast has the metamorphism so characteristic of the gneisses affected a dike. Since some of these dikes are earlier than the batholiths (to be described later) the period of graniti- zation and feldspathization must be earlier than the period of batholitic intrusion. Grouped with these gneisses are some rocks which sug- gest altered basic volcanic flows. These have not been studied in detail. Sedimentary Rocks Upper Carboniferous in Age. General Statement—The Upper Carboniferous rocks form a single group consisting of two formations. The Kittery quartzite is the older of these and the Eliot phyllite the younger. Boundary lines between the two cannot be drawn with any great degree of accuracy, and the lack of exposures and the prevalent glacial drift prevent a close correlation. The two formations appear to be conformable. | Kittery Quartzite—The typical Kittery quartzite is found just north of the bridge of the York Harbor and Beach Railroad that crosses Spruce Creek in the town of Kittery, Maine. At this locality the formation con- sists of a series of thin beds of red phyllite that alternate with thicker strata of a dense fine-grained grayish green or bluish quartzite. Variations from the normal are, however, abundant, the differences being due in part to primary causes during the time of deposition and in part to secondary changes during and after the period of fold- * Paper read before the Geol. Soc. of America, 1916. Portsmouth Basin, Me. and N. H. 145 ing. The thickness cannot be accurately stated. In a section from Godfrey’s Cove northwest to the contact of the sediments with the granites, a distance of eight miles, the rocks dip almost invariably steeply to the northwest, and although several folds seem to be indicated, the covering of glacial drift obscures the structure. Along the coast where outerops are more numerous a duplica- tion of lithologically similar rocks appears at such inter- vals as to sugcest that the formation has a thickness of about 2000 feet. The lower limit of the Kittery could not be established: in the southeastern part of the area the formation is seemingly a faulted contact with the Rye gneiss; in the northwestern part it appears to stand in a faulted— relationship to the Berwick gneiss. Multitudes of dikes cut this formation. Eliot Phyllite—This phyllite is typically developed im the town of Ehot, Maine. It is, as a rule, gray in color but red, brown, black, and buff phases are common. Slight variations in texture and composition are observed and in the formation calcareous and carbonaceous phy!l- htes, true slates, and a hght yellow to brown gray crumpled and easily eroded argillite have been included. Quartz veins and dikes are frequently seen cutting the formation. Because of the lack of exposures it becomes diffeult to establish a standard section, and hence the thickness can at best merely be estimated. South of Kliot where exposures are most numerous the thickness would seem not to exceed 2500 feet. Since the passage from quartzite to phyllite is effected by transitional beds which gradually change from quartzite with thin beds of phyllite to homogeneous phyllite or shale, and because the prevalent dips. are such as to carry the quartzite constantly beneath the shale or phyllite, it seems certain that the Eliot and Ixittery formations are conformable and that the Klhot is the younger. IGNEOous Rocks. General Statement—The igneous rocks of the area include a great many dikes, “several subjacent bodies, a few effusives, and some mixed gneisses. The mixed gneisses are pre-Carboniferous in age and occur in the 146 A. Wandke—Intruswe Rocks of Rye formation. The effusives, or at least rocks resem- bling metamorphosed effusives, occur in a narrow belt at Portsmouth, New Hampshire. No attempt was made to study them. The discussion will center upon the dikes and subjacent bodies which for the most part cut the Upper Carboniferous rocks. Dikes. The dikes, because of their number, their wide range in composition, and the manner and order of their intrusion form a group of rocks well deserving of more detailed study. Although every outcrop carries one or more of them, the best display of dikes occurs along the coastal section from Perkin’s Cove to Brave Boat Harbor. In these eleven miles there are several hundred, perhaps a thousand, dikes and they vary in width from stringers hardly thicker than the blade of a case knife up to 200 feet. Multiple and composite examples abound. In several instances three or more dikes of the same or of contrasted compositions may occupy a single fissure. In composition they range from an olivine-bearing lamprophyre through diabase, diorite, and granite porphyry to paisanite and aplite. Some abound in inelusions, which being fragments either brought up from depth or torn from the adjacent walls, occur in various stages of assimilation. In short, the dikes of the area form a remarkable display and illustrate most of the phenomena associated with intrusions of this type. All of the observed dikes are later than both the period of folding and the period of granitization which produced the Rye gneisses, and for the most part appear younger than the quartz veins and the metamor- phism which characterize the outcrops from Perkin’s Cove to Brave Boat Harbor. In a broad way they may be separated into two groups,!” (a) those earlier, and (b), those later than the stocks and batholiths. On the basis of composition each of these groups may be subdivided and such a sub-division is helpful in gaining a clearer conception of the changes in the magma from which the dikes were derived. “A similar grouping was made by C. H. Clapp for the dike rocks of Essex County, Mass., U. 8. Geol. Surv., Bull. 704, p. 107, 1921. Portsmouth Basin, Me. and N. H. 147 First Group. Although this group has been divided into three sub- eroups,—diabases, diorites, and granite porphyries, no hard and fast line of division can be drawn, since the dia- bases grade into the diorites and the diorites show transi- tion phases which suggest the granite porphyries. Diabases.—F or the most part the diabase dikes are the oldest of the region. In the batholiths other diabasic dikes are seen which indicate a second period of diabase intrusion as a late phase of igneous activity. This region illustrates therefore the initiation of a period of intrusion by a great development of diabase dikes and the recurrence of similar rocks at the close of the irruptive period. Diorites.—As the rocks in the preceding class grow lighter in color they grade into the diorites. The lighter colored members of the group have a banded appearance due to the development of innumerable segregations of quartz and feldspar in subparallel lines that follow the contacts. The development of quartz in these rocks is worthy of note for it may indicate that the magma of which they are offshoots began to approach a quartz diorite in composition. Granite Porphyries.——Under this heading have been placed all of the light-colored typically porphyritic dike rocks of which the phenocrysts are invariably quartz. and feldspar. Some of these are characterized by resorbed quartz phenocrysts, by pyrrhotite instead of pyrite, and by a groundmass which consists almost entirely of myrmekite. The myrmekite may well have resulted from the escape of volatile components as has been suggested by Sederholm." Second Group. General Statement.—This group consists of two sub- groups of diaschistic dikes,—the one contains the paisan- ites, tinguaites, and camptonites; the other the aplites and the late diabases. The first sub-group is gener- ally associated with rocks that belong to the alka- line clan; the second with those which belong to the sub- alkaline clan. “ Bulletin de la Commission Geologique de Finland, No. 48, p. 81, 1916, 148 A. Wandke—Intrusive Rocks of _. First Sub-group. -Tinguaites——The tinguaite dikes vary from a deep blue to a light gray in color. The feldspar is anortho- clase. The aegerite needles which dominate the ground- mass give the rock its characteristic color. — -~ Camptonites—The camptonites are poorly exposed, but wherever found they are characteristically developed. They are full of inclusions and contain large porphy- ritic erystals of glistening poikilitic hornblende. The hornblende is full of feldspar and apatite. - Paisanite.—A. single example of this type of dike was found near the crest of a hill just north of ‘‘Scotland,’’ York, Maine. The minerals present are quartz, albite, microcline, microperthite, aegerite, riebeckite, arfved- sonite, zoisite, and an undetermined titaniferous mineral, brown in color and platy in habit. Both zoisite and the feldspars are poikilitically intergrown.. Second Sub-group. Aplites——The aplites, present in each of the subjacent intrusives, are composed essentially of feldspar and quartz, the darker minerals being sparingly developed. Their composition and texture present no unusual features. : Diabases—The diabases of the second generation differ but little from those of the earlier period. They are found cross cutting all of the other types of rock. Stocks and Batholiths. General Statement.—Large intrusive bodies occupy a considerable part of the Portsmouth Basin. They are of especial interest because of their contrasted composi- tions, their contact actions, and their method of emplace- ment. - For purposes of easy reference these bodies have been named the Rochester biotite granite; Durham quartz diorite; Hampton granodiorite; Agamenticus — complex, which consists of biotite granite, gabbro, sye- nite, and alkaline granite; Cape Neddick gabbro; York Harbor biotite granite; and the Brave Boat Harbor biotite granite. _ Portsmouth Basin, Me. and N. H. | 149 The New England province seems to have been affected by two periods! of batholithic intrusion. The first is usually dated as Devonian (?) and is characterized by eranites, granodiorites, and quartz diorites; the second, or Carboniferous, is characterized by alkaline granites of which the Quincy granite is the typical example. It is probable that the subjacent rocks of the Portsmouth Basin fall into these two groups. In (1) may be placed the Rochester granite; in (2), the Durham, Hampton, Agamenticus, Gape Neddick, and York Harbor ocecur- rences. The granite at Brave Boat Harbor is much more sheared than are the other nearby intrusives. It is doubtfully classified as a Carboniferous intrusive. Rochester Biotite-Granite—This body has no unusual features of mineralogical composition. Outcrops are not numerous, the best exposures occurring in a few small quarries. The rock cuts the Gonic schist and may be a pre-Carboniferous intrusive. Pegmatite veins cut the granite and as a rule carry quartz, perthitic feldspar, and muscovite. Durham Quartz-Diorite—The Durham quartz diorite batholith is an elongated body that extends from two miles southwest of Exeter, N. H., to within one fourth mile of Rollingsford, N. H. It occupies about one third of the Dover quadrangle, has an extreme length of twenty miles, and a maximum width of four and one half miles. Outcrops showing the crosscutting relationships of the body are abundant and the boundaries as shown on the map will need but slight revision. The elongation corresponds to the dominant strike of the invaded sedi- ments. In places inclusions of the Kittery formation occur in various stages of Pesci eho. Although the composition has been indicated as quartz diorite this term merely covers the dominant phase. A distinct gradation from a basic margin to an acidic interior is one of the features of this body. In a section taken across the batholith in a southeasterly direction through the town of Durham, the following variations in composition have been noted: a marginal phase of gabbro, quartz norite, quartz gabbro “quartz augite gabbro; an intermediate phase of quartz augite diorite, *B. K. Emerson, Geology of Massachusetts and Rhode Island, U. S. Geol. Survey, Bull. 597, p. 172, 1917. 150 A. Wandke—Intrusive Rocks of f- Se ae INTRUSIVE ROCKS ¢ - e el oe AT MT AGAMENTICUS he A NRK RE ROK IRIRTK f oo yi au Steg re Caine ie York County Mame / 4 - = . oe Se Se ty Mie KK* KK EKO t N EN x< XK X€ KK K K ‘Berwick Quartz Diorite* « + | Oe eh oe Ue Wane hm ETRE KE KRU Kae Sane 3 4 “ Vacs L IK MORO Keine Rilon we a = a 2a v// v SRR RE ROKR Oe APRS ene an shen ee a Fe : ai, Tee tare Naim Khe OEIC ie. ag? am - & ~ he i ne ca - — a 4 ee pans Se Be = acy Si of} Ce & a oer ici ee = Cm : ; f ¢ : ee Soa ~ « Kittery Quarizit OCEAN Qua 8 = ¢ t iy Ay iy t , 6 iy ' & - an at < Ie NLS Neca = Ca Ratee < ie ac a “a VY oy C2 eee ie =. - Oy 4 e ae a Yy Cx - : ~ ittery Sigs iY v Ne NICK y ae oN t AY SeXy Ay ‘ iN Pe ' EN, , 4 iN (esti tea Ne EN (7 eN ERR EN ahh Os ~ ‘ “ye Se, MeN a Oo = : = <| C b oe = ) V d z / 5 a “ “+ \ < (| e ec Bei. NEN a esate n pila Shi PUA EEN rales Z 3 f v nae Pain? aN fo a Zit ie AN \ 3 DP de ohn ye re a : 3 i es © ‘t ra , hac Se . t eS - PE ey Re Ne 4, STIS » XV ca - & ee Fe y + UTC ae v Vv Vv CEN AND TCL VEG bs eo a x ‘ 2 / RE LTA t f , ‘ s ao & ce e ee # + 4 Vv oy ~ c Were Bes See eos ae : aes ae ial (ee ae Sg ‘ ie oe v Ries / ~/ x anos eee a fi! aN / ~y/ LTS = a Paige e voy i Laat / « 4 s a PP ee e_ 5 t+ + ++ / Vi oe Ties Vv / ) LQ aN , x a - Biotite Granite ; t+ ns i i — v ange Be ay Pires pay ane tle x ++ fF pes si Pier Cont => > = me iS <= oe eee pees au N < fe _— ePIC OIC Sere ~ - = < aM es Nes mien i it . x . . = e N aN iy PU Alkaline Granite @ R Ny ~ ‘ Ve. ic Be ace NAB ve > y : \ . : s N Oye 1 \ x / 2g BZ; < Portsmouth Basin, Me. and N. H. ta quartz diorite, quartz biotite diorite; and a central phase of granodiorite, granite, and granite aplite. Volumetric composition of two phases of the Durham quartz diorite: I II -Plagioclase (Ab, An.—Ab,An,) ....... 63.15 Peal Miecroperthite to oligoclase .......... ees re 56.06 TE SES SO a A elo AES Ae 10.03 17.10 pierce ee ak tae ae ak he 15.92 (SEE IS Et See See ee aie 8.91 rete Meer pPRMe HE eee on ee a ees 1.68 10.10 Pi Dele PS eo ss Sate ee Se ee pie OL 2 DLS eS eter 99.98 g919 I. Quartz diorite 300 feet from the contact. II. Granite from the central portion. Other bodies related to the quartz diorite-—Two other bodies within the area resemble the Durham batholith, not only in composition, but also in a similar gradation from basic margins to a more acidic central phase. One of these, a small stock, occurs about two miles east of North Berwick; the other, also stock-like in habit, occurs at the intersection of the North Hampton, Exeter and Newington boundaries. Cape Neddick Gabbro—The Cape Neddick gabbro forms a small oval stock measuring about one-half by three-fourths of a mile. It is well exposed and shows particularly fine contact phenomena as well as variations in composition. This stock shows four phases: (a) the contact phase, a medium to fine-grained rock rich in olivine, myrmekite, and apatite, and contains abundant inclusions of the invaded quartzites; (b) a dark coarse- grained phase (phenocrysts may show a diameter up to 2 cm.) having about equal amounts of the hght and dark minerals which are poikilitically intergrown and characterized furthermore by a vertical banding parallel to the contacts; (c) a very dark, almost black phase, medium to coar se in grain, ‘containing olivine embedded in large poikilitic crystals of hornblende, biotite, and titaniferous pyroxene; and (d) a light colored central phase composed largely of niaaeces feldspar accom- panied by small amounts of quartz and orthoclase. 159 A. Wandke—Intrusive Rocks of Volumetric composition of the four phases of the Cape Neddick gabbro: | : I EL Til IV Olivine 25402 os ease ee ie iW) 1.50 6216 eager PlagioGlase: G40. eee 45.50 45.60 D185 87.10 Alkaline feldspar 9. baa by amet ee ee ae 16 PYVORONG oe ee ce eee ona 25.00 8.23 ‘9.43 Hornblende ....... ee oom 10.01 21.42 .68 BiOUibe wes Ee eee eee ie erie 7, eee ne Hea | Hypersthene ...... a neeonrc ae 2.09 ete ae eae Macnembe! So0r Sige 29708 etal: 28: jal 2 9 28: 40" 52>? 55 *o 102) 127 OT 14 398 SIF Sais es *1. 201 -115° 26) °499) 59° SS SO ee 2s GQ AN> =34- 195340 25 335s *e O83" 174 Sit a4 Ae ye ees *This study was done through the courtesy of Professor A. F. Rogers of Stanford University, Calif., to whom the writer offers his sincere thanks. ° The calculations of the co-ordinate angles were made mainly according to the formule given by A. J. Moses and A. F. Rogers (School of Mines Quarterly, vol. 24, No. 1, 1902), and partly by the method, proposed by H. E. Boeke (Die Anwendung der stereographischen Projektion bei kristallogra- phischen Untersuchungen, 1911, pp. 41-46). Watanabé—Babingtomte from Japan. 161 erystal faces are often striated and curved, and the appearance of double and multiple images makes it doubtful which is to be measured. In spite of such diffi- culties in measuring, the mean values obtained by measurement closely agree with the caleulated ones. The observed forms and their co-ordinate angles are shown in Table LI. The four forms marked with an asterisk are new to this mineral. The erystal orientation and elements, used for- notation and ealeulation, are those of Dauber,® the advan- tage of which has been stated by Palache and Fraprie.’ It is necessary, therefore, to change the symbols of forms, when these results are compared with the descriptions, which are found in the treatises of Dana and Hintze, or with those of Goldschmidt. The caleulated and measured angles of the forms in the vertical zone agree closely; but with regard to the terminal faces, the deviation of the measured values from the caleulated ones is often great. This is partly due to the general disadvantage of a theodolite goniometer that the possible error by measurement of the meridional angle ¢ increases as the polar distance p diminishes. To compensate this deficieney, the interfacial angles between the faces belonging to the zone (bc) were measured by using the theodolite goniometer as a one-cirele one. The results of these measurements fairly well coincide with the calculated values as shown in Table II. TABLE II. Measured. Caleulated. (mean). 10) ee ret Swe S25 oa. 5 ie AS 15, ae eae 87° 24 87 32 li ae a 44 40 44 08 cs 42, 44 43 O7 ius... ol oak 45 13 45. 22, por. 322)>,4 47 23 47 25 * The crystal elements of babingtonite, given by Dauber (Pogg. Ann., 94 402, 1855) are as follows: one eee dee 2 Oa 1 —— O0n Ul, = 95746". y= 112° 22", ae or. 48’, ac— 81" 28", be =— 92° 30’. These values were obtained by him from the results of measurements on more than eighty crystals of babingtonite from Arendal. * Palache and Fraprie, Proc. Amer. Acad., 38, 382, 1902. Some misprints occur in their table of corresponding forms for the different positions. 162 Watanabé—Babingtomte from Japan, The crystal habits and the zonal relations of the faces are illustrated in the accompanying figures.® Among the observed forms, both b and k are generally well developed and give a prismatic habit to most crystals, although some platy crystals are produced by the pre- dominance of b. These two forms are usually character- ized by vertical striations, caused by their mutual osceil- latory combination. The forms a, h and g all appear as narrow faces, which truncate the acute edges between 5 and k. Among the terminal faces, c is best developed in size, though it is striated parallel to the axia a, owing to the oscillatory combination of c and d. All other forms are represented as either narrow or minute faces. Physical Properties. The mineral is black in color and has a brilliant vitre- ous luster. Crystals are commonly opaque, but in thin sections transmit light and gives deep color. The pleo- chroism is very marked, the axial colors being as follows: Dos oes: Raat ae deep emerald-green, A Ge eS purple-brown, Sa EES deep brown. In this particular point, the mineral is distinguished from other triclinic members of the pyroxene group, which have the similar crystal forms. The absorption is strong in the order of X > Y > Z, and the dispersion is marked. Hence, it is difficult to accurately determine the extinction position. As the averages of repeated measurements on several sections, the extinction angle on b(010) is given as about 37° from the vertical axis c, and that on c(001) is about -5° or -6° from the axis a. *In drawing these figures, a gnomonic projection of the erystal on the plane normal to the prism zone was first made (fig. 1). Each edge in the plans on this plane (figs. 2b and 3b) is normal to the zone line, which con- nects the poles of the faces intersecting at that edge. Next, to make the elevations on the plane of b(010) (figs. 2c. and 3c), the intersection of this plane with the plane of projection and its angle point were found on the projection. In this particular case, they are shown as the line LL’ and the point B respectively. Each edge in the elevations is normal to the line con- necting this point B and the intersection between the line LL’ and the zone line, which passes the poles of the two faces intersecting at that edge. Like- wise, the line LL’ and its other angle, point B’, determine the directions of the edges of elevations on the plane of b’ (010) (figs. 2a and 3a). (See Boeke: Die gnomonische Projektion, 1913, pp. 40-44.) Fig, Oa. Fic. 1.—Gnomonie projection of the babingtonite from the Yakuki mine, Japan. Fics. 2 and 3.—The orthographic drawings of the babingtonite from the Yakuki mine. Fics. 2a and 3a.—Elevations on the plane of (010). Fics. 2b and 3b.—Plans on the plane vertical to the prism zone. Fics. 2¢ and 3¢.—Elevations on the plane of (010). 164 Watanabé—Babingtomte from Japan. The indices of refraction were measured by Becke’s method by means of the standard solutions, which were available through the courtesy of Prof. A. F. Rogers. The minimum value is between 1.710 and 1.720, and the maximum a little greater than 1.740. The intermediate principal index lies between 1.720 and 1.730.° Thus the three principal indices are approximately: - d= Igo == 0:00 =a 120-0005 y = 1.740-++0.00x Optically biaxial and positive. Cleavage is perfect parallel to c(001), and less perfect parallel to a(100) and b(010). The hardness is almost equal to that of ortho- clase, or about 6. Before the blowpipe, the thin edges easily fuse to magnetic globules. The substance is not affected by common acids. Tohoku Imperial University, Sendai, Japan. * Determined by 8S. Tsuboi’s method, Jour. Geol. Soc. Toky6, vol. 25, p. 38, 1918. O. HoltedahI—A Tillite-like Conglomerate. 165 Art. XVL—A4 Tillite-like Conglomerate im the ** Eocam- brian’’ Sparagmite of Southern Norway; by O war HoLrEDAHL. The so-called Sparagmite formation, which covers a very large area of southeastern Norway (see fig. 1), is in several respects a sedimentary series of considerable interest. We meet here with thick beds of coarse-grained elastic rocks, very rich in fresh feldspar, alternating with thinner zones of clayey material and limestones. Of these the Biri limestone is of most importance and best known. No fossils have as yet been found in these rocks and therefore there are somewhat divergent opinions as to their exact age. We know that the sparagmites are older than the Lower Cambrian Holmia shale, and as there is a good transition from the highest sandstone into the Holmia shale, Brogger, Munster, and more recently J. Kier have regarded the sparagmites as closely attached to the Cambrian. Brogger introduced for them the term ‘*Hokambrium,’’ thus indicating that the strata are of the oldest Cambrian, while Kier classifies them as true Lower Cambrian. The Swedish geologist Tornebohm, on the contrary, referred the sparagmites to the Algonkian. Non-Scandinavian authors have also discussed the age of the Sparagmite series or parts of it. Walther, in his paper ‘‘ Ueber algonkische Sedimente,’’ has emphasized the great petrological likeness to the Torridonian of Scot- land, while Rothpletz,? by assuming an overthrust that quite certainly does not exist, held that the Biri limestone is younger instead of older than the Holmia shale. From this viewpoint of Rothpletz, Grabau, in his ‘‘ Comparison of American and European Lower Ordovicie Forma- tions,’’* has discussed the possibility of the Biri limestone being a continuation of the Durness limestone of north- ern Scotland. The main objects of the present article are: (1) to point out the occurrence in the sparagmites of conglom- erates of a tillite-like character, and (2) to give a sum- + J. Walthier, Zs. deutsch. Geol. Ges., 61, 283-305, 1909. * A. Rothpletz, Sitzber. Bayr. Akad. Wiss., 1-66, 1910. ° A. W. Grabau, Bull. Geol. Soc. America, 27, 555-622, 1916 166 O. Holtedahl—A Tillite-like Conglomerate. mary review of the stratigraphic sequence of the series, from which the chronologic position of the conglomer- ates may be seen. A great many Scandinavian geologists have contributed to the clearing up of these features, as Kjerulf, Schiotz, Tornebohm, Munster, Bjorlykke, Gold- schmidt, Werenskiold, and others. The writer has studied the problem of the Sparagmites in the field dur- ing the summers of 1919 and 1920. Fic. 1.—Sparagmite area of Southern Norway dotted. M = Mjosen. The greater and especially the northern and central parts of the region covered by sparagmite rocks have been very decidedly deformed by the Caledonian orogeny, and the rocks are highly metamorphosed. The stratigraphic sequence given below is based especially on the conditions met with in the most southern belt, particularly in the region around the northern part of the great lake Mjosen. Even here, intense folding and thrusts have taken place, O. HoltedahlI—A_ Tillite-ike Conglomerate. 167 making the deciphering of the geologic history a rather complicated matter. The oldest members of the Sparagmite division are known from the more northern district only. Here, as for instance between the Gudbrandsdal and Oesterdal, about 75 km. north of Mjosen, the oldest sparagmite is a some- what metamorphosed rock, having a conglomerate at the very base, and is seen to rest on the somewhat undulating surface of pre-Cambrian gneiss. In the southern part of the area the oldest zone, the gray or older sparagmite, several hundred meters in thickness, is a dark gray, gen- erally coarse sandstone rich in grains of feldspar, with some layers of dark arenaceous shale. Then follows a relatively thin zone with red and greenish shale and thin beds of hmestone. The earlier time of strong denudation and rapid sedimentation of the detritals derived from granites and gneisses, of which the thick sparagmite zone tells, changed later into one with only slow deposition in a playa-like basin of water. Denudation again became active, indeed to-a quite remarkable extent, for above the last-mentioned zone there is a very coarse conglomerate, in places 100-200 meters thick, the Birz conglomerate, consisting of bowl- ders very often of large size, up to 1 meter in length. The bowlders, made up of granite, gneiss, quartzite, dia- base, and limestone, are well rounded and distinctly water-worn. THE TUTTLE, MOREHOUSE & TAYLOR CO., PRINTERS, 123 TEMPLE STREET. Published monthly. Six dollars per year, in advance. $6.40 to countries in the 1 Union ; $6.25 to Canada. Single numbers 50 cents; No. 271, one dollar. inter seco eh ees ae at the Post Office at New Haven, Conn., under the Act These Are Wiley Books | READY OCTOBER ist. 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SONS, Inc. 432 Fourth Avenue New York London Montreal, Quebec CHAPMAN & HALL, Ltd. Renouf Publishing Company AIS 9,22 pf Se 3 fas) AMERICAN JOURNAL OF SCIENCE PEE Pie SE RTE S.. | Art. XVII.—The Determination of the Space Group of a Cubic Crystal; by RatpoH W. G. Wyckorr. Introduction. The theory of space groups presumably defines all of the ways in which elements of symmetry may be distri- buted in space so that their aggregates will possess erystallographic symmetry.t A knowledge of the space group to which a particular crystal should be assigned thus describes completely its characteristics of symme- try, and forms thereby one of the principal goals of descriptive crystallography. On the basis of direct experimental evidence it has hitherto been impossible to carry crystallographic description so far; only in a few isolated cases could the appropriate space groups be inferred.2 Use of the diffraction effects resulting from the action of X-rays upon crystals offers, however, the opportunity in many cases of determining experimentally the space group corresponding to a crystal. The crystal symmetry which is deduced by the use of X-ray methods of study is the symmetry of the arrange- ment of the atoms of which the crystal is composed. The identification of this wnternal symmetry with the external erystal symmetry, obtained from studies of face-develop- . ment and the like, requires an assumption equivalent to one that states that the external symmetry of a crystal is consistent with the arrangement of its constituent atoms. Not only does it appear natural to relate them thus but the generally satisfactory agreement between the exter- nal symmetries and the symmetries of the crystal models of those crystals whose structures have thus far been studied with X-rays points to the correctness of this assumption. 1 A. Schoenflies, Krystallsysteme und Krystallstructur, Leipzig, 1891. ? For instance, C. Viola, Z. Kryst., 28, 225, 1897; L. Sohncke and E. Fed- erov have made similar assignments. Am. Jour. Sct.—Firta Serizs, Vou. 1V, No. 21.—SrptTemBer, 1922. 12 176 R. W. G. Wyckoff—Determination of the The probable space groups corresponding to a few crystals have already been determined by showing that the structures assigned to them by the X-ray studies can be deduced from certain particular space groups.’ It is the intention of the present paper, however, to show, by taking the cubic crystals as the simplest examples, how the space groups of many crystals can be uniquely deter- mined in advance of a complete elucidation of their struc- tures and to state criteria which serve to distinguish between the various cubic space groups where such a distinction is possible. Not only is such a knowledge of the space group of a crystal an ultimate aim of formal crystallography but it may be of great value in the problem of crystal structure study itself. In the crystals whose structures have been determined all, or nearly all, of the atoms of which they are composed have been found to occupy positions within the unit cells whose coordinate values are limited and defined by sym- metry considerations (the corners, center, centers of the edges and of the faces of a unit cube are such positions). Such very special structures can usually be deduced from more than one space group. Most cubic crystals, how- ever, have one or more of their constituent atoms in posi- tions so general that the symmetry requirements permit their #, y and 2 coordinates to have any values. Physical data concerning the mechanism of the scattering of X-rays by atoms are not yet sufficient for the complete determination of the structure of any crystal having one or more atoms in these general positions. A knowl- edge of the space group to which such a crystal should be assigned serves to determine the manner of arrangement of its atoms in many eases, even though the distances between some of these atoms cannot now be established with accuracy. X-ray criteria for distinguishing between the different space groups are most simply and satisfactorily deduced for those crystals having some atoms of appreciable scattering power in general positions. For this reason and also because a knowledge of the space group of such crystals is valuable to the crystal analyst, the discussion which follows will be limited to cubic crystals having one or more atoms in general positions. Similar criteria * A. Johnsen, Physikal. Z., 16, 269, 1915. Space Group of a Cubic Crystal. 177 have been established for other than cubic crystals, although their application to specific instances is not so straightforward. Some _ discrimination among the special cases where one or more of the coordinates of position are defined by considerations of symmetry can likewise be made. Means of distinguishing between cubic space groups as an aid to studies of crystal structure by reflection spec- trum observations of the relative spacings against the (100), (110) and (111) faces have already been given.* For a variety of reasons, however, this method is of little certain value in actual practice. A study of the Laue photographs taken in a single direction through a crystal distinguishes as far as possi- ble between the various space groups. Because of the much larger mass of data with which they deal, space group determinations based upon Laue photographic studies are not open to the same measure of uncertainty as those derived from reflection spectrum measurements. It will be seen from the criteria to be discussed that many of the space groups give diffraction effects which are different from those given by any other space group and thus a method is established for deducing completely and uniquely the (internal) symmetry of a crystal with- out recourse to methods of studying external symmetry, such as those of face-development and etch-figure forma- tion. | These space group criteria have already been used upon a number of crystals of rather complicated chemical compositions. Of these, studies of nickel nitrate hexam- monate® and of sodium hydrogen acetate® have either been published or are in the course of publication; the determination of the symmetry and structure of zine bromate hexahydrate, published elsewhere in this Journal,’ has been written primarily to serve as an illus- tration of the application of these criteria. Methods of Distinguishing between the Cubic Space Groups. The general characteristics of the diffraction effects to *P. Niggli, Geometrische Krystallographie des Discontinuums, p. 492, Leipzig, 1919. > Ralph W. G. Wyckoff, Jour. Am. Chem. Soc., June, 1922. ®* Ralph W. G. Wyckoff, see the third article in this number of this Journal. 7 See the following article in this number. 178 R. W. G. Wyckoff—Determination of the be obtained from atoms arranged according to the general positions of any one of the space groups can be readily calculated with the aid of the customary intensity expression : Rooms (Si \[A2+B*), where (ee aoe (hitm+khYmt km) |, [1] Mm and B is a similar sine term. In this expression® J is the intensity and nm is the order of reflection from a plane whose Miller indices are (hkl); Xn,Ym,Zm are the coordi- nate positions of each of the m atoms (within the unit) over which the summation is to be extended and : No classes of two odd and one even planes are absent; ) T,,*: Planes of the form {0kl}, where & and / are both odd, are absent from odd orders. Holohedal Photographs: T,°, O°, OF and O,°: No classes of two odd and one even planes are absent in the first order. Reflections in the second order from planes of the form {100} are absent . NOTO): T,°: Planes of the forms {hill} where th is even and 1 odd are absent in odd orders. In the second order, planes of the forms {hhl}, where either h is even and / odd, or both h and / are odd, are absent. O7°: Planes of the form {0kl}, where k and / are odd, and oP the form {hll}, where $h is even and / is odd, are absent in the first order. Reflections in the second order are absent for planes of the forms {hhl} where either h is even and / odd or both h and / are odd. Space Group of a Cubic Crystal. 185 It will be observed that a number of space groups give rise to diffraction effects which are different from those resulting from any other space group. These unique acento are a O.7, O18 nO Ones pe ay Out es and, less certainly because they depend upon the presence or absence of planes of the single form 100; T,O7,O0° and O7,0+,08. The symmetry of a crystal corresponding to any one of these space groups can consequently be deter- mined with complete certainty without any reference-to face development, etch-figure symmetry or any other of the customary methods of crystallography. A possible experimental method is thus furnished for finding out what relations exist between the symmetry assigned to a erystal by studies of its external appearance and the sym- metry of the arrangement of its atoms. The experimental establishment of the space group of a particular crystal is simple and can be carried out by the procedure common in crystal structure determination of taking one or more Laue photographs about some con- venient orientation, determining the indices of the various diffraction spots by the usual methods of projection and finding the wave-lengths of the X-rays producing these spots with the aid of a measurement of the dimensions of the unit cell through a reflection spectrum measurement from some convenient crystal face.° Then if the voltage applied to the X-ray tube in producing the photographs is known, the range of the spectrum in which there will be only first-order reflections can immediately be told. It happens that in all cases where it is necessary to go to the second-order region to distinguish between space groups, first-order reflections from the planes involved are also missing. No ambiguity is therefore introduced concern- ing the order of reflection of diffraction spots lying in the region of strong second-order effects. Reflections from faces of the form {100} are as a rule more readily obtained by reflection spectrum measurements than from Laue photographs. It is desirable to reémphasize that, for the reasons already given, only the appearance and not the absence of {100} reflections can necessarily furnish conclusive evidence upon which to base assign- ments to particular space groups. In certain of the cases where the diffraction data are ° Ralph W. G. Wyckoff, this Journal, 50, 317, 1920. 186 R. W. G. Wyckoff—Determination of the insufficient, a knowledge of the numbers of chemical molecules to be associated with the unit cube, such as arises immediately from the density and the dimension of the unit, can be of service. For instance suppose that the diffraction data from a certain crystal assigned it to the two indistinguishable space groups T° and T°, and suppose that the determination of the number of chemical molecules within the unit cube requires but two chemi- eally like atoms within the unit cell, then since only T° contains as a special case two equivalent positions, the crystal may be assigned to it, rather than to T°. In view of the present lack of definite knowledge as to what it is that conditions chemical equivalence in the crystalline state, such information must obviously be used with great caution. 3 There naturally arises a question of whether even with atoms in the most general equivalent positions coordinate values may not exist such that the diffraction results may simulate those corresponding to some space group other than the one to which it really belongs. Any such coordi- nates for a space group can readily be found by practi- cally the same procedure which has already been employed in determining the reflection characteristics of planes in different orders. In this process, however, the sets of equations are to be solved for x, y and 2 rather than for h, k and 1. 7 The space group T° will again serve as an illustration. The previously established set of equations, [2], must now be solved for x, y and zg which can have any values between zero and unity, including the former, instead of for integral values of py,qgandr. For the present purpose care must of course be taken to avoid such values of 2, y and 2 as yield special cases with fewer than the maximum number of equivalent positions within the unit cell. By solving these sets of expressions in a manner analogous to that previously used it can be shown for instance that when «=u, y=0 and 2=0, or when += 4, y—=2 ame 2—0, only all odd planes are to be found in the first order region. When attempting to ascertain the space group to which a crystal should be assigned, it is impor- tant to take into consideration the possibility of atoms occupying exactly or nearly such positions as these. It must likewise be borne in mind that atoms in special posi- Swnace Group of a Cubic Crystal. 187 tions may not give diffraction effects in certain orders; so that in cases where most of the heavy atoms are in such positions, the characteristic effects upon which a choice of space groups is made may some of them be relatively weak. Especially in view of this possibility of atoms occupying in some instances coordinate positions which may alter the qualitative character of the resulting dif- fraction effects, it is necessary to emphasize the fact that though these criteria are not ambiguous when used properly they cannot be apphed blindly. Summary. Criteria, which are valid for crystals which have any atoms of appreciable scattering power in general posi- tions, are established for determining from studies of Laue photographs the space group to which a cubic erystal should be assigned. This knowledge is of value to the erystal analyst because it is thus possible to tell how the atoms in many chemically complicated crystals are arranged, even though existing methods are not suffi- cient to locate these atoms with accuracy, and because an assignment of a crystal to a particular space group defines completely the positions of all of its elements of symmetry. Many of the space groups give diffraction effects which are different from those given by any other groups and hence a method is provided, in the cases of crystals assignable to any of these unique space groups, of defining completely crystal symmetry without making use of the older methods such as face development and the like. Geophysical Laboratory, April, 1922. 188 R. W. G. Wyckof—Symmetry and Crystal Art. XVIII.—The Symmetry and Crystal Structure of Linc Bromate Hexahydrate, Zn(BrO,),.6H,0; by RaupH W. G. Wyckorr.! [Contribution from the Gates Chemical Laboratory of the California Insti- tute of Technology, No. 16.] Introduction. This paper has the two-fold purpose of adding confir- mation to the previously assigned structure of nickel nitrate hexammonate? by the ” study of an analogous compound and, more especially, it is intended to be an illustration of the application of those criteria for distin- guishing between the cubic space groups which are described in the preceding article? Excellent crystals of Zn(BrO.) ;.6H,O, mostly octahe- dral in habit, are formed a solutions both by slow cooling and by slow evaporation. The crystals that grow from a cooling solution usually exhibit a shght anoma- lous double refraction with sectoring.* The Laue photo- graphs to which these crystals give rise do not, however, show any anomalous effects. Completely isotropic speci- mens are obtained by gradual evaporation. Zn(BrO,;),.6H,O is one of a group of isomorphous erystals to which belong the chlorates of nickel, cobalt and probably copper, and the bromates of nickel, cobalt and magnesium.” The Structure of Zinc Bromate Hexahydrate. A reflection photograph from the octahedral face combined with an estimation of the density of the salt indicates that four chemical molecules are to be asso- ciated with the unit cube. The length of the side of this unit was found to be 10.31 A.U. (10.31 * 10*%em.). Laue photographs were prepared through both octahe- *Member of the Staff of the Geophysical Laboratory of the Carnegie Institution of Washington. ? Ralph W. G. Wyckoff, Jour. Am. Chem. Soc., June, 1922. * See page 175 of this Journal. *Marbach, Poggendorffs Ann. d. Phys., 99, 465, 1856. °P. Groth, Chemische Krystallographie, II, p. 112, Leipzig, 1908. . * Ralph W. G. Wyckoff, Jour. Am. Chem. Soc., 42, 1100, 1920; Ralph W. G. Wyckoff and Eugen Posnjak, ibid. 43, 2292, 1921. Structure of Zinc Bromate Hexahydrate. 189 dral and cube faces. These showed clearly an absence of planes of symmetry; hence it is evident that the symmetry of the arrangement of the atoms of this crystal is either tetartohedral or paramorphie hemihedral (pyri- tohedral). Interpretation of these photographs in the usual manner’ showed that in general planes of all sorts appear in the first order region. The fundamental lattice must consequently be the simple cubic lattice. There are four zinc atoms within the unit, and it is both natural and in accord with previous experience to con- sider them equivalent. If, merely to serve as a starting point for considering the various possible space groups, this assumption of the equivalence of the zine atoms is made, we find that there are four tetartohedral and para- morphie space groups built upon a simple cubic lattice which have as special cases four equivalent positions within the unit, namely the groups T",,T,?,T;°. An inspection of the criteria for distinguishing between these space groups (see the preceding article) suggests the investigation of those planes having one of the indices zero. Some data for first order reflections of such planes from a Laue photograph with the X-rays roughly normal to an octahedral face are given in Table I. TasuE I. Laue Photographie Data. From a Plate taken with the X-rays roughly normal to (111). Appearing Planes. Indices of plane Wave Length Form of plane 032 0480. 4. U. 032 340 | .285 034 540 376 054 056 AI5 056 580 : 313 058 074 BT O74 078 .264 078 12,0,5 443 0,5,12 0,7,10 379 0,7,10 0,7,12 484 Orel? 8,0,11 281 0,11,8 * Ralph W. G. Wyckoff, this Journal 50, 317, 1920. 190 R. W. G. Wyckoff—Symmeiry and Crystal Absent Planes. 704 A453 047 053 ase 058 059 439 059 506 336 065 067 325 067 11,0,6 329 0,6,11 507 .460 O75 079 330 079 Oni il 400 0,7,11 850 448 085 OS, EL 318 0,8,11 0,8,13 3851 0,8,18 095 B04 095 7,0,10 338 0,10,7 Ozart5 O62 Oss From this table it will be seen that the only planes of this type which appear in the first order region are of the forms {h0l}, where h is even and lis odd; it is also appar- ent that many planes of the forms {Ohl} and of the forms {Okl}, where both & and / are odd, were in suitable posi- tions to reflect but did not do so. Results in complete agreement with these data and from planes of still difter- ent forms are obtained from the interpretation of a photograph taken with the X-rays approximately normal to a cube face. In comparing the data obtained from two different Laue photographs of either a tetartohedral or paramorphic crystal, it must of course be remembered to choose the H and K axes in the same way in both eases; this is readily accomplished by observing planes of two forms {hkl} and {khl} which show marked differences in reflecting power and are common to the-two photographs to be compared. The data recorded in Table I are seen to be in entire accord with the criteria which determine the space group T°. Since these criteria uniquely distinguish this space eroup from every other group, it is evident that the symmetry of crystals of zine bromate hexahydrate is that of T,°. From this knowledge of the corresponding space eroup and the fact that four chemical molecules are to be Structure of Zinc Bromate Hexahydrate. 191 associated with the unit cube, the manner of arrange- ment of the atoms of zine bromate hexahydrate is defi- nitely determined to be as follows: Zine atoms: Arrangement 4b, 000; 430; 044; 404. Bromine atoms: Arrangement 8h, wuu; utd, 4—u, a; @, u+3, 4—u; 4—v, @, u+4; aad; $—u. ut+4, u; u, ¢—u, u+4; utd, u, $—U. Bromate oxygen atoms: General positions, xyz; e+4, J—y, 2; a, yt+4, $2; 4a, y, 2445 zey; z, +4, 4—y; 4-2, x, yt+4; 244, 4-2, y; yz; 4—-y, z, e+4; yt}, 4-2, w y, 2+, 4-2; xvyz; 4—x, y+, 2; ©, $Y, 244; H+4, Y, 1-2; Zay; 2, 3—x, ytd; 244, ©, $y; 4—2, e+, y; yzx; y+, z, 4x; 4-y, z+-4, x; y, 4-2, w+. Water oxygen atoms: General positions with different values of x, y and 2. Hydrogen atoms: T'wo sets of general positions. The coordinates and terminology are taken from the writer’s book entitled ‘‘An Analytical Representation of the Theory of Space Groups’’ which is shortly to be pub- lished by the Carnegie Institution of Washington. An inspection of the special cases of the space group T,° shows that the arrangement outlined above is the only reasonable one for the atoms of zinc bromate hexa- hydrate, since any other would string out sets of eight equivalent atoms along the body diagonals of the unit cube. Though it is impossible at the present time to obtain the positions of other than the zine atoms, it is probable that the value of wu, the parameter defining the bromine atoms, is in the neighborhood of + and that the values of x, y and 2 for the bromate oxygen atoms are such as to cluster these atoms more or less closely about the bromine atoms. It will also be observed that the groups of atoms constituting the water molecules cannot be unequally distributed between the metal atoms and the bromate groups, but must all be related in exactly the same manner to the zinc atoms (or to the bromate groups). ‘This distribution is in accord with that found AM. Jour. Sct.—FirtH Series, Vou. IV, No. 21.—SEPTEMBER, 1922. 13 192 R. W. G. Wyckofi—Zinc Bromate Hexahydrate. for the ammonia groups in the hexammonate nickel halides* and in nickel nitrate hexammonate.? Summary. From a study of the Laue photographs to which erystals of zinc bromate hexahydrate give rise, it is shown that they must have the symmetry of the space group T,°. Though it is impossible to determine the positions of the atoms in this crystal, such knowledge of the underlying space group defines uniquely the manner of arrangement of its atoms. The length of the side of the unit cube which contains four chemical molecules 18 ‘found to be 10.31 A.U. Pasadena, California, May, 1922 ® Ralph W. G. Wyckoff, Jour. Am. Chem. Soce., June, 1922. ° Idem. ibid. R. W. G. Wyckoff—Sodium Hydrogen Acetate. 198 Arr. XIX.—On the Symmetry and Crystal Structure of Sodium Hydrogen Acetate, NaH(C,H,0.,).; by Ratpu W. G. Wyckorr.! [Contribution from the Gates Chemical Laboratory of the California Insti- tute of Technology, No. 17.] Introduction. This study of the structure of sodium hydrogen acetate was undertaken in the attempt to find the arrangement of the atoms in some organic compound. Sodium acid acetate was prepared by the long con- tinued digestion of fused sodium acetate, glacial acetic acid and acetic anhydride in sufficient quantity to remove the small amounts of water which may be present.” It was thus obtained in cubes which under the polarizing microscope prove to be isotropic. Assignment to a par- ticular class of symmetry on the basis of the ordinary crystallographic evidence has never been made. The Study of the Structure of Sodium Hydrogen Acetate. Comparison reflection spectra from the (100) face of calcite and the (100) face of sodium acid acetate showed three orders of reflection for the latter which stood in the ratio of 2:3:4 (experimental conditions did not permit of the first order registering itself). Measurements upon these photographs combined with the density, p = 1.402, as determined by a flotation Westphal balance method, gives the mean value 3.07 for the ratio m/n?,m being the number of chemical molecules within the unit cube and » the order of the reflection. There are thus either three or 24 chemical molecules of the composition NaH(C,H,0,), within the unit. The length of the side of the cube having three molecules within it, as deter- mined by these same measurements, is 7.98° A.U. (7.989 10°em.). Several Laue photographs taken with the X-rays nearly normal to the cube face of crystals from two dis- * Member of the Staff of the Geophysical Laboratory of the Carnegie Insti- tution of Washington. * The writer is under obligation to Prof. H. J. Lucas and to L. M. Kirk- patrick for some of these preparations. 194 R. W. G. Wyckof—Symmetry and Crystal tinct preparations were studied. Some pertinent data from the interpretation of one of these photographs are given in Table I. In this table the wave-lengths of the Taste I. Laue Photographic Data. Indices of plane Intensity Wave Length 381 m 0.2329 SAc re 581 fe .239 781 f 227 161 S 261 B41 m 263 521 s 21% B81 m .206 jee Oeet f 248 392 f+ 206 213 38 fe 241 Or lone ie 244 ie Os f Zao 572 == 21a 752 f 179 [2 | ee 238 Tiles 4 f .268 752 m 256 BE Se f 240 592 f 248 Note:—In this table spots having an intensity f are faint, those marked m are of medium intensity and those designated by s are amongst the strongest appearing upon the photograph. reflected X-rays have been calculated on the basis of a small unit containing three chemical molecules. The voltage applied to the X-ray tube during the making of these photographs was such that no reflections are ordi- narily present in wave lengths shorter than A = 0.24 A.U. Since, as reference to Table I shows, appreciable effects with values of A as low as 0.180 are to be found upon the photographs, the correct unit must contain 24 and not ‘three molecules. This result was sufficiently unexpected, especially in view of the fact that a simple structure containing three - ee Structure of Sodium Hydrogen Acetate. 195 molecules was not only possible on the grounds of symme- try but was chemically plausible, that it seemed worth while to obtain a direct spectrum observation of a reflec- tion in the first order from this larger unit. This could be done by studying the secondary spectra from a cube face reflection. If a spectrum is taken from a erystal face in the usual manner, not only is the reflection from Figure 1. this face observed upon the photographic plate, but reflec- tions from various other faces which are brought into position by the continuous rotation of the crystal during the course of the experiment will be registered at the same time at various angles to the principal spectrum. Such a composite spectrum was prepared by passing the X-rays through a section of a crystal of NaH(C.,H.0.), mounted so that one of the cubic axes was coincident with the axis of its rotation and hence lay in the plane of the slit of the spectrograph. A reproduction of this spectrum is shown in fig. 1. 1962 Ge Wyckof—Symmetry and Crystal The identification of the secondary spectra on this photograph can be carried out with the aid of the gno- monic net which has previously been described.* The distance from the crystal to the photographic plate can if necessary be accurately calculated from the measure- ment of the principal spectrum (in this case the (100) reflection). It is then a simple matter to prepare a enomonic ruler* for plotting on a radius of five centi- meters the projections of the various secondary spectra. By making the distance from the erystal to the plate exactly five centimeters, it would be possible to use directly the same gnomonic ruler which serves for Laue photographs; by making this distance 10 cm., as is more satisfactory, the same ruler can of course be used by dividing by two the readings of the scale giving distances from the central spot. While, during the course of the experiment, the crystal is rotated back and forth, the enomonic projections of the various reflecting planes will travel along the hyperbolas of the gnomonic net if it is so placed that the zero degree hyperbola (a straight line) coincides in position with the principal spectrum. By rotating the mean projected positions of these. reflect- ing planes (which in the present instance form a simple square network of points) through the angle of rotation suffered by the crystal, portions of hyperbolas will be decribed which will pass through the gnomonic projec- tions of the observed reflections for those planes that can reflect for this particular setting of the crystal. By superposing, then, the gnomonic projection of the photo- oeraph over the series of hyperbolic paths obtained in this manner, it is possible to identify the various reflections upon the photograph. Considerable care must be taken in such a determination and some ambiguity may of necessity arise because it frequently happens that reflec- tions from different planes, especially planes in different orders of reflection, give effects at about the same posi- tions upon the piate. By making this sort of an interpretation of the trans- mission spectrum photograph from sodium hydrogen acetate, reflections from planes belonging to a number of forms, such as {161}, {721}, and {521}, were observed in ‘H. Hilton, Min. Mag., 14, 18, 1904; Ralph W. G. Wyckoff, this Journal, 50, 317, 1920. Structure of Sodiwm Hydrogen Acetate. OY the first order from the large unit containing 24 chemical molecules. The Laue photographs show clearly the absence of planes of symmetry. The crystals of this compound must then have either tetartohedral or paramorphic hemihedral (pyritohedral) symmetry. It was further observed that all of the planes giving reflections in the first order region on the basis of the large unit have two odd and one even indices. This points to an underly- ing body-centered lattice.© The four space groups Ts, T°, T,° and T,’ have the appropriate symmetry and are built upon [,”. Distinction between the first three of these is impossible upon the basis of the diffraction effects to which they give rise. Crystals corresponding T,, would give no reflections’ in odd orders from planes of the forms {0k1}, where both & and / are odd. Neither upon the Laue photographs nor upon the transmission spectrum photograph were any such planes found in odd orders, even though some were in suitable positions for reflection. This would make it necessary to assign to crystals of sodium acid acetate the symmetry of T',’. The unit is so large, however, that with moderate degrees of tilt from symmetrical Laue photographs the few planes which reflect in the first order region have complicated indices and are of weak intensity. Consequently in order to place this assignment of symmetry beyond any legiti- mate questioning, it would be desirable to study Laue photographs from erystals inclined farther from the symmetrical position than those here investigated. It did not, however, seem worth while to make these addi- tional experiments at the present time. Accepting this assignment to the space group T;,’ as correct, the general coordinate positions of the atoms in sodium acid acetate are defined. Depending upon what equivalence is assumed for the two acetate groups and for the atoms within these groups, all of the atoms of the crystal will be arranged according to either the 48 generally equivalent positions® of T,’ or the 24 equivalent ° Ralph W. G. Wyckoff, see the first article by the writer in this number of this Journal. *These general positions are stated in abbreviated form by A. Schoen- flies, Krystallsysteme und Krystallstruktur, p. 551, Leipzig, 1891. Also in detail by P. Niggli, Geometrische Krystallographie des Discontinuums, p. _ 368, Leipzig, 1919. 198 R. W. G. Wyckoff—Sodium Hydrogen Acetate. positions of the special case 24e. It is of course impos- sible now to determine the positions of any of these ~ atoms. The coordinates of both of these arrangements are given in the book by the writer entitled ‘‘The Analy- tical Representation of the Theory of Space Groups”’ which is shortly to be published by the Carnegie Institu- tion of Washington. When it is considered that such a relatively simple sub- stance as this sodium acid acetate has such a very compli- cated structure as it has here been shown to possess, it searcely needs to be emphasized that any studies of the structures of organic compounds should be made with extreme care and in order to be of any value should make use of the most powerful diffraction methods now at our disposal. Summary. It is shown that the unit cell of sodium hydrogen acetate must contain 24 chemical molecules. The length of the side of this unit cube is found to be 15.98 A.U. The determination of the underlying spdce group as probably T’," defines the general manner of the arrange- ment of the atoms of this crystal, though it is impossible to obtain the positions of these atoms. A graphical method is outlined for identifying the planes causing the secondary spectra upon a reflection spectrum photo- graph. Pasadena, California. May, 1922. W. A. Tarr—Cone-in-Cone: 199 Art. XX.—Cone-in-Cone; -by W. A. Tarr. Cone-in-cone is a structural feature found in shales and rarely in coal. It is usually associated with concretions but not necessarily so. An occurrence of cone-in-cone in coal and its development in bands of calcite are such exceptions. The cone-in-cone structure consists of a series of cones within cones, adjacent cones uniting to form lenses or layers. When associated with concre- tions the cone-in-cone may occur on the upper or lower surface, or, more rarely, within the concretion. The structure was recognized and called cone-in-cone in the early part of the last century. It was not so called by all, however. Hildreth, in 1836 (see literature at end for all references), deseribed it as a ‘‘fossil columnar Madrepore.’’ It has also been ealled ‘‘cone-in-cone eoral.’? The German name for cone-in-cone is ‘‘tuten- mergel’’ and was given to it as early as 1825. Cone-in-cone has been described by Marsh, Sorby, New- berry, Jukes, Dawson, Daintree, Young, Sach, Garwood, Gresley, Broadhead, and many others. Their descrip- tions are all very similar, although their conclusions regarding the origin of cone-in-cone differ considerably. Probably the majority of investigators have regarded cone-in-cone as having been caused by pressure which was due (since the structure is so frequently seen in asso- ciation with concretions) to the expansion of concretions through growth. Thus, most cone-in-cone structures are regarded as of secondary origin. Some of those holding this view are Marsh, Geikie, Dana, Gresley, Grimsley, and Chadwick. Others have regarded the structure as being due to crystallization or to ‘‘imperfect crystallization.’’ Owen, Newberry, Geikie, Sach, Grabau, and Keyes have advocated one or both of these methods. Odd suggestions have been made by Sorby, who sup- posed that oolites had formed the sides of the cones; by Daintree, who believed the cones were chemical precip- itates; and by Young, who says unequivocally, that they * The writer wishes to acknowledge his indebtedness to many friends for material furnished for this study. Mr. H. L. Griley and W. H. Twenhofel have furnished some excellent material. The late G. C. Broadhead collection at the University of Missouri contained several excellent small specimens. 200 W. A. Tarr—Cone-in-Cone. are due to gases rising through the muds. | 4 ig NEW HAVEN, CONNECTICUT. 1922. | THE TUTTLE, MOREHOUSE & TAYLOR CO., PRINTERS, 123 TEMPLE STREET. __ Published monthly. Six dollars per year, in advance. $6.40 to countries in the is Postal Union ; $6.25 to Canada. Single numbers 50 cents: No. 271, one dollar. zit ae : March 3, ts we matter at the Post Office at New Haven, Conn., under the Act ; ; Oe ak ¢ 59 ey : REPS See Ppa ay: ne het Tee Sas x = Sr eee eee 4 : a ; . : : Enh aoe ae an oy . , . ASF % B.A ee at # » ag ao ; 4 : a ‘ > 4 . f ft - a n 3 < : ‘ ‘ ; , ‘ : « pa: The Works of G. MONTAGUE BUTLER, E.M., Dean, College of Mines and Engineering, University of Arizona. Geometrical Crystallography ‘Gives the reader the ability to recognize crystal forms and especially systems at sight, and with the use of few, if any, instruments. 155 pages. 4 by 6%. 107 figures. Cloth, $1.50. A Pocket Handbook ae Minerals. Gives all the details needed to identify most of the minerals which mining ‘men, students, or collectors are apt to encounter. The emphasis is always || — placed upon characteristic physical features, 311 pages. 4 by 62. 89 figures. Flexible binding, $3.00. Pocket Handbook of Blowpipe Analysis. ‘Complete directions are presented for the determination of the composition of minerals. gs Deira 80 pages. 44 by 6%. Cloth, $1.25. era a ae Crystallography, Minerals and Analysis, Complete. A handy combination of the three above books in one volume. pee? : 546 pages. 4 by 62. 196 figures. Flexible binding, $4.00. sare | Oe ey i Hayes’ Handbook for Field Geologists. Third Edition, Thoroughly Revised and Rearranged, by SIDNEY PAIGE. A well-known educator says, of this book: ‘‘This work has been used by me and my students in geological surveying since its first appearance. ... Dr. Paige has happily preserved with improvements the quality and the design of the original work.” 166 pages. 4} by 63. 20 figures. Flexible binding, $2.50. JOHN WILEY | & SONS. Ine. : 432 Fourth Avenue | New York London Montreal, Quebec CHAPMAN & HALL, Ltd. Renouf Publishing Company AJS 11.22 dhe ca AMERICAN JOURNAL OF SCIENCE [FIFTH SERIES.] Le Art. XXXI.—The Silicates of Strontium and Barium; | by Pentti HsKoua. CONTENTS. Introduction. Methods of working The system SrO-Si0, The system BaO-Si0, The system CaO.Si0.,-SrO.8i0, The system Ca0O.Si0.-Ba0O.Si0, The properties of the glasses. Absence of diopside analogs. The strontium and barium feldspars. Some general considerations regarding the relations of the alkaline earth compounds. Summary. Introduction. Among the compounds of the alkaline earth metals (calcium, strontium, and barium), the sulphates and carbonates are common as minerals. In the case of the silicates, however, we find those of calcium common, but natural silicates of strontium and barium are few in number, complicated in composition, and of rare occur- * rence. Considering the existence of isomorphous carbo- nates, sulphates, and other compounds of these three ele- ments, the non-occurrence of analogous silicates seems striking and suggests experimental investigation to answer the questions: Do strontium and barium under experimental conditions form such compounds as are known in the case of calcium? And, if they do, what are their properties and relations to the calcium silicates? The calcium silicates which form from dry melts have been studied, but very little is known about the strontium and barium silicates. G. Stein' prepared some silicates and determined their melting points as follows: SrSiO,, 1287°; BaSi0,, 1368.5°; Sr.81i0,, 1593°. RK. Wallace? *G. Stein, Z. anorg. Chem., 55, 159, 1907. **R. Wallace, Z. anorg. Chem., 63, 1, 1909. Am. Jour. Sci.—FirtTH Series, Vou. IV, No. 23.—NovemMBeR, 1922. ~~ 3382 P. Eskola—Silicates of Strontium and Barium. carried out thermal investigations by the cooling curve method on the binary systems of the metasilicates of sodium and lithium with those of strontium and barium. He gives the melting point of SrSiO,, 1529° and of BaSi0,, 1490°. All his melting diagrams resulted in the type of complete solid solutions with a minimum. P. Lebedew,? for the system BaSiO,-CaSi0O., also found a melting curve of the complete solid solution type with the melting point of BaSiO, at 1438° and a minimum at about 1000°. Smolensky,* who studied the system BaSi0,- BaTiO., found the melting point of BaSiO, at 1470°. All these results were obtained by the cooling-curve method, using carbon crucibles and porcelain tubes to protect the thermo-elements. No quantitative optical or other physical diagnostics for the crystalline phases were given. In the absence of such characteristics, and in view of the poor agreement of the results, the melting diagrams merely based upon cooling curves are subject to large corrections and often entirely erroneous. The melting point determinations are, in fact, all considerably too low. Very accurate determinations were carried out by Jaeger and Van Klooster,? who found the melting point of Srsi0;, 1578 + 1°,'and of| BaSi0,, 1604 = 05°53 Ther also, emphasize the unreliability of the cooling-curve method and illustrate this by experimental evidence. They determined further some physical constants of the compounds named. ‘Their results will be mentioned later. The entire field of the physical chemistry of the strontium and barium silicates being open, the first task was to investigate the two binary systems SrO-Si0, and BaO-Si0O,. Among the further problems, those regarding the relations of. the metasilicates to the well- known wollastonite minerals seemed to me most interest- — ing and were chosen for study. For still further com- parison with corresponding calcium compounds I tried to synthesize the strontium and barium compounds analo- vous to two important lime silicate minerals, diopside and anorthite. *P. Lebedew, Z. anorg. Chem., 70, 301, 1911. *S. Smolensky, Z. anorg. Chem., 73, 293, 1912. °F. M. Jaeger and H. S. Van Klooster, Proc. Kon. Akad. Amsterdam, 6, XVIIL, 896, 1915. P. Eskola—Silicates of Strontium and Barium. 333 Methods of Working. The mixtures were made up of pure quartz, specially prepared calcium carbonate, barium carbonate “Squibb’s reagent’? and strontium carbonate from ‘‘Baker’s analyzed chemicals.’’ These substances were dried at 150°C before weighing, and mixed together, melted if possible, chilled and crushed, then reheated and ground twice more. 5 The equilibrium relations were ascertained almost exclusively by the quenching method. Heating curves were run in some cases for the purpose of checking the temperature measurements. The temperatures were determined by potentiometer and a Pt-PtRh thermoelement calibrated against the melting points of diopside and anorthite. The tempera- tures, for the most part, are not far from the diopside- point, so that the calibration against diopside, together with the temperature limits taken in the quenchings, show the actual degree of accuracy of the work. Therefore those calibrations are stated below. Diopside, melting point 1391.5°, in the standard scale corresponds to 14230 microvolts. Date (1921) Crystals Melt Correction The systems under wv mv investigation Berth 4... 14100 14150 + 105 ee 28 April ...... 14110 1413 4.105 eure: eieiryt.S . 14120 14130 +105 BaO-SiO, and SrSiO,-CaSi0, Prune <2 2... 14090 14110 a 130 | 26 Junee ..... 14310 14330 90 aU SUNG: Lss-5:2 2 14310 14330 — 90 BaSiO,-CaSiO; 5 August .... 14290 14310 — 70] 22 August .... 14270 14290 . == 51) a New thermoelement. In the determination of the refractive indices I had the advantage of using the improved immersion method as worked out by Merwin. This method involves an improvement in accuracy as well as in completeness, making it possible to determine at the same time disper- sion as well as refractive indices. One determines directly, using a monochromatic illuminator, the wave- lengths for which the refractive indices to be measured * E. Posnjak and H. E. Merwin, The ternary system Fe,O,-SO,-H.O, J. Am. Chem. Soc., 44, 1965, 1922. 334 P. Eskola—Silicates of Strontiwm and Barium. match those of two or more members in the set of refrac- tive liquids. The dispersions of the whole series of liquids used having been determined and expressed graphically, it now remains simply to locate, on the dia-— eram, the points determined and to read the refractive index for any wave-length desired. The values obtained i favorable substances are dependable in the third deci- mal place, provided due care is taken for variations 1 in the temperature. In the present work the indices of retraction are given for. four wave-lengths corresponding with the spectral lines hy A86up), THA = 535m), D(=589un) and CQ = 656p0)-- In > the actia! geteean eee wave- lengths between 500 and 625 were commonly used, there- fore the values for F and C may sometimes have an uncertainty of + 0.001 or a little more, due to enlarge- ment of the errors in extrapolation. The System SrO-S10,. The results of a thermal study of this system are given in table I. : TABLE I. Composition : wt. per cent Temperature Time Resulting phases SrO Si0, 6 minutes _ i Liquidus of cristobalite 40 60 1636 15 Glass : ; 40 60 1600 60 Glass and cristobalite ‘Eutectic tridymite-SrSi0, 53.82 46.18 1 SO8e soe a0) Glass 53.82 46.18 1361 60 - Glass and a little tridymite 53.82 46.18 1356 60 - Tridymite, SrO.Si0., trace of Soe glass 50 50 : 1363 ' 25 SrO.8i0, and glass _ Liquidus.of SrO.Si0, ‘ 50 50 1430 30 Glass 50 50 - 1420 60 Glass and SrO.Si0, 60 40 1571 60 Glass ~ 60 40 1552 45 Glass and SrO.Si0, Melting point of SrO.SiO, 63.22 36.784 1584 15 Glass 63.22 36.78 1580 ='5 SrO.Si0, and glass 63.22 36.78 1575 15 SrO.Si0, only oyy P. Eskola—Silicates of Strontium and Barium, 335 Eutectic SrO.Si0.-28r0.Si0, 65 35 1554 15 Glass : 65 35 1546 30 Glass and SrO.Si0, 65 35 1538 15 SrO.SiO, and 2Sr0.Si0, 67 33 : 1544 15 SrO.Si0O, and 2SrO.S8i0, Liquidus of 2Sr0.Si0, 67 33 1617 15 Glass 67 xe 1600 15 Glass and 2Sr0O.Si0, (es 28 1628 15 Glass and 2SrO.Si0, 77.46 22.546 1634 5 Sr,SiO, only a — SrO.Si0, b — 2Sr0.Si0.. The equilibrium diagram (fig. 1) is based on the above results; the melting point of cristobalite has been placed atic PALO", according to the determinations of Ferguson and Merwin,’ and the inversion point cristobalite-tridy- mite at 147 0° according to Fenner.’. The liquidus curve of the silica minerals has the same general shape as formerly found in all the other binary systems with silica as one component: starting from the eutectic point first a very steep rise a little above 1600°. The eutectic tridynute-SrO.S10,.—I prepared inciden- tally a mixture of 46.18 per cent SrO and 53.82 per cent Si0,, corresponding to the proportion SrO.2Si0,, to find out whether there was any disilicate of strontium, analo- gous to the barium disilicate known formerly. The result was negative, and this happened to be almost exactly the eutectic composition. The tridymite liquidus lynte only about five degrees above the solidus, the eutectic composition can be located with a fair degree of _ accuracy at 46.5 per cent SrO and 53.5 per cent SiQ,. ~ The temperature is 1858 + 4°. Strontium metasticate, SrO.Si0,.—Strontium metasili- cate was found in only one form which shows a very close resemblance to a-CaSiO,, or pseudowollastonite. Its melting point was determined as 1580 + 4°, in agreement with Jaeger and Van Klooster’s result, 1578+ 1°. Itis apparently of dihexagonal pyramidal symmetry, uniaxial and positive, and its characteristic habit is thick-tabular parallel to (0001). There is a fairly good basal cleavage. 7 J. B. Ferguson and H. E. Merwin, this Journal, 46, 417, 1918. *C. N. Fenner, this Journal, 36, 337, 1913. 336 P. Eskola—Silicates of Strontium and Barium. rie. V. 1700 liquid 4 @ and liquid 1600 Sro:5io TD} e 95r0-Si0, and 2 Sr0-SiOg Cristobalite and liquid = {500 =J = Ot — oO — 2 5S Oo S = ise) ca) o As) tp) Tridymite a Oo and liquid = 1400 on 3 w re) = W ai : . Sr0-:SiGo and —-0 ni diy image ero 25rO-SiO0g DSro0-Sids ia. 1.—Temperature-concentration diagram of the binary system SrO-Si0,. The density, at 30°, determined with a pycnometer, is _ 3.600. This is calculated as real density, compared with water at 4° and making correction for the buoyancy of air. Jaeger and Van Klooster® found d,=3.652 at 25.1°, in good agreement with that found by me which gives d,=3.653. OCS ache: SiOg P. Eskola—Silicates of Strontium and Barium. 387 The refractive indices were determined in granular erystals obtained by cooling a pure melt. They were found to be: a VW Boe 1606 1.646 Mees) 212602 1.641 Die eae 1599 1.637 Graces 1.596 1.634 These values were repeatedly checked and are correct in the third decimal place. Jaeger and Van Klooster give less exact values: n, =1.090 += 0.003, and n, = 1.620 = 60-005... Reese hast a ( <= 1.610; 6(D) = 1611; yD) = 1.654. In the apparent uniaxial positive character and hex- agonal tabular habit the strontium metasilicate is similar to a-CaO.Si0, and, as stated later, they form a continuous series of solid solutions. It would seem necessary, there- fore, that they should be closely isomorphous. Now Wright"! has proved a-CaO.Si0, to be really monoclinic, showing, in plates perpendicular to the optic normal, a polysynthetic twinning along the basal plane. The optie axial angle, though small, is not quite 0°. Much care was taken to find out whether the strontium metasilicate shows a similar deviation from hexagonal symmetry, but no such phenomena were noticed, although apparent twinning was observed in the mix crystals of SrO.8i0, and CaO.S8i10, (cf. below). Wuhedral erystals of SrO.SiO, were obtained from a strontium chloride melt with an excess of silica (cf. below). They are all thick tabular and apparently dihexagonal pyramidal (hemimorphic), one end being terminated only by the basal plane (fig. 2), sometimes with additional narrow pyramid faces, while the other end regularly shows well developed pyramids, usually combinations of two, three, or four simple forms. The pyramid faces are striated parallel to the edge with the basal plane. The greater part of the crystals are twinned on the base (fig. 3). As the erystals are perfectly hexagonal in aspect and 7G. A. Rankin and F. E. Wright: The ternary system CaQ-Al.O,-Si0., this Journal, 39, 1, 1915. 7 E. T. Allen, W. P. White, and F. E. Wright: On wollastonite and pseu- dowollastonite,—polymorphic forms of calcium metasilicate, this Journal, 21, 89, 1906. 338 P. Eskola—Silicates of Strontium and Barium. the measurements failed to reveal any deviation from hexagonal symmetry, I shall provisionally describe them as hexagonal, although the isomorphism with the calcium metasilicate makes it probable that the strontium metasi- licate 1s pseudohexagonal and really monoclinic, in that case belonging to the domatic, or monoclinic hemihedral class. Fig. 4. Fies. 2, 3, 4.—Crystals of SrO.Si0,. In examining these crystals with a binocular micro- scope one was found that was larger (about 0.5 mm in diameter) and better than the rest, but it was incomplete, having only faces in two pyramidal zones developed. These zones were identical, each combined of three different pyramids, p(1011), 0(4045) and (2021) (fig. 4). While searching for evidence of monoclinic symmetry I measured a number of crystals, but unfortunately they were too imperfect to prove anything positively. Often the pyramidal faces were quite curved in their zones so that the signals appeared as lines instead of points. All the forms observed in the best crystals were, however, also identified in other crystals, and some of them at the same time in three pyramidal zones. A further form t (9051) was found to be very common. The following data are based on the best crystal, except for the last named form f. The crystals separating from silicate melts and embedded in glass usually were bipyramidal in habit, with large basal planes, and thinner than those obtained from the chloride melt. | In summarizing the evidence regarding the crystal form of SrO.8i0,, we may ‘state that, from its solid solubility and apparent isomorphism with a-CaO.Si0,, it might be expected to be monoclinic, but actually the ~ crystals agree so closely with the dihexagonal pyramidal P. Eskola—Silicates of Strontium and Barium. 339 p | ° : Observed Caleulated ‘Observed | Caleulated Limits Average | e (0001) —— —— 0° 0’ ar —_- — p (1011) 49> 10' — 49° ° 55! AQ°-39". |... 49° 39! SOrO7 30° — o (4945) 55° 50’ — 56° 2’) 55° 56" CF bor 41 —— a n (2021) G6 oc — 66° 5). 66-44. 66° 55” — — — = t (5051) 78° 20’ — 80°50’ 979° 1%' || 80° 20’ —- — —- — Axial ratioa:c = 0.98 symmetry that, judging only from the characters of the rather poor crystals available, it should belong to this class. Another question that arose from the similarity to a-CaQ.Si0, was whether SrO.8i0, would also appear in more than one form. Several experiments were made to settle this question. SrO.Si0,-glass was held one hour at 1020°. The result was a crystallized mass showing radiating scaly crystals, uniaxial, positive, »=1.600 + 0.0038, «=1.640 + 0.003. It is consequently identical with the crystals separating from the melt. The same result was achieved when the glass was held 4 hours at 950°. SrO.Si0, was melted together with SrCl, in a Fletcher furnace and allowed to cool very slowly. After dissolv- ing the chloride in water to which finally was added a little HCl to decompose the chloro-silicate that had formed, the result was the same form of SrO.Si0, as before. The lastnamed experiment was modified so that the SrO.Si0,-SrCl.,-melt was left in the platinum resistance furnace over night at about 1000°. The product was not metasilicate at all, but strontium orthosilicate, which was identified by its refringence and characteristic twinning. Now, imitating the method that Allen and White?2 found most effective i in changing pseudowollastonite into wollastonite, | prepared strontium vanadate, Sr(VO;)., and melted one gram of this with two grams of SrO.S810,. The mixture was held over night at about 900°. After washing away the vanadate, the mass consisted of the “2. T. Allen and W. P. White, this Journal, 21, 89, 1906. 340 P. Eskola—Silicates of Strontium and Barium. same form of SrO.Si0., as rounded crystal grains and with no euhedral forms. To prevent the formation of orthosilicate in the stron- tium chloride melt I finally heated SrO.Si0, with SrCl, and a considerable excess of silica, added in the form of coarse quartz grains, which dissolved rapidly in the melt above a gas burner. This mixture, held over night at about 1000°, gave well-developed erystals of the same form of SrO.Si0O,. The identity, as in all the other cases, was ascertained by determination of the refractive indices. Thus all the experiments failed to show any other form of SrO.Si0, than the one similar to the pseudowollas- tonite.'? The eutectic SrO.S10,-28r0.810, was located at 65.5 per cent SrO, as is apparent from the diagram (fig. 1). The steep slope of the liquidus curves at both sides is remarkable. While in the 65 per cent SrO mixture the primary phase is SrO.Si0,, it is 2SrO.Si0, in the 67 per cent SrO mixture, and the hquidus has risen 60° ae the eutectic temper ature, 1545°. The existence of 8Sr0O. 2810, not proved.—The primary phase in all the mixtures hetw een the eutectic at 65.5 per eent SrO and 28rO.S8i0, is strontium orthosilicate. The following experiments were carried out in order to es- — tablish whether there might be formed the compound osrO.28i0,, analogous to 3CaQO.2Si0,, known from the studies on the calcium silicates. Strontium earbonate and quartz powder in the propor- tion required to form 38rO.2Si0, (72 per cent SrO), well mixed together, were held 2 hours at 1475° and quenched. The product consisted of SrO.810, and 2SrO.Si0,. Another time the charge was allowed to cool slowly. The - result was the same. The same mixture was heated 16 hours at 1150°. It was now so fine-grained and poorly individualized, that it could not be decided whether there were one or two phases present. Neither SrO.SiO, nor 2SrO.Si0, could be identified. 4% Jaeger and Van Klooster (op. cit., p. 903) heated 0.5 ¢. of pure SrO.Si0, with 1 or 2 g. of sodium tungstate at 860° during 72 hours and always obtained the same form as by direct crystallization from a melt, whether they had started with crystals or with glass. P. Eskola—Silicates of Strontium and Barwm. 341 Strontium orthosilicate, 2SrO0.Si0,—The melting point of 2SrO.Si0, is far above the range of the platinum ‘resistance furnace. In a search for several polymorphic forms of this com- pound IJ heated a preparation of crystalline 2SrO.Si0, at different temperatures: 5 minutes at 1634°, 2 hours at 1415°, 1300°, and 990° respectively. The result was always the same form, well characterized by its refrin- gence and twinning. It was also obtained from a SrCl, melt at about 1000° (ef. above, p. 539). Nor did the substance change when allowed to cool very slowly. The phenomenon of ‘‘dusting’’ in the case of 2Ca0.8i0, apparently has no analog here. For the determination of the optical properties the preparation quenched from 1634°-was used, with the following results. a B Y Ee eer) 1.744 1.766 ol Dd beat a 2 DE as LEV oMte 1.760 dB easaher ean yay) 1 ee 56 (Giaecaoariceenl AST ZA. de ZiT Eee, The crystals are optically positive with 2H = 58° approximately, or 2 V = 32°30’. In many of the crystals a twinning was observed, often repeated (fig. 5). In sections normal to y, the acute bisectrix, the trace of the axial plane forms, with the composition planes of the twinning lamelle, angles of 17°. Thus, if the crystal system is monoclinic, the plane of the optic axes is normal to the plane of symmetry. The repeatedly twinned erystals, in their outlines, often display the habit of orthorhombic crystals, and when the lamella are very narrow they have apparent straight extinction. “ Free strontium oxide attacks platinum on heating. Every mixture does SO as soon as it contains an excess, however small, of SrO over 2SrO.SiO., while the more acid mixtures may be heated in platinum crucibles without any danger. The phenomenon appears as a blackening of the surface of the platinum and of the charge. This black substance is soluble in HCl, forming chloroplatinie acid. A probable explanation is that the strontium oxide dissociates at high temperatures, either into metallic strontium or into a strontium suboxide which forms an alloy with platinum. This may be connected with the fact that the strontium oxide is somewhat volatile. Both the dissociation and the volatilization are, however, very slight at the temperatures of the platinum resistance furnace. 0.300 g. SrO, wrapped in platinum foil and held 4 hours at 1580°, lost only 0.0017 g. in weight. 342 P. Eskola—Silicates of Strontium and Barium. Strontium oaide, SrO'*.—All the’ mixtures which contained more SrO than 2SrO.SiO,, resulted in two phases, 28rO.Si0O, and SrO, when heated at high temperatures. In these mixtures the strontium oxide could always be identified from its isotropic character and high index of refraction. : FICO: CERI 8 p ; Oo Fig. 5.—Crystals of 2SrO.S8i0.. Pure SrO was prepared in two ways, from strontium carbonate and from strontium nitrate. In the first case it forms minute rounded, though clear grains. When these were held 4 hours at 1580° they reacted slowly with water and even with HCl. From nitrate the oxide may be obtained as large clear crystals showing a perfect cubic cleavage.'® The determination of the index of refraction was very difficult, because the oxide instantly reacts with the high refractive liquids containing iodine. It was found to be somewhat higher than 1.86 for all the colors and may be very roughly estimated at 1.87. * See also G. Briigelmann, Z. anorg. Chem., 10, 415, 1895. P. Eskola—Silicates of Strontiwm and Barium. 3438 The specific gravity has been determined by Brigel- mann (loe. cit.) as 4.750. According to H. Moissan,‘® str ontium oxide melts more easily than calcium oxide, but nothing more is known about its melting temperature. Wyckoff? has determined, by Debye and Scherrer’s method, the erystal structures of CaO, SrO, BaO and mixtures of CaO with SrO and BaO, respectively, in samples prepared by me. His results have interest for us in so far as they prove SrO to be perfectly isomor- phous with and to form a series of solid solutions with CaO. The System BaO- S10,. The quenching experiments pertaining to the system ~ BaO.Si0, are described in table II. Tasue IT. Composition wt. per cent Compounds Oxides BaO. 2BaO. Temper- Time BaO SiO, 2Si0O, 3810, ature°C minutes Resulting phases Liquidus of tridymite 40 60 1551 90 Glass and tridymite 45 55 1472 120 Glass 45 55 1447 90 Glass and tridymite Eutectic tridymite-BaO.2Si0, 45 55 1372 135 —~ Tridymite and BaO.2Si0, 47.5 52.5 1390 120 Glass 47.5 52.5 1377 60 Glass and tridymite 47.5 52.5 1373 120 BaO.2Si0, and tridymite 50 50 1598 120 Glass 50 50 1385 60 Crystals and glass 50 50 1369 120 Tridymite and BaO.2Si0, Melting point of BaO.2Si0, 55.98 44.02a 1425 90 Glass 55.98 44.02 1421 30 Glass 55.98 44.02 1419 60 Ba0O.2Si0, (with some glass) Liquidus of the solid solutions BaO.2Si0,-2Ba0.3Si0, 58 42 fat 29 1441 60 Glass 58 42 71 29 1435 60 Glass 58 42 (a: 29 1432 60 Glass and mix crystals 60 40 42 58 1448 60 Glass 60 40 42 58 1443 60 Glass and mix crystals 61.25 38.75 23.9 76.1 1451 60 Glass 61.25 38.75 23.9 76.1 1448 60 Glass and mix crystals 1° H. Moissan, Ann. Chem. Phys., (7) 4, 136, 1895. * Ralph W. G. Wyckoff, unpublished data. 344 P. Hskola—Silicates of Strontium and Barium. Solidus of the solid solutions BaO.2Si0,-2Ba0.3Si0, 58 42 fall 29 1418 60 Crystals 58 42 elk 29 1424 60 Mix erystals with little glass 60 40 42 58 1435 60 Mix crystals and glass 60 40 42 58 1431 60 Mix erystals O12 Boel mmol: 1443 60 Mix erystals and glass 6120 22 BSW epao.oL aoa 1440 60 Mix crystals and glass Ol 2Dr Paul Oenezao onl 1438 60 Mix erystals Melting point of 2Ba0.38i0.,. 62.90 37.100 1451 60 - Glass 62:90) Sear o 1451 30 Glass 62:00" 237-10 1448 30 Glass and 2Ba0O.3Si0, Eutectic 2Ba0.3S8i0.-Ba0.Si0, 65 35 1439 15 Glass BaO.Si0, and 2Ba0.3S8i0, 65 35 1435 30 with a little glass. 65 35 1431 30 BaO.8i0, and 2Ba0.3Si0,,. Hutectic BaO.S8i0,-2Ba0.Si0, 75 25 1556 15 2BaO.Si0, and glass. 75 25 1546 15 2Ba0.S8i0, and BaQ.Si0, a — BaO.2810, 6 = 2Ba0.38i0, From these determinations results the equilibrium diagram fig. 6. v. Birefringence is very weak. Grains parallel to By, showing the trace of the good cleavage along af, display abnormal blue interference colors. The indices of refraction were determined as follows: a. B Y War Ge 1.684 1.688 Daeg LOG 1.678 1.682 acti lebiaes 1.674 1.678 Or oe L669 1.670 1.673 352 P. Eskola—Silicates of Strontium and Barwm. The density at 4° was determined to be 4.399. The melting point of BaO.S10, is, according to Jaeger and Van Klooster, 1604 + 0.5°. To find out whether the barium metasilicate could be inverted into some other form I heated a sample of the crystallized compound, first alone and a second time with one-fifth of its weight Ba(VO;)., over night at about 1100°. No change took place.?® Eutectic BaO.Si0,-2Ba0.810,—A mixture of these compounds, containing 75 per cent BaO, gave at 1546° erystals of both kinds, but at 1556° only crystals of 2BaO. SiO, and glass. From this it may be concluded that there i is a eutectic at about 74.5 per cent BaO with a melt- ing point of 1551 + 6°. No other compounds except the two named above occur in this part of the system. Barwm orthosilicate, 2Ba0.Si0,.— Barium orthosili- cate appears as a granular mass of rounded grains and does not show any cleavages or twinning. The melting point is higher than that of platinum. a(D) =1.810 + 0.005; y(D) = 1.830 + 0. 005. Barium oxide, BaO.— Mixtures of barium orthosilieate and barium oxide were not studied more closely. The fact that all the mixtures containing an excess of BaO over the orthosilicate ratio attack platinum, seems to prove that they contain free BaO.”° Coarsely crystalline barium oxide was prepared from barium nitrate by heating slowly in a graphite crucible. It was obtained in clear translucent crystals showing cubic cleavage. The refractive index is very high, but difficult to deter- mine; the substance absorbs moisture from the air almost immediately when exposed and also attacks the high-refractive media (in this case mixtures of sulphur and selenium). I found (in red light): == 2AG > Os: Brugelmann has determined the specific gravity of barium oxide as 5.722. | * Jaeger and Van Klooster (loc. cit.) were not more successful in their attempt to effect a change by heating 0.5 g. barium metasilicate with 1 g. sodium tungstate at 860° for 72 hours. *° Barium oxide attacks the platinum in the same way as strontium oxide, but still more strongly. P. Eskola—Silicates: of Strontium and Barium. 353 The System CaO.8i0,-Sr0.810, The quenches made to establish the melting diagram of mixtures of the metasilicates of calcium and strontium are recorded in table IY. TABLE LV. Composition wt. per cent Oxides Silicates Temper- Time CaO. SrO. ature min- Resulting phases CaO Ser SiOs SIO, HS10,.-. C= utes meee tog) 346.06. 79 ~ 20. 1495°> “15° Glass S613 15.81 48.06 75 25 1485 . 15. Mix erystals 30.11 23.71 46.18 62.5 37.5 1482 15 Mix erystals and glass eb asf et OLS. 62.0. 37.5 1474-15 Mix crystals 24.09 31.61 44.30 50 50 1482 15 Glass 24.09 31.61 44.30 50 50 1478 15 Glass and mix crystals 24.09 31.61 4430 50 50 1474 15 Mix erystals 21.08 35.56 43.36 43.75 56.251477 15 Glass 21.08 35.56 48.36 43.75 56.251472 15 Mix erystals 12.05 47.41 40.54 25 75 1511 15 Glass 12.05 47.41 40.54 25 75 1507 15 Glass and mix crystals 12.05 47.41 40.54 25 75 1500 15 Mix erystals and glass 12.05 47.41 40.54 25 7 1496 15 Mix crystals As these data, together with the optical study of the mix crystals obtained, seemed fully to establish the general character of the melting diagram (fig. 10), it was considered unnecessary to determine the curve in more Pte. 10: Cad0-Si0g Sr0:Si09 Fic. 10.—Temperature-concentration diagram of the binary system CaO.S8i0,-SrO.SiO, showing a complete series of mix crystals with a minimum. detail. Assuming as the melting point*! of «-CaO.Si0,, 1540°, and of SrO.S10,, 1578° (cf. above, p. 335), we get the diagram reproduced in fig. 10. *G, A. Rankin and F. E. Wright, this Journal (4) 39, 1, 1915. 354 P. Eskola—Silicates of Strontium and Barium. The minimum melting temperature in this series was found to be 1474 + 3° at the composition 44 per cent CaQO.S10,—06 per cent SrO.Si0,. The mix crystals were found to be crystallographically very like a-CaO.SiO,. Considerable care was taken to find out whether they show that twinning on the base which, in the case of pseudowollastonite, indicates mono- clinic symmetry. In a-CaO.Si0, I found frequently polysynthetie twin- ning along the basal plane, as described by Wright (loe. eit.). In mix erystals with 12.5 per cent SrO.Si0, the twinning was no less clear; in one case I measured an extinction angle of 3°. In the mixture with 25 per cent SrO.Si0, twinning was clearly observed, while, in mixtures with 37.5 per cent, 56.25 per cent and 62.5 per- cent SrO the extinction angles were apparently so small that the twinning lamelle, though occasionally positively identified, always appeared extremely faint. In a preparation with 75 per cent SrO.Si0, the occurrence of faint twinning along the base was still clearly observed. In the pure SrO.Si0, I did not succeed in finding definite twinning appearing as oblique extinction, in spite of much search. In summary, therefore, it may be stated that all the crystals containing calcium and strontium metasilicates in solid solutions are pseudohexagonal and really mono- clinic. In the pure strontium metasilicate, although it may belong to the same class of symmetry as the mix crystals, no deviation from hexagonal symmetry was observed (cf. p. 337). The indices of refraction for the solid solution series were determined with the following results. TABLE V. Wt. % CaO.Si0, 100 TD 50 43.75 2S 0 Wt. % SrO.S8i0, 0 25 50 BG 225) (5) 100 a(F) 1.618 1.617 1.614 1.612 1.609 1.606 a(T1) 1.614 1.612 1.609 1.608 1.605 1.602 a(D) 1.610 1.608 1.606 1.6045 1.602 1.599 a(C) 1.607 1.604 1.602 1.6015 1.599 1.596 1 (F) 1.663 1.646 y(T1) 1.667 1.641 ~(D) 1.654. 1.651 1.646 (4 21.648 nes v(C) 1.649 1.634 P. Eskola—Silicates of Strontium and Bariwm. 355 The same is expressed in the diagrams (fig. 11) in which is also shown the variation in the index of refrac- tion in the strontium and calcium metasilicate glass. Fic. 11.—Variation of the indices of refraction in the mix crystal series Ca0.Si0,-SrO.Si0,. The System Ca0.8i0,-Ba0.810,. While strontium and calcium metasilicates give-a complete series of solid solutions and apparently are perfectly isomorphous, barium metasilicate does not mix at all with calcium metasilicate. Instead of this there occurs a double compound, 2CaO.BaO.38i0,, which, how- ever, has no true melting point, but breaks up into a-CaO. SiO, and liquid. Those quenches which yielded impor- tant results are quoted below in table VL. 356 P. Hskola—Sihcates of Strontium and Barium. TABLE VI. Composition wt. per cent Oxides Silicates Temper- Time CaO. BaO, ature min- Resulting Phases CaO BaO SiO, .SiO, Si0,.- °G-- utes Liquidus of a-CaO.SiO, 36.13" 17.95 4592: --75 25 1466 15 Glass 36.13 4417. 9a 45-92 75 25 1457 15 Glass and a-CaO.Si0, 36e13 517-99. a4 02 aaa 25 1441 15 Glass and a-CaO.Si0, Py Seley cetiea LKAO ay = ll CO 77) 25 13844 15 aq-CaSiO; and glass 28.90» P28:71-- 42.38 2.260 40 1394 15 Glass 28.90 28.71 42.38 60 40 1380 15 Glass and a-Ca0.Si0O, 24.09 35.89 40.02 50 50 1342 15. Glass 24.09 35.89 40.02 50 50 1330 15 Glass and a-CaO.Si0, 24.09 35.89 40.02 50 50 13826 15 Glass and qa-CaO.Si0. 24.09 35.89 40.02 50 50 1325 25 Glass and a-Ca0.S8i0, Invariant point a—CaO.8i0,-2Ca0.Ba0.38i0.—liquid. 24.09 35.89 40.02 50 50 1321 $15 Glass and a-CaO.Si0, 24.09 35.89 40.02 50 50 1319 15 Glass and 2Ca0.Ba0.3Si0, 24.09 35.89 40.02 50 50 1817 15 Glass and 2Ca0.Ba0.3Si10, 24.09 35.89 40.02 50 50 1300 15 Glass and 2Ca0.Ba0.3S8i0, 22.88 81.00: (a0 tere 41-5 Toco loo, = lo) Glass 22.88 37.69 39.43 AD) eres ae oes 15 Glass and 2Ca0.Ba0.38i10, 22.88 387.69 39.43 47.5 52.5 1314 15 Glass and 2Ca0O.Ba0.3Si0, Decomposition of 2CaO.Ba0.3Si0, 25.13 34.32 40.54 52.18 47.821320 30 a-CaO.SiO, and glass — 2Ca0.Ba0.3Si0, 25.13 34.32 40.54 52.18 47.821315 20 2Ca0O.Ba0O.3Si0, only ) Liquidus of 2Ca0.Ba0.3S8i0,. 21.68 39.48 38.84 45 55 A321 == 300=Glass 21.68 39.48 38.84 45 55 1316 30 Glass and 2Ca0O.Ba0.3810, 21.68 39.48 38.84 A5 55 1301 30 Glass and 2Ca0O.Ba0.3S8i0, 16.99 46.47 36.54 35.26 64.741306 20 Glass (BaO.Ca0.2Si0,) 16.99 46.47 36.54 35.26 64.741300 20 Glass and 2Ca0O.Ba0.3S8i0, 16.99 46.47 36.54 35.26 64.741294 20 Glass and 2CaO.Ba0.3S8i0, WBS A Boe 34 66 1293 20 Glass and 2Ca0.Ba0.3Si0, Grail MABE Ho) Bb 66 1290 20 Glass and 2Ca0.Ba0.3Si0, 15.66 48.45 35.89 32.5 67.5 1289 15 Glass and 2Ca0.Ba0.3Si0, 1 5r4 2 M4881 135s 32 68 1290 15 Glass i 15.42 48.81- 35.77 32 68 1284 25 Glass and 2Ca0.Ba0.3Si10, 144) ee eo Opes O 70 1280 20 Glass 14.45 50.25 35.30 30 70 1276 20 Glass and 2Ca0O.BaO.3Si0, | abel ED SO) © 8X0) 70 1274 20 Glass and 2Ca0O.Ba0O.3Si0, Eutectic 2Ca0.Ba0.38i0,—Ba0.Si0, : 16.99 46.47 36.54 35.26 64.741273 2CaO.Ba0O.3Si0, and glass 16.99 46.47 36.54 35.26 64.74 1271 2Ca0.Ba0.3Si0, and glass 16.99 46.47 36.54 35.26 64.74 1265 2Ca0.Ba0.3S8i0, and BaO. SiO, sige P. Eskola—Silicates of Strontium and Barium. 357 PEAS. DUS 35.30-..30 70 1270 2CaO.BaO.3Si0, and glass ea as 50:29 35.30. - 30 70 »~=1268 2CaO.BaO.3Si0, and BaO. Si0, ieee De04) 34.71 — 27.) 72.5: 1274 Glass Beene 2.04. 1847 hs 9 27.5-- 72.5 1271 Glass taco, - 92.04 34.71 . 27.5 72.5 1268 2CaO.Ba0O.3Si0, and BaO. Si0, fo. 53-83 34.12 = 25 Toe BaO.Si0, and glass Prey “0o.co 34:12 .. 25 Tole AOE BaO.SiO, and. 2CaO.BaO. 3810, W6a,- 0(.42- 32.95: 20 80 1267 BaO.Si0O, and 2Ca0O.BaO. 3810, . liquidus of BaO:Si0, #205 250.00 34.12%. 25 io 2.4300 Glass PA 95.05 34.12.29 (Sa Ae Glass and BaO.Si0O, 9:63 = 57.42 32.95. 20 80 1367 Glass and BaO.Si0, The melting diagram resulting from these facts is given in fig. 12. The liquidus curve of a-CaO.Si0, was followed to 50 per cent BaO.Si0,. The «-CaO.SiO, which always separated in the form of thin crystals tabular parallel to the basal plane did not seem to take any BaO.Si0, in solid solution, as the crystals in all cases showed the indices of refrac- tion characteristic of pure pseudowollastonite: «(D) = 1:609 + 0.002; -»(D) = 1.652 + 0.002. Dicaleium barwm silicate, 2Ca0.Ba0.3S10,—When the mixture composed of 50 per cent BaO.SiO, and 50 per cent CaO.Si0O, was allowed to crystallize on cooling, it formed a coarsely crystalline, fibrous mass, almost like natural wollastonite. The fibers were speckled with minute crystals of another substance (BaO.Si0,). Supposing the fibrous erystals to have the composition 2CaO.BaO.3Si0, I prepared such a mixture, which was now found to crystallize as homogeneous crystals and on heating to break up at 1320 + 4° into-a-CaSi0, and liquid. The crystals are uniaxial and negative, probably hex- agonal, and have good cleavages in their prismatic zone. A crystallizing mass develops negatively elongated fibers. The indices of refraction were determined as follows: PERO € Bree 1.690 1.678 PP ais E685 1.672 Bat: 1.681 1.668 Oe sae: OFT 1.664 358 P. Hskola—Silicates of Strontium and Barium. Fig. 12. 1 640 1600 I560 1520 14380 1440 1400 1360 1320 Bad-Si 0g a and liquid 2€a0:Ba0-35i10g ~*% and liquid 9 = &-CaQ:Si Og + 1280 1940 and 2 Ca0-Bad-3Si0g 2Ca0- BaO-35i0g and Bad-Si0g | 200 10 $6) 30 40 50 60 70 80 90 100 Ca0:Si09 Ba0-Si09 Fig. 12.—Temperature-concentration diagram of the binary system Ca0.8i0,-Ba0.Si0.. As it was thought possible that there could exist solid solutions between the double compound and BaO.Si0,, I determined the refractive indices of the exceedingly small crystals in preparations with 55 and 60 per cent P. Eskola—Silicates of Strontium and Barium. 359 BaO.SiO,. I found in both cases o(D) = 1.683 + 0.003; «e(D) = 1.669 + 0.003. The results are not significantly different from those of the pure compound. The variant point Ca0.810,-2Ca0.Ba0.3S10.-melt.— In a mixture containing 50 per cent of CaO.Si0, and as much BaO.Si0, the erystals of 2CaO.BaO.3810, break up into a-CaO.SiO, and liquid before melting entirely. In another mixture with 47.5 per cent CaO.SiO, the last erystals before complete melting consist of the double compound. The invariant point therefore is between these limits, and the course of both liquidus curves meet- ing there indicates it to be at 52 per cent BaO.Si0O, and *48 per cent CaO.SiO,, with the temperature of complete melting 1320 + 4°. The liqudus of 2Ca0.Ba0.38i0, has, from the invariant point, a regular course towards a eutectic. I followed its course very closely, because it was suspected that another double compound, CaO.BaO.2S10,, might possibly form here, its composition corresponding to _ 30.26 weight per cent CaO.Si0, and 64.74 weight per cent BaO.SiO,. But no such compound could be isolated, and the corresponding mixture crystallized within an interval of 32° into a very fine mixture of BaO.Si0, and 2Ca0O. BaO.3Si10,. The liquidus of BaO.SiO, was determined, with only a few quenches, to have a steep course towards the high melting point of the barium metasilicate. The crystals of this compound in melts containing 75 to 80 per cent BaO.SiO, were not equant grains as in the system BaQO.Si0,, but needle-like, sharp at both ends. As they have formed at much lower temperatures than the crystals in BaO-SiO, melts, it may be possible that they represent another form of BaO.Si0O,. The refrac- tive indices, however, so far as they could be determined, were identical, and experiments carried out to establish - the transformation expected failed, even when minerali- zers were applied (cf. p. 352). The Properties of the Glasses. The physical properties of representative glasses studied in the present work are tabulated below. 360 P. Hskola—Silicates of Strontium and Barium: TasLE VII. 3 Glasses in the system SrO-Si0O,. Wt. % SrO 46.2 50 60 63.2 67 Wt.% SiO, 53.8 50 40 36.8 33 Formula Sr0O.2Si0, — — Sr0O.S8i0, — ER Re 1.591 1.598 632 1.640 1652 n(T1) 1.587 1.595 1.627 1.636 1.648 n(D) 1.584 1.5915 1.624 1.632 1.644 n(C) 158 1.589 1.621 1.629 1.641 Density 3.201 — a 3.0014 — ¢ Calculated from the value of specific gravity, d(4°) — 3.540, given by Jaeger and Van Klooster, op. cit. 902. TABLE VIII. Glasses in the system BaO-Si0O,. . Wt. % BaO 45 : 50 56 65 Wt. % SiO, 55 50 4+ 35 Formula —_ — BaO.2S8i0, n(F) 1.576 gS) lee 1.617 1.653 n(T1) 1.571 1.589 1.612 1.648 n(D) 1.5665 1.585 1.6085 1.645 n(C) 1.5635 1.582 1.605 1.641 Density — 3.441 — — Fies. 13, 14. 40Wt? Sr 50 60 7o 40 Wt? Bad 70 60Wts SiO, = 50 40 30 60WtsSi0, 50 40 30 Fig. 13.—Variation of the indices of refraction in strontium silicate glasses. Fic. 14.—Variation of the indices of refraction in barium silicate glasses. P. Eskola—Silicates of Strontium and Barium. 361 Figs. 13 and 14 are diagrams of the variations in the refractive indices of glasses of the systems SrO 810, and BaO-Si0, showing also the dispersions. |.800 1.750 1.700 1.650 1.600 }.550 1.500 .450 : — 100 80 60 40 20 O Si0O9 Fic. 15.—Variation of the index of refraction in strontium and barium silicate glasses. Fig. 15 represents the same for the sodium light. The curves are drawn as far as the point corresponding to the index of refraction of silica glass and extrapolated up to the points of the hypothetical refractive indices of barium and strontium oxide glasses. In this part the curves, of course, can not give the values of the indices 362 P. Eskola—Sviicates of Strontium and Barwm. very exactly, while those of the acid end should be fairly accurate, and the data given here may be, in the case of the barium silicate, of some practical interest to the manufacturer of optical glasses. . In tables [IX and X are given the determinations of refractive indices of glasses in the systems CaO.Si0,- SrO.810, and CaO.Si0,-Ba0.S10,..° “Lhe samesas expressed in fig. 16. Fig. 16. 1.670 1.660 INSECT BASSO N\ N | | i iH \oOwt% 80 60 40 20 0 Ca0:Si0g Fig. 16.—Variation of the indices of refraction in glasses of CaO.Si0.. SrO.8i0O, and CaO.Si0.-Ba0.Si0.. P. Eskola—Stlicates of Strontium and Barium. 363 7 TABLE LX. Glasses. in the system Ca0.8i0.-Sr0.Si10.. Wt.% Ca0.S8i0, 100 87.5 62.5 43.75 37.5 0 Wt. % SrO.Si0, 0 12.5 37.5 56.28 62.5 100 n( FE) 1.635 1.634 1.634 1.636 1.637 1.640 n( TI) 1.631 1.630 1.630 1.633 1.632 1.636 n(D) 1.628 1.6265 1.627 1.628 1.628 1.632 n(C) 1.625 1.6245 1.625 1.625 1.626 1.629 TABLE X. Glasses in the system CaO.Si0,—Ba0O.Si0O.. Wt. % CaO.SiO, 100 75 60 50 40 25 0 Wt. % BaO.Si0, 0 25 40 50 60 75 100a n(F) 1.635 1.643 1.649 1.6525 1.658 1.6655 (1.681) epee ont ge ARGSS. O45). 1.647) W653 ~ 1.6605" 1.675) n(D) 1.628 1.6345 1.6395 1.644 1.649 1.657 (1.672) n(C) 1-625 ~- 1.6305 1.636 - 1.640 - 1.645 1.653 (1.668) Density 3.633 a Extrapolated. Absence of Diopside Analogs. A few experiments were made to ascertain whether strontium and barium metasilicates form double com- pounds with magnesium metasilicate, analogous to diop- side, the calcium compound, CaO.MgO.2Si0,. Mixtures corresponding to these proportions were prepared and quenched from different temperatures. A mixture corresponding to SrO.Mg0O.2Si0, gave only glass at temperatures above 1520 and, at temperatures down to about 1200°, glass and crystals that from their optical properties may have consisted of chnoenstatite. Another mixture of the composition 2SrO.Mg0.3810, gave SrO.Si0O, as a primary phase. It therefore seems that the metasilicates of strontium and magnesium do not form any double compound at all. At any rate, there is no compound SrO.Mg0.2Si0.,, analogous to diopside. Furthermore, I made a mixture of 25 weight per cent SrO.M¢0.2810, and 75 weight per cent CaO.MgO.2Si0,, heated it above 1400° and let it cool slowly. The product contained diopside, showing a(D)=1.665 + 0.002; poe — on 0005-7 D) — £695 = 0,002 and.2V = 60°. These properties agree perfectly with those of pure diopside and consequently the crystals do not contain any strontium compound as isomorphous mix- Am. Jour. Sci.—FirtH Series, Vou. LIV, No. 23.—-NoveMBER, 1922. 364 P. Eskola—Sihicates of Strontium and Bariwwm. ture. This conclusion, however, is not very dependable, as our experience is that strontium replacing calcium changes the optical properties of crystals very little. More weighty evidence proving positively that the amount of the strontium compound entering into solid solution in the diopside must be very small, is that the product consisted of more than one phase, the other phases besides the diopside being present as a fine crystalline mass. The preparation of the composition BaO.Mg¢g0O.2Si0.,, on cooling from a melt heated not above 1370°, also gave several phases, and no double compound analogous to diopside was formed. This negative result is very remarkable, especially in the case of strontium, which in other ways showed such elose similarity with calcium. The Strontium and Barium Feldspars. Former wvestigations— From melts of the corre- sponding oxides Fouqué and Michel-Lévy** believed they had prepared strontium, barium, and lead analogs of anorthite, oligoclase and labradorite. Their different ‘‘feldspars’’ had the following specific eravities: 3 Sr Ba Pb Olieoclase ie. a. 1.619 2.906 3.196 Habradomre 2a. oe 22807 nooo 3.609 A MORHIIC see et 3.043 Soe 4.093 The products were not well crystallized and their crystal system could not be determined with certainty. The barium feldspar, BaAl,Si,O,, always formed microlites showing parallel extinction with negative elongation, and the crystals, being usually rectangular in cross section, seemed to be orthorhombic. Later investigation by EH. Dittler,?? on artificial barium feldspar, confirmed this result and also established it to be biaxial. Ginsberg,?* * F. Fouqué et A. Michel Lévy: Sur la production artificielle de feldspaths & base de baryte, de strontia et de plomb, correspondant 4 1’oligoclase, 4 labradore et a l’anorthite; études des propriétés optiques des ces miner- aux, Bull. soc. min. France 3, 124. 1880. 23H. Dittler, Tscherm. Min. Petr. Mitt., 30, 122, 1911. *4 A. S. Ginsberg, Ann. de 1’Inst. Polytech. Pierre le Grand 4 Pétrograde, ISIS DOUEL, P. Eskola—Silicates of Strontium and Barwm. — 365 however, states that crystals of BaAl,Si,O, obtained by cooling of the pure melt were uniaxial, positive, and he regards this form as presenting a nephelite analog. There is some evidence to the effect that some amount of lime, in plagioclase feldspars, may be replaced by baryta without changing the triclinic symmetry. Des- cloizeaux”® found this to be the case in a natural feldspar from unknown locality, whose optical and erystallo- eraphic properties were similar to those of labradorite, while its composition resembled that of oligoclase more closely, with 7.30 BaO, 1.83 CaO, 7.45 Na.O, and 0.83 K,O. Ginsberg’*® investigated the binary system CaAI1,81,0¢- BaA1,Si,O, in artificial products and found that the tri- elinie anorthite may take up limited amounts of barium feldspar in solid solution, whereby the optic axial angle diminishes. The hexagonal BaAl,Si,O0,, on the other hand, may take up some lime feldspar.*" The relation of barium feldspar and orthoclase is far better known. Penfield?* described barium-bearing orthoclase from Blue Hill, Delaware County, Pennsyl- vania. Later Sjogren?® and Strandmark®® studied the barium feldspar, or celsian, from Jakobsberg, Sweden, and proved it to have the composition BaO.Al,O,.2Si0,. The latter establishes its monoclinic symmetry and erystallographie similarity to adularia. The crystals are usually elongated parallel toe. The angle «a A ¢ = 3°V’ in the acute angle 8. a=—1.5835; 8=1.5886; y = 1.5941. Sp. g. 3.387. Strandmark also proved that the hyalo- phanes are isomorphous mixtures of celsian and ortho- clase. Rock analyses including determinations of BaO and SrO commonly show small amounts of both of these oxides. As Washington*! has pointed out, the highest amount of both of these oxides have been found in certain highly potassic rocks of Wyoming, showing up to 1.10 per cent BaO and 0.380 per cent SrO. (D) Artificial barium feldspar®...... 1.587+0.002 1.5930.002 1.600+0.002 Beste Celsian ss. tad 4. po. och oi 1.5835 1.5886 1.5941 The differences in the indices of refraction are some- what greater than the probable errors, but not more than may be accounted for by the fact that the natural celsian carries a few tenths of a per cent of alkalies and lime. Artificial strontium feldspar, SrO.Al,O3.2S10,.—The strontium feldspar obtained from the vanadate flux formed a crystalline mass showing radiating fibrous development but no well-formed crystals. No twinning could be discerned. Therefore nothing can be said about its erystallographie characters. The indices of refrac- tion, however, were readily determined and are stated below, compared with those of anorthite. a(D) B(D) y(D) EROMALOEASIO, (25 0505 05s 1.5740.002 1.582+0.002 1.586+0.002 PATO, 2Si0; 522i. Soe ee st. 1.576 1.584 1.588 It was thus found that the strontium feldspar is, in its optical properties, exactly like the calcium feldspar within the limits of the possible errors. This is not very surprising in itself, as we have found in some cases the indices of refraction of the strontium compounds some- what lower and in other cases somewhat higher than those of the calcium compounds. A mixture of 50 weight per cent SrO.A1,0,.2Si0, fd 00 weight per cent Cad. Al,O3.2810, was prepared and heated at about 1500°. It formed ‘clear homogeneous- looking grains whose indices of refraction agreed with those of anorthite. It did not melt at this temperature and it is therefore probable that the strontium feldspar forms a complete series of solid solutions with anorthite. 34 (F) — 1.593; a(T1) = 1.590; a(D) =1.587; a(G) = 1.585 368 P. Eskola—Silicates of Strontium and Barwm. Some General Considerations Regarding the Relations of the Alkaline Earth Compownds. With the exception of some rare titanosilicates, the only natural anhydrous silicates of barium known are barium feldspar, or celsian, BaAl,Si,O,, notable for its isomorphism with potash feldspar, barylite, Ba,A1,Si,- O,,, and taramellite, Ba,Fe’Fe’’,Si,,0,,. Hydrated silicates are more numerous, mostly belonging to the zeolite group, namely: brewsterite, H,(Sr,Ba,Ca) Al,Si,- O,, + 3H.O, harmotome, H.(K.,Ba)Al.81,0,; + 48.0, edingtonite, BaAl,Si,0,,. + 3H.O and wellsite (Ba,Sr,Ca,- K,) Al,81,0,. + 3H.O. Micas sometimes contain appre- ciable amounts of barium. No strontium silicates are known as minerals, though this element, in smaller quantities, is contained in some rock-forming feldspars, probably plagioclases (cf. p. 365), and in hancockite, a lead-epidote, and in zeolite minerals heulandite, H,(Ca,Sr) Al,Si,0,, + 3H,O, and wellsite and brewsterite, named above. The present study adds some information concerning the isomorphous relations of a number of other silicates of strontium and barium. Thus the compound BaO. 2810, which was suggested by Bowen (loc. cit.) to be isomorphous with the potassium disilicate studied by Morey and Fenner,** has now been found to be also iso- morphous with 2Ba0.58i0,. A strontium metasilicate was found to be isomorphous with a form of calcium metasilicate, and a strontium orthosilicate is probably isomorphous with either the « or the 6 form of calcium orthosilicate. A strontium feldspar was found to be probably isomorphous with the lime feldspar, anorthite, which is also isomorphous with a soda feldspar. Now taking into account all the compounds of the alka- line earths, silicates as well as others, we may diserimi- nate, according to their isomorphous relations to com- pounds of other elements, at least four different classes: (1) Calcium, strontium, and barium compounds iso- morphous with each other (all or two of them) and also isomorphous with lead compounds. Examples: The tetrahedral-pentagondodecahedral nitrates of Ca(?), Sr, Ba, and Pb. The orthorhombic carbonates, aragonite, strontianite, witherite, and cerussite. The sulphates, 5G. W. Morey and C. N. Fenner, J. Am. Chem. Soe., 36, 215, 1914. P. Eskola—Silicates of Strontium and Barwin. 369 celestite, barite, and anglesite, form an isomorphous series which excludes calcium sulphate. Among silicates we note the group of hancockite and epidote, and we have now found that the metasilicates form an isomorphous series to which belong only the calcium and strontium, but not the barium metasilicate.*° (2) Calcium and strontium (also barium?) com- pounds isomorphous with each other and also isomor- phous with sodium compounds. Example: Anorthite and strontium anorthite. (3) Barium compounds isomorphous with potassium compounds. Example: Barium disilicate. Among the natural silicates named above, celsian and harmotome are representatives of this class. (4) Calcium compounds isomorphous with corre- sponding compounds of magnesium, ferrous iron and a number of other elements, but not with those of barium or strontium. Example: The rhombohedral carbonates, calcite, magnesite, siderite, ete. It seems to be a rule that in the compounds in which the lime may possibly be replaced by magnesia and ferrous oxide, it can not be replaced by strontia or baryta. Thus it was found in the present work that there are no strontium or barium compounds analogous to diopside, CaO.Mg0O.2S810,. Accordingly we find, in nature, strontium and barium compounds forming mix crystals with lime and alkali minerals, but not with ferromagnesian, although the latter may contain calcium. In other words, these elements are likely to be found in salic rather than in femic rocks, a circumstance that is really very striking in their distribution in the igneous rocks. The authors of the so-called quantitative classification of igneous rocks make a distinction between salic and femic lime. Now these terms gain added significance, as we find that only the sale but not the femic lime may be replaced by strontia. It may be of interest, for the sake of comparison, to present together some important properties of the members of some well known simple compounds of the three alkaline earth metals. * Bourgeois (Ann. chim. phys., 29, 445, 1883) records a lead metasilicate of a similar appearance to those of calcium and strontium. 370 =P. Eskola—Silicates of Strontwum and Barium. Mol. vol. aspae Carbonates:, « Araconiter, 3.) 408 .- 34.01 1.632 Strontiianibes.. (oe. 59.87 1.615 Wathert Gees: cues ese 45.82 1.627 Sulphates: > Anhydiiies =) vce 45.99 86 Celestite Is > Sec 46.18 1.626 Barite.. ats sea 51.96 1.641 Metasilicates: 8B-CaO.S10, ........ 40.09°° 1.625 — a CaO SiO we. utes 40.11°° 1.625 DEO SIO Vay rceweee 44.91 1.612 Ba@-SiOe Peas 48.57 | 1.675 The carbonate series exemplifies the rule found to hold good in many other instances that the molecular volumes, in an isomorphous series, increase regularly with the atomic weights of the substituted elements. Compounds which are not isomorphous often show a discrepancy in their molecular volumes, as for example pL in its relation to celestite and barite. The metasilicate series, in the regular increase of the molecular volumes with the atomic weight, behaves more like an isomorphous series, although we know that barium metasilicate is not isomorphous with the others. Our knowledge of the solid solubility relations of the carbo- nate and sulphate series is too incomplete to allow any closer comparison. In the refringence one can hardly see any regular rela- tion. The barium compounds have mostly -the highest indices of refraction, but the carbonates make an excep- tion, aragonite having higher indices than witherite. Among the strontium compounds some have higher and others lower indices than the corresponding calcium compounds, without any apparent regularity. ‘Schaefer?’ carried out a thermal study of the binary systems CaCl.-SrCl, and CaCl.-BaCL. He found, in the former case, a complete solid solubility with a minimum in the melting curve, while the latter do not mix at all, but ** These values have been obtained by computing the specific gravities at 25°, compared with water at 25°, as found by Allen and White (this Journal, 21, 103, 1906), for a-CaO.SiO, 2.912 and 6-CaO.SiO, 2.214, in terms of density, i. e. comparing with water at 4° and making the correction for the buoyancy of air. Thus, for a-CaO.Si0., d=2.901 and, for g-CaO.Si0, C7903. 7 Walter Schaefer, Neues Jahrb. Min. Geol., 1, 15, 1914. : gee i P. Eskola—Silicates of Strontium and Barium. 371 form a double compound CaCl,.BaCl, which shows an incongruent melting, breaking up into crystals of BaCl, and liquid. These relations are in all particulars, except in the molecular proportion of the double compound, strictly analogous to those of a-CaO.SiO, to the metasili- eates of strontium and barium. In the lime-silica system there occur the basic silicates 3CaQ0.Si0, and 3Ca0.2S8i0, the analogs of which were not found in the systems strontia-silica or baryta-silica. The last-named system, on the other hand, is the only one in which occur silicates more acid than the metasilicate, namely, 2BaO0.3Si0, and BaO.2Si0,. Among the alkali metals, in a similar way, the one having the lowest atomic. weight (lithium) forms the most basic silicates and those with higher atomic weights (potassium, ete.) more acid silicates. Summary. Fig. 17 gives a synoptical view of the melting diagrams for the three binary systems CaO-Si0., SrO-Si0., and BaO-SiO,. To make the diagrams really comparable they are all expressed in terms of molecular percentages. The compositions and melting or decomposition points of the compounds and eutecties, ete. in the three systems are listed in table XI. Table XII gives all the impor- tant properties determined for the strontium and barium silicates. In the system SrO-Si0, the following compounds were found: SrO, 2SrO.Si0,, SrO.8i0, and SiO,. With the exception of silica each of them was found in one form only, although the temperature of formation of the strontium silicates was varied from the melting points down to about 900°. Especial interest was taken in the strontium metasili- eate, SrO.Si0., which was found to be closely isomor- phous and optically very similar to a-CaO.SiO,. It there- fore probably belongs to the monoclinic crystal system, but its crystals agree so closely with the hexagonal system that, judging only from its own properties, it would seem to belong to this system. The crystals are apparently hemimorphic and might belong to the dihexa- gonal pyramidal or, if they are monoclinic, to the mono- clinic domatiec class. 372 P. Eskola—Stlicates of Strontium and Barium. Pye 172 S104 Fic. 17.—Synopsis of the binary systems BaO-SiO, SrO-SiO., and CaO-Si0, in mol. %. P. Eskola—Silicates of Strontium and Barium, 373 TABLE XI. Compositions and temperatures in the systems CaO—Si,, SrO., and BaO—Si0,. | Tempera- Character of Wt. % Mol.% ture °C change CaO SiO, CaO Si0, Eutectic eristobalite (?)- GOA LOD vats Sols fone 37.0 63.0 38.7 61.3 1436 Melting GCAO SION Coa «shoe au wks 48.2 51.8 50 50 1540 Melting Eutectic a-Ca0.Si0,-3Ca0. IST Osea ealy easier ee ea 54.5 45.5 56.3 43.7 1455 Melting SOAOWSIOS: foisces le cie 8 58.2 41.8 60 40 1475 Decomposition Invar. pt. 3Ca0.2S8i0.— PAO SIO) oe cites che sv ke 55.5 44.5 57.3 42.7 1475 Melting PROTO SIOD aoe ties be cece a 65:0" 35.0 66.7% 33.3 2130 Melting Be AO DSIOS sos he, «be epee 73.6 26.4 75 25 1900 Decomposition Kutectic 2Ca0.Si0.—CaO.. 67.5 32.5 69.1 30.9 2065 Melting Cal ORES EO ae 100 — 100 — 2570 Melting ° SrO SiO, SrO Si0, Kutectic tridymite-SrO.Si0, 46.5 53.5 33.6 66.4 1358 Melting STOLL OE Ee ie ee eee 63.2 36.8 50 50 1578 Melting Eutectic SrO.Si0,-2Sr0O. Sak Oe See ere ae 65.5 34.5 52.5 47.5 1545 Melting 4Si OS Series ener We 2206640 - <3a.0 Eutectic 2SrO0.S8i0,-SroO.. ee SUE eos toch ec oss Sos wavs 5 100 — 100 ~—— BaO SiO, BaO SiO, Eutectic tridymite-BaO. STO | ee renee 47 53 25.9 74.1 1374 Melting eee sIOn ees ee ke ee 56 44 33.3 66.7 1420 Melting Pe OLS SIO lacs ot << dee testes C2290 Mail. 40 60 1450 Melting Eutectic 2Ba0.38i0,—BaO. STO Bia eer ee ere 65 BG) 57.8 42.2 1437 Melting 1 5:(2 1 0) GY Ses ae eet aa eae (AS) PAS ey SEXO) 50 1604 Melting Kutectic BaO.Si0.-2Ba0O. SOUS ve (cece Sater meen 74.5 25.5 53.5 46.5 1551 Melting ZA BOM STO te oan See aor SSO GH Ge BRB? Eutectic 2Ba0.S8i0,.-BaO.. — — SS BEA) ae ar aan ok a a ie Or 100 — 100 — In the system BaO-SiO, the compounds BaO, 2Ba0O. S810,, BaO.Si0,, 2BaO.38i0,, BaO.2Si0,, and SiO, have been found. Of these compounds the dibarium trisilicate, 2Ba0O. ~ 8810,, and the barium disilicate, BaO.2Si0,, showed very remarkable behavior, being isomorphous, of ortho- rhombic symmetry, and forming a complete series of solid solutions. The melting diagram of this series belongs to Bakhuis Roozeboom’s type 1, without maximum or 374 P. Eskola—Silicates of Strontium and Barium. ‘A0'T-JOYI pue onbnoy Aq poutuitozop 13 ‘dg , ‘uuvupsnig Aq pouluseqyop “ad ‘dg » ‘ase[Ooy Wo TIM [to9]poo8 SUOTFNIOS PTLOS 0@9°E — |LOLO}}oeF20d e81e] “OPIGFLOUB YALA SUOTJN[OS PT[OG 80'S ; vd1R] aes oryeuistad Ap pus Ag poos “SUOIZNOS [ eL'e | dv yoajaod iGVovh Ap pure 1]OS JO Ee obi 4 gp rood Seltes ago[duloy e6°e | Ag yoojrz0d 0858S a Opus cit. p. 54. 390 Johnston—-Imbricated Structure im River-gravels. also shown, in places, in comparatively fine gravel as in fig. 1. This figure shows a section of river gravels in the bed of Trent river, at Campbellford, Ontario. The largest pebbles in the section are about 8 inches in diame- ter. The direction of the current was from right to left. Imbrication of the pebbles is not well shown because of the fineness of much of the material, but the pebbles have a fairly uniform dip in an upstream direction and le with their longer axes in the direction of the current. The face of the section is vertical except in the lower part which is talus. Fig. 2 shows a vertical section of Tertiary conglome- rate exposed on the south side of Burrard inlet near Vancouver, British Columbia. Imbricated structure is fairly well shown in the conglomerate and shows that it was formed from river gravels. It is therefore non- marine. The section is an east-west one, and the stream which deposited the gravel flowed west, that is, from left to right in the section. The conglomerate beds have a general dip of 10 to 15 degrees towards the south. As the depositional dip must have been in the direction of the current, the. dip towards the south is structural. Imbricated structure may be occasionally used, therefore, both to distinguish marine from non-marine deposits and for structural purposes. P, Armstrong—Zircon as Criterion, ete. 391 Arr. XXXIV.—Zircon as Criterion of Igneous or Sedi- mentary Metamorphics; by P. ARMSTRONG. The complete recrystallization of some igneous and sedimentary rocks with consequent total loss of their dis- tinguishing characters has led petrographers to search for some definite criterion by which, in the absence of con- clusive field evidence, the genetic origin of such reerystal- lized rocks can be accurately determined. Various means to this end have been proposed, amongst them the use of zircon.t This method rests on the assumption that zircon, like grains of sand, may undergo rounding during water transportation; those zircons contained in igneous rocks always show sharp erystal boundaries. A second postulate on which this method rests is that the extreme stability of zircon enables this mineral to resist physical and chemical changes even under the greatest of metamorphic forces. Doubts as to the reliability of this method, which has been endorsed or employed by various geologists,? were expressed orally to Professor A. Knopf by several petrog- raphers and led to its critical investigation py the writer. The conclusions arrived at are briefly set forth below. The rocks to be investigated were pounded, not ground, in a mortar to pass an eighty-mesh sieve, panned down to the heaviest constituents, and dried. Under a binoc- ular microscope, equipped with a 24mm. objective, a number of zircon grains, up to twenty in some trials, were isolated and carefully mounted on glass fibers. Kach grain was then placed under a No. 4 objective of a petrographical microscope and by means of the glass fiber, resting on the stage, rotated so as to give a complete view of the grain from all sides. In the latter operation reflected light was used. A preliminary study of four unmetamorphosed sand- stones showed that the degree to which zircons are rounded diminishes with increasing coarseness of the 1J. D. Trueman: The value of certain criteria for the determination of the origin of foliated crystalline rocks, Journal of Geology, vol, 20, No. 3, 1912. 2A.N. Winchell: The Dillon quadrangle, Montana, U. S. G. 8., Bull. 574, p- 129, 1914. Leith & Mead, Metamorphic Geology, 1915, p. 225 (H. Holt & Co.). 892 Armstrong—Zircon as Criterion of sand grains; some of the coarser sandstones yield zircons which under the high power show sharp-edged and lus- trous faces. It is in highly zirconiferous sandstones, Figs. 1 to 9. 9 Figs. 1, 2, 3—Typical water-worn zircons from zirconiferous sands, Pablo Beach, Florida. Fig. 4.—Deformed zircon, showing single secondary crystal face; from the Stony Creek gneiss (igneous), Connecticut. Figs. 5-8.—Zircons from Stony Creek gneiss; all are covered with blistery growth and show small secondary faces. Fig. 9.—Rounded zircons in a normal, undeformed granite; Norcross quarry, Stony Creek, Conn. such as those described by Watson and Hess,*? which are evidently the result of repeated re-concentration, that the rounding is most highly developed and gives rise to shapes characteristic of water-worn grains, such as flat- 2'T. L, Watson and F. L. Hess, Univ. of Virginia Phil. Soc., July, 1912. Igneous or Sedimentary Metamorplics. 393 tened spheres or lenses, kidney or bean shapes, (figs. 1-2), and another which by virtue of its general form and ‘feve’’-like depressions distributed over its surface may be likened to that of a potato (fig. 3). Associated with more or less rounded zircons are others in the same rock showing smooth, unbroken, and lustrous prism faces. Two explanations can be advanced for this fact: That the rounded grains had their source farther away from their point of sedimentation, or that the prismatic grains were transported, enveloped in a protective biotite flake. The latter explanation seems to be the correct one, as zircon grains attached to biotite have been observed in some of the sandstones, by the writer as well as by others. The study of undeformed granites led to the conclusion that zircon, the earliest mineral to crystallize out, may undergo during consolidation of the rock a certain amount of magmatic corrosion, as is evident from a more or less pronounced rounding and glassy smoothness, such as observed on the edges of a melting cake of ice, of its edges, principally those of its pyramidal terminations. Furthermore the zircons were found to show a peculiar pitting, not in isolated patches, such as might have been caused by the process of crushing, but all over the prism faces. It was found impossible to distinguish this kind of pitting from that seen on sedimentary grains and caused by the chipping of the grain during water trans- port. That magmatic corrosion of zircon is possible has been shown by C. Doelter,’ who exposed this mineral to contact with molten basalt and produced a broad zone of corrosion around the zircon grain. The zircons in unde- formed granites are generally prismatic, although some were found that show a distinctly ovoid form, due to a combination of magmatic corrosion and the development of numerous vicinal faces. The latter already have been described elsewhere.°® In examining igneous and sedimentary gneisses the fundamental assumption is often made that zircon has * A. Gilligan: The petrography of the Millstone grit of Yorkshire, Quart Jour. Geol. Soc., London, vol. 75, No. 300, p. 266, 1920. °C. Doelter, Handbuch der Mineralchemie, Vol. III, Part 1, p. 142. ° A. Gilligan, op. cit., p. 266. 394 Armstrong—Zircon as Criterion of been absolutely stable under the conditions of tempera- ture and pressure to which it was subjected. However, the evidence collected during this investigation would speak against this assumption. The zircons of igneous as well as sedimentary gneisses were found to show a peculiar rough surface, blisterlike in appearance, the nature of which it was impossible to determine under the microscope. In the belief that this blisterlike appearance is due to a coating of silica, several grains were treated with warm hydrofluoric acid, but without result. The biisterlike covering has either destroyed, or, in any case, now completely obscures the original crystal face. ; how- ever, rotation of the grain under the microscope brings in view a great number of apparently irregularly placed, small, and more or less round faces of rather dull luster which appear to have developed on and within the blistered surface. Possibly the latter represents a decomposition product of zircon and may be one of the hydrous forms of this mineral, e.g. malaconite, described by Doelter.* A zircon, isolated from the igneous Maro- mas gneiss of Connecticut consisted of a splinterlike plate, extremely irregular in outline but having all its edges rounded by the blisterlike covering just mentioned. Similarly, parts of prisms were found in other igneous as well as sedimentary gneisses, one of their ends showing a pyramidal termination, the other a conchoidal fractnre, the latter modified in exactly the manner as described under the Maromas gneiss. It should be of greatest interest to determine whether the composition of this blisterlike surface is either identical with or related to that of the zone of corrosion of Doelter’s, previously mentioned. Our conception of the stability of zircon may then, perhaps, be greatly modified. That zircons are deformed under metamorphic stress can be confidently asserted. From an igneous gneiss the writer separated a grain, having a curved sausage shape and showing on its concave side a single crystal face, embedded, so to speak, in the blistery growth which covered the rest of the grain (fig. 4). Others show pear or club shapes, and many are such perfect spheres that they would apparently fully justify the belief that they “Opacit: 1p.) va6- Igneous or Sedimentary Metamorphics. 395 are of sedimentary origin. (See illustrations, figs. 5-8.) All these grains had the peculiar blisterlike covering, some, like the sausage-shaped grain, showing also small erystal faces, previously described. It is possible that the development of the latter is due to local solution and recrystallization under stress; in any case, the blisterlike covering seems to have been caused by conditions under which zircon was unstable. Figure 9 shows three zircons imbedded in, what its thin section shows to be, a normal granite of undeformed hypidiomorphie granular texture, from the Norcross quarry, Stony Creek, Conn. The roundness of their out- lines is striking, and a comparison of these grains with those shown by Trueman and Hess in their papers pre- viously cited, it is believed, gives convincing proof that the origin of a gneiss cannot be determined from the study of its zircons in thin sections. Since the ultimate source of both igneous and _ sedi- mentary zircons is the same, it was thought that the rounding due to abrasion superimposed on magmatically corroded zirecons in sedimentary gneisses might,lead to a means of distinguishing such gneisses from those of purely igneous origin. But no such distinction was found to be possible. Figs. 5-8 show zircons found in a distinctly igneous gneiss. It will be noticed that some of the grains are pearshaped and others are more or less curved. From the foregoing the conclusion would appear justi- fied that the rounding of zircons is no eriterion of the sedimentary origin of the metamorphosed rocks in which they are enclosed, that the degree of rounding due to corrasion may not even be large enough, in some of the coarser sandstones, to serve as a distinguishing char- acter, and that the diagnosis of a rock, so completely recrystallized as to obscure the petrological evidence of its origin, cannot be effected by the use of zircon as criterion. Petrological Laboratory, Yale University, New Haven, Conn. Am. Jour. Sct.—FirtTH SeriEs, Vou. 1V, No. 23.—NovemBer, 1922 26 ~ 3896 C. R. Stauffer—The Minnesota Devonian. Art. XX XV.—The Minnesota Devonian and its Relation- ship to the General Devonian Problem of North America; by Cuinton R. STAUFFER. The Devonian of Minnesota has lone been known and roughly mapped, but a detailed study of the rocks belong- ing to this system has been very much neglected. This is probably because the area in which it occurs is a drift- covered plain that has been only partially dissected by erosion and the outcrops that may be found are neither frequent nor very satisfactory. But the country has now been settled for a longer period than when the early surveys of Minnesota counties were made, hence more wells have been drilled and more quarries have been opened in the region so that the rocks of this system are now very much better known than they were thirty or forty years ago. Moreover certain parts of the Devonian have been found to be filled with fossils thereby making the age determination a certainty. In all about 1,200 square miles of southern Minnesota are covered by Devonian rocks. This area lies in Fillmore, Mower and Free Born counties*(1). In the northern and western parts of this region, much of the surface is comparatively level and well covered by drift so that it is not always possible to trace the Devonian border in those — directions. On the east side it approaches the driftless area and the mantle of glacial debris is reduced to a thin film, often insufficient to conceal the bed rock, and the possibilities for satisfactory stratigraphic work are much improved. Knough outcrops can be found to make it certain that the Devonian is slightly more extensive in this region than it is indicated to be on the present geo- logical maps. Numerous masses and fragments of fos- siliferous Devonian rock are known or have been picked up in the drift of central Minnesota, even as far north as Todd and St. Louis counties. Some of these masses are quite large (2). This has suggested that possibly there are other areas of Devonian, existing as outliers, which have not yet been recognized or which may be entirely drift covered. It is noticeable, however, that the larger frag- * For references see the end of this article. C. R. Stauffer—The Minnesota Devonian. 397 ments are all found in southern Minnesota and may indi- cate a somewhat greater extent of the present Devonian- covered area rather than the existence of other Devonian areas. Over the great ridge area of the buried Minnesota mountains the Devonian fragments in the drift are some- what smaller and usually less abundant. Hence it seems probable that these seattered limestone bowlders and loose Devonian fossils have been brought down by the Pleistocene glaciers from the great outcrops of Devonian in the vicinity of Lake Winnipegosis and Lake Manitoba, and that the Minnesota Devonian deposits are confined to the southern part of the state. The Devonian, as outcropping in the southern part of the state of Minnesota, consists chiefly of limestones of varying purity. Probably the great body of it runs as high as 17% to 18% MgCO, but occasionally layers are found with 97% to 98% CaCO, and only a fraction of a per cent of MgCO,. The best outcrops are to be found in the central and southern parts of Fillmore county where the Devonian is usually exposed in every highway eut. Where both the top and the bottom show, the Devonian apparently rests disconformably on fossili- ferous Maquoketa shale (Ordovician) and usually has no covering other than the drift. In the vicinity of Austin, however, the uneven upper surface of the Devonian lime- stone is covered by eight to ten feet or more of rather soft gray to red clay which has usually been classified as a Cretaceous(3) deposit, and which it probably is as clays and lignitic beds of that age have been reported in the deeper wells of Freeborn county to the west. However, some of the similar clays of central and southern Min- nesota contain glacial pebbles and are undoubtedly of elacial origin. It has been suggested that a remnant of the higher Devonian shales may occur in western Mower county and perhaps in certain parts of Freeborn county, but up to the present this has not been certainly deter- mined. The Western margin of the Devonian is lost under a covering of drift which in Freeborn county has been estimated to have a thickness of one hundred feet, (4) with perhaps even greater thicknesses in the adjacent county(5) to the west. There is thus little hope of contin- uing the Minnesota Devonian section, except by the drill, 398 CC. R. Stauffer—The Minnesota Devoman. to the upper shales which are so well developed a short distance to the south of the state line. It seems entirely probable that these upper beds thin out in Iowa before the Minnesota line is reached. The limestones therefore earry the whole of the known Devonian record, as far as Minnesota is directly concerned. These rocks dip gently to the west and south thus bringing in higher beds along a line from northeast to southwest. Much of the Devonian is a porous, weathered, impure, buff limestone but it changes rapidly in color and character as it is followed to the southwest. Where this former character is prevalent it is undoubtedly to be assigned, in large measure, to the leaching and weather- ing of a rock quite different from that which is now exposed. Following the direction of dip there are numerous shades and grades between a porous, abund- antly fossiliferous buff rock, and a sparingly fossilferous blue, or a non-fossiliferous compact gray to white rock. A number of sections were measured for detailed study and others might have been added. A few of them are given herewith to show the Devonian section of the state. They include some of the more important outcrops and give a good idea of the above mentioned variations as well as of the changing character of the fauna which seems to attend it. Section along the South Bank of Bear Creek at Hamilton, Fillmore County, Minnesota. Pleistocene and Reeent. Thickness T~ Soi-and. drift hte Onin eae ee rane Pena ah 6.2.00 Devonian (Cedar Valley limestone) 6. Limestone, gray to buff, containing the followimg fauna. Athyris fultonensis (Swallow) (c) Chonetes scitulus Hall (r) Productella subalata Hall (a) Sehizophoria striatula? (Schlothemm) (r) Trochonema: Sp. Cm) er Gee ee oe gee ga ee 5. Limestone, gray to buff or brown, massive, abund- antly fossiliferous. C. R. Stauffer—The Minnesota Devonian. Athyris fultonensis (Swallow) (r) Atrypa histryx Hall (c) _ _Atrypa spinosa Hall (1) Chonetes scitulus Hall (¢) Cyrtina hamiltonensis Hall (c¢) Gypidula leviuseula Hall? (1) Martinia sp. (¢) Productella subalata Hall (a) Schizophoria striatula (Schlotheim) -(c) Spirifer bimesialis Hall (a) Spirifer iowaensis Owen? (¢)_ Stropheodonta demissa (Conrad) (r) Stropheodonta halli musculosa Cleland (?) (1} Bellerophon perplexa Walcott (¢) Pleurotomaria sp. (r) Trochonema sp. (¢) Coleolus sp. (1r) Proetus sp. (¢) SF ele So ae ON Ree RE ea ae BUN eR OD 16’ PeeinimMes Lone, partly Covered <7). Gcl ics ke SG 10’ eM OMereO: MpeIValo S02. kc se eo eh COREE OE EES he Ordovician (Maquoketa shale) 2. Limestone, buff to brown, shaly, containing Stro- phomenadlucLuosa-balbnes i. 4). cs se ‘Ly 1. Shale, buff to brown, massive, extending to the level of Bear creek. It contains the following fauna Dalmanella testudinaria (Dalman) Lingula elderi Whitfield Plectamonites sericeus (Sowerby ) 399 Qj? Qu 8” These same Devonian beds outcrop abundantly around Spring Valley, Etna, and southward into Iowa. In Spring Valley the old city quarry, at the corner of Church Street and Broadway, exposes about eighteen feet of shghtly higher limestone, but Larsen’s quarry in the southwestern part of town is essentially the same horizon and affords better collecting. 400 OC. R. Stauffer—The Minnesota Devonian. Section of Larsen’s Quarry in the Southwestern Part of Spring Valley. Pleistocene and Recent. : Thickness 4. Soil and drift 2-3 as tatoos tee eee 140" Devonian (Cedar Valley limestone) 3. Limestone, gray to brown or buff, badly weathered, containing Atrypa reticularis (Linnaeus) (c¢) Productella subalata (Hall) (c) 2. Limestone, buff, massive, with abundant fossils of which the following are the more important: Atrypa reticularis (Linneus) (c) Cyrtina hamiltonensis Hall (c) Gypidula laeviuseula Hall, (r) Productella subalata Hall (aa) Nuculites sp. (r) Murchisonia ef. dowlingi Whiteaves (r) Trochonema sp. (r) Trochonema monroei Cleland? (r) Crinoid stems (c) 1. Limestone, brown to buff, with fossils common Chonetes scitulus Hall (ec) Cranena iowaensis (Calvin) (c) Cyrtina hamiltonensis Hall (t) Productella subalata Hall (a) Reticularia fimbriata (conrad) (r) Spirifer bimesialis Hall (r) Spirifer iowaensis Owen? (a) Spirifer ‘sp. (r) Stropheodonta demissa (Conrad) (c) Paracyclas sp. (1) Bellerophon sp. (¢) Trochonema sp. (1) ~ Coleolus sp. (¢) Proetus sp. (c) Somewhat higher beds occur along the state line high- way. About five miles west of Granger the surface is strewn with fragments of the Devonian limestone and in some of the fields there are great heaps of rock that have been gathered from the surface in clearing the land for C. R. Stauffer—The Minnesota Devonian. 401 cultivation. At no place is this part of the Devonian well shown but there is a fair section shown on Mr. Grimm’s farm where it sticks out along the road and in the field. Section on Mr. Charles Grimm’s Farm Five Miles West of Granger. Recent. Thickness Be ST a FRE EE eee eee ee ae ee O26. Devonian (Cedar Valley limestone) 3. Limestone, rough brecciated, brown in color...... oF OY 2. Limestone, fairly massive, rough, and gray to brown in color. It contains occasional masses of chert, and cavities filled with calcite crys- tals. Fossils are abundant. Cladopora magna Hall and Whitfield (r) | Cladopora sp. (¢) Favosites sp. (¢) Zaphrentis solida Hall and Whitfield (a) Polypora sp. (c) Atrypa reticularis (Linnaeus) (c) Camarotechia sp. (1) Cyrtina hamiltonensis Hall (c) Gypidula laeviuscula Hall? (c) Spirifer asper Hall (r) Stropheodonta demissa (Conrad) (r) Nucleospira sp. (r) Schuchertella chemungensis arctistriata (Hall) (c) Conoecardium sp. (¢) Leptodesma sp. (r) Palaeoneilo sp. (r) Bellerophon perplexa Walcott (a) Cyclonema sp. (r) Eunema sp. (c) Murchisonia dowlingi Whiteaves? (c) Pleurotomaria sp. (c) Raphistoma terrelli Cleland (r) Hyolithes alatus Whiteaves (r) Orthoceras sp. (1) Poterioceras 2 sp. (r) Phacops sp. (1) Proetus sp. (r) a 402 OC. R. Stauffer—The Minnesota Devonian. 1. Limestone, gray to brown, rough, with numerous eorals and stromatoporoids Acervularia davidsoni Edwards and Haime (c) Favosites sp. (c) Stromatoporella erratica (Hall) (c) Re Se eg ee ee 5 a Along the same highway, about two miles farther west, fourteen feet of brown to buff limestone outcrop in section 34, York Township, Fillmore County, and lie at a higher horizon than those beds given in the preceding section. Although these layers are not exceptionally fossiliferous, the fauna found here is rather large and consists of the following forms— Idiostroma sp. (1) Dictyonema 2 sp. (r) Zaphrentis sp. (c) Polypora 2 sp. (¢) Semicoscinium rhombicum Ulrich? (r) Taeniopora Exigua Nicholson? (c) Atrypa histryx Hall (c) Atrypa reticularis (Linnaeus) (c) Chonetes scitulus Hall (c) Chonetes manitobensis Whiteaves (1) Cyrtina hamiltonensis Hall (c) Gypidula comis (Owen) (c) Pentamerella multicostata Cleland? (r) Productella sublata Hall (1) Reticularia fimbriata (Conrad) (r) Spirifer asper Hall (r) Stropheodonta arcuata Hall (r) Stropheodonta halli musculosa Cleland? (r) Stropheodonta perplana (Conrad) (ec) Stropheodonta variabilis Calvin? (r) Stropheodonta sp. (1) Phacops sp. (¢) The next beds above this are apparently those out- cropping in the vincinity of LeRoy where the following section occurs— Section of the Fowler and Pay Quarry One Mile East of LeRoy, Minnesota. Pleistocene and Recent. Thickness 11.0: Soiktancdearirtxns 3 ene a ee ee eee S's C. R. Stauffer—The Minnesota Devonian. 402 Devonian (Cedar Valley limestone) 10. Limestone, gray to brown, thin bedded, probably Somme wham CSG Cds a) fe ariiihe)s SG ass Are Oy 9. Limestone, gray to white, usually weathering to brown, fairly massive. It contains a few fos- sils among which are the following: Crinoid stems (r) Leptaena rhomboidalis (Wilckens) ? (1) Stropheodonta demissa (Conrad) (1) Nuceula sp. (r) Pleurotomaria sp. (r) ee pe ent ea SO alae 4 os 2 = 0° 8. Limestone, gray to brown, with occasional traces TEE CRESS A Oe ee ea Soe ree i Siar. 7. Limestone, gray, fairly fossiliferous Crinoid stems (c) Athyris fultonensis (Swallow) (c) Cyrtina hamiltonensis Hall (c) Spirifer orestes Hall and Whitfield (c) FF naa ce Ae aa Be OPO, 6. Limestone, gray to brown, containing indistinct masses resembling stromatoporoids ........ Op on 5. Limestone, gray to white, compact and apparently COM ALMNTT MO SKOSSIG= ccrece Sas Sse ns oo See we De Oe, 4. Shale, green to gray, caleareous, irregular in | {FST ET BIST 5 ae ee eS i ea sanyo ee aa Oe 6. 3. Limestone, gray to white, compact, rather mas- sive. It contains a few fragmentary fossils. 2’ 4” Segee ONETCCR ALOR clases oF eS Bk as bok a wk ibe ies 1. Limestone, gray to brown, apparently lower than She beds,onvensabOVves tact, cass siesne & sodas de, 0 Recent drilling in thts vicinity indicates that the total amount of the high-grade white limestone may exceed sixty feet. How much of the brown magnesian limestone may be interstratified with it is not definitely known but it is probable that there is as much in the deeper strata as there is mingled with the beds exposed at the surface. Certain layers of the limestone of this locality resemble the lithographic beds of Iowa and they may possibly represent the same horizon. Higher beds occur in the vicinity of Austin. It is quite probable, however, that there is a covered interval of importance between this outcrop and the one just dis- 404 OC. R. Stauffer-—The Minnesota Devonian. cussed. There is at least a marked change in sedimenta- tion between the light gray to white limestone near LeRoy and the impure ‘‘cement. beds’’ characteristic of the Austin region. The best outcrop in this latter region is along Rose Creek, about three miles south of Austin, where quarrying has been carried on for many years. Formerly this rock was used as a building stone but it weathered badly hence it has long been abandoned as a . construction rock. It is now used only in the manu- facture of a natural cement. Section of the Fowler and Pay Cement Quarry along Rose Creek, Three Miles South of Austin. Pleistocene and Recent. Thickness 4. Soil and drift, the latter chiefly eravels...—-2.5,- 2 Oe Cretaceous ? 3. Clay, blue and red, in pockets over the uneven sur- fac.or she MMeStOne fon. oe oe we eee Oe te Devonian (Cedar Valley limestone) 2. Limestone, blue to gray, weathering to buff, and containing a few fossils— Athyris fultonensis (Swallow) (r) Spirifer iowaensis Owen? (r) Fish plates and scales (1) Baa eet rite aie® esos eit Sih Bash 5 10°08 1. Limestone, gray to buff, rather massive, containing some chert and with pebble-like masses of limestone occurring in some of the lower lay- ers. These beds extend to the level of Rose Lee aaa d AR) Ste etre ra aire A eete Ritcnaee eR SS Tote The beds which appear to be the highest of the Devon- ian limestone section in Minnesota, outcrop along Cedar River in the southwestern part of Mower County. Section along Cedar River, Three Miles West of Lyle, Mower County. Recent. Thickness Bh SS Oa Leg eS SEEN I eae 8 ee one oO gia ee 2 oe C. R. Stauffer—The Minnesota Devonian. 405 Devonian (Cedar Valley limestone) - 3. Limestone, gray to buff, massive to thin bedded, it 3 contains an abundance of a few fossil forms— Athyris fultonensis (Swallow) (aa) Atrypa reticularis (Linnaeus) (1) Murchisonia sp. (1) eae ra Ney eh Crs Se State otek gia vidas Sus kte ioe 4’ Q” 2. Limestone, gray to buff, or brown, rough, hard, and massive. Fossils very abundant in some layers but limited to one form Atrypa reticularis (Linnaeus) (aa) Beets eee ee Es cid etn a Weks A Os 6 1. Limestone, gray to brown in color, partly covered, pone tevelot Cedan River ..40c.5. eee oe wih 6°. OF It is quite impossible to present a complete section of the Minnesota Devonian at the present time. In fact it may never be possible to complete it satisfactorily unless at some future time the region should be drilled for water or other natural resources that may seem worth while. But it may be pieced together, from scattered outcrops and other information in somewhat the following manner. General Section of the Minnesota Devonian. Devonian (Cedar Valley limestone) Thickness 9. Limestone, buff to brown, massive, coarse, fossili- ferous. These are the beds exposed along the PhyeIe usin WestaOl Pivlers oe. ine oO ae ose a's 20 408. 8. Limestone, blue to brown, argillaceous, forming the cement: beds south of Austin=... 0.5.5 626.2. ae sO fe COMeCred miter ydllrs Seren. ies ee ee ee. HOE Os Limestone, gray to white, compact, fine-grained, often alternating with coarser brown beds... 22’ 0” fey CONELCOMMECTV Aly: oe ees eae ee 5 Sere te ee ee ek 12’-++0" 4. Limestone, brown, brecciated, w ith MO! LOSSIIS S72 G0" 3. Limestone, gray to buff, massive, fossiliferous.... 10’ 0” 2. Limestone, gray to brown, massive, full of corals ALi SULOMALO POL OTS ery. fs -sisrecs ue ge ers Ore 1. Limestone, buff, massive, abundantly fossiliferous. 20’ 0” It is noticeable that all portions of this section are not equally fossiliferous and that the fauna is not uniform 406 CC. R. Stauffer—The Minnesota Devonian. for the whole formation. Thus the lowest beds are full of fossils and the species, the most abundant of which is Productella subalata, belong chiefly to the various genera of Brachiopoda. These beds are succeeded by others which are also quite fossiliferous but the number of .— species is small and they belong mostly to the Anthozoa. Then comes the most widely varied fauna of all in the beds which have been made the third division of the general section. Although the Brachiopoda are still abundant the conspicuous forms are Gastropoda and the whole fauna differs decidedly from that of both the basal beds and those higher in the section. The breeciated beds appear to contain few if any fossils. The fine-grained compact limestone and the associated brown beds are sparingly fossiliferous. The argillaceous limestone beds of the cement quarry near — Austin contain fish remains and an occasional Spirafer, while the uppermost portion of the section is again fairly fossiliferous but the number of species is small. These latter are chiefly Athyris fultonensis and Atrypa reticu- laris. The brecciated beds, or the unknown deposits which doubtless. occur between the outcrops from which the section herewith was made, may represent important breaks in sedimentation during which marked faunal changes occurred, but the evidence so far obtained is not sufficient to determine that point. It is perhaps signifi- cant that similar faunal changes have been observed in the equivalent beds of Iowa (6). The following is a list of the genera and species that have been collected from the Devonian outcrops of Minnesota. Fauna of the Minnesota Devonian. Dictyonema 2 sp. Idiostroma sp. Stromatoporella erratica (Hall and Whitfield). Acervularia davidsoni Edwards and Haime. Cladopora magna Hall and Whitfield. Cladopora sp. Favosites sp. Hederella filiformis (Billings). Zaphrentis sp. _ Crinoid stem. C. R. Stauffer—The Minnesota Devonian. Polypora sp. Semicoscinium rhombicum Ulrich? Taeniopora sp. Athyris coloradoensis Girty. Athyris fultonensis (Swallow). Atrypa histryx Hall. ~ Atrypa reticularis (Linnaeus). Atrypa spinosa Hall. Camarotechia sp. Chonetes manitobensis Whiteaves. Chonetes scitulus Hall. Cranena lowaensis (Calvin). Cyrtina hamiltonensis Hall. Gypidula comis (Owen). Gypidula leviuscula Hall?. Leptaena rhomboidalis (Wilckens) ?. Martinia sp. Nucleospira sp. Pentamerella multicosta Cleland ?. Productella subalata Hall. Reticularia fimbriata (Conrad). Schizophoria striatula (Schlotheim). Schuchertella chemungensis arctistriata (Hall). Spirifer asper Hall. Spirifer bimesialis Hall. Spirifer euryteines Owen. Spirifer iowaensis Owen?. Spirifer orestes Hall and Whitfield. Spirifer pinonensis Meek?. Spirifer sp. Stropheodonta arcuata Hall. Stropheodonta demissa (Conrad). Stropheodonta halli musculosa Cleland ?. Stropheodonta perplana (Conrad). Stropheodonta variabilis Calvin?. Stropheodonta sp. Tropidoleptus occidens Hall. Conocardium sp. Nuculites sp. Nyassa parva Walcott. Palaeoneilo sp. Paracyclas sp. Bellerophon perplexa Walcott. Bellerophon sp. Coleolus sp. Cyclonema sp. Eunemia sp. 407 408 OC. R. Stauffer—The Minnesota Devoman. Loxonema sp. Murchisonia dowling1 Whiteaves?. Murchisonia sp. Pleurotomaria ef. koltubanica Tschernyschew. Pleurotomaria sp. Raphistoma disciformis Tschernyschew?. Raphistoma terrelli Cleland. Straparollus clymenoides? Hall. Trochonema monroei Cleland ?. Trochonema sp. Hyolithes alatus Whiteaves?. Tentaculites sp. Orthoceras sp. Poterioceras 2 sp. Phacops sp. Proetus sp. Fish scales. In all the Minnesota Devonian is known to contain sev- enty-seven species and some of them are probably new. The formation continues southward into lowa where it is said to have a much larger fauna. It is apparently the equivalent of the Cedar Valley limestone of iowa and this is a satisfactory formational name in Minnesota because much of it is found outcropping in the vailey of Cedar River and its tributaries. It is possible, however, that the limits of the Cedar Valley limestone of Minnesota do not correspond exactly to those of the same formation in lowa if the entire Minnesota Devonian is included in that formation. The Devonian of Manitoba and the Mackenzie valley carry a few of the same fossil forms that are common in the Cedar Valley limestone of Minnesota. Unfortunately the fauna of that northern region is not as well known as might be desired. Whiteaves studies (7) have given a very good idea of several divisions especiaily that of the Stringocephalus zone in Manitoba and a fair knowledge of the same zone at the ‘‘Ramparts’’ on the Mackenzie River (8). Although the finding of two drift specimens of Stringocephalus burtini has been reported in Minne- sota (9) the species is not known in the Devonian lime- stones of this state. In fact the Cedar Valley limestone fauna of Minnesota has nothing in common with the Stringochalus zone except certain long range species that are likely to be found in the Middle Devonian of most any C. R. Stauffer—The Minnesota Devonian. 409 part of North America. A comparison of the Minnesota fauna with that of other northwestern Canadian localities, as mentioned by Whiteaves (10), gives ne more encour- aging results. Whiteaves himself says, of his whole list ARCTIC OCEAN \ eR OS 7 wf \ 5 f = \ 23 PACIFIC OCEAN wea fate 1 Lr ‘ “a. OCEAN MISSISSIPPI \ Say. | BASIN. dh aa. ek IN Sor? a Ga ase eee fh NN | PALEOGEOGRAPHIC MAP OF THE NORTH AMERICAN REGION DURING LATE MIDDLE DEVONIAN. from the Mackenzie valley, ten species are common to the Jowa (11) Devonian while twenty-two species are found in the Hamilton of Ontario and New York. This is a very significant suggestion as to the relationships of the north- 410 CC. R. Stauffer—The Minnesota Devonian. western Devonian faunas but there are still others equally suggestive. Of those common to the lowa Devonian half are general Hamilton forms while most of the others belong in the fauna of the Lime Creek shales and are hardly to be considered the most characteristic Iowa Devonian fossils. And at any rate the Lime Creek fauna is quite different from the Cedar Valley fauna and decid- edly a later development as far as North America is con- eerned. The Stringocephalus zone of Manitoba carries about 20% Onondaga forms but less than 5% Cedar Val- ley species. The later Devonian faunas of the northwest are also decidedly different from that of the Cedar Valley and appear to have even less in common with it. In short, so remote is the relationship between the fauna of the Minnesota Devonian and that known from Manitoba and the Mackenzie valley that the idea of a direct sea con- nection between these two regions, during the deposition of the Cedar Valley lmestone, should be abandoned. Unless the studies at present being pursued in Canada by Dr. Kindle, in lowa by Professor Thomas, and in Mis- souri by Dr. Branson, should show a closer relationship for the upper beds than is indicated by our present knowl- edge it is probable that the supposed sea connection across Minnesota during Upper Devonian should also be abandoned. The buried granite ridge, which crosses central Kan- sas (12) in a north-northeast direction, was land during Devonian time and probably an extension of the land area of the Lake Superior region. In fact the pre-Cam- brian of this latter region crosses Minnesota as a buried ridge and disappears, under the Sioux quartzite, near the southwestern corner of the state. While the sea evi- dently crossed part of this old mountain range during cer- tain periods such as the Upper Cambrian and the late Cre- taceous, there are no definite indications that any part of it was submerged during the Devonian and the lack of the expected relationship between the Devonian faunas on either side of the ridge seems to indicate that there was a land barrier in that region during the hfe of these faunas. The Devonian is represented by 8000 feet of limestone and shale in the Great Basin. Its fauna is only partially known but Walcott (18) found it to be a large and varied C. R. Stauffer—The Minnesota Devoman. 411 one with many similarities to that found typically in the Onondaga of New York and Ohio, but Hamilton and Chemung species are apparently not lacking in it. This relationship cannot be wholly accidental. But perhaps the most significant fact about this Devonian deposit is that it carries such a large percentage of species not known as a part of the eastern fauna. Many of these occur in the Iowa Devonian fauna especially in the upper beds. But there is still a considerable residue of forms most of which have not been specifically identified. It is in this latter that hope lies in an attempt to trace the Cedar Valley fauna, which probably has its ultimate origin in the Devonian of Russia and western Europe, or some region which supplied emigrant to all three of these areas. About 20% of the Minnesota Devonian species occurs in the fauna of the Great Basin Devonian and 30% more of it may be the same as those listed by Walcott (14). In the 6000 feet of limestone, which make up the lower division of the Devonian of the Great Basin, nearly the whole of Waleott’s collection came from the lower 500 feet, thus leaving more than 5000 feet of massive limestone almost unexplored and a fruitful field for future research. The relationship that exists between the fauna of the Cedar Valley limestone of Minnesota and that of the Devon- ian limestone of the Great Basin, and somewhat more remotely of the middle Devonian of some of the Alaskan islands, has suggested the Paleogeographic map which . accompanies this paper. It is in part a modification of one of Professor Schuchert’s Devonian maps but it con- tains much for which he bears no responsibility. A map of this sort can only be suggestive of the conditions as they probably existed during any period or epoch. This follows from the fact that there has been so much erosion during subsequent time and this has probably removed all traces of the older deposits over wide areas, while land barriers that once existed have been likewise obliterated. Such maps are therefore subject to constant revision as new facts are discovered and new relationships become evident. The most striking fact that comes out during this study is the remoteness of the relationship between the fauna of the Cedar Valley limestone of Minnesota and that of the Devonian of Manitoba. Am. Jour. Sc1.—FirtH Seriges, Vou. IV, No. 23.—Novemser, 1922. 27 412 “IO OTH Go DOH beat AS LN ON NIN ON TONS © & © NETS C. R. Stauffer—The Minnesota Devonian. REFERENCES. Geological Survey of Minnesota, vol. I, 1884, pp. 303-307; 357-361. Idem, vol. I, 1884, p. 384; vol. IT, 1888, p. 184. Idem, vol. I, pp. 353-356. Idem, vol. I, p: 385. Idem, vol. if p- 460. Iowa Geological Survey, vol. XIII, 1903, pp. 268-279. Contributions to Canadian Paleontology, vol. I, pt. 4, 1892, pp. 250- 309, pls. 23-47. Idem, pt. 3, 1891, p. 249. Referred to by Schuchert in U. 8. G. S., Bull. 87, p. 417. Op. cit. pp. 247-250. Idem, p. 251. Bull.-Am. Assoc. Petroleum Geologists, vol. 4, No. 3, 1920, pp. 250- 261. U.S. G. S., Monograph VIII, pp. 4-8, 1884. Idem, pp. 99-211;° 274-278; 284-285; and pls. II-VIlL; XIX VEt- University of Minnesota, Minneapolis. Chemistry and Physics. 413 SCIENTIFIC INTELLIGENCE. I Cnyemistry Anp Puysics. 1. A New Method of Separating Arsenic from All Other Metals —L. Moser and J. WuHRLIcH have been led by theoretical considerations to a modification of the well-known method of separating arsenic from other metals by the distillation of arsenic trichloride. Instead of carrying out this operation in a Stream of gaseous hydrochloric acid, or also with the vapor of methyl alcohol, they employ a stream of air with successive additions of strong hydrochloric acid solution. The apparatus and the method of operation are very simple. A flask of 300 ee. capacity is used as the retort, and this is heated by placing it in boiling water up to the neck. A rubber stopper with three holes closes the flask, with a glass tube through which air is led to the bottom of the flask, with a glass dropping funnel supplied with a stop-cock for the introduction of hydro- chlorie acid solution, and with a bulbed outlet tube which leads to the receiver. The latter is a 400 ec. beaker containing 250 ee. of water. Starting with the substance, with the addition if necessary of a reducing agent, such as ferrous sulphate or potassium bromide (which has been recommended by Gooch and Phelps for this reduction), 50 ec. of hydrochlorine acid (sp. gr. 1.19) are added, the apparatus is placed in the hot water, a rapid stream of air is passed through, and, after periods of ten minutes each, 20 ec. of the hydrochloric acid are added. With 0.15 to 0.25 ge. of As,O, the whole of it passes over in about 40 minutes. Very good results were obtained by test-analyses where the arsenic was determined volumetrically in the distillate, and it was found that no antimony passes over under these conditions.— Berichte 55, 437. H. Ll. W. 2. A New Volumetric Method as Applied to Certain Problems in Inorganic Chemistry.—Paut Durorr and Ep. Grorer have devised a method which is unique in furnishing evidence of the existence of certain compounds. From a burette which is thermally isolated a solution is delivered into a Dewar ilask containing another solution where a reaction takes place between the two dissolved substances. A thermometer graduated to 0.01° is read during the titration, and the burette reading is plotted against the changes in temperature. Straight-line curves are found, with sharp breaks at the ends of reactions. Such diagrams show breaks when H,SO, is half neutralized by sodium hydroxide, and also when the normal sulphate is formed. The several stages of neutralization of H.PO, by NaOH are clearly indicated. Addition of HNO, to Na,PO, give curves 414 Scientific Intelligence. with breaks at each step of the reaction with the trivalent salt. The addition of NaOH to Zn(NO,), gives breaks corresponding - to the formation of ZnNO,OH, of Zn(OH), and of Zn(ONa), and similar results are obtained with NaOH and lead, mag- nesium and copper salts. The salts of Cu, Co and Ni give evidence of the formation of successions of complexes as NH, is added. It is to be expeected that this method of investigation will be of great value in furnishing a very simple method for the investigation of many chemical reactions—J. chim. pharm., 19) S20 ASZ2 iy: H. L. W. 3. Theories of Organic Chemistry; by FERDINAND HENRICH. Translated and Enlarged by Treat B. JoHNSoN and Dororuy A. Hann. 8vo, pp. 603. New York, 1922 (John Wiley & Sons, Ine.). The wonderful achievements in connection with the theories applied to the carbon compounds are extremely well presented in this book, and it furnishes a most excellent source of informa- tion for advanced students and teachers of chemistry. The translators deserve much praise for making this important German work available for the use of EKnglish-reading chemists, as well as for the introduction of several new chapters and other additions which deal particularly with the work of Ameri- can investigators, especially with that of the late J. U. Nef and of Arthur Michael. The German author has furnished a preface to the American Edition in which he approves of these additions and modifications. : The subject is presented historically, with naturally less attention to the older, superseded views than to those now pre- vailing or under active consideration. The discussions of the modern theories are very full and clear, the translation of the German text into English appears to be most excellent, and the difficult typography involving many, frequently complex, structural formulas has been very well done. H. L. W. 4. The Chemistry of Combustion; by J. NEwton FRIEnpD. 12mo, pp. 110. New York, 1922 (D. Van Nostrand Company. Price $1.25 net).—This monograph is the outcome of a series of lectures recently delivered by the author in the Birmingham Municipal Technical School. It gives a clear and satisfactory presentation of the subject in its modern aspects, and since it appears that there has been no small text-book of this kind to which students may be referred, it may be regarded as filling an obvious gap in our literature. The first chapter is devoted to definitions, then the phlogiston theory is briefly discussed, while the other sections are devoted to the combustion of solid carbon, flame, the combustion of gaseous hydrocarbons and other gases, ignition temperatures, the inflammation of gaseous mixtures and the propagation of Chemistry and Physics. 415 flame in them, and surface combustion. The references to the literature are numerous and satisfactory. Ele) We AW 5. Petroleum, Where and How to Find It; by ANTHONY Buum. 12mo, pp. 367. Chicago, 1922 (The Modern Mining Books Publishing Company ).— his book has been prepared by an operator in the ‘‘oil business,’’ who has evidently had much experience in it, for the benefit of those who are or may become interested in this great industry. It is a popular, rather than a scientific, book. It presents many interesting facts and Statistics, and gives much practical information and advice in regard to the production of petroleum. Tels 1b 6. The Heavier Constituents of the Atmosphere.—Sir J. J. THomson has recently applied his method of positive ray analysis to several problems involving possibly unknown constit- vents of certain gases. For the first case he had been supplied by Professor Dewar with a considerable amount of the residues obtained by evaporating many thousand tons of liquid air. These residues had been absorbed by charcoal and the subsequent evaporation of the gases from the charcoal apparently effected a fractionation so that only components heavier than krypton were retained by the charcoal. - The positive ray photographs showed the line of xenon very prominently and also lines of at least two heavier constituents corresponding to atomic weights of approximately 163 and 260. The author is of the opinion that these lines are due to mole- ecules of krypton and xenon, as these numbers are about twice the atomic weights of the respective gases. Experiments were further made to see if these constituents showed any properties analogous to the emanation of radio active substances, but evidence of ionization resulting from such presumed emanation could not be detected. Another application by Professor Thomson of his method was to the analysis of the gases obtained from a tube in which 70 mgm. of radium chloride had been sealed, after exhaustion of the air, for a period of thirteen years. The positive ray line for helium was very strong and a faint line corresponding to m/e = 5 was also found. This latter he ascribes to a compound of helium and hydrogen. Neon was not detected. A third problem was the testing of gases which had stood over radium and also gas lit by deflagrating wires. In these cases quadruply charged atoms of nitrogen were detected and triply charged atoms of oxygen, nitrogen, and carbon. The compound OH, invariably carried.a double charge.—Proc. Roy. Soc. 101, 290, 1922. Pe HB. 7. The Corrosion of Tron and Steel.—Careful estimates of the amount of steel and iron structures or materials which are annually rendered unserviceable by rusting place it as high as 416 Scientific Intelligence. 40 million tons. Whether these figures are exaggerated or not the wastage by corrosion is so great that the concerted efforts of engineers to produce some form of steel alloy with a capacity for resisting corrosion seems imperatively demanded. Apart from the known valuable properties of chromium steel which is too expensive for use on any considerable scale the most promis- ing suggestion has been the introduction of a small percentage of copper into a mild steel, which has been thought by several investigators to give it a superior resisting power. The report of a new series of corrosion tests by Sir Robert Hatfield upon some American steels containing from .02 to .27 per cent. of copper has just been published. The results of the author’s observations may be stated as follows: (a) Under atmospheric corrosion copper steel was rather less affected than ordinary steel especially in the more corrosive condition of an industrial atmosphere. The superiority was of the order of 10 per cent. in pure air and 25 per cent. under the industrial contamination. As is generally the case, material with the rolling scale removed was more resistant than with the scale on. (b) In sea water ordinary steel corrodes more rapidly at first but the rate of corrosion for both materials slows up showing a certain degree of self-protective action which was a little greater for ordinary steel. The total corrosion of the copper steel however was shghtly less at the end of 16 weeks than that of ordinary steel. (c) In tap water (Sheffield, England) there was little to choose between the two materials. Though initially not so corrosive as sea water, over a long period it was more corrosive due to the absence of any self-protective action in the presence of tap water. (d) In a 50 per cent. sulphuric acid bath both materials were rapidly attacked at first but whereas the solution of ordinary steel continued at a steady rate, that of the copper steel showed a very much reduced rate after the scale had been removed. The steel containing copper was apparently very resistant to a 50 per cent. sulphuric acid solution. (e) A 20 per cent. sulphuric acid solution showed a more vigorous action than the 50 per cent. solution but the superior resistance of the steel containing copper was again confirmed. The deductions to be drawn from these experiments are (1) that the superiority of copper steel under atmospheric corrosion is due to and dependent on the amount of sulphurous impurity earried by the air; (2) that no advantage will be gained by the use of copper steel in ordinary fresh water; and (3) that for long immersion in sea water this alloy is. probably inferior. The author is further of the opinion that as in the majority of service conditions iron or steel is subjected to total or partial immersion in natural waters it is by no means certain that a copper content as a commercial constituent of mild steel might not be deleterious.—Proc. Roy. Soc. 101, 472, 1822. F. E. B. Geology. 417 8. The Mathematical Theory of Probabilities; by ARNE FisHer. Vol. I, pp. XXIV, 289. New York, 1922 (The Mac- millan Company ).—The author who is an actuary by profession has written this treatise chiefly for students of statistics, but the reader will have to be an expert mathematician to follow the analytical development of the theorems. In this second edition twelve chapters are devoted to the theory of probabilities of homograde statistics, by which is to be understood such series of events as appear in games of chance. Two chapters are given to the fitting of various analytical formulas and series to statistical data or frequency distributions. The remaining four chapters explain and illustrate in detail the method of computing the parameters in numerical series. It is difficult to believe that any set of data could justify the expenditure of so much labor in analyzing the curve into what is after all but an arbi- trary set of functions. The author’s work is characterized by his devotion to the methods of Laplace in the development of the theory, and the use of the semi-invariants of Thiele, in preference to Pearson’s method of moments, in the calculation of the parameters of the frequency function. im, 1d, 18. Il. Groroey. 1. The Paleontology of the Zorritos Formation of the North Peruvian Oil Field; by EpmMunp M. Spieker. Johns Hopkins University Studies in Geology, No. 3, 196 pp., 10 pls., 1922.—In 1867, Mr. EK. P. Larkin and Professor F. H. Bradley made collections of Miocene fossils in the area of Zorritos, Peru, and these were described three years later by Edward T. Nelson. Recently far more material was collected in this region by Professor Singewald, and all of the known collections are here reported on in detail. The Zorritos formation now is known to have 44 species of gastropods and 57 of pelecypods. Of these, 64 are new. The time appears to be in the main Burdigalian, though the higher beds may be of Helvetian age. The fauna is a shallow-water one, of warm waters, and cor- relates best with similar faunas of Panama and the Antillean areas. CLS: 2. The Recession of the last Ice Sheet in New England; by Ernst Antevs. Amer. Geog. Soc., Research Ser., No. 11, 120 pp., 6 pls., 19 text figs., 1922.—In this well printed and edited book, the author describes the De Geer method of determining the rate of annual deposition of ‘‘varved’’ glacial clays and also the rate of recession of the ice lobes in the lake-filled river valleys. This method is, in addition, the only known one for measuring earth chronology in actual years. Antevs’ work relates in the main to the Connecticut valley from Hartford, 418 Scentific Intelligence. Connecticut, north almost to the Canadian border. It took the ice something like 4100 years to melt back this distance. How long ago the American continental ice sheet began its melting away is not yet known. The average recession of the ice appears to have been about one mile in 22 years, though locally the rate varies from 83 to as much as 1100 feet per year. At times there was even a slight re-advance of the ice sheet. It took about 5000 years for the ice to melt back from southern- most Sweden north for 480 miles. Since the ice melted away, another 8500 years has elapsed, so that it is about 13,500 years: since the continental ice sheet began its recession in southernmost Sweden. The term ‘‘varve’’ is a Swedish word, and in geology signifies the annual cycles of sedimentation of glacial clays, beginning in the coarser, lighter colored material of summer deposition and ending in the darker winter deposit of the finest blue muds, having a greasy feel. Varved clays are all laid down in fresh-water lakes in front of ice lobes, and when glacially derived muds are laid down in the sea, it is said that they are not varved but are homogeneous, in that the coarser material is mixed with the finest of muds. In fjords, however, such muds may also be faintly varved. The measuring of the varves and the making of the local graphs to show the varying rate of annual deposition is not a difficult matter, but requires patience, since the work is both laborious and time-consuming. The greatest difficulty of the method lies in finding a succession of closely adjacent clay (not sand) exposures and in correlating these by means of the eraphs from place to place. The method tends somewhat to underestimate the total time and never to overestimate it. Commonly, there are two easily distinguishable layers to a varve, but often the lghter colored summer portion will be much thicker and more or less banded, while the darker greasy winter layer is usually not banded. The normal varve, or the cyclic material for one year, is usually much less than one ineh in thick- ness, but in the vicinity of drainage the summer deposition, when - of sand, may rise to as much as 12 feet. The De Geer method of evaluating varves also reveals the elimatic periodicity of the time of deposition, not only as to the short cycles, but the long ones as well. When fossil leaves are abundant, one can also discern in years the rate of floral adapta- tion and migration. The memoir is coneluded with a most interesting map by Professor Goldthwait, which plots for the area of New York, Pennsylvania, New Jersey, and the New England States the direction of ice flow, boulder trains, terminal and recessional moraines, and the position of the ice-edge for every 100 years, Obituary. “419 as determined by Antevs between Hartford, Connecticut, and the Canadian boundary. A ready means is now at hand for a definite chronology of post-glacial time, and our thanks and congratulations are due to Doctor Antevs for his successful results. Cig S's 3. A Section of the Paleozoic Formations of the Grand Canyon at the Bass Trail; by L. F. Nopuz. U.S. Geol. Survey, Prof. Paper 131-B, pp. 23-73, pls. 19-25, 4 text figs., 1922.—In this memoir the author brings together in great detail all that he has learned about the Paleozoic sequenecee—Cambrian, Devo- nian, Mississippian, Pennsylvanian, and Permian—of the marine and continental strata in the Grand Canyon of the Colorado River, during the years 1914, 1916 and 1920. Various sections are described from Bass Trail eastward for 35 miles, and all of the zones and sections correlated into a generalized sequence having a thickness of 4014 feet, besides 506 feet of Triassic formations. The Grand Canyon should be the Mecca for all stratigraphers, and the worshippers at this grandest of Nature’s shrines will find guidance and inspiration in Doctor Noble’s careful study of the sediments deposited here by an epeiric sea, from shore to deeper water. Co 4. Essentials for ‘the Microscopical Determination of Rock- Forming Minerals and Rocks in Thin Sections; by ALBERT JOHANNSEN. Pp. 53, with 24 text figures. Chicago, TE 922% (The University of Chicago Press, $2.00.)—This work is a revision of the author’s well-known laboratory manual, ‘‘A Key for the Determination of Rock-forming Minerals in Thin Sections,’™ which was published in 1908. The new edition appears in a markedly different format, being now in quarto instead of octavo, and by rearrangement of the determinative tables it has been very notably reduced in bulk—from 542 pages to 53. The descriptions of the individual minerals have been slightly condensed. Brief notes on the modes of geologic occurrence have been added, and the diagnostic differences between minerals of somewhat similar optical properties are more adequately emphasized. A summary exposition of the author’s quantitative mineralogical classification of igneous rocks has also been added. ApOLPH KNopF. 5d. The Rocks of Mount Everest.—tThe efforts of the members of the Mt. Everest expedition of 1922 to reach the Summit of the mountain have already been fully given in the public press. That it was found possible to reach an altitude of 27,300 feet, with the aid of oxygen, is sufficiently noteworthy. It is still more interesting that a third expedition is already being tentatively considered and a greater degree of optimism is felt by the climbers as to ultimate success than after the effort 420 Scientific Intelligence. of 1921; this is based practically on the fact that the physio- logical effects at altitudes of 26,000 and above were found to be less serious than anticipated. Dr. A. M. Herron has given the results of the examination of rock specimens collected at heights from 23,000 to 27,000 feet. The conclusion is reached that ‘‘Mount Everest is a pile of altered sedimentary rocks—shales and _ limestones—converted into banded hornfels, finely foliated cale-silicate schists, and erystalline limestones. The hornfels and fine schists are in the field blackish or dark green rocks, conspicuously slabby and with a general low dip to the north, which, I believe, adversedly and even dangerously affected climbing. The crystalline lime- stones are fine-grained pure white rocks. The specimens from 23,000 and 25,000 feet show in microscope sections a very fine- erained aggregate of quartz and a greenish mica, with irregular lenticles and veins of chlorite and epidote, and in addition sometimes calcite pyrites and sphene. | ‘*The mountain, from 21,000 to 27,000 feet, is made up of these black and dark green rocks, with occasional beds of white lme- stone, and veins of quartz and muscovite granite. From 27,000 to 27,500 feet extends an almost horizontal belt, a sill in fact, of schorl muscovite granite, along the whole leneth of the mountain, which rock presumably, by its superior hardness, gives rise to the prominent shoulder of the mountain north-east of the main peak (shown as 27,390 on Major Wheeler’s photo- graphic survey map). Above this again are black schists. Captain Finch informs me that he saw ammonites at a height of about 26,500 feet, but was unable to collect them. ‘“As to the age of the rocks forming Mount Everest, they may perhaps be assumed, for the present, to be Jurassic or Trias.’’ London Geological Journal, September, 1922, pp. 219, 220; see also July, pp. 67-71, August, pp. 141-144 and October, pp. 288-291, with fifteen beautiful reproductions from photographs. 6. A newly Found Tennessee Meteoric Iron; by G. P. MERRILL (communicated ).—State Geologist Wrllten A. Nelson has forwarded to the U. 8S. National Museum a mass of meteoric iron recently found by Messrs. C. D. McKnight and M. W. Spen- cer while working on the roadway leading from Savannah to Cerro Gordo, some four miles northeast of the first named town in Hardin county, Tennessee. The mass is 18 inches in length, roughly dumb-bell shaped and weighs 132 lbs. It is an octahe- drite in crystallization and much weathered, undoubtedly repre- senting an old fall. A cast will be made of it, after which it will be cut and analyzed a portion being retained at the National Museum and a portion returned for the State collection at Nashville. 7. Minor Faulting in the Cayuga Lake Region ; by 2H Lone.—The following corrections should be made in the above article in the number for April (pp. 229-248). Miscellaneous Scientific Intelligence. 421 The first line on p. 232 should read: The Watkins Glen-Cata- tonk folio deals with, ete. Page 233, line 26 from top, Enclinal should read Enecrinal. Page 236, line 4 from top, north should read south. Page 247, line 18 from top, Cayuga should read Cayuta. Page 247, line 23 from top, Cayuta should read Cayuga. III. Misce.uAnetous Screntiric INTELLIGENCE. 1. Foundations of Biology; by LorRANDE Loss WoopRUFF. Pp. xvii, 476, with 211 illustrations. New York, 1922 (The Macmillan Company ).—This text book, designed particularly to supplement the laboratory work of college students in the ele- mentary course in biology, has been prepared with more than usual care both as to scope and proportion. In it the reader will find a logical and comprehensive account of the underlying principles of the organic world, leading from a simple discussion of the physical basis of life through the organization, metabolism, reproduction, differentiation, heredity, and adaptation of organ- isms, to the evidences of organic evolution. The nineteen chap- ters embracing this part of the work are so skilfully correlated as to make a continuous and harmonious account of the vital phe- nomena in both plants and animals. In the final chapter is told the story of the historical development of biological science from the earliest times to the present, with a brief account of the work of those who have made the most important contributions to the subject. A synoptic classification of organisms and a concise glossary of technical terms are appended. Many well-drawn original diagrams are found among the numerous illustrations. The book has so many points of excellence that it is not too much to say that its careful reading will give to those who pur- sue the subject no further a clear, broad, comprehensive and well- balanced conception of life and its evolution, while to those who contemplate further work in biology it will furnish an ideal foun- dation for their more advanced studies. W. R. C. 2. The Study of Living Things: A Course in Biology for Sec- ondary Schools; by W. H. D. Merer. Boston, New York, ete. (Ginn and Company).—This laboratory guide is issued in the form of a pad of sheets of generous size to be filled out by the pupil with answers or drawings according to the special instruc- tions on each sheet. Ninety-six exercises, covering the entire field of elementary biology, are included, each requiring a practi- cal investigation on the part of the pupil and compelling him to do some independent thinking. No better plan has been devised for bringing the pupil into direct contact with the most important aspects of the subject. W.R. C. 4.29 Scientific Intelligence. 3. Field Museum of Natural History. Annual Report of the Director, D. C. Daviss, to the Board of Trustees, for the year 1921. Pp.:75, with 16 plates. Chicago, 1922.—This report is made of especial interest since it opens with a notice and portrait of Dr. Frederick J. V. Skiff, who served as director from Decem- ber 16, 1895, until his sudden death on February 21, 1921. _ What Dr. Skiff did towards the development of the museum during a period of service extending over nearly thirty years is best appre- ciated by those who were closely associated with him. The museum has also suffered by the loss of Dr. Frank W. Gunsaulus, one of the original trustees, and of Charles B. Cory, curator of Zoology. The Museum was reopened in its new building on May 2, 1921, at that time everything was in readiness of the renewal of its work. The entire deficit in the building fund has been | assumed by President Stanley Field, who had earlier contributed the sum of $150,000. Capt. Marshall Field has agreed to contrib- ute $50,000 annually for five years to pay for expeditions in the field, for new exhibition cases and for the publication of papers by members of the staff; he had already’ contributed $65,000 toward the deficit in the building fund. 4, Publications of the British Museum of Natural History.— Recent publications are the following: Catalogue of the Fossil Bryozoa (Polyzoa) in the department of Geology: The Cretaceous Bryozoa, volume IV. This volume (pp. 1-404, with 8 plates) by W. D. Lane is part II of the cata- . logue of the Cribrimorphs, completing the Cretaceous Cribri- morph Cheilostomata. See introduction to volume III. Catalogue of Books, Manuscripts, Maps and Drawings. Vol. VI, Supplement, AtoI. Pp. 551, 4to. With Addenda and Cor- rigenda to vols. I and II, A to Hooker. Pp. 48. The first vol- ume of this Catalogue was published in 1908; volumes II-V fol- lowed in 1904-1915. These were prepared by B. B. Woopwarp, who, with some clerical aid has compiled the present Supplement. 5. National Academy of Sciences—The autumn meeting of the National Academy will be held in New York City, November 14 to 16. The opening session will be on Tuesday morning in Schermerhorn Hall, Columbia University, at 10 o’clock. The ses- sion for the presentation of papers will immediately follow the business session. This will be opened by a brief address of wel- come from President Butler. So far as possible, papers from the Sections of astronomy, chemistry, geology and paleontology will be assigned to this day. On Tuesday evening President and Mrs. Butler will receive the visiting members and their friends at the President’s house, 60 Morningside Drive, beginning 8.30. A subseription dinner will be held on Wednesday evening, at a place to be announced later. Geology. 423 On Wednesday, November 15, the meeting wili be held at the Rockefeller Institute, Avenue A and 66th Street. So far as pos- sible, papers from the Sections of botany, zoology and animal morphology, physiology and pathology, anthropology and physiology, will be given on this day. The meeting of Thurs- day will be held in the auditorium of the United Engineering Societies Building, 29 West 39th Street. Papers from the Sec- tions of mathematics, physics, and engineering will be given on this day. Thursday evening has been left open for informal gvatherines of members. The headquarters of the Academy are at the Hotel Astor, 44th St. and Broadway. OBITUARY. Dr. ALEXANDER SmiTH, professor of chemistry and head of the chemical department in Columbia University from 1911 to 1921, died in Edinburgh, his birthplace, on September 8 at the age of fifty-seven years. Professor Smith held many University positions, contributed important researches on the forms of sulphur, and (with A. W. C. Menzies) on vapor pressures, wrote numerous useful textbooks and in brief was a man of great energy and wide influence. Dr. F. T. Trouton, emeritus professor of physics in the Uni- versity of London, died on September 21 at the age of fifty-eight years. Born in Dublin in 1863, he was graduated from Trinity College where he early showed his rare keenness of mind. He was made at once assistant to the professor of physics, and in 1902 became Quain professor in University College, London. He will be remembered for many important researches, those leading to the establishment of Trouton’s Law, on Hertzian waves, on the viscosity of solids and others of no less importance. Dr. Davin SHARP, the veteran English entomologist, died on August 27 at his home in Brockenhurst, at the age of eighty-two years. Dr. WinuiAM KELLNER, the eminent chemist, died on Septem- ber 12, in his eighty-third year. He was born and received his education in Germany, but came to England in 1862 as assistant to Sir Henry Roscoe at Manchester. He was made chemist to the British War Department in 1902. Dr. ARTHUR LALANNE KiMpBa tL, for thirty-one years professor of physics at Amherst College, died on October 22 at the age of sixty-six years. Dr. ALBERT AVERN STURLEY, instructor in physics in Yale Uni- versity, died on October 22 at the age of thirty-five years. Ps = — A eg a ae =, 7 ie a, erat ue ~ Warns Naturat Science EstasiisHMent ae Supply-House for Scientific Material. Founded 1862. Incorporated 1890. A few of our reeent circulars in the various departments: Geology: J-32. Descriptive Catalogue of a Petrographic Col- lection of American Rocks. J-188 and _ supplement. Price-List of Rocks. Mineralogy: J-220. Collections. J-288. Minerals by Weight. J-224. Autumnal Announcements. Paleontology: J-201. Evolution of the Horse. J-199. Pale- ozoie index fossils. J-115. Colleciions of Fossils. 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Ge _ This new edition has been revised to represent present-day i western portion of the United States. ran 237 pages. 44 by 7. 48 figures. Flexible, #3. 50, ~ = io eae Send for any Wiley book on Free Examination 3 P JOHN WILEY & SONS, 432 F ourth Avenue N ew ‘York | London CHAPMAN & Nee Lid. THE AMERICAN JOURNAL OF SCIENCE PEELE TH SE RTH S.4 ——_ woe Art. XXXVI.—John Day Felide in the Marsh Collec- tion; by GrorcE FE’. Karon. [Contributions from the Othniel Charles Marsh Publication Fund, Peabody Museum, Yale University, New Haven, Conn.] To the surviving personal friends of O. C. Marsh, and also to the younger generation of vertebrate paleontolo- gists, Marsh’s eagerness to secure fossils from newly reported localities in the western United States, and the success of the collectors he employed, no longer present any novelty. It need therefore occasion no surprise that the Marsh Collection of Vertebrate Fossils in the Peabody Museum of Yale University should contain a considerable-amount of material, from the John Day Valley of Oregon, that was collected principally between the years 1870 and 1877. The present short article is based on that portion of this material from the John Day Valley which includes the Felide. While it would be ungracious to criticise the methods of collecting in vogue in the seventies of the last century, it appears that the superior value of a good skull over the other skeletal parts, which were then somewhat dis- paragingly termed ‘‘joints,’’ was a little over-emphasized in Marsh’s instructions to his collectors. A result of this is possibly to be seen in the predominance of cranial material, unaccompanied by other skeletal parts that might otherwise have been saved, and that would now greatly enhance the value of the collection. Then, too, the stratigraphy of the region was neither so well under- stood nor regarded as of the same importance in con- nection with the search for fossils as it has been of recent years, and accordingly it would be unwise to accept as authoritative, in some instances, the recorded statements of the collectors regarding the horizons from which speci- mens were obtained. For this reason the present article Am. Jour. Sct.—FirtTH Serres, Vou. IV, No. 24.—DEcEMBER, 1922, ~ 426 Katon—John Day Feliide in Marsh Collection. must be lmited, in the main, to a discussion of the osteology and affinities of the material examined, and less attention can be paid to stratigraphic considerations than would otherwise be desirable. Yet notwithstanding real or suspected shortcomings in field work during pioneer days, the fact remains that this material, collected half a century ago, is worthy of careful study, and con- tains forms specifically distinct from those previously described. It is a pleasant duty therefore to express the admiration that is felt for the generous enthusiasm that led Professor Marsh to be one of the first paleontolo- gists to visit the John Day Valley and to encourage the search for fossils in that region. Tables—For convenience in comparing the new species, here described, with the earlier types, cranial measurements have been arranged in parallel columns in Table A (page 442). While most of the measurements, selected for this purpose, conform with those used by previous authors, three new measurements have been introduced, and an external palatal length has been substituted for the old mid-line measurement. This table as originally constituted included practically all the measurements of, cranium and mandible used by Merriam and by Thorpe; but while extremely useful in the study of material in the laboratory, it was thought too large for convenience of publication at the present time. The table has therefore been cut down to about one third of its original size by the omission of all mandi- bular and nearly all dental measurements, as well as of several cranial measurements that, on trial, did not yield satisfactory differential indices. Although the number of measurements and indices has been reduced, it has seemed desirable that the series of specific types, and other crania, tabulated under the several genera, should be as complete as possible, in order that the range of the indices characterizing these genera might be reliably determined. For this purpose four of the best preserved crania of the genus Nimravus in the Marsh Collection have been measured and the resulting indices recorded. Examination of several of Cope’s types, now in the American Museum of Natural History in New York, has been possible through the courtesy of Dr. W. D. Matthew of that institution; and Professor John C. Eaton—John Day Felide wm Marsh Collection. 427 Merriam, lately of the University of California, has very kindly supplied certain measurements of his types of Pogonodon davist and Nimravus (Archelurus) debilis major in addition to those given in his original description of these two types. The illustrations accom- panying this article are by Mr. R. Weber, and have a value of their own quite apart from the text. Where the number of species to be compared is large, interpretation of the absolute measurements is facilitated by a further table expressing relative cranial pro- portions. The system of indices, so extensively used by anthropologists, eliminates the factor of mere size and is admirably adapted to this requirement. Accordingly the basal length, measured from basion to prosthion, which is probably the most rational single element of size, has been chosen as a convenient basis for the com- parison of the major cranial proportions. From several of the cranial measurements in Table A, indices have been derived by the simple process of dividing these measurements, as taken on each skull, by the basal length of that skull, and multiplying the quotient by 100. In the ease of minor cranial proportions and dental pro- portions, other dimensions than the basal length are more suitable as the bases of comparison; but as in every case the definitions of the indices, arranged in Table B, refer to the serial numbers of the absolute measurements, recorded in Table A, no confusion regarding the identity of the indices in Table B need arise. The measurements recorded in Table A eall for little explanation. The axial length from the prosthion to the posterior surfaces of the occipital condyles has been retained principally because of its long use by previous authors as a convenient over-all dimension; but the basal length from basion to prosthion, which can be readily taken in some skulls where Cope’s axial length is impracti- cable, has been preferred as a basis for the comparison of size and proportion. There has been little uniformity in the past regarding the measurement of palatal length. The margin of the palatine bones bounding the posterior nares is seldom perfectly preserved, and even when com- plete it seems to be subject to some individual variation of form due to the development of a posteriorly directed mid-line process homologous with the posterior nasal 428 Haton—John Day Felide in Marsh Collection. spine of the human skull. It has seemed desirable therefore to discard the mid-line palatine length, and to substitute for it a palatal length measured from the prosthion to a line tangent to the posterior surfaces of the maxillary parapets. This is precisely the same as the external palatal length of human craniometry. Since the index of palatal length, computed from this dimension and the basal length, is remarkably constant in all the species of Nimravus, Dinictis, and Pogonodon examined during the preparation of these tables, the palatal length furnishes an excellent basis for computing indices of palatal breadth. Pogonodon Cope. This genus was founded by Cope! on the characters of a skull that he had originally described as Hoplo- phoneus platycopis.2. In a later article® he stated that ‘“This genus |Pogonodon] represents a station on the line connecting Dinictis with the higher sabre-tooths, being intermediate between the former genus and Hovplo- phoneus,’’ and provisionally referred to the same genus incomplete material which he had made the type (partim) of Macherodus brachyops* Pogonodon platycopis and P. brachyops were transferred by Adams?® to Dinictis, the reason for this change being that ‘‘The genus Pogono- don as proposed by Cope does not differ from Dinictts as regards tooth structure, and the absence of the second inferior molar, which in Dinictis is much reduced, is not sufficient grounds for retaining it as a distinct genus, since in several specimens of Dinictis it is variable in size and in one is absent from one side.’’ Matthew® referred Pogonodon platycopis to Cope’s genus Nimra- vus, regarding Pogonodon as a distinct sub-genus; and to the same genus he referred P. brachyops also, stating his opinion that the latter species was ‘‘like N[wmravus] gomphodus and doubtfully separable from it except by — absence of the infracarnassial exostosis.’’ In the same 1. D. Cope, Am. Nat., 14, 143, 1880. * i. D. Cope, Am. Nat., 13, 798a, 1879. °K. D. Cope, Am. Nat., 14, 847, 1880. *E. D. Cope, Proc. Am. Phil. Soe., 18, 72, 1878. (+, I. Adams, This Journal (4), 1, 433, 1896. °W. D. Matthew, Bull. Am. Mus. Nat. Hist., vol. 28, 310, 1910. Eaton—John Day Felide in Marsh Collection. 429 article, in his discussion of Hoplophoneus, Matthew notes that Merriam’s Pogonodon davist, which Matthew had not then had an opportunity to examine, ‘‘appears from Merriam’s figures to be referable to this genus [Hoplo- phoneus| and distinet from any of the Dinctis phylum.”’ On the other hand, Merriam’ in his announcement of Pogonodon davisi has stated at considerable length the reasons for which it seemed to him ‘‘advisable to use the arrangement proposed by Cope, and to separate platy- copis, brachyops, and davisi [from the deinictid group in the John Day beds] as the Pogonodon group, of at least subgeneric rank.’’ In this status Pogonodon has rested for several years. My colleague M. R. Thorpe® has recently found it expedient to recognize the validity of Cope’s Pogonodon in order satisfactorily to record the affinity of a feline mandible from the White River beds of South Dakota. Similarly in the case of the skull | about to be described, the practical convenience of retaining Pogonodon as a distinct genus, or subgenus, is not to be denied. Pogonodon serrulidens, sp. nov. (Fies. 1-3.) Holotype, Cat. No. 10520, Y. P. M. Upper Oligocene (John Day), Turtle Cove, John Day Valley, Oregon. Collected by L. S. Davis in 1875. The type material consists of a cranium, not particu- larly well preserved, together with two fragments of the right mandibular ramus, the proximal portion of the right ulna, and the proximal portion of the left metatarsal Ill. From the indications of age afforded by the sutures alone, this skull would appear to be that of an animal nearly or quite adult, but the dentition proves that the animal was immature. The permanent premolar and molar series is, or was, complete, while the deciduous canine of the left side is still present, being but partly overlapped, on its inner side, by its permanent successor. On the right the deciduous canine has been lost with part of the maxilla, so exposing considerably more of the permanent canine than the portion that had actually protruded beyond the parapet. The premaxillary alveolar border has been damaged, and none of the “J. C. Merriam, Univ. of Calif., Bull. Dept. Geol., vol. 5, 57, 1906. °M. R. Thorpe, This Journal (4), 50, 223, 1920. 430 Haton—John Day Felide im Marsh Collection. incisors are preserved. While the immature develop- ment of the skull admittedly detracts somewhat from its value as a specific type, this deficiency is nearly compen- sated by the fact that the teeth of the permanent set exhibit practically no signs of wear, and therefore present, so much the more clearly, their characteristic form. The material is provisionally attributed to the upper John Day because of the gray color of the ashy matrix, which, although slightly tinged with green, can not be described as bluish-green; but as this stratigraphic reference is unsupported by field records or other data, it should not be regarded as established beyond question. Fie. 1—Pogonodon serrulidens, sp. nov. Holotype. x %. Dentition.—I?, Ct, P®, M‘. The upper canines are compressed. The anterior margin of the right upper canine, which is exposed to view for nearly half its length, is sharper than in Nimravus, the serrated anterior ridge following the actual anterior margin of the tooth for a greater distance from the point than is the case in Nimravus. P? is very small, practically vestigial, and_ single-rooted. P? is much smaller in proportion to P* than in Dinictis and Nimravus, in this respect nearly resembling Pogonodon davisi. P* is without a positive inner cusp (protocone), the inner root being small and closely adpressed to the anterior root. It has a small but definite anterior accessory cusp (parastyle) distinctly separated from the sharp anterior margin of the para- Eaton—John Day Felide in Marsh Collection. 431 cone by a narrow oblique cleft. This is a character which the present species shares with Pogonodon davisi, but not with P. platycopis, for according to Cope? the upper sectorial of the latter species has no parastyle. The paracone and metacone of P* are separated by a deep notch much as in Dinictis and Nimravus, and judging from the illustrations of Pogonodon davist, as in that species also. M! is small with much reduced inner lobe. P, which is fortunately preserved in one of the mandib- ular fragments, has a relatively greater transverse breadth than J have observed in specimens of Nimravus. In this greater breadth and in the extent and form of the notch separating the posterior basal tubercle from the principal cusp, this tooth closely resembles the P, of Thorpe’s Pogonodon cismontanus, Cat. No. 10053, vero My. The cutting edges of all the teeth, including even the vestigial P?, are finely serrated. This condition would facilitate the sectorial action of the teeth of a young and comparatively weak animal. It would be of progressively less advantage as the jaws and their mus- - cles acquired greater strength. By the time the animal was fully adult, the serrations would probably be nearly or quite worn away from all the cheek-teeth, while on the canines, which because of their special function are less subject to detrition, the serrations might be expected to persist much longer. Sand and gritty substances taken into the mouth with food are a constant cause of dental detrition among the Carnivora, not excepting even the cleanly Procyon lotor, and in view of the habit of some recent large felines of crunching bones,'° it is probable that similar habits, acquired as the large extinct felines approached maturity, would hasten the destruction of the serrated sectorial edges. ‘The resemblance of these serrated teeth to small saws has suggested the specific name, but it is not assumed that the cheek-teeth were serrated only in this species, or indeed in this genus alone. One of the mandibular fragments supports a lower permanent canine lacking the upper half of the crown. °E. D. Cope, Report of the U. S.. Geol. Survey of the Territories, vol. 3, 981, 1884. * Dr. W. Reid ‘Blair, D. V.S., of the New York Zoological Park, informs me that the lion, tiger, leopard and puma all use the large cheek-teeth for this purpose. 432 Haton—John Day Felide in Marsh Collection. The tooth is not quite fully protruded. The order of dental replacement, exhibited in this skull, should be noted. Disregarding the incisors, none of which have been preserved, there are actually in place and functional, in the lower jaw, a permanent canine and a permanent: P,, and in the upper jaw, on one side, all the permanent premolars and molars. On the left side the alveolar margin where P? should be has been destroyed. From ae »)) ANY NIM ~S" SAWN ZX" SSF SS x WWYYW- SQ! YGYvv¢ FZ SS yy Niaekealy AY es Ta CC Ui oh i i 1 ! via og i) g Fite. 2.—Pogonodon serrulidens, sp. nov. Holotype. "192. \ SS ‘ ‘ SNS way ANY ~My Wy) \\ wy £ ~ ww X SS . x LORS WAAAY Veal Veh \\N y Li is ith I i oi My er ce mh Mi, j\}! Uj “ANNIE Es PAN Wu“ \\\\ RYN yet \W ry ti W a, Lit TM tei { Ge acre ere | | YQ, Wty \ ify | ra \ lll \\ \| . va ahh ——— the foregoing it appears that the deciduous upper canines remained in place until all the permanent upper cheek teeth were fully erupted. The presence of P, in the mandible renders it probable that the replacement of the lower cheek-teeth also was nearly if not quite completed, for in recent carnivores the lower carnassial is the first permanent cheek-tooth to appear. The best example at hand of a recent wild feline, showing the dental replacement, is a skull of the bay lynx (Lynx rufus), No. 0926, Y. P. M. Comparison of this lynx skull with that of Pogonodon serrulidens shows that, the replacement of the canines being at approximately the same stage in the two skulls, the replacement of the cheek- Eaton—John Day Felide wm Marsh Collection. 433 teeth has been relatively earlier in the fossil skull, for here the permanent cheek dentition is nearly or quite complete, while in the recent skull the upper deciduous earnassials and all the lower deciduous cheek-teeth are still in place and functional, although, on each side, the principal cusp of P*® has just appeared, and the crowns of P* and M' have protruded to about half their height. If preferred, the cheek-teeth may be taken as the basis of comparison, in which case it would appear that the replacement of the canines was relatively tardier in the fossil skull than in the recent lynx. Cranum—The basal length of the skull, measured between the basion and the probable position of the prosthion,is167mm. ‘This shows the skull to be consider- ably shorter than that of Pogonodon davist where the similar measurement is about 198 mm. Viewed from the side, the general proportions of the skull of P. serruli- dens resemble those of P. davisit more closely than they do those of Nimravus. This is especially noticeable in the low and straight nasal region, and in the frontal profile which rises higher from the base-line in the neighborhood of the bregma than in the region between the postorbital processes. The sagittal crest does not however, rise as high posteriorly in the: present species as in P. davist. The maxilla and the jugal, on each side of the skull, contribute to the formation of what may conveniently be termed the anterior zygomatic pedicle. It is believed that the widely varying proportions of this part of the skull will be found of considerable taxonomic value in the extinct Felide. In certain genera the anterior zygomatic pedicle affords two excellent measurements, namely, a height, taken as the minimum distance between the inferior margin of the orbit and the alveolar margin of the maxilla, and a length, taken as the minimum distance between the external margin of the infra-orbital foramen and the posterior margin of the zygomatic process of the maxilla. By dividing the measured height by the length, and multiplying the quotient by 100, an index is obtained, admirably suited to the comparison of cranial form, since it is entirely independent of actual size. The anterior zygomatic pedicle of Pogonodon serrulidens is considerably higher than long, as it is in 434 Haton—John Day Feliide im Marsh Collection. P. davist and P. platycopis, the indices of this part of the skull, in these three species, being 120, 148, and 162 respectively, and so differing greatly from Nimravus where the length of the pedicle is equal to, or slightly greater than, the height, the corresponding index of N. gomphodus being 100, of N. debilis 88, and of N. debilis major 92, while in Dimictis cyclops it is 106, and in D. squalidens (No. 8777, A. M.N. H.) itis 107. aS 7 LAA We CCCs WAAAY? (ZB ae AS ey SOIR » Quwieibuld 4A Fie. 3.—Pogonodon serrulidens, sp. nov. Holotype. « %. Another remarkable characteristic of Pogonodon serrulidens is the large size of the infra-orbital foramen. The vertical and transverse diameters, taken within the foramen, not at its outlet, are respectively 13 mm. and 10mm. This isa variant toward the typical Hoplophonic form that at once distinguishes the present species from Nimravus. The true significance of very large infra- orbital foramina in certain groups of extinct Felide is not clear. As the foramina are traversed by important branches of the external carotid artery and trigeminal nerve supplying the lower eyelid, side of the muzzle, and the upper lip, it may ultimately appear that the size of these foramina was directly correlated with the size and mobility of the upper lip in those extinct species that Eaton—John Day Felide in Marsh Collection. 435 had long upper canines. It is not known to what extent the long knife-like upper canines of the true saber-tooth eats were curtained by pendulous upper lips when the mouth was closed in a state of rest; yet obviously such lips would have to be raised to avoid injuring them in the act of biting. Whatever the explanation, the fact remains that in the typical saber-tooth Smilodon the infra-orbital foramina are very large and in the false saber-tooth Nimravus comparatively small. The fragment carrying P, shows that the mandible at this section is much shallower and broader than the mandible of Nemravus. The vertical and transverse measurements of the mandible of Pogonodon serrulidens, taken immediately behind P,, are 283 mm. and 14 mm. respectively, and in P. cismontanus 32 mm. and 14.5 mm. respectively. JI can not quote exact corresponding measurements in the types of the several species of Nimravus, but in other material, referred to that genus, the height is uniformly about three times as great as the transverse diameter. Cope evidently thought this character to be of taxonomic value, for he stated of Nimravus gomphodus': ‘‘The ramus of the mandible is longer, deeper, and more compressed than in the recent species of Uncia and the Pogonodon platycopis’’; and of Pogonodon platcopis'* he wrote ‘‘The mandibular rami are robust, and not so high and compressed as in Nimravus and its allies.’? Regarding the form of the anterior portion of the mandible in Pogonodon ser- rulidens, little can be ascertained from the fragment carrying the lower canine; but the broad and flat anterior surface and the thickness of the bone external to the root of the canine are distinctly favorable to the sup- position that there was a flange for the protection of the upper canine. The foramina of the basicranial region, so far as it has been possible to locate them, occur as in Dinictis and Nimravus. The mastoid process, in point of size, resembles Nimravus rather than Dinictis, but it is directed a little more forward than in Nimravus, in this respect being more like Dinictis. The glenoid surfaces 4 E. D. Cope, Report of the U. S. Geol. Survey of the Territories, vol. 3, 965, 1884. 2 E. D. Cope, Report of the U. S. Geol. Survey of the Territories, vol. 3, 984, 1884. 436 Haton—John Day Feliide im Marsh Collection. are not projected downward as in Hoplophoneus, but, on the contrary, they rise considerably above the level of a line adjoining the basion and prosthion. The two fragments of limb-bones, already mentioned, have been compared with the corresponding parts of a puma, Felis concolor, No. O15, Y. P. M., whose skull is of almost exactly the same basal length as that of Pogono- don serrulidens. The lengths of the ulne of the two. animals can not be accurately compared, owing to the imperfection of the fossil bone, but a well-marked difference is presented in certain other proportions. While the shaft of the ulna of the fossil species is the more slender of the two, the diameter of its greater sigmoid cavity, measured in the axial direction of the limb, is considerably greater than in the recent species. This indicates also a greater diameter of the trochlea of the humerus. An analogous condition is presented ~ by ‘the fragmentary metatarsal III, the proximal articular surface of the bone being of almost exactly the same extent as in the example of Felis concolor, while the shaft of the fossil bone is slenderer. The present species is differentiated from Nimravus and Hoplophoneus by the aggregate of the cranial and dental characters, mentioned above, although, as might be expected, not by each of these characters severally. From Dinictis its differentiation is not so clearly denoted ; yet in consideration of the low nasal region and the relatively high parietal region, the reduction in size of upper premolars 2 and 3, the reduction of the inner root of P* with loss of protocone and addition of a well-marked parastyle, I cannot consistently assign to it a place with Dimctis felina, D. cyclops, D. squalidens, and D. pau- cidens. Pogonodon alone of known genera seems open to its reception, and the species to which, on the whole, it shows the closest affinity is Merriam’s Pogonodon davist. From this it is specifically distinguished by its smaller size, relatively lower sagittal crest, more com- pressed form of superior canines,'? relatively greater diameter of the postorbital constriction, relatively lower and longer anterior zygomatic pedicle, and judging from Merriam’s illustration of the teeth, by the lesser prom- ** The canine alveoli of P. davisi, although they do not furnish an exact basis for comparison, indicate a considerably greater transverse diameter. Eaton—John Day Felide in Marsh Collection. 437 inence of the inner root of the P*. Yet so close to Pogonodon davisi is the present species, that the two must share the same fate, should Pogonodon in the final analysis fail of recognition as a distinct genus or sub-genus. Dinelurus crassus, gen. et sp. nov. (Fas. 4-6.) Holotype, Cat. No. 10518, Y. P. M. Upper Oligocene (upper John Day), Turtle Cove, John Day Valley, Oregon. Collected by Wm. Davis in 1875. ~ The type is a cranium without the mandible. It is well preserved, except that the posterior part of the sagittal crest and the contiguous parts of the lambdoid ridges have been destroyed and the postorbital process of the right frontal has suffered some abrasion. Hig.. 4. ot ee Fie. 4.—Dinelurus crassus, gen. et sp. nov. Holotype. « %. Dentition.—l?, Ct, P?, Mt. The teeth are worn to a degree that indicates middle age, but not to such extent as to involve any modification of the alveolar parapet. The incisors, in their present condition, closely resemble those of Nimravus. Of the right canine only the base of the crown remains protruding from the alveolus. The left canine too has been broken, and a little of the base of the crown is lacking, but its characteristic form is shown sufficiently well to differentiate it from Nimravus, Dimctis, Pogonodon, and Hoplophoneus. Briefly charac- 438 Haton—John Day Felide in Marsh Collection. terized, it is more truly feline than the canines of these genera, being more nearly elliptical in section through- out its length and less flattened on the inner surface. The maximum (antero-posterior) diameter of the canine at the alveolar margin is 15.5 mm. and the transverse ~ diameter 11 mm. Dividing the transverse diameter by the maximum diameter, and multiplying the quotient by 100, an index of 71 is obtained.. The corresponding indices of the superior canines of several well-known species of extinct Felide are as follows: Nimravus gomphodus 47, derived from Cope’s measurements; JN. debits 57; N. debilis major 56; Pogonodon platycopis 04; P..davist 52, derived from alveolar diameters; — Dimctis cyclops 64; D. felina 47. The diameters of the superior canine of Pseudelurus quadridentatus, at the level of the neck, given by Filhol,* transverse 8 mm. and antero-posterior 12.7 mm., yield an index of 71. In examples of three recent feline species I find the corre- sponding indices to be: Felis tugris 73; Felrs concolor 81; Cynelurus jubatus 79. The vertical length of the canine in the present species cannot be exactly determined because of its. imperfection. Its length, however, appears to have been about the same, relative to the length of the skull, as in Nomravus debilis, and relatively less than in N. gomphodus. Except in young adult animals the length of the canines is of course an unsatis- factory quantity. The anterior ridge of the tooth hes further back from the actual anterior margin than in Nimravus, and in this respect also the present species is further advanced and more cat-like. The posterior ridge is not continued along the neck of the tooth to the alveo- lar margin. This has much to do with the broad, ellipti- eal section of the neck of the tooth. There is no trace, on either side, of P? or its alveolus. For this reason two premolars only are postulated in the dental formula stated above. If in early adult life there was a P?, it can hardly have been other than exceedingly small and vestigial, as the shortness of the postcanine diastema, 9.5 mm. on one side and 10 mm. on the other, renders the presence of a P? of any considerable size highly improb- - able. The shortening of the posteanine diastema with reduction of P? to vestigial size would have practically the same significance as the shortening of the diastema 14. Filhol, Annales des Sciences Géologiques, 21, 76, 1891. Eaton—John Day Felide in Marsh Collection. 439 with total loss of P?; either condition would denote a variation from the more complete dentition of Nimravus. P? is a large tooth, its principal cusp being sub-equal in size to the paracone of Pt, as in Nimravus debilis. From the last named species it differs in having a slightly - greater transverse diameter of the crown relative to the antero-posterior diameter, and the inner division of the BYES 5: x \\ / YO AT fi “14; On, o— by = Efi ase * ae fei i By : yal”. WA i/ A e, =43 ©): . oe: - > Ves ois Pees se. aa Wee os Se Sk ee eas. oe mS cs ren ols RH “Uh SH oes Os oS =) S SS a iS Some) Sie 8 RE ORME eR RG Ei" o's 3 Ss =) ag tQ s . SS a Q S ~ J, D Q Q Qi AQ Q ef Se Sa oe gi PE SS 28 4h we we 8 2s oa S ue kG en oS = = BO gee as Go Sees So 4 Weiwe we Ge Se ne RS SS ia oS @. ip % SS : ONS f “~~ ; aS cS Sas fi SS ae, SS ee at te ee eer eeus resis ~ © “9 = Me b> % O. O b>" : : s : iS C Ss d= bs ee oo aon Ore Ge Os we we og BS ae ee picasa ee IA mabe tz Ole) a2 Be Soa ye sy: ww Ww DUDIQ Jo syuamaimsnaTT ‘V WIavVil 442 Haton—John Day Fede m Marsh Collection. m= ‘HN ‘WY ‘€869 ‘ON ‘od 44070 ‘adog snpoydwob snanwwua ‘oyeutxoiddy = v ‘UIBIp ‘suBsy ‘ours ‘dng ‘UIvIp “xe ‘ourued “dng eptped “siz yue zo yA Suery eprped “siz 4ue zo yystoTT yypvoig peyeped qsoq Ypverq Teyered -yuy Yysuel [eyepeg WOTZOLIYSUOD [e4Iq10JSOg Sessooord [eyiqtoysod zo -uerq YPveiq [B}Iq 1010, UT Sorvu juv JO Ypvorg JoyowVIp o1yeu0sdz1g Y}ouel [eixy Y}suel [ese “S}UOULIANSBOUL FO “SOU [VIIEC AAD HMO Or OD TABLE BS: Indices of Crania., Eaton—John Day Felide in Marsh Collection. 443 ‘Wd ‘A ‘8ISOT ‘ON ‘ed4q0f0H "Aou “ds yo “tas ‘snsspio snunjoury "Wd ‘A ‘0SS0T “ON ‘od4g0j07H7 “aou “ds ‘suapyniias wopouobog "JIpVO “Alu ‘681 “ON ‘edAjo[oH "Lloyy wiavp wopouobog "H N ‘W ‘V ‘869 ON “od4}070H ‘(ado ) sidoohizn)d wopouobog ‘addy pg 8, Apre'y “AproryT vuyas suo ‘HON WV 2118 ON ‘(edog) suapyonbs syowg "HON ‘WV ‘2869 ‘ON ‘od4y0[077 ‘adog sdojoha suo meu ‘W ‘d “A ‘9F00T “ON ‘ds snapiwiny ‘W ‘d “A “41S0T “ON *(edog) syrgqap snavwwin WA acd AP SPOOL “ON "(adop) syrqap snavimin ‘Wd “A ‘PP00T ON ‘(adon) siyiqap snapiwin "FTO “ATU “TS9T ‘ON “oddyoToH (Ilo) LOlDU SYLQAP SNADAUWAN ‘HON ‘WW.Y “0869 “ON ‘od4joj0H “(adog) syigqap snavswin "H (N “WV ‘6869 “ON “od4j0T0H ‘adog snpoydwob snaviwin (Heavy-face numerals refer to serial numbers in Table A.) SH fon) 85 82 76 78 74. HA (0 76 71 75 72 72 ) 3 x 100 1 Bizygomatie index ( 5 xX 100 Index of interorbital breadth ( — Ye) ia) 28 28 27 26 24 26 27 27 28 33 28 25 ) e100) 1 SO Gree all0/7, DOE Pa1G2. L4aSe SZ 0s lon 89 92 93 88 100 } 6 “tH 52 49 45 47 46 47 48 ) 9 x 100° i Index of palatal length e [e.e) oD 36 a7 ol 30 36 8 10 sx 100 8 Index of ant. palatal breadth ( 55 54 51 52 50 57 58 14 >< 100 Index of post. palatal breadth ( 71 52 54 47 57 56 59 53 54. 57 64 47 13 ) Diametral index of sup. canine ( 444 Haton—John Day Felide in Marsh Collection. Pogonodon davist 43 (approx.); P. platycops 31 (approx.); P. serrulidens 36 (approx.). From the follow- ing values of this index for Dimctis, it will be seen that only one species of this genus is known to have a relatively greater postorbital breadth than Dinelurus crassus: Dinictis cyclops 51; D. squalidens, No. 8777, A. M. .N. H., 35;—D. felma 34; Di fortis 31 (am illustration). The breadth of the anterior nares, relative to the basal length, when reduced to an index of 21, 1s also greater than in the other species with which it has been compared in Table B. Pogonodon platycopis with an anterior narial index of 19 approaches the present species most closely in this character, but this index has been computed for only a few type skulls. The breadth of the postorbi- tal constriction, which may in like manner be expressed by the index 25, separates the present species from Nimravus, but not from all the species of Dinictis and Pogonodon, Dinctis cyclops having a corresponding index of 27 and Pogonodon serrulidens of 25 (approx.), while the highest value in Nomravus is an index of 21 for N. debilis. The bimastoid diameter is relatively ereater than in Nimravus gomphodus, N. debilis, Pogonodon platycopis, P. serrulidens, and Dunctis squali- dens (No: 8777, A. M. N. H.), but shghtly less than m Dinctis cyclops and D. felina. With regard to the bicondylar diameter, the series of type skulls, on which. this measurement has been taken, is too limited to admit of any definite statement about the generic value of the bicondylar index. in conformity with the remarkable breadth of the fore part of the skull, the palate also is broader than in the alhed genera with which comparison has been made. This is especially noticeable in the posterior palatal breadth as expressed by the transverse measurement between the inner roots of the upper ecarnassials. In the present species the index derived from this measure- ment and the palatal length is 72, which greatly exceeds the corresponding indices computed for Nimravus debilis, N. debilis major, Pogonodon davisi, P. platycopis, P. serrulidens, and Dimictis cyclops. The species that approaches nearest in this respect is Namravus debilis major with an index of 59. The three species of Pogono- don and Dinctis cyclops fall short of this last value. Eaton—John Day Felide in Marsh Collection. 445 For the other species of Dinictis this index has not been computed, but, judging from published illustrations none of them appear materially to exceed D. cyclops in the rela- tive posterior palatal breadth. The entire posterior por- tions of the maxille, including the zygomatic processes, are exceedingly massive, and the palatine processes of the maxiule, instead of forming thin, sharp-edged orbital floors, as in the examples of Nimravus, Pogonodon, and Dinictis that I have examined, are thick and rounded posteriorly. The palatal vault is much deeper than in Nimravus. This is caused, not by a more pronounced arching of the palatines and the palatine processes of the maxille, but entirely by the greater vertical depth of the alveolar processes which form the sides of the vault. 3 \ .: ty sere \) WAN \\\ \\ y 1 Mati \\\ 1 | it : i {iat Veedt MIT Wee yi) 4 4 ws, 17) 9 Wie Wiis J YL, fh i ( ZL; < si \N NAS \ WN) YW. Sh it F E ZEEE WN iN \ \\ \ . \\\ AN Fig. 11.—Nimravus debilis (Cope). Cat. No. 10045, Y. P.M. x %. of NV. debilis and N. debilis major than with N. gompho- dus; and the same may be said with reference to the height index of the anterior zygomatic pedicle. The fourth skull, No. 10046, Y. P. M. (fig. 12), whose Measurements and indices are given under the genus Nimravus, is much smaller than the three last enumer- ated, being in fact even smaller than the type of N. debilis. The superior canines are relatively longer than in that type, yet their measured diameters are almost exactly equal to those of NV. debilis. The posteanine diastemata are short; and in the reduction of the premolar teeth, as well as in the slight development of the infracar- nassial exostoses, this specimen differs from the type of 452 Haton—John Day Felide in Marsh Collection. N. debilis. Viewed in profile, the anterior surface of the mandible appears to rise more nearly at a right angle with the horizontal ramus than in the types of N. debilis and N. gomphodus; and this squarely truncated appear- ance of the mandible is increased by the development of a prominent mental rugosity. Labels accompanying this skull show that, at one time, it was provisionally identified as NV. gomphodus, at another time as N. debilis. On the whole its indices point to a closer affinity with N. debilis than with N. gomphodus. The skull of Cope’s BIG, Fig. 12.—Nimravus sp. Cat. No. 10046, Y. P.M. x. N. confertus is but little smaller than No. 10046; but as N. confertus is represented only by a very imperfect mandible, a satisfactory comparison of the specimens is impossible. There is, however, a remarkable simi- larity in the form of their mandibular symphyses. In each the symphysis is very short horizontally and extends but little to the rear of the posterior margins of the lower canine teeth. “No. 10046 is supposed to have been found in the middle John Day. Hubbard—Antimony Mines of Shiu Chow. 453 Aur. XXXVIL—The Antimony Mines of Shiu Chow, China; by Grorce D. Hupparp. Introduction.—Shiu Chow is a walled city in the north- ern lobe of Kwangtung province, where the boundary between the two provinees of Hunan and Kiangsi comes south to their more famous neighbor, Kwangtung. It is about 30 miles from the Kwangtung border both west, northwest, and north, where the latter curves around in the midst of rather mature but little used mountains. It stands at a fork in the Pei Kiang, or North River, which has opened up a valley leading south to Canton and Hongkong. A railroad has also been constructed from Canton northward as far as Shiu Chow in its reach to connect with Changsha and Hankow. Topography. —Shiu Chow has grown up in fuer aphy: a little more mature than that along the provincial border west and north, but not nearly so “old as that which has been partly submerged to make the great fingered and island-spattered Canton bay, into which both Pei kang and Si Kiang or West River flow. Stratigraphy—The rocks of the region are very deeply weathered Paleozoic limestones, sandstones, and shales, probably ranging in age from Ordovician to Carbon- iferous inclusive. The strata have been elevated in rather closely pressed folds whose trend is practically north and south, or perhaps north-northeast and south-south- west. While in many places within a few miles east and south the rocks dip more gently, all about the mines they dip very steeply, usually over 80°. Strikes observed at several points range from N 10° EK to N 20° EH. One can get strikes of very diverse angles in this region, but those departing far from the above are local. The trend of the big limestone ridges very nearly north and south is quite systematic. Beginning some 5 or 6 miles north of Shiu Chow and just west of the mines (fig. 1), the rocks crossed im a sec- tion eastward for a mile or more do not seem to repeat at all. Provisionally, the massive, dark blue, calcite-veined limestone, west of or above the mines, has been called the Ordovician. The evidence is both in its position with 454. Hubbard—Antimony Mines of Shu Chow. reference to the succeeding beds to the east, including the coal, and in its fossil content. 2. ieee pete fe ed) aS iw: by NS Bo Z Eater sale g Messe gh es Oy Re SC TG AE acinar Se eine aos tee “Mle, GMC ete ake time re RSL B EAC wal ihe — AO FOOTE, Fe ty ee Dts seach SS BS tac mts OLD LCDR G0 =— Se wee SS a <== SS = =o rey pd SS ey = I — = = a pu oS == = J} SSS SE — aes Rie “* BOI OF ny —— A 450 ———S TS tee) te Tree ter Peers: Dele eds Gihe7 artis mich eiyeohe ce, Cae ry LAR = ele, Oe NO mir = OB me wee, ort ee = =— —= 2 | ee = —— — === = => — DOE Ee Ye te? * eet % 2° tists ae = —— IT, oo - ae ANS ain —— ——- = = — a ———s == =. OF Dy es Sar iedicer i AL tars fy Str A ae “ss me oes aime mel gue ele. Ree aK i Ot ee rete Fic. 1—Geologic map, Shiu Chow to antimony mines. though no species are identified. I saw none of the big cephalopods so commonly found in the Ordovician in other parts of China, but learn from Chinese observers Hubbard—Antimony Mines of Shiu Chow. — 455 that they occur near here. (Exact location and horizons unknown.) This big limestone makes a rather rugged ridge of very uneven height, yet continuous southward to the west branch of the river-and several miles beyond. A shale bed, probably as thick as the limestone, follows the latter and, is sueceeded by a quartzitic hmestone. The shales give low, open country, but the quartzite makes a small ridge. Next comes a thick series of shales of many colors,—blues, greens, reds, and browns. Some beds of this series are a little more resistant than others, but none of them are strong enough to hold up ridges. Farther east than the shales and about a mile from the blue limestone is another ridge-maker, parallel with the first. Its beds are thinner and mostly gray, not blue, and not as dark as the former, but violently contorted and plicated. It has a few veins of calcite, but no such development as the other limestone has. No fossils were seen in any of these series except in the western limestone, but no search could be made because of lack of time. Structure.—Coal is reported a short distance east of this second limestone and is mined 6 or 7 miles down- stream, which would probably be not more than 5000 feet east, stratigraphically, of the contorted limestone. In the vicinity of the coal, the dips in shales and sand- stones are 8S. E. by E. and not strong, while in the lme- stones and quartzites above Shiu Chow, nearly everything is about on end. Time did not permit scouting to the west to ascertain certainly, but the structure has the appearance of a great anticline, the east half of which is two miles or more across. The rocks in the west part of the sections would then be the oldest seen, and the coal and associated rocks the youngest. The most probable interpretation for the ages of the rocks, then, is that the western or dark blue is, as suggested, Ordovician; the lower shales may be Silurian; the quartzites and upper shales then would follow as Devonian; and the contorted limestone may be Mississippian, with Coal Measures above or on eastward. Ores.—F or several years, in the stream beds leading down eastward from the older limestones, the peasants have been picking up pieces of stibnite and more or less oxidized masses of antimony ore. In the summer of 1920, 456 Hubbard—Antimony Mines of Shiu Chow. Mr. 8. P. Chen became interested in this locality and began digging to find the ore in place. Several prospect pits and a shaft 25 feet deep were made. Ore was found in most of them in float, and still more was found in the stream beds, especially after rainy seasons. Finally, when prospecting had shown the more favorable course to pursue, a horizontal tunnel was directed straight into the hill from a point well up, but believed to be safely below the source of the ores. Before this tunnel was extended 100 feet, it struck the stibnite body in, the lime- stone. The ore body is at least 3 or 4 feet thick, seems to be nearly perpendicular, though it probably dips with the rocks, hence 80° to 85° eastward. The distribution of the float ore indicates that the vein of ore runs more or less continuously along the top of the - limestone beds and below the shales. This contact seems especially favorable for ore deposition. The author sug- gests that the deposits may have been put in place as a vein before the folding occurred, or in part a replacement accumulation in the limestone, and that the less pervious beds of the shales above may have prevented the waters | from rising higher and thus localized the deposition of the ore. No igneous rock could be found in the vicinity, and inquiry of the operator and others brought the uni- versal testimony, ‘‘No granite; all limestone, shale and sandstone.’’ In the impregnated lmestone occur oceca- sional little clusters of tiny pyrite crystals. Toward the top, the vein is weathered, and the weathered products of stibnite occur. The only primary ore is this sulphide of antimony; the weathered ores are rarely stained more than a tint, confirming the belief m the absence of pyrite. - Some 12 to 13 miles south to southwest of these works, the float ore has also been found and followed up by the same exploiter, but so far, no primary deposits have “been found. These finds are along the same limestone beds, but 7 or 8 miles south of Shiu Chow. In its intimate associatrons, the ore varies from almost pure stibnite to stibnite and calcite gangue with only small per cents of the sulphide. ‘The mixed ore is very pretty, for the calcite is coarse-grained, crystalline, and nearly clear, and is thrust through in every direction by the prismatic crystals of shiny metallic stibnite. The best stibnite ore runs about 65% antimony. Pure stib- Hubbard—Antimony Mines of Shiu Chow. 457 nite, Sb.S,, carries 71.4% of metal. The black, less crystalline ore runs about 50%, but those rich in the gangue calcite can be worked down to 30% antimony. The oxide ores, mostly stibiconite, produce 50 to 55% antimony, not a very pure ore. About 33 miles north by northwest from Shiu Chow are small native workings for antimony ore in float and in stream beds. Some of this is practically pure stibnite. It is brought to Shiu Chow to be smelted. Mining and Transportation—All the work in this whole region is carried on by the simple, laborious, native methods. Ore and dirt are moved in baskets on carrying poles or carried in the hands. Hoisting is done with a hand windlass. ‘Tools, too, are quite crude and inefficient. The ore is carried over a tortuous path, usually paved with limestone slabs or with irregular quartzite blocks, five miles, from the mines to the smelter at Shiu Chow. About 100 men were digging and picking at the time of my visit, and nearly 200 carriers were tramping along the road. Probably 2/3 of the porters were women. Strong men carry a picul or 100 catties (about 130 pounds). Most of the carriers are content with 60 or 80 eatties and make three trips a day. They get the muni- ficent sum of 25 cents a picul. Thus these hard workers obtain from 45 to 75 Chinese cents a day, and walk 20 to 30 miles, loaded one way. The operator, Mr. Chen, leases these lands at a fixed sum per year, with no royalty. Then he hires all the help he can use, and mines as much ore as possible. The Smelter—The same man owns and runs the simple smelter in Shiu Chow. It contains two brick reverbera- tory furnaces, fed by hand and fired with wood, because ‘“wood seems just as good and is cheaper than coal or charcoal.’’ The metal is drawn out at the side from the floor of the furnace, and the sulphur goes up the stack with the smoke. The plan of the furnaces is shown in the accompanying drawings. (Figs. 2, 3,4.) When drawing time comes, the antimony is run into molds of two kinds. One is small and oblong and holds only 25-30 pounds, and the other is about 8 or 10 times as large. These mould- ings or ingots of antimony are sold both in America and in England. The smaller ones are considered essentially Am. Jour. Sc1.—FirTa SERIES, Vou. 1V, No. 24.—DEcEMBER, 1922, 30 458 Hubbard—Antimony Mines of Shiu Chow Pigs. 2-4. Fig. 2.—Front elevation of antimony furnace used at Shiu Chow to reduce stibnite ores. Fie. 3.—Section, front-back, through ore side of furnace. Fig. 4.—Horizontal section through furnace about two inches above grates. -Oblique hatched part is made of bricks and mortar; cross hatched — doors. Seale, 1” = about 4’. a—stack; b—chute to draw off metallic antimony; c—mold for ingots of antimony; d—fire door; ¢—ore door; f—grates; g—air draft; h—ashes. Hubbard—Antimony Mines of Shiu Chow. 459 pure antimony; the larger ones are called ‘‘erude anti- mony.’’ Antimony m Other Parts—China seems wonderfully well supphed with antimony. Her mines near Changsha have been known for years. Here two great bodies of ore are worked. One is 150 miles west and the other about 80 miles northwest. They may have been on the same strike, but this connection seems not to be sub- stantiated. The ore is in hmestone and is extensively Le. Oy Fie. 5—Masses of ore. On right, one piece of solid stibnite; large piece next to it = antimony oxide, stibiconite; large piece on left, dark blue limestone with calcite veins and 5% of stibnite; the four remaining pieces are from a vein of ore and consist of white calcite penetrated with long erystals of brilliant stibnite. worked. The deposits to the northwest are a real vein 5 inches to 2 feet thick, having definite contacts with the limestone. Work has been in progress here 20 years, and the shafts are now 200 to 300 feet deep. The body is a nearly perpendicular sheet, and the stibnite is of very good quality. It has a weathered zone of antimony oxides, as has the Shiu Chow vein. The other deposit west of Changsha is not a vein proper. Much float is collected, and the mines are in a limestone more or less impregnated with stibnite. No igneous rock is known near either deposit. Antimony production is reported from several other provinces. Arranged in order of output, they stand as 460 Hubbard—Antimony Mines of Shiw Chow. follows:—Hunan, Anhwei, Hupeh, Kwangsi, Kwangtung, Szechuan, and Yunnan. Of these seven provinces, Hunan is far in the lead, and the Tze Kiang or Su Ho valley is the richest area known on earth. The deposits extend from Yi Yang in the north close to the south side of Tung Ting Lake to Paoking, 150 miles upstream or southwest. Hunan, Anhwei, and Hupeh constitute an antimony petrographic province with less characteristic extensions south into Kwangtung and southwest into Kwangsi. Smelters are reported from Chihtsun in Yun- nan and Samshui in Kwangtung, besides at Changsha and Shiu Chow as noted above. ~ Oberlin College, Oberlin, Ohio. Raymond—Trilobite Retaanng Color-Markings. 461 Arr. XXXVIII.—A Trilobite retaining Color-Markings; by Percy IK. Raymonp. It has often been questioned, whether trilobites shared the brilhant coloring of some of the modern Crustacea, or whether they in hfe exhibited the rather dull and drab appearance which characterizes most of thei fossil remains. This problem still remains unsolved, but a small pygidium which I collected from the Cambrian of Chero- kee County, Alabama, in 1921, shows a distinct banding, indicating that in some eases, at least, the body was not of a uniform color. The pygidium mentioned is 9.5 mm. long and 16 mm. broad, and lies upon the surface of one of the siliceous fragments into which the shales of that locality weather. The banding is not very conspicuous, in fact, the specimen was examined several times before I became assured that it was not of accidental origin. The surface is covered by transverse stripes of lght and dark gray, the latter almost black. At the anterior margin is a narrow heht band, followed by the broadest one of all, quite dark in tone. The two remaining pairs of dark bands are much narrower, the last almost in line with a continuation of the dorsal furrows. The first two pairs cross the axial lobe, but as all turn backward they have a somewhat radial effect. In addition to the bands, there are many small, irregularly placed spots of a yellowish hue. These markings probably do not retain the original colors, which may well have been brillant. It is interest- ing to note that the pattern is such that the animal would not easily have been detected if viewed from above were the surface of the water gently agitated, and also suggests patches or shadows of sea weeds. This trilobite seems in fact to have been protectively colored, although it lived at a time before the advent of jaw-bearing fishes or cephalopods and could have had few if any active enemies. The specimen is unique, not only as the only trilobite yet found showing a color pattern, but also as being the most ancient fossil so marked, the next oldest 462 Raymond—Trulobite Retaining Color-Markings. being a little gastropod, Holopea harpa (Hudson), described by the writer from the Chazy.! IT am not sufficiently familiar with the colors of recent crustaceans to make any extensive comparisons, but it appears that those of the deep sea are often brightly colored, but without markings, those inhabiting caverns and other dark places are very pale to dead white, whereas those in the shallow photic waters are of many colors, and often mottled, banded, striped and shaded. iG 1s — Fie. 1—A pygidium of Anomocare vittata, retaiming color-mark- HR, « SK Be } Pelagic crustacea usually have pigmentless tests, and owe their brilliant colorations to chromatophores, cireu- lating fluids, or the structure of their shell. The present specimen, as was to be expected, falls in with the group in the shallow waters. 3 The shells of the branchiopods and copepods do not commonly contain pigments but among the amphipods and isopods are to be seen some patterns which are simi- lar to the one on this trilobite. Dela Valle in particular has published colored figures of Amphipods? showing strongly contrasted transverse bands of pink, alternating with yellow, white, or green. According to Newbigin,? red lpochromes are the dominant pigments in the Crustacea. Where the shell is thin, red and pink prevail, as in the deep sea crus- taceans. When much lime is present in the shell an orange tint is often produced. This being the case. and = MheoNautiluss toss ps Ode 06s *Gammarini del Golfo di Napoli, 18938, pls. 3-6. * Colour in Nature, London, 1898, p. 128. Raymond—Trilobite Retaining Color-Markings. 4638 the tests of many trilobites being rather thick and eal- careous, it may be possible to predict various shades of orange in their coloration. With an appropriate organic base the red lipocrome apparently produces a_ blue compound, which with the yellow and red produces green and brown. With the aid of these general: principles and applying previously gained knowledge of the prob- able habits of any particular form, it may be possible to approximate somewhat reasonably to the actual appearance of one of these animals in nature. Trilobites usually possess colors which are obviously considerably influenced by the nature of the sediment in which they are imbedded, and since carbon and its compounds or oxides of iron are the most common color- ing agents in the rocks, the specimens are usually from rusty brown through dark gray to black. A_ light- colored limestone would seem to be the most favorable matrix for the preservation of original colors, for in this case there would probably be only loss of pigment, with- out much chance of substitution except where reerystalli- zation has taken place. A number of light-colored lhmestones yield fossils, and I have always felt that there’ must be some significance in the fact that the trilobites of the Maquoketa of Iowa, the Upper Ordovician ot southern Ohio and Indiana, and the Lower Ordovician of the Ladoga region east of Petrograd were all of about the same color. On the best preserved specimens from which the matrix has been chiseled away the color is a rich chocolate-brown, whereas the ones which have weathered out naturally are usually much lighter, rang- ing toward yellow or cream-colored. It seems entirely possible that both red and yellow pigments may have entered into the composition of the original coloring matter of these specimens. The fact that all the trilo- bites of these localities, whatever the family, show the same chromatic characteristics may indicate one of three things; that the color is really in some way due to the composition of the matrix; or, that only the basie colors have left traces; or, that the Ordovician trilobites were rather uniformly colored and exhibited only shades of the primitive red which is dominant among: crustaceans at the present time. Trilobites from the light-colored lime- stone of the Silurian of Indiana, England, and Bohemia, 464 Raymond—Trilobite Retaining Color-Markings. and other examples which could be cited from Ordovician and Devonian, also show the chocolate tints, so that it seems hardly possible that the constitution of the matrix has anything to do with it. There is practically no literature on this question of coloration in the trilobites, but henceforth specimens will probably be scrutinized more closely, and it is hoped more evidence will be produced. Banding of the clean eut sort exhibited by this individual seems not to be especially common among modern Crustacea and one would expect that shadings of one color, mottling, and splashes would be more common among the trilobites. The identification of this individual with any described species has not been possible, and it may therefore bear the name of Anomocare vittata sp. nov. Waleott* has described Anomocare convexa as a com- mon fossil from the Conasauga formation in north- eastern Alabama. This pygidium can not be referred to that species because it has a narrower axial lobe which extends as a very low ridge almost to the posterior border. ‘The axial lobe shows very faintly a pair of rings, and the pleural lobes a pair of ribs which are so inconspicuous that they are not put on the figure. The specimen was collected by the writer from the Conasauga shale near Moshat’s Cross-roads, 3 miles southeast of Center, Cherokee Co., Ala., during the Shaler Memorial Expedition of 1921. Museum of Comparative Zoology, Cambridge, Mass. “Smithson. Miscl. Colls. vol. 57, p. 87, 1911. Hayasaka—Richthofema m Japan. 465 Art. XXXIX.—On the Occurrence of Richthofena in Japan; by Icutrd Hayasaka. ‘The eastern, or Pacific half of the northernmost part of the main Island of Japan, the area between the strait of Tsugaru and the Bay of Sendai, is called Kitakami mountainiand. The southern part of this plateau-like land has for a very long time been known to yield many interesting and important fossils of Paleozoic as well as of Mesozoic ages. The famous locality of Triassic ammonites, described first by Mojsisovies and later by Diener, called Inai, is situated in the southernmost part of the mountainland; Pseudomonotis occurs at several localities a little north of Imai. Many other animal fossils, as well as land-plants, are found a little further north. These Mesozoic formations rest unconformably upon the abraded surface of a complex of black clay slate, with sandy clay slate and limestone, that together com- pose the younger Paleozoic system of the region under consideration. The Paleozoic rocks also are at certain places very rich in fossils, and several of the latter have been described by Yabe and by myself. The Paleozoic of southern Kitakami yields, besides a few species of Fusulina, several forms of brachiopods and corals. Of the former, Lyttonia was described by Yabe' in 1900, and more recently by myself? in 1917. In addition, I have described several other species of brachiopods, and the paper is now ready for publication. Yabe and myself* have described several-species of corals, and a part of this has been published in a preliminary form. Another species worthy of notice is Amblysiphon- ella*, which was formally recorded as Steinmanna by Yabe.° In general, brachiopods are associated with Fusulina, but corals do not occur with either of them as a rule, *Yabe: The Brachiopod Lyttonia, ete., Jour. Geol. Soc. Tokyo, No. 79. * Hayasaka: On the Brachiopod Genus Lyttonia, ete., Ibid., No. 288. * Palaeozoic Corals from Japan, etc., Ibid., vol. 22. *Hayasaka: Amblysiphonella from Japan and China, Sci. Rep. Tohoku Imp. Univ., vol. 5, No. 1, 1918. °Yabe: Materials for a Knowledge of the Anthrac. Fauna of Japan, Jour. Geol. Soc. Tokyo, No. 104, 1902. 466 Hayasaka—Richthofema im Japan. though there are a few corals in the Fusulina limestone. The geological and stratigraphical relations between the latter and the coral limestone are now being studied. The above summarizes our knowledge of the pale- ontology of Kitakami mountainland. In this paper I intend to report the occurrence of Richthofenia, an asso- ciate of Lyttonia and Amblysiphonella at several localities Ries oi _ Fic. 1—An oblique section of a Richthofenia from Japan; 3 times nat. size. in other countries. My material of Richthofenia consists of only one piece of black limestone in which a fragment of the fossil is buried. This was presented to me by Uyemura of the Imperial Geological Survey, in the summer of 1915. By eutting this piece of limestone IL got an oblique section of Richthofenia, which is shown by fig. 1. Its specific determination is not possible owing to the fragmentary condition of the specimen. Figure 1 shows a thin section cut obliquely through Hayasaka—Richthofena in Japan. 467 the body chamber (cavita ventrale of Di-Stefano)® of a conically elongated ventral valve. The dark substance oceupying the median elliptical area is the matrix filling the chamber. The wall directly surrounding it is the innermost layer of the shell, and is composed of a fine lamellar tissue with silky lustre. This inner shell layer is remarkably well represented in the illustrations of Waagen* and Di-Stefano. The median shell layer is composed of small vesicular dissepiments arranged vertically. Waagen calls this layer ‘‘the median cystose shell layer,’’ while Di-Stefano names it ‘‘struttra cellu- losa dello strato media.’’ Bose® describes it as follows: ‘‘Tt is formed by a network of cells which are constituted in the lower part of the apex region by nearly hemispheri- eal cysts, while on the side of the animal chamber these :cells are more irregular, their bottoms being directed obliquely towards above and towards the out- side.’’ In the present specimen, this median layer is only partly exhibited. The outermost shell layer is almost entirely broken away, although there remains a very small fragment, showing its former existence. The shell is penetrated by numerous canals which are said to pass into hollow spines projecting upon the exte- rior surface of the shell. Inside the visceral chamber these canals open into cireular pits, each of which is lying on a wart. Such warts give rise to longitudinal ridges that gradually become indistinct, or fade away down- wards. Sucha feature is very well shown by Waagen in one of his plates (fig. 7, pl. 83), while it is indicated in the present thin section by the cut edges of warts and ridges. Just below the lower portion of the cut edge of the body chamber, something like an axial region of a tetra- coral is exhibited. It is a section of a part of the so- ealled ‘‘eavitaé miofora’”’ of Di-Stefano, but is not, as it first appears to be, that of the lower, tabulated portion of the visceral cavity, since further below the median cystose layer is once more shown, this time in a nearly transverse section. Vertical septa are also very indis- tinctly seen. °Di-Stefano: Le Richthofenia dei Caleari, ete. Palaeontogr. Italia, vol. 20, 1914. *Waagen: Productus-limestone Fossils, Brachiopoda. 1885. *Bose: Contributions to the Knowledge of Richthofenia, ete. Bull. Univ. Texas, No. 55, 1916. 468 Hayasaka—Richthofenia im Japan. On the whole, the section cuts through a Richthofenia obliquely from the upper part of the opposite side of the hinge line to a little below the hinge line. It was only by chance that I was able to prepare such a thin section from the limestone piece. Distribution of the Genus.—Richthofenia attracts attention not only because of its peculiar form and shell structure, but also because of its wide geographic distribu- tion as contrasted with its limited time range. So far as I know, the genus has been discovered in the following places: 1 Palermo Sie typi: te ee ce ee ee Palaeo-dyas. 2. Carnie Alps.*° 3. Ammer a ost oe cee eee Permian. 4.-Salt mance. india «eke eee Permian. ). Lo-ping, prov. Kiang-hsi, Chinat® ...Upper Permian. 6. Semenow Mountains, Nan-shan'* ....Permian. 7. Sutschan, near Wladiwostok’® ...... Schwagerina stage. 8. Kobama, prov. Rikuzen (Kitakami TMOLUN OMIM VCANINAVCL eens, Asmat ay Sn hon Lower Permian. 9. Texas (Gaudalupe Mountains, etc.)*®. Permian. Geological Age.—As to the geological age of the genus, we must conclude, from what has been given in the above list, that it 1s an important index fossil of the Permian, although the detailed range in the Permian is as yet to be determined. Detailed examination of all the species described may throw some light upon the specific differences and stratigraphical positions. Institute of Geology and Paleontology, Tohoku Imperial University, Sendai, Japan. °Gemmellaro: La fauna dei caleari con Fusulina della valle del fiumo Sosio (after Frech, Lethaea palaeozoica). Schellwien: Die Fauna des karn. Fusulinenkalks, I. Palaeontogr., 39, 1892. 1 Stoyanow: On Some Permian Brachiopods of Armenia, Mém. Com. Géol., Nouv. ser., 111, 1915. ® Waagen: op. cit. 18 Kayser: Oberearb. Fauna von Loping, Richthofen’s China, vol. IV, 1883. 14 Schellwien: Palaeozoische u. ‘Triadische Fossilien aus Ost-Asien, Futterer’s Dureh Asien, III. 1% Tschernyschew: Die oberearb. Brachiopoden des Ural u. des Timan, 10, (hail ** Girty: The Guadalupian Fauna, 1908. Bose: op. cit. W yckoff—Crystal Structure of Ammonium Chloride. 469 Arr. XL.—On the Crystal Structure of Ammonium Chloride; by RaupH W. G. Wycxkorr. Introduction —Crystals of ammonium chloride are of interest because their symmetry as previously deter- mined by the conventional methods of face development and etch figure formation are completely at variance with the symmetry of the arrangement of their atoms as found from studies of crystal structure using X-rays. Studies of face development and of etch figures that seem fairly definite both agree in assigning crystals of ammonium chloride to the enantiomorphic hemihedral (plagihedral) class of cubic symmetry.t X-ray powder measurements? (and a single spectrometric observation) ,* on the other hand, have been interpreted as yielding a structure which is possessed of hemimorphic hemihedral (tetrahedral) cubic symmetry. On the basis of space- group reasoning it has also been shown that the powder data are such as to seem to preclude the possibility of any atomic arrangement possessing enantiomorphic symmetry being in agreement with them.+ In view of the importance of the conclusion which must be drawn from these conflicting observations, both for crystal structure study and for crystallography itself, it has been considered desirable to study Laue photographs of ammonium chloride to see if the greater number of data which they can furnish will be in agreement with the powder measurements. Laue Photographic Data for Ammonium Chloride°— Clear optically isotropic erystals in the form of rectangu- lar prisms several millimeters on one side and usually from one to two millimeters thick were obtained by desic- cating a solution of ammonium chloride containing urea. A measurement of the refractive index of one of these crystals for the purpose of insuring their purity was *See P. Groth, Chemische Krystallographie, Vol. I, p. 182 (1906) for references. *G. Bartlett and I. Langmuir, J. Am. Chem. Soe. 43, 84, 1921. ?W. H. and W. L. Bragg, X-rays and Crystal Structure, p. 110 (London, es ok W. G. Wyckoff, this Journal, 3, 177, 1922. > Some of these experimental data were collected in the Gates Chemical Laboratory of the California Institute of Technology. 470 Wyckoff—Crystal Structure of Ammonium Chloride. made by H. EK. Merwin, to whom the writer wishes to express his sincere gratitude not only for this determin- ation but also for discussions of the crystallographic HiGS als FicurE 1. A Laue photograph of ammonium chloride produced by passing the X-rays in a direction roughly normal to a cube face. aspects of this problem. He says: ‘‘The refractive index of ammonium chloride crystals grown from solu- tion with urea was the same as that of the pure salt used for the solution, 1.639+0.001. This is lower than Grailich’s rough value usually quoted. Contamination Wyckof—Crystal Structure of Ammonium Chloride. 471 by urea would presumably lower the index about 0.001 for each per cent.’’ Passage of a beam of X-rays in a direction roughly normal to a cube (100) face of several of these crystals yielded a series of very beautiful Laue photographs. A reproduction of one of these is given in figure 1; the FIGURE 2. A gnomonie projection of a Laue photograph of ammonium chloride which had very nearly the orientation of the photograph of Figure 1. With the aid of Table I (which refers to the photograph of Figure 2) and an enlargement of this projection it is possible to reconstruct the original data. enomonic projection of a photograph having an orienta- tion very close to that of figure 1 is shown in figure 2. With the aid of these two figures and the plate distances of typical spots which have been recorded in Table I, it is possible to reproduce approximately the original data found upon this second photograph. From the powder photographic data® the length of °G. Bartlett and I. Langmuir, op. cit. 472 Wyckof—Crystal Structure of Ammonium Chloride. the side of the unit cube which would contain a single chemical molecule of NH,Cl was found to be 3.859A.U. This information is of course all that is required to cal- culate the value of nA, where x is the order of the reflec- tion and 2 is the wave length of the reflected X-rays, for each spot upon the Laue photographs. If this is done and if the true unit cube were a larger one contain- ing not one but eight chemical molecules within it, then Taste I. Typical Laue Photographic Data (for application to Figure 2). Indices Distance from Kstimated Wave Length Central Spot Intensity (n 2) Zou 2.35¢em | 0.450A.U. Poa 2.32 a 445 951 2.65 0.5 40 431 2.62 il 065 13 I Del 2 573 031 2.87 10 .650 931 3.75 6 .650 some reflections should be found with a value of. nA less than 0.24, which is the smallest wave length in the X-ray beam employed in these experiments. On none of the photographs, one of which was given an exposure from four to five times as long as usual in order to bring out faint reflections, were any spots found having such a low value of nA; the Laue photographic data are thus in agreement with the powder data in assigning one chemical molecule to the correct unit cell for this form of ammonium chloride crystals. The approximate inten- sity calculations, carried out in the usual manner,’ are readily shown to be in accord with the only structure containing one molecule within the unit which the theory of space-groups indicates as possible. There can conse- quently be no legitimate doubt of the correctness of the usual structure assigned to ammonium chloride. In this structure the atoms have the following positions: Nitrogen atoms: 444. Chlorine atoms: 000. Hydrogen atoms: uuu; uu; tua; uti, where the value of u is not determinable. The arrangement is shown in Figure 3. ™Ralph W. G. Wyckoff, this Journal, 50, 317, 1920. Wyckof—Crystal Structure of Ammonium Chloride. 473 Conclusions —The conclusions which were given previ- ously can now be stated in even more definite terms.® If the hydrogen atoms of ammonium chloride have an arrangement which conforms to the symmetry of the erystal as a whole, then this symmetry must be hemi- morphic hemihedral (tetrahedral) ; if, as is perhaps con- eeivable, the hydrogen atoms have a more or less hap- PiGaeo: @N @H FiGuRE 3. The unit cube of ammonium ehloride. hazard distribution about the nitrogen atoms, its symmetry will be holohedral. In no case, however, can the symmetry of the arrangement of the atoms of this erystal agree with the enantiomorphic hemihedry which ‘studies of both face development and etch figures assign to it. If these crystallographic data are correct, it will therefore be necessary to conclude that such studies even when carried out under ideal conditions to yield the maximum amount of data conceivable can not always indicate the symmetry of the arrangement of the atoms within a crystal. This conclusion is not only of significance to crystallog- eur, cko is Journal, 3, 3 * Ralph W. G. Wyckoff, this J l, 3, 177, 1922 Am, Jour. Sct.—FirtH Series, Vou. IV, No. 24.—DrEcEemBER, 1922. 31 474. Wyckoff—Crystal Structure of Ammonium Chloride. raphy itself but it is of the greatest import to students of crystal structure. By making uncertain a choice of the appropriate class of symmetry in advance of X-ray studies, it considerably lengthens the problem of crystal structure determination. The difficulties of crystallographic description in the case of crystals to which different symmetry characteris- tics are assigned by different methods of study have recently been emphasized.? It has been suggested that such crystals should be especially segregated into a group by themselves and that a complete description of their symmetry will include both a statement of the symmetry of the crystal as obtained by such ‘‘physical’’? methods as a study of the electrical or optical properties or the X-ray diffraction effects and a statement of the ‘‘latent’’ symmetry which is supposed to be made evident by the ‘‘chemical’’ means of etch figures and growth forms. The creation of this additional classification is not satisfactory if only for the reason that the concept of ‘‘latent’’ symmetry is not precise. The symmetry of a erystal as deduced by the various ‘‘chemical’’? means is different in many instances not only for these various methods but it may even be different for the same method ~ earried out under changed external conditions. Thus the symmetry deduced from the face development upon scheelite (for face development must be reckoned among the ‘‘chemical’’ means of symmetry determination) is hemihedral though the etch figures that have been obtained are strictly holohedral’®; or in the case of dolomite etch figures have been produced which show sometimes holohedral't and sometimes hemihedral?? characters. From the point of view of those students of erystal structure who have felt the force of the diffi- culties into which such cases as this one of ammonium chloride have led them, the symmetry characteristics which have here been called ‘‘latent’’ are probably deter- mined not by the symmetry of the crystal itself but rather by certain properties inherent in the constituent atoms. Etch figures, face development and the lke are therefore ' to be considered as essentially surface phenomena, and ®°H. T. Wherry, this Journal, 4, 237, 1922. 70H. Traube, Zeitsch, f. Kryst. 30, 398, 1899. 1 'P, Gaubert, Bull. Soc. franc. de Min., 24, 326, 1901. 22, Koller, Neues Jahrb. Min. Beil. Bel., 42, 488, 1919. Wyckoff—Crystal Structure of Ammonium Chloride. 475 the internal symmetry of the crystal itself is only one of a number of important factors which bear upon the nature of these surface phenomena." For the crystal analyst, at least, the formal part of these difficulties must, however, be met by a greater preci- sion in the definition of what is meant by the symmetry of a crystal. Symmetry, from this point of view, can only mean that of the arrangement of the constituent parts (the atoms) of which a crystal is composed. This case of ammonium chloride seems to require that both the crystal analyst and the crystallographer must make a considerable revision in their estimate of the value of the usual crystallographic information relating to the symmetry of a crystal, and it is therefore worth while to reemphasize the desirability of a repetition of the purely crystallographic study of ammonium chloride. SUMMARY. It is shown that the Laue photographic data obtained from crystals of the low temperature form of ammonium chloride are in agreement with the powder data in assign- ing to it a structure containing one chemical molecule within the unit cube. The consequences introduced by the disagreement between the symmetry of this uniquely determined structure and the symmetry as obtained bv ordinary crystallographic means are discussed. It is pointed out that it is not permissible to accept etch figure data and face development as definite indications of the symmetry of the arrangement of the atoms within a crystal. | Geophysical Laboratory, Carnegie Institution of Washington, Washington, D. C. October, 1922. * Tt would seem that Wherry’s views (op. cit.) are in accord with these, but it is not at all clear from his discussion that such is the ease, 476 Wells—Alleged Variable Composition of Art. XLI—The Alleged Variable Composition of Triple Chlorides Contaning Silver and Gold; by Horace L. WELLS. [Contribution from the Sheffield Chemical Laboratory of Yale University.] A few months ago I made! a re-investigation of - Pollard’s ammonium-silver-auric chloride? and showed that this salt has the formula (NH,),Ag,Au,Cl,, instead of the shghtly differing one, (NH,),A¢,Au,Cl,,, aseribed to it by Pollard. There was no indication, however, from the results of either of us, that this compound has a variable composition. Soon afterwards I described? the salt Cs,AgAuCl, as one of five analogous triple chlorides, the others of which contained zinc, mercury, copper, and aurous gold in place of the silver of the first one (Cs,Zn- Au,Cl,, ete.), these compounds, also, were undoubtedly of constant composition when free from isomorphous and other impurities. It is much to be regretted that when these salts were described I was unaware that Professor Emich and his associates, of Graz, Austria, had previously published results of investigations upon triple halides containing silver and gold. Emich published* a preliminary commu- nication upon a new microchemical reaction for gold, silver and rubidium (and cesium), based upon the formation of magnificent blood-red crystals when solu- tions of the three chlorides (in the case of rubidium) are evaporated upon the microscopic object-glass. These tests are evidently very excellent and useful ones. My thanks are due to Professor Emich for a very courteous letter, together with reprints of the articles published by himself and his associates, calling my attention to their priority in work with triple halides containing silver and gold. ‘This priority is, of course, acknowledged, but it may be observed that only one salt, the one to which I have ascribed the formula Cs,AgAuCl,, has been analyzed both by me and by them, and that they *This Journal, 3, 257, 1922. > Jour. Chem. Soc., 117, 99, 1920. ° This Journal, 3, 315, 1922. * Monatsh. f. Chem., 39, 775, 1918. Triple Chlorides Containing Silver and Gold. 477 arrived at a variable composition for it, very far from the correct one. EK. Bayer® made a further and very satisfactory study of Emich’s microchemical tests, including the application of cesium chloride for the purpose, and he attempted to determine the composition of the two products containing rubidium and cesium. After making six analyses of the rubidium salt he came to the conclusion that it had the formula Rb,Ag,Au,Cl,,. This result is very interesting, as this formula corresponds exactly to mine for Pollard’s ammonium compound, and, since the two things appear to correspond closely in the color and form of their erystals, it seems very probable that this formula is the correct one. However, after obtaining astonishingly variable results with the cesium salt, Bayer made two more analyses of the rubidium compound, using products only slightly freed from the liquid by suction on the filter paper, and consequently contaminated to a greater extent than usual with the mother-liquors which were rich in rubidium chloride. He says that this was done because it was only the proportion of silver to gold that he wished to fnd. He thus obtained slightly varying results and concluded that the rubidium salt also was a variable compound. The following table gives his results, where the last two analyses represent the more impure products: Caleulated for Bayer’s Analyses Rb,Ag,Au;Cl,; Spee O60) 21.3) 82 15.~,20.6-., 26:8... 26.9) 26.4. 28.8. 28:2 ae tt. 22 12.2. 12.0, OFS lees lee ee Does 9.76.2 10:8 re ye 301304 390%, 305, 30.7, 309, 311. . 30.7 elo i, 1 31S, 35, 313, 319, 31.8 From these results, considering the difficulty of purify- ing such small crystals, and the nature of the last two products, there can be no doubt that the compound has a constant composition and that this is probably repre- sented by the given formula. Moreover, the formula Rb,(Ag, or Au,)Cl,, which Bayer gives to the salt to make it analogous to his results with the cesium com- pound, agrees very poorly with the analyses, as can be ° Monatsh. f. Chem., 41, 230, 1920. 478 Wells—Alleged Variable Composition of seen by referring to Bayer’s article, where the atomic ratios are given. Bayer gives no less than 14 analyses of the cesium salt, the results of which vary widely, particularly in the percentages of silver and gold, and in no instance do they correspond to my formula for the compound. The variations may be shown as follows: Calulated for Bayer’s extreme Cs,AgAuCl, results Cs, 33.90 34,1—35.7 Ag, 13.77 3.9—10.9 Au, 25.17 27.6—32.2 Cl, 27.16 27. 4—28.2 The most reasonable explanation of Bayer’s results is that he analyzed mixtures, and it appears to be absolutely certain that his products were such from his statement® that the crystals of the cesium compound showed different colors, varying from black, through violet, to dark brown, since the salt, as prepared and analyzed by me, was entirely and absolutely black, even in the finest state of division. From the wide variations in the percentages of silver it appears that Bayer’s mixtures contained a constituent that was free from that metal, and the double salt Cs;Au,Cl,,, recently described’ by me, is the probable impurity, as it is very slightly soluble in strong hydro- chloric acid containing a rather large amount of cesium chloride, so that it would be expected to be deposited with the black triple salt under the conditions employed by Bayer, where gold and cesium were in excess over the silver required for the formation of the black compound, and where strong hydrochloric acid was employed as the solvent. The following calculations have been made to find how well Bayer’s results agree with the mixture that has been mentioned, the proportions of the two salts being based upon the percentage of silver: * Loc, cit., p. 241. “This Journal, 3, 414, 1922. Triple Chlorides Containing Silver and Gold. 479 o—. a" Caleulated for Caleulated for Bayer’s black triple salt, dark red double salt, analysis § —~Caileulated A Boy: with for Cs,AgAuCl, Cs;Au;Cl,, highest silver 0.8A + 0.2B Cs, 33.90 37.90 34.1 BAe ee. oh 77 es 10.9 11.0 Au, INE Soni, NERS 26.9 Cl, 27.16 28.33 27.6 214 Another Caleulated Another Caleulated Another Calculated analysis for 0.73A analysis for 0.6A analysis for 0.544 by Bayer -+0.27B by Bayer -+0.4B by Bayer -+0.46B Cs, 34.9 30.0 34.6 39.00 30.0 30.74 Ag, 9.92 10.0 827 8.26 TAT 7 AA PAU ey) 27.9 29.3 28.61 29.6 29.13 Ci ta 2 Dhl 20.63 239 ZielO Another Caleulated Another Calculated Analysis by Calulated analysis for0.5A analysis for0.4A Bayer with for 0.28A by Bayer -10.5B by Bayer -10.6B least silver -+0.72B fe 853 359 354 36.30 Be GES he 699 6.9 5.55 «45.51 8.90 3.86 Mr 29.9 095 PUL bees: BD Oe 35-386 Ge oe 07:7 Bn 20 27.23 28.00 Such calculations have been made for all of Bayer’s 14 analyses, but only half of them are given here. These have not been chosen on account of giving better agree- ments than the others, for the results of the comparisons are very uniform, but they have been selected to show the comparisons in connection with variations in the percentages of silver. The agreements of the calculations with the analyses are remarkably good in all cases, as the greatest differences are 1.2% of cesium and 0.84% of gold. There seems to be no doubt, therefore, that the two salts under consideration were the chief constituents of Bayer’s mixtures. It is to be noticed, however, that in all cases the analyses show less cesium and more gold than the calculated quantities, whereas variations in the opposite directions would be expected on account of con- tamination of the products with mother-liquors rich in cesium chloride. Therefore it is necessary to assume that the products contained a third constituent, in fairly 480 Wells—Alleged Variable Composition of constant proportion, containing less cesium and more gold than the dark red double salt Cs,Au,Cl,,. The sparingly soluble, yellow double salt CsAuCl,, into which the red one is instantly converted by the action of water, with the loss of cesium chloride by its going into solution, fulfills the requirement in its composition. It is easy to explain the presence of moderate and fairly constant amounts. of this yellow salt in Bayer’s products in connection with his method of removing mother-liquor from his crops of erystals by suction, presumably with moist air, for IL have found that when some of the minute, brilliant crystals of the-red salt were placed upon a perfectly clean, dry watch-glass in a closed vessel containing air in contact with water, for a few hours at room temperature, the crystals were changed to droplets of liquid containing clusters of minute crystals of the yellow salt. The deliquescent character and consequent decom- position of the red double salt, therefore, explains perfectly the presence of the yellow compound in all of Bayer’s analyzed products. ‘The proportion of this salt necessary to bring the calculations into perfectly satisfactory agreement with the analyses is from about 2% to about 10% of the whole mixture. One per cent of it in the place of the same amount of the red salt increases the gold to the extent of 0.08% and decreases the cesium about 0.10%. Two calculations are given below where the presence of 5 and 10% of the yellow salt is assumed: Cs Ag Au Cl Caleulated for Cs,AgAuCl, (A) 33.90° 13.77 9 25.17 992786 Caleulated for Cs,;Au,;Cl,, (B) 37.90 es BOntT | GAGs Calculated for CsAuCl, (CO). 28.15. . ae ATS One of Bayer’s analyses, - 34.8 8.00- 2970 27.8 Calculated for 0.617A-+0.383B, 35.43 8.50 28.46 27.61 Cale. for 0.617A+0.333B-+-0.05C, 34.94 6.50 28.86] Zia Another analysis by Bayer, 350) 747. 29.6 21:85 Calculated for 0.54A-+0.46B, 30.14 LAL. 29.15 aie Cale. for 0.54A-+0.36B-L0.10C, 34.76 144. 29.93 - Ated In the first of these two calculations very close agree- ments with the analysis are obtained by assuming 5% Triple Chlorides Containing Silver and Gold. 481 of the yellow salt, while in the second one, with 10%, the result gives lower cesium and higher gold than the analysis, as would be expected from actual mixtures, slightly contaminated. Similar caleulations, based upon three constituents, give very satisfactory agreements with the rest of the analyses made by Bayer, so that it seems to be absolutely certain that his preparations were mixtures of the three things. The very consistent results that have been obtained here from calculations with Dr. Bayer’s analyses show that the latter were undoubtedly very accurate ones, and that he deserves much credit for his analytical skill and reliability. His failure to get.a pure triple salt with cesium may be attributed to the fact that the red double salt had not been described at the time that he made the investigation. Dr. Bayer’s conclusion that his results indicated the existence of a variable triple salt in which 3Ag¢Cl and AuCl, mutually replaced each other in their combination with CsCl, was hardly in accord with prevailing chemical views, but it was very astonishing and important if true. His application of the same idea to the rubidium triple chloride which had given him analyses satisfactorily agreeing with a definite, constant formula appears to have been entirely unwar ranted. Immediately following Bayer’s paper, eng teeer Emich published® an interesting theoretical discussion in favor of the supposed variable triple chlorides, but he presented no new facts in regard to them. Somewhat later, E. Suschnig gave® an account of an investigation on the triple bromide of rubidium, silver and gold and the corresponding cesium ‘compound. From four analyses of each of the salts he came to the conclusion that they were variable, and that they cor- responded to Bayer’s formula (certainly uncorrect) for the chlorides. From analogy it seems safe to say that Suschnig also analyzed mixtures, but since these bromides have not been investigated by any one else, it is impossible to decide what the mixtures were. * Monatsh. f. Chem., 41, 249, 1920. ° Monatsh. f. Chem., 42, 399, 1921. 482 W ells—Composition of Triple Chlorides. SUMMARY. The conclusion has been reached from a consideration of Bayer’s statements and from calculations made in connection with his analyses that the triple salt Cs,Ag- AuCl, is a definite, invariable compound, and that Bayer analyzed mixtures of this salt with Cs,Au.Cl,, and CsAuCl,. It has been concluded also, from Bayer’s own analyses, that the rubidium salt is also invariable and has the formula Rb,Ag,Au,Cl,, corresponding to that of Pollard’s ammonium salt. Finally it has been concluded from analogy that Suschnig’s confirmation with the bromides of Bayer’s incorrect theory in regard to the © chlorides must also be wrong. New Haven, Conn., September, 1922. Russell—Great. Triassic Fault. 483 Arr. XLIL—The Structural and Stratigraphic Relations of the Great Triassic Fault of Southern Connecticut ; by Wiiuiam L. Russet. GENERAL GroLtocic RELATIONS AND SUMMARY. The area studied extends from Lighthouse Point, on New Haven Harbor, to the vicinity of Durham, and is over 15 miles in length and several miles broad. The general geologic relations of this tract are quite simple. The Triassic rocks of the Newark series form an east- ward dipping homocline, cut off on its eastern border by the Great Fault, where the Triassic rocks abut against the crystallines. The sedimentary rocks are of consider- able thickness, and contain three intercalated lava flows,—the lower, main and upper sheets. Normal faults, which tend to repeat the strata, are of frequent occurrence. The main conclusion of the present paper is in strong support of the hypothesis of Prof. Joseph Barrell' that the depression in which the Triassic rocks of Southern Connecticut were laid down was produced by intermit- tent movement along an eastern fault plane during the course of sedimentation. The evidence for this conclu- sion is two-fold. In the first place, fanglomerates, com- posed of huge, angular bowlders, occur at various hori- zons in the Newark series close to the fault plane, and gerade abruptly into finer sediments along the strike to the west. The second line of evidence is furnished by a large quartz lode that occurs along the eastern side of the fault zone. This lode appears to have been formed in pre-Triassic time, and therefore movement had taken place along the present fault zone even before the Triassic. Pebbles of this vein are found in several hori- zons in the Triassic, indicating that when the rocks in which they occur were laid down, faulting had already taken place, for the lode was formed along a fault that existed before its formation, and also proving that at that time the Triassic did not extend east of its present eastern boundary. Acknowledgment.—The field work upon the problem under discussion was carried on in the fall of 1921 and the 1 For references see the end of this article. 484 Russell—Relations of the Great spring of 1922. The present article is an abridgment of an essay submitted to Yale University for the degree of master of science. The writer is greatly indebted to Prof. C. R. Longwell and Prof. Adolph Knopf, of Yale University, for advice and criticism in preparing the report. GENERAL DESCRIPTION OF THE H'ORMATIONS. 1. The crystallines and altered crystallines——The rocks to the east and south-east of the great fault consist of granites, gneisses, and schists. Ata distance from the fault the granites near Lighthouse Point show little or no evidence of shearing or gneissic banding. Near the fault plane they frequently present a streaky appearance, due to the crushing and drawing out of the minerals by shear- ing. Under the microscope the normal granites may be seen to be subject to strong cataclastic deformation, but the sheared rocks are much more intensely deformed, _and some of them have been reduced to mylonites. The minerals have been crushed and granulated until they are mere lines, and sericite has been developed along shear planes and zones of microbrecciation. These sheared rocks and mylonites are found at intervals along the course of the fault. They were not observed at a distance from it, and the amount of shearing increases irregularly towards the fault plane. The sheared rocks are often cut by quartz veins which are not sheared. North of Branford, where these rocks are best exposed, the shear planes are nearly horizontal, or dip slightly towards the fault. 2. The quartz lode—One of the remarkable features of the region is the presence along the eastern edge of the fault plane of a quartz lode of considerable extent and size, which affords indications of the age of the fault, and the dip of the fault plane. In general this lode consists of white, bluish, or greenish quartz, cut by a network of veins of white, coarsely granular quartz. In addition there are occasionally cubical erystals of pyrite, and rarely fluorite. A composite sample of the lode con- tained $0.31 of gold to the ton. On its eastern border this vein in many places passes into the crystallines by a. eradual transition from the quartz of the lode to altered erystallines partly replaced by quartz, and finally to Triassic Fault of Southern Connecticut. 485 unreplaced granite. In other places the transition is of another type. As the fault plane is approached, a net- work of small quartz veins cutting the erystallines is encountered, which forms a larger and larger percentage ified I FANGLOMERATE ( TRIASSIC ) = OTHER TRIASSIC SEDIMENTARY ROCKS (CHIEFLY SANDSTONE AND SHALE. ) -EXTRUSIVE BASALT (TRIASSIC ) INTRUSIVE BASALT i eS. Ze Quonnipaug TT NN ey TA ET Tw ) Ee. 2S saa D jonmeens aaa = N awe iNet, West Pond CRYSTALLINE ROCKS ‘ ( PRE-TRIASSIC) OUTCROPS OF 7 LODE PRE<} TRIASSIC? ) Fault y aN 3 4 SCALE OF MILES LONG ISLAND SOUND Fic. 1.—Geologic map of the region of the Great Triassic Fault between Lighthouse Point and Durham, Conn. of the whole rock, until near the quartz lode the rock has the appearance of a breccia. The fragments of ecrystal- lines become more altered and silicified and less numer- ous towards the lode. Where the crystalline rocks 486 Russell—Relations of the Great contain abundant dark minerals, the lode is apt to have a bluish or greenish tinge, apparently derived from their alteration. -A thin section of this bluish portion shows remnants of unreplaced minerals. Besides angular altered inclusions of the crystalline rocks, the lode oeca- sionally contains small angular or rounded pebbles of quartz, produced by brecciation and grinding. This lode is apparently due chiefly to replacement, though parts of it may be actually fissure fillings. As shown by the map (fig. 1), it outcrops at nearly every point where the erystallines and the Triassic are found close together, and its largest exposure, north of Bran- ford, is over half a mile long, and averages over 150 feet wide, not including the slopes of quartz talus. Other outcrops, beyond a concealed stretch, indicate that it is probably over 3,500 feet long. 3. The fault zone and brecciation—Near the course of the Great Fault, and for some distance to the west of it, there are zones of shattered and crushed rocks. Bree- clas are of frequent occurrence, and there are zones of rounded basalt fragments embedded in crushed or quite firm basalt. Veins or dikes of sandstone and shale occur in the basalt, and sometimes reach a width of several feet. Large basalt blocks, sometimes hundreds of feet long, have been brought up by distributive faulting from lower horizons, and occur at intervals along the course of the fault. These features are a striking testimonial to the great movement and shattering that affected the region in post-Newark time. 4. The fanglomerates——For convenience in mapping, rocks largly composed of pebbles over three inches in diameter, some of which are somewhat angular, have been considered fanglomerates. These rocks are unlike any- thing else observed in the Triassic trough. They are composed of angular bowlders of various sizes, cemented by sandstone. In some places the bowlders are sharply angular, though usually the larger ones are somewhat rounded. The bowlders reach several feet in diameter in several places, and in one place the rock was chiefly composed of hugh bowlders of basalt, several reet in diameter, some of which are vesicular. Both the size and angularity of the bowlders increases quite rapidly towards the Great Fault, though in an irregular manner. The rock is quite variable, contains numerous finer Triassic Fault of Southern Connecticut. 487 lenses, and here and there gives place to a sandstone within a few feet of vertical distance. As shown by the accompanying map (fig. 1), the fan- glomerate never extends more than about half a mile from the fault plane. To the west it interfingers with the sandstones and conglomerates. Long lenses of the fanglomerate run out into the finer rocks. It outcrops at a number of different localities, some of which may have been originally continuous. The actual thickness of each mass is difficult to determine, two or three hun- iG. 2: LAKE SALTON- Se Fig. 2.—Generalized section from Beacon Hill to the South end of Pond Rock, showing the gradation from fanglomerate to shaie with increasing distance from the Great Fault. dred feet being the maximum thickness actually measured. The fanglomerate is found below the lower basalt flow, immediately below the main sheet, below the upper basalt flow, and above all the flows. The rocks close to the Great Fault are all concealed in the horizons much below the lowest trap sheet, and therefore there is no direct evidence as to whether or not fanglomerates exist in them or not. The rocks immediately above the main sheet are usually fine-grained even close to the Great Fault. The pebbles of the fanglomerate consist of all the erystalline rocks found to the east of the Great Fault, pegmatites, masses of vein quartz and feldspar several inches long, large bowlders of basalt, some of which are vasicular and highly angular, and pebbles of the quartz lode. Sometimes abundant pebbles of a rock are found in the fanglomerate, though there is no such rock in the vicinity on the crystalline side of the fault plane. This may mean that the rock once occurred east of the fault, 488 Russell—Relations of the Great but has been removed by erosion. The basalt bowlders were not found below the lower trap flow. They will be referred to later. The pebbles of the quartz lode were of its most characteristic type—whitish or bluish granular quartz traversed by a network of veins, and altered inclusions cemented by quartz—and some of them were angular and a foot in diameter. ‘They occur between the main and upper basalt flows, and above the upper basalt flow. Ere. 3 Pond i: Rock Lake ¢ 4 Saltonstall. at t L aS Li CRYSTALLINES a a Shoe wim : ee Z = — 5 SCALE OF MILES. ‘Fie. 3—Generalized section westwards from the neighborhood of the Branford Water Company’s Pond north of Branford. o. Lhe other sedimentary rocks——The sedimentary rocks west of the fault plane and the fanglomerates con- sist of conglomerate, sandstone, and shale in frequent alternation. The folds or warps enable one to follow the same horizon away from the fault, and when this is done it is found that the rocks in general become finer and finer for a mile or two away from the fault plane. In some places the gradation can be traced along the same horizon from a fanglomerate to a conglomerate, then to a sand- stone, and finally to a shale. These relations are shown in figs. 2, 3 and 4. THE LARGER FAULTS OF THE Triassic TROUGH. That the larger faults also have a general northeast- southwest strike is apparent at once from Davis’s map of the Connecticut Triassic. He considered that the fault separating Bluff Head and Pistapaug Mountain uplifted Triassic Fault of Southern Connecticut. 489 the strata on the north about 2,500 feet, and cites as proof of this the fact that the main sheet outcrops considerably eastwards to the north. Nevertheless, the strata to the north must have sunk, the amount of sinking increasing eastwards, for near Pistapaug Mountain the upper surface of the main sheet is brought close to the horizon of the lower basalt sheet, with the latter on the south, while near the Great Fault the upper and lower basalt sheets are brought nearly opposite each other, with the Fig. 4. is Peo €¢o ow eis os fo} 5a a oO ae i 3 a ae, : 7 se” Main Sheet / x UA 7 éM. pasictles — ae == Se REY i sheet ea ; : Fic. 4.—Section west-northwest through Pistapaug Mountain. lower sheet on the south. The former case corresponds to a throw of about 1,500 feet, the latter to a throw of about 2,500 feet. The displacement of the main sheet to the east on the north is not due to the fault, but to a warp or fold, like that between Pond Rock and Totoket Moun- tain. THEORETICAL CONSIDERATIONS: THE GREAT FAULT. The Dip of the Plane of the Great Fault. Davis? believed that the fault plane was nearly vertical, and cited as supporting evidence the fact that the outcrop does not advance to the west in the great anticlinal folds or warps. In another publication? he says that the fold- ing probably came before the faulting. If this is the case it is evident that the fault plane could not have been warped by it. However, it will be shown later that part of the movement probably took place before the warped sediments were laid down. Am. Jour. Sci.—FirtH Series, Vou. IV, No. 24.—DrcremBer, 1922 32 490 Russell—Relations of the Great The great half-saucer-like folds which give the out- crops of the basalt flows their crescentic outline are one of the most remarkable features of the structure of the region. They vary in diameter from about 1,000 feet, in the vicinity of North Guilford, to many miles. As they all have the same relations to the Great Fault, and all die out rapidly west of it, they appear to be.connected with its formation. Possibly they are due to unequal subsi- dence along the fault plane. If this were the case, there would be no tendency for the fault plane to advance to the west in the upwarps. A normal fault, such as the one under consideration, probably had some dip to the west at its origin, and this would probably be increased by the tilting of the region. The faults of the central portion ofthe Triassic dip both northwest and southeast, while those near the Great Fault, which are probably shear faults more or less parallel to it, dip only to the northwest, and dip steeper where the dip of the fault was not affected by the tilting. The occurrence of a precipitous eastern slope and a gentle western slope in the great outcrop of the quartz lode north of Branford, together with the apparent band- ing dipping west at about 30°, all point strongly to a west- ward dip of the fault plane. Moreover, in the actual exposure of the fault plane found by Davis at Highland Park the dip was 55° W. It is also reported that a well drilled in the Triassic near the fault penetrated the erys- tallines. For these reasons it is believed that the fault plane dips to the west at an angle of from 30° to 60°. THE RELATIVE DATES OF FAULTING AND SEDIMENTATION. The evidence of the Quartz Lode and the Fanglomerates. The fact that the quartz lode follows closely the out- crop of the Great Fault indicates that it was formed by solutions that travelled along its plane. The great size of the quartz lode along the fault; the total absence of anything resembling it in the Triassic; its general character and striking similarity to the oreat quartz mass at Lantern Hill, Connecticut, which is thought to have been formed by heated magmatic waters,* all render it probable that the quartz lode was also formed by heated magmatic waters, most nkely at the close of the Appala- chian Revolution. | Triassic Fault of Southern Connecticut. 491 The occurrence of pebbles of this quartz lode in the fan- glomerates between the main and upper trap sheets shows that by the time these fanglomerates were laid down three separate events must have taken place: first, there must have been movement along the fault plane; second, this fault plane must have been sealed by the formation of the quartz lode; third, there must have been further movement to bring the lode to the surface again. These bowlders also show that during the formation of these fanglomerates the Triassic did. not extend more than a few feet east-of the outcrop of the fault. If there were any previous Triassic deposits, they must have been already eroded away. The lowest horizon at which fanglomerates were found is Just below the lower basalt sheet. The bed rock of the _horizons below this is all concealed for considerable dis- tances from the fault, so that it is impossible to tell whether fanglomerates occur in them or not. They were found at various horizons from below the lower basalt sheet to well above the upper. In one place the upper flow dies out against the fanglomerate, indicating that the surface slope of the alluvial fan was probably several hundred feet per mile. The bowlders are of such great size and so angular that they could not have been trans- ported far. Therefore, their source in the crystallines must have been nearby, and the contact with the Triassic rocks must have been a fault at that time, for the Newark strata at that time were very thick immediately west of the fault, but did not exist close to the east of it. Tur Basaut BOWLDERS OF THE FANGLOMERATE. The occurrence of huge, angular bowlders of vesicular basalt in the fanglomerates tends to support the fore- going conclusions. These basalt fragments do not occur solely in or near the same horizons as the basalt flows as Davis believed they did. They are found in between them, and above them all. They might be supposed to have been derived from voleanoes in the hills or moun- tains east of the fault, or they may have been derived from basalt flows that had spread over on the east side of the fault, and then been uplifted. The bowlders are so huge and angular that it is difficult to see how they could have been carried far, and moreover their occurrence 4.92 Russell—Relations of the Great follows the fault plane. The flows are sometimes quite thick near the fault, and the scarp could not have remained a steep slope during the whole of Newark time. It seems probable, therefore, that the bowlders were derived from portions of basalt that were lifted up by the faulting. | POS = TRIASSIC| \ a THROW SW FOTAL THROW 16,000 FT.+ eee —— ss | TRIASSIC ; THROW . Fie. 5—Diagram to illustrate the discussion of the throw of the Great Fault. THe THROW OF THE GREAT FAULT. Any estimate of the throw of the Great Fault must be based on the thickness of the Triassic to the west. ‘There appears to be great uncertainty about the thickness of the lower sandstones. Davis estimated their thickness to be 5,000 to 6,000 feet. The wells drilled in the Triassic near its western border give a definite indication that these lower sandstones are thicker than this. The facts about these wells may be listed as follows: Triassic Fault of Southern Connecticut. 493 Distance expressed as a fraction of that from the erystallines on west to the out- Distance from erys- Depth tallines to west in Location in feet miles crop of the lower sheet Near Northampton.. 3.700 not over 2 or 3 not over 1/2 Winchester Arms Co. New Haven ..... 4,000 about 2 about 1/3 Near Cheshire, about 4,000 about 1-1/2 less than 1/2 None of these wells penetrated the ecrystallines. In view of these facts the thickness of the lower sandstones may be estimated at 8,000 feet or more. Their thickness in the Pomperaug Valley, about 15 miles to the west, is only 1,200 feet, which may indicate that they thicken to the east. The accompanying fig. 5 shows the various elements which enter into the estimation of the throw of the fault. The throw is the sum of the following values: The thickness of the lower sandstones....... 8,000 feet or more The thickness of the remainder of the Triassic ame TINA IIT OFS os. esas) EAE Res, UA RS 0,000 feet or more (The sum of these two is shown as HK on the diagram. The movement along the fault plane was AB). The thickness of possible Triassic sediments above the highest beds now exposed (Move- ment BC, Throw CUD es AREAGs Faas Spent 8 Marge Ere Unknown Thickness of upraised block worn down dur- ing Triassic to provide sediments for the Triassic strata (Movement CD, Throw MD) Probably at least several thousand feet; may have been greater than the whole thickness of the Triassic. Post-Triassic Faulting (Movement DE, Throw PE) The tilting of the sediments; the apparent appearance of lower and lower horizons of the metamorphie rocks in going west towards Derby; and the great shattering of the highest Triassic horizons exposed indicate that this was great. 4g4 Russell—Relations of the Great Possible throw before the New- Unknown. ark deposition (Movement ES, Throw RS) If part of the Newark strata accumulated a warped or folded depression, this would introduce a correction which should be subtracted from the sum of the foregoing values. However, as the quartz lode probably indicates . that there was faulting before the formation of the Newark strata, and as the fanglomerates and the pebbles of the quartz lode occurring in them show that faulting had begun again at least by the time when the trap sheets were extruded, and that the Triassic did not then extend ~ east of the outcrop of the fault plane, it seems unlikely that any appreciable part of the depression was produced by warping. Taking all the foregoing facts into ocneilen yaaa the minimum throw of the fault may be estimated at 16,000 feet. However, it may well have been 20,000 feet, and it is possible that it was as much as 30,000 feet. THE PROBLEM OF THE Cross FAULTS. Where the three great northeast-southwest faults of the Triassic intersect the Great Fault, the latter turns and runs along the cross fault in a northeast direction. As this happens three times it can hardly be a coincidence. Davis explained this by assuming that the cross fault brought down the sandstones which he thought existed east of the Great Fault.2 ™?* The relations as he imag- ined them are shown in fig. 6. There is definite field evidence for the faults AB, BC, CD and CF. (5 and 6) Davis believed that fault KB continued to the north to form BE, while CF continued to the south to form HC, though no field evidence for the existence of these faults is given. The cross faults, according to Davis, have a throw of about half a mile, and this he believed to be sufficient in each case to bring the base of the Triassic below the surface of block EBCF. Assuming that the base of the sandstones in this block was originally nearly on a level with the present surface of the upland, Davis estimates the depth of the lower sandstones on the eastern side of block EBCF to be about 1,600 feet in the case of the South Manchester Fault block, and 1,400 feet in the case of the South Glastonbury block. It would be Triassic Fault of Southern Connecticut. 495 qwte a coincidence if in the case of each one of the cross - faults the base of the Triassic were near enough to the present surface of the upland to be brought down below the level of the lowland by such small faults; and, as the South Manchester Block is over two miles wide, and the South Glastonbury Block is 4 or 5 miles wide, it is still more remarkable that the erystallines are not brought to the surface by the normal 10 to 15° dip of the Triassie. If, as has been shown previously, the Triassic did not extend east of the Great Fault, we must seek some other method of explaining the offsets. Three hypotheses may be considered: (1) The main fault may have been dis- WG. 6: Fic. 6.—Diagram to illustrate Davis’s theory of the cross faults. placed to the east on the north side of the offsets by great horizontal movement; (2) The apparent displacement may be caused by the w esterly dip of the fault plane; (3) The cross faults may have been lines of w eakness when the course of the great fault was determined, and where it met one of these lines of weakness it may have followed it for some distance before continuing its north- ward course. The first theory need not be considered further, for 496 Russell—Relations of the Great there is no evidence of such a tremendous horizontal displacement. The second theory would be reasonable, if it could be shown that the dip of the plane of the Great Fault were as small, or the throw of the cross faults as great, as is demanded. The throw of the Paug-Bluff Head fault is about 2,500 feet where it intersects the Great Fault, and possibly 3,000 feet further northeast, and the Great Fault seems to be offset between a mile and a half and two miles. A dip of the fault plane of 14° to 21° would be required -to produce this offset. This difficulty is more serious even farther north, where the offset seems to be several miles. The throws of these faults are given by Davis as about half a mile, and even if it be assumed that they increase to the northeast, an extraordinarily low dip of the fault plane must be assumed to account for the offset. The question might be settled by finding fanglomerates and the pre-Triassic quartz lode along the cross-faults where they bound the Triassic. Near Durham, where the portion of the fault examined ended, there was an outcrop of the fanglomerate and the quartz lode which were - apparently associated with the cross fault. This inter-- esting problem cannot be settled without further investi- gation, but the evidence seems to favor the third hypoth- esis. THE PHYSIOGRAPHY OF NEWARK TIME. During the deposition of the Newark sediments of the region periods of movement along the fault plane alter- nated with times of relative repose. This is shown by the fact that at some horizons fanglomerates occur near the fault plane, while at others fine shales and sandstones are found. The average rate at which the fault scarp rose above the plains to the west during Newark time was probably not rapid, perhaps something like one foot na thousand years. It is probable, therefore, that the scarp was at times reduced to a gentle slope. If the same hori- zon is followed till it intersects the fault plane in several places, it is sometimes found that fanglomerates are developed in the horizon at some of these places and not in others. The rivers may have caused this by building alluvial fans only where they issued on to the plains, or it may be due to unequal movement, of different portions of the fault. lA Triassic Fault of Southern Connecticut. 49% The topography of Newark time was, of course, quite different on the two sides of the fault. To the east there were the hills or mountains whose erosion suppled material for the strata near the fault. These mountains were bounded on the west by a scarp, the height and steepness of which varied from time to time. Bordering the scarp on the west was a belt of alluvial fans, the slopes of which were occasionally as high as several hundred feet a mile. Farther west were the flat, featureless plains, diversified only by occasional lakes or playas. Summary oF GroLocic History. Probably during the closing stages of the Appalachian Revolution, almost certainly by the middle of Newark time, movement began along the Great Fault. The erys- tallines along the fault plane were first sheared and crushed, and later they were partly replaced by a quartz lode, and the fissure was temporarily healed up. During this time the larger cross faults of the Triassic were probably either faults or zones of weakness. During Newark time the sediments accumulated in a depression formed by intermittent movement along the Great Fault. Alluvial fans were built into the plains to the west by streams draining from the fault block range formed at this time. Three or more lava flows were poured out, one of which at least thinned out against the fans. Por- tions of the flows that had spread over east of the Fault Plane were raised up and their fragments washed into the trough. After the deposition of the sediments, further movement took place along the great fault, and the sedi- ments were tilted, shattered, faulted, and, near the Great Fault, warped into saucer-like folds. List OF REFERENCES. 1. Joseph Barrell: Central Connecticut in the Geologic Past, Conn. State Geol. Survey, Bull. No. 23, 1915. 2. William Davis: The Triassic Formation of Connecticut, U. S. G. S., 18th Ann. Report, pt. II, p. 126, 1896-7. William Davis: The Eastern Boundary of the Connecticut Triassic, Geol. Soe. Am., Bull., Vol. 5, p. 526, 1894. G. F. Loughlin: The Gabbros and Associated Rocks at Preston, Con- necticut, U. 8. G.S., Bull. 492, p. 143, 1912. William Davis: The Triassic Formation of Connecticut. U. S. G. S., 18th Ann. Report, pt. II, p. 129, 1896-7. 6. William Davis: The Eastern Boundary of the Connecticut Triassic, Geol. Soc. Am., Bull. vol. 5, p. 528, 1894. ew Sete 498 | Scientific Intelligence. SCIENTIFIC INTELLIGENCE. I. Cuemistry anp Puysics. 1. The Presence of Cobalt and Nickel in. Vegetables — BERTRAND and Moxkragnatz have worked out a process for the quantitative determination of very minute amounts of these two metals in complex mixtures, and they have thus examined the ashes of twenty vegetables, selecting preferably the parts used as food, and including carrots, onions, potatoes, spinach, lettuce, the fleshy part of apricots, tomatoes, beans, several grains such as wheat, oats, buckwheat, maize, and a single fungus, the chantarelle. The amounts of the fresh substances employed for the analyses were one kilogram of the grains and two kilograms of the softer materials. The cobalt and nickel were obtained as potassium cobaltic nitrate and nickel dimethyl- slyoxime. The results were positive for nickel with all of the plants, while cobalt was found in all but two of them, the carrots and the oats. The amounts for a kilogram of fresh substance varied for cobalt from less than 1/200 milligram up to 0.8 mg. (in buckwheat), and for nickel from 0.01 mg. (tomatoes) to 2.0 mg. (peas). These results are interesting, since heretofore there have been but a few, perhaps uncertain, statements in regard to the presence of cobalt in the ashes of plants, and still less informa- tion concerning nickel. It as yet unknown whether the presence of these metals in vegetables is merely accidental, or whether they are a _ physiological requirement.—Comptes Rendus 173, 458, H. L. W. 2. Standard Methods of Chemical Analysis; by WitFRED W. Scorr. 8vo. Volume I. pp. 714; Volume II. pp. 616. New York, 1922 (D. Van Nostrand Company. Price $10 net).— This very important work of reference now appears as a revised and much enlarged third edition, which, on account of its size, has been divided into two volumes. On the title-page Mr. Scott designates himself as the editor of the work and gives a list of thirty-six principal collaborators, but by far the greater part of the book has been prepared by him. 7 The work is a very impressive one in furnishing a vast amount of reliable information in regard to analytical chemistry. The first volume takes up the elements in alphabetical order and discusses their detection, their separation from other elements, and the gravimetric, volumetric, and other methods for their estimation. This volume also gives an elaborate and excellent series of tables of useful data, including a very extensive one dealing with conversion-factors. The second volume deals app ncaa Chemistry and Physics. 499 particularly with technical analysis, for instance, the examina- tion of acids and alkalies, alloys, soaps, paints, coal, rubber, gases, waters, ete. It appears that all practical analytical chemists should find this work very useful. H. L. W. 3. Outlines of Theoretical Chemistry ; by FREDERICK H. GeTMAN. 8vo, pp. 625. New York, 1922 (John Wiley & Sons, Ine.). This is the third edition of this well-known text- book. Richthote tia em Japan, 465. Henrich, F., Chemistry, 414. Hober, R., Physikalische Chemie der Zelle, und der Gewebe, 499. erate in Norway, 165. Hubbard, G. D., colloids in geo- logic problems, 95; antimony mines of China, 453. ; Hunter, G. W., Civic Science, 91. Huntington, E., Earth and Sun, 503. Hylander, C. J., Mid-Devonian Cal- lixylon, 315. Hyrachyus, genus, and its groups, Troxell, 38. sub- I | Iron and steel, corrosion, 415. Japan, Richthofenia in, Hayasaka, 405. Johannsen, A., Microscopical de- termination of Minerals, 4109. Johnston, W. A., Sedimentation in Lake Louise, 376; imbricated structure in river-gravels, 387. K Knowlton, F. H., fossil dog-wood flower, 136. Kodym, O., Silurian of Bohemia, 53- L Lake Louise, sedimentation, John- ston, 376. Laue, photographs, Wyckoff, 192, 193, 469. Lewis, J. V., cyprine, Franklin, N. J 249. Life Tables, United States, Glover, QI. Lippmann, W., Public Opinion, 92. Living Things, Study of, Meier, 421. Long, E. T., faulting in Gaye Lake region, errata, 420. Longwell, C. R., structure of Tri- assic rocks in So. Connecticut, 223° Lull, R. S., primitive Pecora in the Yale Museum, IIT. M Macbride, T. H., Slime-moulds of North America, 87. Maquenne, L., Précis de Physiol- ogie Végétale, 87. Marsh Collection of Vertebrates, Troxell, 31,38, t11;, Eaton, 425- satis , si oben j abies 4 ' Index. Megadiastrophism, Chamberlin, 253. Meier, W. H. D., Study of Living Things, 421. Merrill, G. P., New Meteoric iron from Kentucky, 3209. Meteorite, iron, Kentucky, new, Merrill, 329; Tennessee, 420. Mineral Resources of the Philip- pines, 1919, 1920, 82. Minerals, Microscopical mination, Johannsen, 419. —-New Crystal Forms, Whitlock, 83. MINERALS. Andradite, New Jersey, 251. Babingtonite, Japan, 159. Busta- mite, New Jersey, 250. Cyprine, New Jersey, 240. Ilsemannite, new, 50. Polyadelphite, New Jersey, 251. Polyhalite, Texas, 84. Rhodonite, New Jersey, 250. Vesuvianite, New Jersey, 240. Zircon in igneous and_ sedi- mentary rocks, Armstrong, 391. Deter- Minnesota Devonian, Stauffer, 306. | Mohler, F. L., Origin of Spectra, 502. Monier-Williams, G. W., Power Alcohol, 76. Morey, G. W., Melting of potash | feldspar, I. Mount Everest, rocks of, 419. N New York State Museum, Seven-’' teenth report, 503. Nobel prizes, 1921 and 1922, 507. Noble, L. F., Paleozoic formations | of Grand Canyon, 419. Norway, Das Fengebiet in Tele- mark, Brogger, 80. s Noyes, A. A., Chemical Pee ies | 73- O OBITUARY. Bacot, A., 94. Bell, A. G., 252. Box. G: H:, 320. Howe, H. M., 94. Meigen Wes. - Kimball, A. I. 423. Mayor, A. G.,, Ranvier, L. re Ge Salisbury, R. D., 329. Sharp, D.,| 423. Simonds, Gy 04e smith, Paes. * Smith: Co. Mi sez. Sturley, A. A., 423. | | 51 “kchweaiey.- L.A; 507. Lrouton, BY. Aas: Wacnerm., GW... 15072 Vater house, J., 507. Wesley, W. H., 507. Wilson, R. W., 507. Observatory publications, 94. Ohio, Pottsville fauna, Morning- Star, 502. Outline of Science, Thompson, 88. Pp Pan-Pacific Commercial ence, 252: Parker, G. H., Smell, Taste, etc., the Vertebrates, 327. Pecora, primitive, in Museum, Lull, 111. Pennsylvania geol. survey, 83. Perner, J., Silurian of Bohemia, 53. Peruvian oil field, Zorritos forma- tion, Spieker, 417. Petroleum, Blum, 415. Probabilities, Mathematical ory, Fisher, 417. Public Opinion, Lippmann, 02. Confer- in the Yale The- Queensland Museum, memoirs, ot. R | Radium in Africa, 506. Raymond, P. E., markings, 461. River gravels, structure, Johnston, 387. “ROCKS. pes trilobite color- of Norway, Eskola, ne of Cape Neddick, Maine, Wandke, 2095. Intrusive, of Maine and New Hampshire, Wandke, 130. Mount Everest, 419. Sparagmite, Eocambrian, So. Norway, Holtedahl, 16s. Tillite-like conglomerate in So. Norway, Holtedahl, 165. Zircon as criterion of igneous metamorphics, 301. Round, E. M., ‘Crossotheca of Rhode Island Carboniferous, 131. Russell, E. J., Soil Conditions and Plant Growths, 88. Russell, W. L., great Triassic fault of So. Connecticut, 483. 512 Ss Science, Civic, in the Home, Hunter, and Whitman, OI. — Outline of, Thompson, 88. — Human Affairs, and Biology, Curtis 327° Scientific Tnstruments, Journal of, Scott W. W., Chemical Analysis, 408. Sea-Shore Biology, Walton, 328. Sea water, relation to ground water along coasts, Brown, 274. Shaw, J. B.; Vector Calculus, 5or. Flattely and Sherrill, M. S., Chemical Principles, | 73- Smith, A. L., British Lichens, 88. Smithsonian Institution, tions, 8o. Spectra, Origin, Foote and Mohler, 502. Spectrum of Aurora, 324. Strontium silicates, Eskola, 331. Stauffer, C. R., Minnesota Devo- nian, 306. 504. Svedberg, T., Formation of Col-|! loids, 490. Ah Tarr, W. S., Cone-in-cone, 190. Temperature, Spectral determina- tion, 500. . Thecodontia, Triassic reptilian order, von Huene, 22. Thompson, J. A., Outline of Sci-| ence, 88. Troxell, E. L., horned Eocene Ungulates,°31; Genus Hyrachyus and its sub-groups, 38. U United States geol. survey, 79, 507. | — Life Tables, Glover, or. publica- | | Wandke, Swedish Olenid beds, Westersard, | “Els: Pi Index. Ungulates, horned Davey Troxell, aT: Vv Verrill, A. E., Arctic Alcyonaria and Actinaria, 84. Vertebrates, Smell, Parker;-327. Virginia geol. survey, 83. Visher, S. S., Earth and Sun, effect on climate, 503. von Huene, F., Triassic reptilian order Thecodenaa 223 von Richter, V., Organic Chemis- chy, 74 ‘Paste; ete,, W | Walter, H. E., Genetics, 84. Walton, C: Vises Biology of the Sea- Shore, 328. A., intrusive rocks of Maine and New Hampshire, 139; Study of Cape Neddick gabbro, 205. |Watanabé, M., babingtonite from Japan, 150. L., discussion of triple Composition of triple silver and Salts, 27; chlorides containing gold, 476. | Westerfield, R. B., Banking, 9o. | Wherry, Be ES amphisymmetric ery stalss-237. | Whitman, W. G., Civic Science, 91. Women in Chemistry, 323. Woodruff, L. L., Biology, 421. Wyckoff, R. W. G., space group of a cubic crystal, 175; Structure of zinc bromate hexahydrate, 188; of sodium hydrogen acetate, 193; of ammonium chloride, ZOOLOGY. Aleyonaria and Actinaria, Arctic, Verrill, 84. — See BIOLOGY. ES a eee The American Journal of Science ESTABLISHED BY BENJAMIN SILLIMAN IN 1818. THE LEADING SCIENTIFIC JOURNAL IN THE UNITED STATES, Devoted to the Physical and Natural Sciences, with special refer- ence to Physics and Chemistry on the one hand, and to Geology and Mineralogy on the other. y Editor: EDWARD S. DANA. Associate Editors: Professors WILLIAM M. DAVIS and REGINALD A. Day. of Cambridge; Professors H. L. WELLS, C. SCHUCHERT, - H. EK. GrReGorY, W. R. CoE and F. E. BeacH, of New Haven: Professor EDWARD W. Berry, of Baltimore; Drs. FREDERICK L. RANSOME and WILLIAM Bowls, of Washington. Two volumes annually, in MONTHLY NUMBERS of about 80 pages each. 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Po yf aN # 2 : ee ‘s ; NRE is a Fa é A Cis ¥ Pa e Laeeae Pop arth tie, ff ena nee Ser eo E Tesh th aah Wick Tah, A UE OE Se See ae oi, < Be is jaar oe Gs i dee try bn Seg G0 areagthes Seiad EF eee Teen Beene etre hy mie Wea. iii A ott Load fe ey aN 7 awaits G si He ag Pa sy sca ee Ne Sars Fp we a fy ve \ BE MEL Te, ba 1 ! oH Ppp y ot at Y rte uniNcrom ee pasar a Nhl “aye dl 1) "WMA 3 9088 01298 6071