earning and Xabor. LIBRARY niversity of Illinois. BOOK. VOLUME. 30 ee ~ ) Az a : pea a Pee OD GEOLOGY LIBRARY Return this book on or before the Latest Date stamped below. ee Theft, mutilation, and underlining of books are reasons for disciplinary action and may result in dismissal from the University. University of Illinois Library OCT 0 A 10096 ; JAN 1 7)1008 L161— O-1096 re py a THE fee lCAN GROLOGIST A MONTHLY JOURNAL OF GEOLOGY AND ALLIED SCIENCES. Editor: N. H. WINCHELL, Minneapolis, Minn. ASSOCIATE EDITORS: FLORENCE Bascom, Bryn Mawr, Pa. CHARLES E. BEECHER, New Haven, Conn. SAMUEL CALVIN, Iowa City, Iowa. JOHN M. CLARKE, Albany, N. Y. ULYSSES S. GRANT, Evanston, III. HERMAN L. FAIRCHILD, Rochester,N. Y. OLIVER PERRY Hay, New York,N. Y. PERSIFOR FRAZER, Philadelphia, Pa. GEORGE P. MERRILL, Washington,D.C. WARREN UPHAM, St. Paul, Minn. ISRAEL C. WHITE, Mcrgantown, W. Va. HORACE V. WINCHELL, Butte, Mont. VOLUME XXX Juty To DEcemMBER, 1902 MINNEAPOLIS, MINN. THE GEOLOGICAL PUBLISHING Co. 1902 THE UNIVERSITY PRESS OF MINNESOTA. Digitized by the Internet Archive in 2010 with funding from University of Illinois Urbana-Champaign http://www.archive.org/details/panamericangeolo301902desm px & py BP? CONTENTS. JULY NUMBER. Tue Oricin oF Esxers. JW. O. Crosby.. Ne CSE ea ee I On THE DECEPTIVE FOSSILIZATION OF ere Bess Se AND on THE Genus Eurymya. F. W. Sardeson................ 39 HussaAkiTe, A New MINERAL, AND ITS RELATION TO XENOTIME. EROS 1 Md 2 re 46 Nore oN THE So-CaLLepD BASAL GRANITE OF THE YUKON VALLEY. ReMEMIITSOIIITICL SS. cc 'e soles cc p cck nah Phi w ho cte pce Sea eeb of tnew « 55. EpiTorrAL CoM MENT. “The Monthly American Journal of Gasloes and Natural pe Bereta ICI td Ee ceg tA a warts ek Rae 0.5 She wo wee 62 Review oF RECENT GEOLOGICAL LITERATURE: Summary Report of the Geological Survey Department for the calendar year 1901. Robert Bell, Director.....:.....1.. 64 Monturiy AutHor’s CATALOGUE OF AMERICAN GEOLOGICAL LiT- BRAIEURS 4 Lc Sera trtac Sree Bekele sane ie eet sine green aD ee 65 CoRRESPONDENCE. | Columbia University Summer School. H. W. Shimer...... 69: PERSONAL AND SCIENTIFIC News. memiexico school (of Mines. 2 ..6.6 5.0201 Ae ee dn J item el gon. Miller Centenaty.s. 5. ss scan fais sto do donor ees elated ma eMlenit. 11; ATUL GA s)-:. 2-5 scnssne viens ease Gielen Le AUGUST NUMBER. Two Cases or METAMORPHOSIS WITHOUT CRUSHING. B. K. Em- Bewarps “|LP Yano Cel Dee aes he ieee eee Le Rr Cnet en See ii 73 - ON THE CrINOID GENERA SAGENOCRINUS, FORBESIOCRINUS AND Soweenseiaeen, “orms, Frank. Springer... ..00 cc. ee vaseline | 8S - Notice or A New CoMATULA FROM THE FtoripaA’ Reers. Frank 4 LOT TE ing GRA AIR gn See Se iy ara 0 ange Re a ei Seay ¢ ee 08 _GroLocicat AcE or CerTAIn Gypsum Deposits. Charles R. Keyes, 99: ~ GRowTH oF THE Mississippr Detta. Warren Upham........... 103 it List oF THE Most IMporTANT VoLcANIc Eruptions AND EARTH- QUAKES IN WESTERN NICARAGUA WITHIN HistTortcAL TIME. AS CAGES DGG. a LER Rg A ae Be Be SR RA ete RON Oe OR Pee IIE IV Contents. EprrorIAL COMMENT. The Ore Deposits of Monte Cristo, Washington............ The: Sutton) ‘Mountains: ees eet. oe eee Review or Recent GEoLocicAL LITERATURE. United States Geological Survey, Twenty-first Annual Re- 0]9) ers eR mam hicns “1h mH ULES ORE Cite On Some Fossils from the Island of Formosa, and Riu-Kiu (Loo-Choo). FR. B. Newton and R. Holland.............. The Eparchean ‘Interval:. 4. C. Lawson... .:...<).2 eee Geological Survey of New Jersey, Annual Report for 1901. LP RUIN ET oii OR et Onc es he ee eee ie The Story of the Prairies, or the Landscape Geology of North Dakota, “DieE-SWallard... 2 00 0 oe An Introduction to Physical Geography. G. K. Gilbert and AP. BRNO ORR Se wk a hs LO ee Western Interior -Coal-Pield.. Al. FF. Bain... 2.250) eee MontHLty AuTHor’s CATALOGUE OF AMERICAN GEOLOGICAL Lit- ERATURE 2o 5% free ree aloe wie a shy ee CoRRESPONDENCE, . Richard, Burton "Rowe: °C. -S. Prosser... 4.24 eee PERSONAL AND SCIENTIFIC NEws. International ‘Congress of ‘Geologists: ..9. 7! at. 3.50 oe University \of-Texas ‘Mineral Survey: ......:2-.. seep Harvard University, Geological Department................ Prof... Angelo “Heilprine on “Mont. Pelée...<... . 5-2... Geological; Exeursions. “at Pittsbure:........:. 5. ..8 eee SEPTEMBER NUMBER. MAN IN THE Ice AcE AT LANSING, KANSAS, AND AT LiTTLE FALLS, Minnesota. Warren Upham. [Plate II and III.].......... THE TRAINING AND Work oF A Geotocist. C. R. Van Hise.... INFLUENCE OF CouNTRY-Rock oN MINERAL VEINS. W. H. Weed EpiTror1AL COMMENT. The Lansing’ Skeletons 2is.52 2. 2-00 = ire pete elaean oe ee Montuity AuvtHor’s CATALOGUE OF AMERICAN GEOLOGICAL LiT- ERATURE... .s..5..c:cepiaabaniomncaere Sadttnels eata Pike od oes CORRESPONDENCE. The New Madrid Earthquake. W. J. McGee...... eee PERSONAL AND SCIENTIFIC News. Wisconsin Geological and Natural History Survey.......... Columbia. University” (Nofes 92 .c'2). «1. 6.5 ee OCTOBER NUMBER. On Bacusirito oR THE GREAT METEORITE OF SINALOA, MEXICco. Henry A. Ward. "{Plate/TVewal |... 4.20 aes es Se 113 118 120 122 122 123 123 123 124 125 128. 130 130 131 132 132° 135. 150 170: 189: 194. 200° 202° 202 203: Contents. Lists or FossiIns FROM THE LowER HALF oF THE CONEMAUGH FORMATION NEAR MorcANTowNn, W. VA., CoLLEcTED IN 1870 By Dr. JouHn J. STEVENSON, AND IDENTIFIED By F. B. MEEK. IOC )WALT ee ne ona SSE ine Rae Pn ED cas SRE Se A Brier SumMMAry oF GLAcIER Work. A. C. Scott............ EprrorrAL COMMENT. Was the Development Theory Influenced by the “Vestiges of the Natural History of Creation?”...... SR ah denice yee Pe Review oF RECENT GEOLOGICAL LITERATURE. Pleistocene Geology of Western New York. H. L. Fairchild Montuity AvutHor’s CATALOGUE OF AMERICAN GeEoLocicaL Lirt- SPLASHES: 5 GORI 3 Se Rie es rene le PO pe ‘CORRESPONDENCE. A Carboniferous Coal in Arizona. E. T. Dumble.......... PERSONAL AND SCIENTIFIC News. ; Columbia University, Geological Department.............. Meme olicse of, Mines: ..... .s).2 00%. conve Wiaduon costae dower, cbacchisccr i tab coer acacel reeset 1 Evidence of existing glaciers and ice-Sheets......... 0. sscccessceccscnccuscccccccecceccsees 2 SOE MIMICS TOIICHKOUN sn adssee ace vodcbaptcevercssss tessstacba-chs tetsiicende Tooosse sea auslusecchicov ess 46 127 CLE scuce tchiacuectsd seria te Bont oat SAS Seg ane SRE ES ene coor ice) SER EOEeoE en CE BOR CORE aCE SESE 16 Sree PONIIIOM, ANG SUNUCLULE rcs cca cade. ocada: cose eaxssceccees otcs: sderessesse-atesuvucesecess 8 MATOLTADRICANG SCeOlOLIC TELATIONS®.. -occccessccccscorsescacsvessescctcavancocccccvesseses 8 Probable status of the ice-sheet during the formation of eskers.................. 9 Comparison of hypotheses...... .........ssseeeees Seinen rece meee ea entnect as seavece canal aeestr eres 17 sO eae GOERIS: poet ncrccansar ses ce oecbhccscanes ceded ance varaqe va wee cvccvenesentnetas vec 19 SHRSACIAL HYPOTHESIS... cccceccessssseses sence Haman essa e unten anontansecelaceuncscate, peresreesare 22 PUES ICRI OE rn ads y ccbpachisninasees spine satis dose sdeveacedwasc: coe seeder taence veces secesccscses cecse 24. MPS EICIEOLLCL OTIC Gls ERK OCNS save. cccecee'e screcntsdcossacncosinscsascascde cc sccesssesbasncae* sass 24 NeETeL OTCSKETS ‘ANG CSKEL SY SLOMS sc2.-c.scc:sc0ccsiceess cose scccsccsescceccocnvacseucs 26 Varying width of eskers.......... Pon anadcccccstipencoh neko tnwatcesesacuxiass su seecses seaneveesaree 28 Mee PR HIP E OL ESICCES co5)nnacectap-sbcorenosenasascsidsssvescase\ss. socuscces ssesseenee alesse 29 ATSC LORERECLS « sieca veneer adseassdapecasyssosasescs34) ‘forussresscniecteciednasts sban-wetde) des 30 VRPT TE CIC ALOE (CSRETB soa. s-casccs saacl «cscovcsens evnces evens: cseussesepeiacess,loseces 31 Topographic relations of eskers..............0065 « Sas lien copii snaechioaasatenesoeeapeesiieceres 32: Relations of eskers to the ground MOraine.........00:ccccesscare ecosecccccescccocsece 33 Relations of eskers: to frontal and delta plaink......:0.6.c, siececceosccecesascnscesece 35 Conponirion ann structure Of CSKETSs.i: (4) = 55 34° .55.30 | 55 22 55584 As already mentioned, the crystals are generally trans- jarent, especially when quite thin. When thick, translucent. ey *American Journal of Science, Nov., 1888, 36, 380-383. +Dana, System of Mineralogy, 1892, 748. tGroth, Tabellarische Uebersicht der Mineralien, 1898, 84. §E. Hussak, Tschermak’s Mittheilungen, 1891, 12, 457. °H. Gorceix, Compt. rend. 1886, 102, 1024. Hussakite—Kraus and Reitinger. or The crystals, which were measured, possess vitreous lustre ; those more or less rounded have a greasy or pearly lustre. The color is yellowish white, honey yellow, brown, or dark brown. Hardness=5. The specific gravity, determined by means of the hydro- static balance, was found to be 4.587 at 20°C. Perfect cleavage parallel to m (110). Fracture uneven; streak white to yellowish white. In a thin section, perpendicular to the c axis, hussakite shows in convergent polarized light a normal unaxial interfer- ence figure. The character of the double refraction is positive. From a transparent crystal about 1 cm. long and 0.5 cm. thick Voigt and Hochgesang of Gottingen ground a prism with the refracting edge parallel to the c axis. This prism was used to determine the indices of refraction for lithium, sodium, and thallium lights. The method employed was that of minimum deviation. The results are as follows: Ww e e-w Lithium light 1.7166 1.8113 0.0947 Sodium ” 1.7207 1.8155 0.0948 Thallium 1.7244 1.8196 0.0952 The images produced by the sodium and lithium lights were very sharp and hence these observations are re- liable. The image of the ordinary ray for thallium light was not as well defined as for the other colors but this determin- ation may, nevertheless, be considered as fairly accurate. The image of the extraordinary ray for this same color was very much blurred and hence two separate determinations were made, namely, 1.8183 and 1.8209, which differ considerably from one another. The value given above is the mean of these two observations. If we consider the determination for lithium and sodium lights as reliable and then calculate the indices of refraction for thallium light by means of Cauchy’s formula Gee AD 72 3) we obtain Ww = 1.7245 e = 1.8194 as the theoretical values for this color, which agree quite closely with the observations given above. 52 The American Geologist. su, | Aer “Yhe values e-w show that hussakite has a very strong double refraction and consequently the fine powder gives very vivid interference colors in polarized light. Relation of Hussakite to Xenotime. From the foregoing, it is evident that several points yet re- main to be explained, which we now wish to discuss, briefly. The different results obtained by Gorceix and ourselves are very striking, for the material analyzed by Gorceix is from the same locality from which our crystals were obtained. Ac- cording to Gorceix, the mineral examined by him is without a doubt identical with that which we possess. For the sake of comparison we wish to give both analyses side by side. Gorceix: Reitinger : P.O; 35-64 33-51 R20: 63.75 60.24 re.: ——— 0.20 Insol. 0.40 SO, ee 6.13 99.79 100.08 The 6.13% sulphuric acid found by us is evidently divided in Gorceix’s analysis between P,O, and R,O,. We cannot, with any degree of certainty, account for this difference; we- infer, however, that Gorceix simply overlooked the sulphuric acid and decomposed his material with either concentrated sulphuric acid or potassium bisulphate and thus had no oc- casion to determine the sulphuric acid, which he had no rea- son to suppose present. Nevertheless, we would like to em- phasize the fact that all undecomposed hussakite crystals from Dattas have the composition given by us above. Why is it that the crystal form of hussakite is identical with that of xenotime. In general, we are accustomed, when two substances have the same crystal form, to consider them as identical. This question has a simple solution when we consider that all analyses of xenotime, aside from those of Gorceix and one by Blomstrand,* were made with more or less decomposed material. It seems plausible to consider that, which is called xenotime, as nothing else than a hussakite from os *Zeitsch. f Krystal. etc.,16,68. Blomstrand indicates that the mineral was decomposed with sulphuric acid and hence it was impossible for him to. determine whether sulphuric acid was present in the mineral or not. Hussakite—Kraus and Reitinger. 53 which the sulphuric acid has been extracted by the circulating waters in nature and thus converted into an orthophosphate. In order to determine whether or not this might be the case, we treated finely pulverized hussakite with a solution of sodium carbonate for a short time on the water bath. It was clearly shown that the sulphuric acid can, in this manner, be easily removed from the mineral; for after an hour’s heating, the filtrate gave a very distinct reaction for sulphuric acid. No doubt the circulating waters in nature, which gen- erally give a weak alkaline reaction, may have acted on hus- sakite in a similar manner and in due time changed it to an orthophosphate. If this supposition be correct, it would be reasonable to as- sume that the opaque xenotime crystals are pseudomorphs of yttrium orthophosphate after hussakite, and that the partial- ly decomposed crystals must show a presence of sulphuric acid, In a sand from Banderia de Mello (Bahia) opaque crys- tals of a pyramidal habitus were found, which Dr. E. Hussak* determined and described as xenotime. Through the kindness of Dr. Hussak a larger quantity of this sand, which aside from xenotime also contains corundum, quartz, garnet, mona- zite, and other minerals, was placed at our disposal. The crys- tals of xenotime were carefully isolated and examined chemic- ally. On crushing them it was found that they were opaque and partly decomposed. The quantitative analysis gave a distinct reaction for sulphuric acid. The results of the quan- titative analysis of this ““xenotime’ from Bandeira de Mello are as follows: + Tq: bie PO 27.40 27.35 ~ en 2.62 2.74 SiO, 0.65 0.59 \ Os R2O, 60.03 59.87 Er,Og Fe,O, 4.58 4.50 ] Gd,Og ALO; 1.10 1.22 CaO 2.51 2.60 MgO 0.49 0.41 FO 0.34 0.40 99.72 99-68 *E. Hussak, Tschermak’s Mitteilungen, 1891, 12, 457. _. tRecently Dr. J. REITINGER (Analytische Untersuchungen uber die natur- lichen Phosphate, etc., Munich, 1902.) made another anaylsis of finer specimens from this same sand and found only 1.14 per cent SO3. 54 The American Geologist. Sie Roe The molecular weight of the mixture of rare earths, R,O, determined by the method indicated above, was found to be, 249.7. The earths are present in the following percentages: I Il. Y,O, 45.93 45.80 Ht); 13.68 13.65 Gd,O,. 0.42 0.42 60.03 59.87 Of course it is just as impossible to obtain a rational form- ula from this analysis as from Blomstrand’s* very careful analyses made with material from Hvalé and Naresté near Arendal. The small percentage of sulphuric acid found in this material from Bandeira de Mello makes it very interesting for it is evi- dent that this is a transition product between hussakite and xenotime in which only a portion of the sulphuric acid has been extracted by the circulating waters in nature. During this decomposition, other substances as indicated in the analysis above, have been deposited in the cracks and pores of the min- eral. The crystals of this so called xenotime are of a pyramidal habitus, very much rounded and worn and hence the faces are dull so that very accurate measurements could not be made; but nevertheless, it was shown that the angles of these crystals agree very closely with those given above for hussakite. Inasmuch as the crystals were opaque it was im- possible to examine them optically. Hence, there seems to be no doubt but that those xenotime crystals, which are opaque and free from sulphuric acid, as used for most analyses, are pseudomorphs after transparent hussakite. As further evidence in proof of this theory, we wish to state that we are able to show the presence of sulphuric acid in several crystals from Htter6,+ which are in the possession of the Bavarian Mineralogical Museum in Munich, and which Prof. P. Groth kindly placed at our disposal. These crystals were partially decomposed, hence in some places opaque, while *Blomstrand, Geolog. Fér. Férh., 1887, 9, 185, also Zeitsch. f. Krystall. 15, 99. *Until now, only one analysis has been made from the xenotime {from this locality, namely, that by Schiétz. The large percentage of water present shows that the material was decomposed and hence all the sulphuric acid had doubtlessly been extracted in the manner cited above. Hussakite—Kraus and Reitinger. 55 in others they seemed quite fresh and undecomposed. Two such crystals were examined for sulphuric acid and in both instances it was found to be present. These reactions were even more distinct than those obtained with the material from Bandeira de Mello. The material placed at our disposal was insufficient for a complete quantitative analysis. Several other Norwegian xenotimes, which are also in the Mineralogical Museum at Munich, were examined but they did not con- tain sulphuric acid. These specimens were from Arendal, Ra- ade, near Moss, and Htterd, and were very much decomposed and absolutely opaque, having doubtlessly been formed from hussakite, as mentioned above. Hence, we believe that from what has been said in the foregoing, we are justified in stating that if yttrium orthophosphate be called xenotime, then xeno- time, in so far as it occurs in crystals, is to be considered as a pseudomorph after hussakite. Since the publication of this paper in German,* Dr. H. Roslert has shown that hussakite occurs quite frequently as an accessory constitutent of granites and quartz porphyries, as also of the kaolinites resulting therefrom. Rosler also ob- served several crystals of hussakite, which show a distinct pleochroism; w= pale rose to yellow brown, e =brownish yellow to gray brown; absorption e>w. tNOTE ON THE SO-CALLED BASAL GRANITE OF THE YUKON VALLEY R. G. MCCONNELL, Ottawa Distribution and general description. Granite gneisses closely resembling the Laurentian gneiss- es of eastern Canada are widely distributed along the upper part of the Yukon valley. They have been traced by various members of the Canadian and U. S. Surveys from the Nor- denskiold river in a northwesterly direction across the White river valley to the Tanana and down this stream to near the mouth of Delta river, a total distance of about 380 miles. The northwestern boundary crosses the Yukon from the south a *Zeitschr. f. Krystall, 34, 268-277 +Neues Jahrbuch fiir Mineralogie, Geologie, etc., 1902, B. B. XV, 231-393. A iPublished by permission of the Director of the Geological Survey of Can- ada. 56 The American Geologist: vay eae few miles below the mouth of Pelly river, and recrosses it above the mouth of Fortymile river. Between these two points areas of granite gneiss and other igneous schists are of constant occurrence. The gneisses are also found on the lower fifty miles of the Stewart river a northeastern tributary of the Yukon and on the lower part of White river, a stream entering the Yukon from the opposite direction a few miles above the mouth of the Stewart. The width of the gneissic belt on the Stewart and White rivers, the only point at which it is even approximately known, measures 110 miles. The area roughly defined above, 380 miles in length and 110 miles in width, is only partially underlaid by gneisses. In the region examined by the writer, the gneisses alternate with bands and areas of altered clastics consisting mostly of dark and lead gray quartz-mica schists, hard quartzytes and crystalline limestones, and they are overlaid by wide areas of comparatively recent sedimentary and pyroclastic rocks, as- sociated with andesytes, rhyolytes and basalts, all of which have been referred provisionally to the Tertiary. The gneisses, as might be expected considering their wide areal distribution, exhibit great variety in texture, composition and general appearance in the field. The ordinary variety is a grey medium textured, granular rock, passing on the one hand into a fine grained schist, difficult and occasionally impossible to distinguish from the recrystallized clastics with which it is often associated, and on the other hand into an exceedingly coarse grained and unmistakable gneissoid granite. Porphyr- itic phases are also not uncommon. Hatcher, Pittsburg; R.R. Hice, Beaver, Pa.; J. R. Macfarlane, Pittsburg; G. C. Martin, Baltimoré; Miss L. K. Miller, Groton, Mass.; Miss Ida H. Ogilvie, New York City; Po. Oliphant, Oil City, Pa.;'A. E. Ortman, Princeton, N. J.; Pee. eck,” Easton, Pa; Sidney Prentice, Pittsburg; C. S. Prosser, Columbus, O.; H. W. Shimer, New York City; A. E. Turner, Waynesburg, Pt.; I. C. White, Morgantown, W. Va.; J. C. Williams, Ridgeway, Pa. The following geological papers were read at the Pittsburg meetings : 1. “Geology of the Pittsburg Region.” (45.) I. C. White. . “Lower Carboniferous of the Appalachian Basin.” (title.) J. J. Stevenson. _3. “A New Meteoric Iron from Algona, Wis.” (20 m.) (Lantern. ) to W. H. Hobbs. 4. “Meteorites of Northwestern Kansas.” (20 m.) (Lantern Views.) Oliver C. Farrington. . “The Mohokea Caldera on Hawaii.” (10 m.) (Lantern Views.) C. H. Hitchcock. 6. “Ellipsoidal Structure in Pre-Cambrian Basic and Intermediate Rocks of Lake Superior Region.” (20 J. Morgan Clements. . “Vermilion District of Minnesota.” (20 m.) (Lantern Views.) J. Morgan Clements. 8. “The Pacific Mountain’ System in British Columbia and Alaska. Arthur C. Spencer. on NI 134 TOs us The American Geologist. AMEREL) ee “Development of the Southeastern Missouri Low lands.” (10 m.) C. F. Marbut. The International Geographic Congress of 1904 under the Au- spices of the National Geographic Society.” (10 m.) (title.) Gilbert H. Grosvenor. “Possible Effects of the Glacial Period Upon the Land Levels of Central ‘Asia.” (10 m.) G. Frederick Wright. “Recent Geology of the Jordan Valley.” (14 m.) G. Frederick Wright. . “History of the Discoveries and Discussions Concerning the Glacial Terraces in the Upper Ohio and Its Tributaries.” (20m. ) G. Frederick Wright. . “Submerged Valleys in Sandusky Bay.’ (10 m.) E. L. Moseley. . “Some Geological Notes in Honduras, Central America.” (15m.) (title. ) J. Francis Patch Le Baron. “Great Canon of the Euphrates River.” (20 m.) Ellsworth Huntington. . “Systematic Geography.” (20 m.) W. M. Davis. . “Some Topographic Features in the Southern Appalachians.” (15 m.) (Lantern Views.) J. A. Holmes. . “The Petrographic Province of Neponset Valley, Boston, Mas- _ sachusetts.” (10 m.) (title.) F. Bascom. “The Occurrence of Liquid Petroleum Hermetically Enclosed with Quartz Crystals, from Alabama.” (5 m.) F. L. Stewart. . “Restoration of Embolophorus dollovianus.” (10 m.)_,title.) E.G; 'Gase: . “Synopsis of the Missourian and Permo-Carboniferous Fish Faunas of Kansas and Nebraska.” (10 m.) C. R. Eastman and E. H. Barbour. “Phylogeny of the Cestaciont Group of Sharks.” (10 m.) C. R. Eastman. “On a Complete Skeleton of a New Cretacean Plesiosaur, Il- lustrated by Photographs from Mounted Skeletons.” (10 m.) S. W. Williston. “The Bacubirito Meteroite.” (20 m.) He AS Ward ‘““Palaeontological Notes.” (title.) (a) Notes on Gastropods, (b) Spirifer mucronatus and its becuse (20 m.) (Lantern Views.) . W. Grabau. The following papers were read under the suspice ne the National Geographical Society. 27. 28. 20. Scientific Results of the Recent Eruptions in the West ‘Indies. Re eae The Magnetic Disturbances during the Time of the Recent Vol- .canic Eruptions in Martinique. i LAY Bauer. Atmospheric Phenomena in connection with the Recent Erup- tions in the West Indies. A. J. Henry. (Read by G. H. Grosvenor.) LIBRARY ~ ’ 2. OF THE . UNIVERSITY of ILLINOIS ‘SHNO@ HOIHL AHL HLIM “IONS ONISNVI HHL AO MAIA LNOW "Il ALV 1d ‘XXX “IOA “LSIDOTOND NvoUawy any, RY ITY of ILLINGic LIBRA OF 7: NIVERS ae u 2h PUL MR TIN TRAN TE DbEE OHO Ud ' yiryyy A aL ! VEL Med dad . \ Wwi\ Vmyeeeh ayes Vis yb THE Pewee wICAN GEOLOGIST. VoL. XXX. SEPTEMBER, 1902. No. 3. MAN IN THE ICE AGE AT LANSING, KANSAS, AND LITTLE FALLS, MINNESOTA. By WARREN UPHAM, St. Paul, Minn. PLATES II AND III. In a short article, entitled ““A Fossil Man from Kansas,” published in Science for August 1 (pages 195-196), Prof. S. W. Williston, of the Kansas State University, gave an account of his examination of a human skeleton and the locality, near Lansing, Kan., where it was discovered, about six months ago, under 20 feet of the Missouri valley drift. Through the kind- ness of Hon. J. V. Brower, an earlier newspaper account of this discovery had brought information of it to Prof. N. H. Winchell of Minneapolis, and to myself, which had led us to plan a visit to the Lansing locality for the purpose of study- ing the drift there in its relation to the recognized time divisions of the Ice age. Our visit was made on Saturday, August 9. In response to correspondence, we had the great advantage to be accompanied by Prof. Williston and Prof. Erasmus Haworth, of the State University, Lawrence, Kan., and M. C. Long, P. A. Sutermeister, and Sidney J. Hare, of Kansas City, Mo. The skeleton was discovered February 20, 1902, in exca- vating a tunnel for storing fruit, vegetables, milk, butter, etc., in (and near the middle of the south edge of) the N. W. Y% of sec. 28, T.9 S., R. 23 E., close southwest of the Missouri river and of the narrow bottomland that skirts it there on the southwest side; being on the farm of Martin Concannon and only a few rods from his house, at the distance of about two and a half miles southeast from Lansing and about eighteen 136 . The American Geologist. Beptempe aaa. t{}} miles northwest’ from Kansas City. His sons, Michael T. and Joseph F. Concannon, found the skull and most of the bones in their digging near the end of the tunnel, 69 to 71 feet from its entrance, 2 to 6 feet from its east side, and 1% to 2 feet above its floor. The bones were disjointed, and were partly broken, decayed, and irregularly strown about; but mainly they were huddled together in one place. The ribs and vertebre were mostly decayed, so that they could not be preserved. Half of the broken lower jaw had been previously discovered, ten feet nearer the entrance and about one foot lower, that is, only a foot above the floor of the tunnel; and near that spot a phalangeal bone was founda embedded in the wall of the tunnel by one of our party. The other half of the lower jaw, matching that found before, was with the chief parts of the skeleton. No bones besides these of a single human skeleton were found in the entire excavation of the tunnel; nor were any implements, artificially chipped stone flakes, or other articles of human workmanship discovered. The illustrations in Plates II and III are kindly contributed by Mr. M. C. Long, to accompany this paper. Mr. Coneannon and his sons supplied lights for our exam- ination of the section displayed in the tunnel; and they kindly showed us where the bones were encountered, with detailed relation of the circumstances of their discovery. At first they had not suspected its scientific importance, and nearly a month passed before the first newspaper mention of it appeared in the Kansas City Star. Within a few days later the locality was examined by M. C. Long and Edwin Butts, of Kansas City, Mo., the former being curator of the City Public Mu- seum, and the latter civil engineer of the Metropolitan Street Railway, by whom the skeleton was obtained with the design of placing it in that museum. The skull was found entire, but had afterward been accidentally broken ‘into many pieces, which Mr. Long fitted together, depositing it in the museum; but the other bones, including both parts of the lower jaw, were at the time of our visit in the possession of Mr. Butts, at whose home they were examined by all our party. From where the skeleton was found, the overlying loess deposit has a thickness of 20 feet, as determined by Mr. Butts, to the surface of the ground above. Measurements of the tunnel were also — eo oh > i Ps » ee ee Tee Oe ae ee ee Man in the Ice Age.—Upham. Reg made by him, showing it to be 72 feet long, about 10 feet wide, and about 7% feet high. Its walls are vertical to the hight of about six feet, above which the top is flatly arched, with no other support than is supplied by the well known coherent texture of the loess formation in which this upper part of the tunnel is dug. Resulting from their visit, a second article in the Kansas City Star, of March 23, written by Mr. Suter- meister, announced the provisional reference of the skeleton to a part of the Glacial period estimated as 35,000 years ago. Upper Carboniferous limestone, determined from the abun- dant fossils collected by Mr. Hare in the region about Kansas City, outerops at the site of the tunnel, and at much higher elevations close southeast, and somewhat farther away to the _ south, west, and northwest; but mainly it is covered and con- cealed by the extensive and very thick valley drift deposit of loess. ‘The limestone, in a compact bed several feet thick, forms the floor of the tunnel, rising nearly two feet along its extent of 72 feet south-southeast into the bluff. Fragments of limestone and shale, with much earthy debris, rested on this floor along all the area of the tunnel, having a variable thick- - . / . . -ness of 2 to 4 feet, but mainly about 2% feet, and being thick- est and most stony, as seen in the section, at the east wall of the tunnel. In the debris which thus formed the lower third of the excavation, fragments of the limestone, and’ of its as- sociated thin shaly layers, are common up to 6 inches long, and several masses I to 3 feet long were encountered. One measuring 12 by 20 inches is imbedded in the head of the tun- nel, only two or three feet from the site of the. skeleton, and at a littie greater hight. The skeleton lay in the upper foot of the debris, or perhaps in-a hollow of its surface; but the half of the lower jaw found separate, a foot lower, was cer- tainly imbedded in the stony debris about a foot below its top where it is overlain by the loess. The Carboniferous lime- stone, from which its fragments in the debris appear to have been derived, outcrops within 50 feet southeast of Mr. Con- cannon’s house, or only about 150 feet southeast of the tunnel, having there a hight of 50 or 60 feet above the tunnel floor. Thence the rock outcrop gradually rises southeastward as a spur ridge, attaining within the distance of an eighth of a mile a hight of fully 125 feet above the floor of the tunnel, or 138 The American Geologist, September, 1903 about 150 feet above the ordinary level of the Missouri river; and the overlying loess rises onward to a hight of 200 feet, or more, above the river, within another eighth of a mile, reach- ing there the general level of the top of the river bluffs and adjoining uplands. According to the surveys of the Missouri River Com- mission, the extreme low and high stages of the river here during the period from 1873 to 1885 were respectively 735 and 760 feet above the sea level, the vertical range being 25 feet.* The extreme high water was in 1881, being the highest within the thirty-five vears since Mr. Concannon settled here; . but it was exceeded, probably six or seven feet, by the high water of 1844, of which a record was made at Kansas City. The skeleton was at a hight of 41 to 12 feet above the high water of 1881, or 772 feet, nearly, above the sea; and the house is about 35 feet higher, with the limestone outcrop extending from near it up to about goo feet above the sea, while the higher crests of the loess near by are at 950 feet, estimated approximately. The coarse debris in the lower part of the tunnel contained, so far as we could observe, no glacial drift pebbles or stones of foreign origin, though they are frequent in the thin gla- cial drift which overlies the rock surfaces near. Many of these drift stones and boulders are of the red Sioux quartzite, which outcrops 300 to 350 miles northward, in southwestern Minnesota, the northwest corner of Iowa, and the southeast part of South Dakota. It occurs in this Kansan drift mostly in small fragments, but often one to two feet in diameter, and occasionally even measuring five feet, or more, and weighing several tons. The southern boundary of the glacial drift, marking the limit of the continental ice-sheet in ‘its extreme extension during the Kansan stage of the Glacial period, is at a line passing irom east to west, as mapped by Chamberlin and McGee, about 12 or 15 miles south of the Kansas (com- monly called the Kaw) river, and 25 or 30 miles south of Lan- sing. T ‘Above the debris, which exhibits no marks of water assort- ing and deposition, the section, very clearly seen in each side *U. S. Geol. Survey, Bulletin 72, 1891, p. 166. +U. S. Geol. Survey. Seventh Annual Report, for 1885-86, pl. viii (map of the drift area and glacial striz of the United States.) ne Man in the Ice Age —Upham. 139 and at the end of the tunnel, consists for its upper two-thirds of the very fine siliceous and calcareous yellowish gray silt called loess, containing no rock fragments nor layers of gravel and sand, excepting a thin layer of fine gravel, with limestone and shale pebbles up to a half inch in diameter, which was noted by Mr. Butts near the roof of the tunnel, having a thickness of about four inches and an observed extent of some 30 feet. Soon after the skeleton was imbedded in the stony debris, or lay exposed on its surface, the geologic conditions that appear to have long prevailed were somewhat suddenly changed, and there ensued a more rapid deposition of the very fine water- laid loess, deeply enveloping the bones before they had time to be generally removed by decay under the influences of the weather and infiltrating air and water. From the horizon of the skeleton, the loess extends up to the surface, a vertical thickness of 20 feet, and continues in a gently rising slope to a slight terrace on which Mr. Concannon’s house stands. With similar irregularly eroded slopes, the loess continues up- ward to the general elevation of about 200 feet above the river within a distance of a fourth of a mile to a half mile south- ward and westward, attaining there a general level which was probably the surface of the river’s flood plain at the maximum stage of the loess deposition. This plain appears to have been built up by gradual! deposition from the broad river floods during many vears and centuries, and to have stretched then over the present valley and bottomland of the Mis- souri, in this vicinity two to four miles wide, from which area it has been since removed by the river erosion. The great val- ley, as to its inclosing rock outcrops, is of preglacial age; it was not much changed by glacial erosion and deposition of the boulder drift ; but it was deeply filled by the loess, in which the valley was afterwards re-excavated. Professor Williston noted a distinct darker layer of loess, mostly about two inches thick but in part merely a threadlike line, traceable continuously through 2ll the 72 feet of the west wall of the tunnel, running about 3 to 4 feet above the lime- stone floor, and one foot or a littie more above the base of the loess. Pegs driven by our party at the line of this stratum along all its extent were seen to be in a straight plane, which by a hand level was found to have a descent of 7 or 8 inches 140 The American Geologist. SephemRee yale from south to north in this distance. Other lines of almost horizontal stratification exist, but are less observable, through- out the loess, which is thus clearly shown to be an aqueous de- posit. Several small gastropod shells were found in it by mem- bers of our party, but they were too delicate to be preserved for determination of their species. Three others, which have been carefully preserved by Mr. Butts, are said to have been found at the same place with the skeleton. To ascertain the date of this fossil man in the sequence of the time divisions or stages of the Ice age, we must have re- course to the classification of these stages in their chronologic order as defined during the last ten years by the field observa- - tions*and writings of Chamberlin, James Geikie, and other eminent glacialists, both of America and Europe. In the Uni- ted States we owe more to the careful studies of glacial geol- ogists in Iowa than in any other state, in respect to the series and probable duration of the stages recognizable in the Gla- cial period. Calvin, McGee, Call, Leverett, Bain, Udden,; Shimek, and others, have worked very advantageously on the drift series in Iowa; and their work has been supplemented, for the later drift deposits farther north, by Chamberlin, Sal- isbury, Winchell, Todd, and the present writer, in Wisconsin, Minnesota, the Dakotas, and Manitoba, and by the late Dr. George M. Dawson and his associates in the Geological Sur- vey of Canada. From these very thorough explorations and discussions of the history of the Ice age, we have received, chiefly through. the systematic correlations of .Chamberlin, Dawson, Calvi, and Leverett, an elaborate classification of ‘its successive epochs and stages, which, fer definite statement of the geologic date of the loess and the Lansing skeleton, need to be here briefly noted, as follows. 1. The.culmination of the Ozarkian epeirogenic uplift, in the later part of the Lafayette period, the earliest of the Qua- ternary era, affecting both North America and Europe, raised the glaciated areas to so high altitudes that they received snow throughout the year and became deeply ice-enveloped. Sub- merged valleys and fjords show that this elevation was at least 1000 to 4000 feet above the present hight. Rudely chipped stone implements and human bones in the plateau gravel of southern England, 90 feet and higher above the Thames, and wit ‘ ‘ - Man in the Ice Age.—Upham. TAI the similar traces of man in early Quaternary sand and gravel deposits of the Somme and other valleys in France, attest man’s existence there before the maximum stages of the uplift and of the Ice age. The accumulation of the ice-sheets, due to snow- fall on their entire areas, was attended by fluctuations of their gradually extending boundaries, giving the Scanianand Norfolk- ian stages, named by Geikie, in Europe, the Albertan formation of very early glacial drift and accompanying gravels, described by Dawson, in Alberta and the Saskatchewan district of west- ern Canada, and an early glacial advance, recession, and re-ad- vance, in the region of the Moose and Albany rivers, southwest of Hudson bay. In that region, and westward on the Canadian plains to the Rocky mountains, there seem to have been thus three stages recognizable in the glacial results of the epeiro- genic uplift, namely, the Albertan early ice accumulation, the later time represented by the Saskatchewan gravels, of abun- dant glacial melting and extensive retreat, and afterward a vast growth of the continental icefields to their farthest limit, when they reached south to Kansas. The first recognized stage of glaciation in North America is therefore called the Albertan stage. : On the Atlantic coastal plain of the United States, south of the glacial drift, this stage is probably represented by the Lafayette formation; and the subsequent deep fluvial erosion of the Lafayette beds I attribute to the very long ensuing Aftonian and Kansan stages. 2. A deposit of glacial drift, the lowest and oldest observed in the Mississippi river basin, probably of Albertan age, stretch- es south at least to southern lowa, where it is overlain by in- terglacial beds, inclosing peat, well displayed in sections at Afton, lowa. The Aftonian interglacial time, especially notable for its extensive buried forest bed, containing trunks of hardy northern coniferous trees, has been ascertained to be earlier than the Kansan readvance of glaciation. It is therefore probably equivalent with the Saskatchewan stage of Canada, which name it should then displace according to the rule of prioritv. This second time division of the Glacial period, in- cluding a very important recession of the ice border, uncover- ing the previously glaciated country as far north, probably, as 142 The American Geologist. September, 1902 to the southern half of Minnesota, is therefore named the 7 tonian stage. During this time, apparently, the Mississippi river in the vicinity of Minneapolis eroded a rock channel which is now mostly filled by the drift of the later glaciation, but is marked by a series of lakes, namely, Cedar lake, the Lake of the Isles, lakes Calhoun and Harriet, and others farther south. Prof. N. H. Winchell from his study of this interglacial channel of the Mississippi, has estimated the duration of the interglacial stage there as about 15,000 years.* It seems to be represented also in the history of the Quaternary lakes Bonneville and La Hontan, respectively described by Gilbert and Russell, as a pro- longed stage of desiccation of those lakes under a drier cli- mate, while their earlier and iater flood stages are correlated with the Albertan and,Kansan stages of glaciation. Near the southern limit of the glacial drift, the Aftonian interval was doubtless much longer than in Minnesota. 3. During the Kansan stage the ice-sheet attained its farth- est extent in the Missouri and Mississippi river basins, and in northern New Jersey. It is correlative with the Saxonian stage of maximum glaciation in Europe. The area of the North American ice-sheet, with its development on the Arctic arch- ipelago, was about 4,000,000 square miles ; and of the European ice-sheet, with its tracts now occupied by the White, Baltic, North, and Irish seas, about 2,000,000 square miles. 4. In the Helvetian stage, named by Geikie from its re- cognition in Switzerland and elsewhere in Europe, the ice- sheets receded far from their Saxonian and Kansan bounda- ries. The Buchanan gravels and sands, as named by Calvin in Towa, were deposited during the retreat of the Kansan ice- fields; and this time is also represented by the Yarmouth weath- ered zone and erosion of the Kansan drift, noted by Leverett in Iowa and Illinois. The greater part of the drift area in Russia was permanently relinquished during this stage by the much diminished ice-sheet, which also retreated considerably, on all sides. 5. The Jowan stage was marked by renewed accumulation of snow and ice, extending over a part of the country that had been laid bare by the preceding retreat. Before the farthest *4m. Geologist, vol. X, Pp. 69-80, with map and sections, Aug., 1892; and p. 302, Nov., 1892. Man in the Ice Age.-—Upham. 143 extension of this glaciation in Iowa, on the west side of the Wisconsin driftless area, the ice-lobe east of that area advanced from Illinois into the edge of southeastern lowa, giving an [1 linoian stage of glaciation which somewhat antedated the maxi- mum of the lowan, though not probably by a wide difference of time. Between the retreat of the Illinoian ice-lobe and: the deposition of the Iowan loess, Leverett notes interglacial depos- its and a zone of weathering, the records of his Sangamon stage. Iowan time seems correlative with the Polandian stage of renewed growth of the European ice-sheet. In this late part of the Glacial period the northern lands, which had long stood at greater altitudes than now, sank at last under their heavy ice-load until they mostly were somewhat be- low their present hights. This Champlain depression, as it is called, permitted the glacial drift of coastal regions to be cov- ered by fossiliferous marine beds, which through later re-ele- vation range up to 300 feet above the sea in Maine, 560 feet at Montreal, 300 to 400 feet from south to north in the basin of lake Champlain, 300 to 500 feet southwest of Hudson and James bays, and similar or greater altitudes on the coasts of British Columbia, the British Isles, Germany, and Scandinavia. Glacial melting and recession from the Iowan boundaries was rapid under the temperate (and in summers warm or hot} climate belonging to the more southern parts of the drift-bear- ing areas when reduced from their great preglacial elevation to their present hight or lower. The finer portion of the drift, swept down from the icefields by the abundant waters of their melting and of rains, was spread on the lower lands and along valleys in front of the departing ice, as the loess of the Missou- ri, the Mississippi, and the Rhine. In or just beneath the basal beds of the Missouri loess was the Lansing fossil man, belong- ing thus to the culmination or beginning of decline of the Io- wan stage of glaciation. To this time the Columbian formation seems referable, succeeding the Lafayette and its erosion in our Atlantic coast region. In a Columbian gravel deposit, at Claymont, Del., probably of a little later date than the base of the loess at Lan- sing, Mr. Hilborne T. Cresson in 1887 found an argillite im- plement, as described and figured by Prof. G. F. Wright in his works cited on a following page. 144 The American Geologist. September, tate 6. Moderate re-elevation of the land took place during the Wisconsin stage, in the northern United States and Canada advancing as a permanent wave from south to north and north- east. The ice border continued mainly in a wavering retreat along most of its extent, but attained its maximum advance in southern New England. This last well defined stage of the Glacial period was characterized by slight. fluctuations of the ice front and the formation of prominent marginal moraines. Great glacial lakes were held by the barrier of the waning ice- sheet on the northern borders of the United States. At the same time the Mecklenburgian stage in Europe was attended by the formation of conspicuous moraine accumulations at the gradually receding ice boundaries in Sweden, Denmark, Ger- many, and Finland. It is clearly seen, from this review of the Ice age, that the Lansing skeleton and the deposition of the loess are referable to its later part, when the high land elevation that caused the growth of the vast sheets of snow and ice was succeeded by the Champlain depression, which brought the period of glaciation to its end. Man at Lansing was contemporaneous with the be- ginning of the tilling of the Missouri valley with the loess, prob- ably a few thousand years before the very remarkable marginal moraines in Wisconsin, Iowa, Minnesota, and all our northern states, as well as in Canada, were formed on the boundaries of the departing ice-sheet. Most of the other observations of traces of men contemporaneous with glaciation in this country indicate merely an antiquity equal to that of the moraines formed during the glacial recession. Such are the discoveries of stone imole- ments and the chips of their manufacture in the Late Glacial gravels of the Delaware valley at Trenton, N. J., in the similar valley deposits of Ohio, in the ancient floodplain of the Mis- sissippi at Little Falls, Minn., in a beach ridge of the glacial Lake Agassiz in northwestern Manitoba, and the discovery of a fireplace under a beach ridge of the glacial Lake Iroquois in western. New York, where geologists have found traces of man’s presence during the closing scenes of the Ice age. Fora comprehensive review of these traces of Glacial man, the reader may be referred to Wright’s “Ice Age in North America” (1889), and his ‘“Man and the Glacial Period” (1892). ms Pb Man in the Ice Age-—Upham. 145 Even these Late Glacial indications of man’s existence in America, however, have been doubted in recent years by some of our ablest geologists and archeologists, for which reason Prof. W. H. Holmes, of the U. S. National Museum, has given much attention to this subject, visiting many of the reputed lo- calities of evidences of man contemporaneous with the Ice age. His excavations and discussion of the locality of abundant ar- tificially flaked quartz chips at Littie Falls, Minn., led him to the conclusion that they were the work of modern Indians. But within the past year this place has been again very carefully studied by Brower and Winchell, with new excavations, leading them to refer the quartz chips to the later part of the Wisconsin stage of the Glacial period, while the waning ice-sheet yet cov- ered the ground of the headwaters of the Mississippi.* To this view I have continuously given my support from the time when these quartzes were first brought to my attention by the paper concerning them presented by Miss Franc E. Babbitt at the meeting of the American Association in Minneapolis in 1883. We owe to Prof. Winchell the first discovery twenty-five years ago, of artificial quartz chips at Little Falls referable to the Glacial period, his observations there in 1877 heing published in the Sixth Annual Report of the Geological Survey of Minnesota. This was only one or two years after the earliest discoveries of stone implements in the glacial gravels of Tren- ton. Brower gives to his work the title “Kakabikansing,” which is the Ojibway word meaning Little Falls. His investigations, supplemented by aid of Prof. Winchell, seem to me to leave no room for doubt that men there, on the upper Mississippi river in central Minnesota, were contemporaneous with the accumu- lation of the great Leaf Hills moraine and with the glacial Lake Agassiz. In the appendix of this volume I contributed a short paper, entitled “Primitive Man in the Ice Age,” from which I may here quote two paragraphs to give my view of the probable *Memoirs of Explorations in the Basin of the Mississippi: Volume V. Kakabikansing, by J. V. BROWER, President of the Quivira Historical Society, with a Contributed Section by N. H. WINCHELL, President of the Geological Society of America, Councilors of the Minnesota Historical Society. Page 126; with many maps, and photographic illustrations of the quartz chips and implements. St. Paul, Minn., 1902. F 146 The American Geologist. September, 1902 time and conditions of man’s first coming to America, as fol- lows: The first people in America appear to have migrated to our con- tinent from northern Asia during the early Quaternary time of general uplift of northern regions which immediately preceded the Ice age, being its principal cause, and which continued through the early and probably the greater part of that age. Then, land undoubtedly ex- tended across the present area of the shallow Bering sea. It is not improbable, too, that another line of very ancient immigration, coming by a similar early Quaternary land communication where now are wide tracts of the sea, passed from western Europe by the way of the Faroe islands, Iceland, and Greenland, to this continent. The very distant and dim antiquity of these migrations, however, will perhaps always forbid our looking back with clear and certain view, to trace their relative importance and their respective contributions to pre- historic American industries, trafic, customs, myths, and racial char- ACLCES AME oe An objection against migrations of primitive man to this western ~ hemisphere during the Glacial period may be based on the ice-covered condition of North America at that time, wholly enveloped by an-ice- sheet upon its northern half, northward from the Ohio and Mississippi rivers, excepting the greater part of Alaska. If the preglacial and early Glacial altitude of the continent had been the same as now, this objection would be valid, and we should be obliged to refer these an- cient migrations wholly to a time before the accumulation of the North American ice-sheet, which reached both east and west beyond the present coast lines. But the land elevation then, as known by old river valleys submerged beneath the sea and by marine shells of lit- tora. and shallow water species dredged at great depths, was 3,000 to S.o0o feet greater than now. During the epoch of ice accumulation and culmination, its boundaries probably failed to reach generally to the coast line of that time. Along the sea border, where food supplies such as savages rely upon are most easily obtained, preglacial and Glacial man may have freely advanced on a land margin skirting the inland ice, as along the present borders of Greenland. It was only in the Champlain epoch, closing the Glacial period, that the ice-burdened lands sank to their present altitude or lower, bringing the edges of the ice-shect beneath the encroaching sea. Winchell and others have computed or estimated the dura- tion of the Postglacial period as 7,000 to 10,000 years, basing their estimates on the rates of recession of waterfalls, of weath- ering and dissolving of exposed surfaces of limestone, of wave erosion and beach gravel accumulation by lakes, and of sedimentation by iakes and streams. This measure, sup- plied by many independent observers in America and Europe, Man in the Ice Age.—U pham. 147 may be confidently accepted as the approximate duration of Postglacial time. For the antiquity of man at Trenton and at Little Falls, it may be stated as about 7,000 years. If we should adept the ratio given by Chamberlin, who estimates the Iowan stage as five times as long ago,* it would give the antiquity of the Lansing fossil man as about 35,000 years, agreeing with the first newspaper estimate before mentioned. My studies of the glacial Lake Agassiz, however, warrant no longer time for its duration than 1,000 years.t Ona similar scale, I think the time cf glacial recession from the Iowan stage to the north end of Lake Agassiz may be no more than 5,000 years, giving a date about 12,000 years ago for the Lansing man and the loess. Further back, I may also give my estimates of the earlier parts of the Glacial period, as about 10,000 years for the growth of the icefields during the Iowan stage, before the Champlain subsidence caused them to melt and supply the loess in its chief abundance; about 10,000 years for the pre- ceding Helvetian or Buchanan glacial retreat, giving thus some 25,000 years before the end of the Ice age as the time of the Kansan maximum glaciation; a previous slow ice accumulation and transportation of the Kansan glacial drifi, that is, the Kan- san stage of the Ice age,also about 25,000 years; the previous Aftonian stage of glacial recession, another such allowance of about 25,000 years; and, earliest of all, the Albertan stage of ice accumulation and formation of its drift deposits, likewise about 25,000 years. All the Ice age I would thus comprise within about 100,000 years. This estimate seems to harmonize well with the geologic time ratios of Dana, Walcott, and others, which indicate about a hundred million years as the duration of life on our globe. Man in the Somme valley and other parts of France, and in southern England, made good palzolithic implements fully 100,000 years ago, according to my estimate of the length of the Ice age.t When the earliest men came to America cannot probably be closely determined. It was during the Glacial per- iod, or possibly earlier. The Lansing skeleton affords probably our oldest proof of man’s presence on this continent; but it is *Journal of Geology, vol. iv, pp. 872-876, Oct.-Nov., 1896. +U. S. Geol. Survey, Monograph xxv, 1895, pp. 200, 210, 225, 238-244. tAm. Geologist, vol. xxii, pp. 350-362, Dec., 1898. } - 148 The American Geologist. Septompen a only a third, or, as I think more probably, only about an eighth, so old as the flint hatchets of St. Acheul and other localities of . the old worid. . ; . It will be objected, to my estimate of the antiquity of the Lansing man, that the suberial erosion, weathering, and var- ious other features of the Kansan, [llinoian, Iowan, and Wis- consin drift deposits, with the associated interglacial beds, ne- cessitate a much greater duration of these stages of the Glacial period than | have here suggested. Instead, I would reply that the old till sheets and the loess are spread somewhat evenly on the preglacial rock surface, all the valleys and grand topo- graphic forms of the country in the southern part of our drift area being of preglacial origin. The drift earliest eroded from the preglacial latid was also largely the residuary clays and de- caving rock of the surface, accounting for the great contrast in composition of the more southern and the more northern drift deposits, even when of the same mode of formation and the same age. Concerning the depositien of the loess along the Missouri river and on the older drift to long distances at each side, | think that its derivation chiefly from the englacial and finally superglacial drift is clearly demonstrable. Swept by the sum- | mer floods from the melting ice-surface, it was laid down as a ; deep valley drift deposit, thickening and lifting the great river on the vast floodplain until it flowed, during the hot part of each year, in a lakelike sheet of water, probably from 5 or 10 to 30 or 40 feet deep and far wider than the present bottomlands, / ‘at the general hight of the loess bluffs and uplands. During the cool but not wintry parts of the year, in the spring and autumn, when the floods were reduced to comparatively small channels, or sometimes throughout several years together having less plentiful melting of the ice-sheet, land vegetation and air-breath- ing mollusks could occupy the newly deposited loess tracts. But the scantiness of vegetation on areas subject to summer over- flow permitted the winds to carry off much of this very fine loess and to spreadit over the contiguous country in massive swells and ridges, conforming in a general way to the previous contour, With decrease in the supply of both water and loess, when the lowan ice-melting was nearly finished, the rivers eroded deep and wide valleys in their loess plains, the valley of the Missouri ° Man wn the Ice Age-—Upham. 149 ranging from three to fifteen miles in width, and attaining a depth below its present bottomlands. During the Wisconsin moraine-forming stage the land was re-elevated te about its present hight. The Missouri and its tributary streams, laden with gravel, sand, and fine silt, sup- plied plentifully from the melting ice in this stage, built up again their floodplains to hights siightly above the present river bot- toms. Between Sioux City and Council Bluffs, Iowa, a distance of 90 miles, this alluvial plain of the Wisconsin modified drift is mainly 6 to 12 miles wide on the east side of the river, a mest fertile tract for corn-raising. The Lansing discovery gives us much definite knowledge of a Glacial man, dolichocephalic, low-browed, and prognathous, having nearly the same stature as our people today. As stated by Prof. Williston, he was doubtless contemporary with the Equus fauna, well represented in the Late Pleistocene deposits of Kansas, which includes extinct species of the horse, bison, mammoth and mastodon, megalonyx, moose, camels, llamas, and peccaries. He was also the contemporary of the Late Paleolithic men of Europe, who in the Solutrian and Mag- dalenian development of implement-making from flint and bone, . and in various other manifestations of artistic skill, were far advanced beyond primitive savagery. It may be reasonably expected that many other evidences of the men of the loess-forming stage of the Ice age will be found, and will give some knowledge or hints of their mode of life. Two such items of testimony are already known in Iowa. Prof. F. M. Witter, superintendent of schools at Mus- catine, in a paper read before the lowa Academy of Sciences in 1891, described ‘“‘a rather rudely formed spear point of pink- ish chert,’ found in the loess in that city about 12 feet from the surface, and an arrow point in the same loess section, “‘at least 25 feet below the surface.” Both were discovered in place by Mr. Charles Freeman, the proprietor of a brickyard. Again, in volume XI. of the Iowa Geological Survey, published last year, Prof. J. A. Udden, reporting on Pottawattamiec county, writes: “In tunnelling the cellars into the loess hills back of Conrad Geisse’s old brewery, on Upper Broadway in the same city [Council Bluffs!, it is claimed that a grooved stone ax was taken out from under thirty feet of loess and forty 150 The American Geologist. September, 1902 feet from the entrance of the cellar excavation. The ax has an adhering incrustation of calcareous: material on one side, evidently deposited by ground water. The loess at this place has possibly been disturbed by creeping or by rain wash, but its appearance suggests nothing of the kind. It is quite typical loess for this region. The ax was discovered by the workmen engaged in excavating the cellar and immediately shown to Engineer Robert F. Rain, who superintended the work, and who still has possession of it.” i Since man is shown to have lived in this region, probably 10,000 to 15,000 years ago, with elephants and mastodons, it seems quite possible that he left some token of them in the forms of some of his mounds, or in their contents, as the much dis- cussed sandstone pipes found in Louisa county, southeastern Towa, and cwned by the Davenport Academy of Natural Sci- ences, carved to represent the elephant or mammoth of the Ice age. In Europe, at about the same time, the spirited cary- ings of the outlines of mammoths and reindeer, on their own tusks and antlers, by the Late Paleolithic men, give indubitable evidence that they and these animals of the Glacial period subsisted together. Indeed, very probably the extinction of the mammoth, and of the horse in America before Columbus came, may have been due to the prowess of the aboriginal hunters in killing them for their food. THE TRAINING AND WORK OF A GEOLOGIST.* | C. R. VAN HIsSE, Madison, Wis. GEOLOGY is a dynamic science, subject to the laws of ener- gy. Geology treats of a world alive, instead of, as commonly supposed, a world finished and dead. The atmosphere, or sphere of air, is ever unquiet; the hydrosphere, or sphere of water, is less active, but still very mobile; the lithosphere, or sphere of rock, has every where continuous, although slow, mo- tions. The motions of the atmosphere, the hydrosphere, and the lithosphere alike include motions by which the positions of large masses of material are changed, and interior motions, through which the mineral particles are constantly rearranged *Vice-Presidential address, Section E, Geology and Geography, American Association for the advancement of Science, Pittsburgh Meeting, 1902. ‘ § ; Training of a Geologist—Van Hise. I51 with reference one to another, and indeed are constantly re- made. Furthermore, the molecules and even the atoms which compose the atmosphere, hydrosphere and lithosphere have motions of marvelous intricacy and speed. These motions of the atmosphere, the hydrosphere, and the lithosphere are all superimposed upon the astronomical motions—the wob- bling revolution of the earth about its axis, the revolution of the earth-moon couple about their common center of gravity, the movement of this couple about the sun at the rate of 68,000 miles per hour, the movement of the solar system among other systems. If it were possible for one to fix in space coordinates by which to measure these various motions, the movement of an air particle, of a water drop, of a mineral grain, would be seen to be extraordinarily complex. It is clear that there is every reason to believe that no atom or molecule in the world ever occupies the same absolute posi- tion in space at any two successive moments. Indeed, it must have been an extraordinary accident, if a single particle has oc- cupied in all the history of the universe exactly the same posi- tion that it has occupied at any previous time. No such thing as rest for any particle of matter anywhere in the earth or in the universe is known. On the contrary, everywhere all particles are moving in various ways with amazing speed. No science is independent of other sciences, but geology is peculiar in that it is based upon so many other sciences. Astronomy is built upon mathematics and physics. Chemis- try and physics to a considerable degree are built upon each other. Physics also requires mathematics. Biology demands a limited knowledge of physics and chemistry. However, it cannot be said that a knowledge of the basal principles of more than one, or at most two, other sciences is an absolute prerequisite for a successful pursuit of astronomy, chemistry, physics or biology. This is not true of geology. In order to go far in general geology one must have a fair knowledge of physics, chemistry, mineralogy and biology. These may be called the basal sciences of geology. In certain lines of geol- ogy the additional sciences, mathematics, astronomy and met- allurgy, are very desirable. 152 The American Geologist. Rentomier name Geology treats of the world. In order to have more than a ~ superficial knowledge of geology, it is necessary to know about the elements which compose the world, how force acts upon these elements, what aggregates are formed by the elements and forces, and how life has modified the construction of the world. Chemistry teaches of matter; how it is made up, both in life and in death. Without an understanding of its princi- ples we cannot have an insight into the constitution of'the earth cr of any part of it. Physics teaches of the manner in which the many forms of that strange something we call force acts upon matter. Without a knowledge of its principles we can never understand the transformation through which the world has gone. The elements which compose the earth are combined under the laws of physics and chemistry into those almost life-like bodies which we call minerals. The minerals are commingled in various ways in the rocks. Without a knowl- edge of mineralogy no one can have even a superficial under- standing of the constitution of rock masses. Biology teaches of the substances alive which clothe the outer part of the earth. Life is one of the most fundamental of the factors controlling the geological transformations in the superficial belt of weather- ing; it has acted as the greatest precipitating agent in the sea. Life has had, therefore, a profound and far-reaching effect in determining the nature of the sedimentary formations. The sciences of chemistry, physics and biology have been built up by using minute parts of the materials of the world. If geology, or a science of the earth, is to be constructed, it must apply to the earth as a whole the principles which have so enlightened us as to the nature and relations of the fractions of the world which we observe and handle in our laborator- ies of physics and chemistry and biology. It thus appears that geology is a composite science. It might, in a certain sense, be called an applied science. Indeed, I have often defined geology as the application of the princi- ples of astronomy, of physics, of chemistry, of mineralogy and of biology to the earth. Certainly the earth is the single enormous complex aggre- gate of matter directly within the reach of man. This highly composite earth is the joint result of the work of astronomical, physical, chemical, and biological forces, working on an in- NE Training of a Geologist—Van Hise. 153 comparably vaster scale than can ever be imitated in our labora- tories. A study of these mighty results has already advanced at many points astronomy, physics, chemistry, and biology, ‘and future studies, made with direct reference to the causes which have produced the earth, are sure to lead to even greater advances in these sciences. Ii geology is to become a genetic science, or more simply, is to become a science under the laws of energy, geology in large measure must become a quantitative science. In the past it has been too frequently true that because a single force or agent working in a certain direction is a real cause of a” the phenomenon; another holding that this is the explanation>— cause. Only occasionally has the question been asked ‘Is this cause not only a real cause, but is it an adequate cause?’ Very often differences of opinion have arisen between geol- ogists, one holding that this cause is the one which explains the phenomenon, another holding that this is the explanation, and each insisting that the other is wrong. In such cases very rarely is the question asked whether the explanations offered are contradictory or complementary. In many cases the ex- planation is not to be found in one cause, but in several or many, and thus frequently the conclusions which have been interpre- ted to be contradictory are really supplementary. To illus- trate: But few writers have assigned more than a single cause for crustal shortening. One has held that secular cooling is the cause; another has given a different one, and has held that secular cooling is of little consequence. But it is certain that secular cooling, vulcanism, change of oblateness of the earth, change of pressure within the earth, changes in form of the material of the earth, and various other causes are not exclus- ive of one another, but are all supplementary. The ability to perceive the supplementary nature of various explanations of- fered for a phenomenon is one of the most marked, perhaps the most marked, of the characteristics of the superior man. The new geology must not only ascertain all of the real causes for crustal shortening, and other phenomena, but in order satis- factorily to solve the problems it must determine the quantita - tive importance of each. Geology within the next few years is certain to largely pass to a quantitative basis. 154 The American Geologist. Beptensber,, aie If I have correctly stated the relations of geology to the other sciences, it follows as a corollary that those only can greatly advance the principles of geology who have a working knowledge of two or more of the sciences upon which it is based. By a working knowledge of a science I mean such a knowl- edge of its principles as makes them living truths. One must not only be able to comprehend the principles, but he must see them in relations to one another; must be able to apply them. It is not sufficient for a carpenter to be able to explain how the hammer, saw, plane, and chisel work; he must be able to use them. He must be able to hit the nail on the head, to cut: straight, to plane smooth, to chisel true, and do all upon the same piece of timber so as to adapt it to a definite purpose in a building. Just so the geologist must be able to apply as taols the various principles of physics and chemistry and _ bi- ology and mineralogy to the piece of geology upon which he is engaged; and thus shape his piece to its place in the great structure of geological science. This is what is meant by a working knowledge of the sciences basal to geology. It is not supposed that any one man has a comprehensive knowledge of all the basal sciences, or even a working know- ledge of their principles; but such knowledge he must have of two or more of them if he hopes to advance the principles of ge- ology. He will be able to handle those branches of his subject with which he deals in proportion as he has a working knowl- edge of the basal sciences upon which his special branch is based, and will properly correlate this branch with the other branches of the great subject of geology in proportion as his working knowledge of the basal sciences is extensive. For instance, to advance geological paleontology one must have a working knowledge of the principles of biology and of stratigraphy. To advance any of the lines of physical geology, one must have a working knowledge of the principles of phys- ics, and especially of elementary mechanics. To advance physio- graphy one must havea working knowledge of physics and che- mistry. To advance knowledge of the early history of the earth, one must not only have a working knowledge of physics and chemistry, but of astronomy. To advance petrology, one must have a working knowledge of physics, chemistry and miner- Training of a Geologist—Van Hise 155 alogy. To advance the theory of ore deposition or metamor- phism, one must know not only the principles of physical geology, with all that implies; but he must have a working knowledge of chemistry, mineralogy, and petrology. It is unnecessary to add that a geologist must be able to read some of the modern languages, and be able to express him- self clearly and logically in one language. Considering the breadth and thoroughness of the necessa- ry preliminary training for the successful pursuit of geology, one might anticipate that geology would suffer but little from pseudo-scientists. But this anticipation is based upon the idea that no one attempts geological work, and especially to write - geological papers, until he is prepared to do so. All sciences have their cranks. Many a little town has its philosopher who believes that all of the principles of astronomy, of physics, of chemistry, which have been discovered by the great men of the past, are absolutely erroneous, and who makes a new start upon the construction of the world, building out of his brain strange vagaries which have no relation to the facts of the uni- verse. While there are temptations to pseudo-scientific work in all scicnces, the temptation is nowhere so great as in geology. The planets, sun and stars, are far off; the elements are elu- sive; to do anything with force one must have at least seen the inside of a physical laboratory; the manner of the transforma- tions of living forms is not obvious, or even apparently so, and few write about the constitution of plants and ani- mals who have not closely studied them. But one ts born upon the earth; he lives upon the earth; he sees the surround- ing hills and valleys. ‘The dullest sees something of the trans- formations going on. Many naturally become interested in the phenomena of the earth and, without preparation, think that they are able to make important contributions to the subject of geology. Thus not only in every city, but in many villages, is a geologist of local repute who has ready explanations for the order of the world. Geology starts as an easy observational study, and gradu- ally becomes more and more complex until it taxes the master mind to the utmost. This easy start leads to the multitude of local geologists, but geology suffers comparatively little from them. The real injury which the science receives is from 156 The American Geologist. Reptambes, 2aie some of those who call themselves professional geologists, are teachers of geology in academies and colleges, or even members of the staff of state or government surveys. These men have gone further than the local geologist, but perhaps they have been led into the subject for somewhat the same rea- son{—its easy start as an observational science. A man may begin his career as a geologist by making a few observations here and there and giving a guess as to their meaning. With this beginning he becomes more and more interested, until finally he decides to make geology his profession. In some cases, following this decision, the necessity is seen for obtaining a working knowledge of the basal sciences. But too often men who have entered upon geological work have received no adequate training in chemistry, in physics, in biology, and therefore at the outset wholly lack the tools to successfully interpret the phenomena which they observe. Such inadequately trained men feel that a satisfactory explana- tion of any phenomenon must involve a statement of the un- derlying chemical or physical or biological principles, and in such cases it is safe to say that-the explanations given are extremely partial, including only a modicum of truth, and more often than not are absolutely fallacious. Indeed, no other re- sult can be expected from one who tacks a working knowledge of the principles of physics, chemistry, and biology. Occas- ionally there is a clear-sighted. capable man, lacking in ade- quate training, who does important geological work simply be- cause he knows his limitations, and there stops. But this is very exceptional indeed; and the physical explanations offered by many for various geological phenomena are no less than grotesque. It has been made plain that a working knowledge of the sciences basal to geology is necessary in order to advance its principles. But f go even further, and hoid that such basal knowledge is absolutely necessary in order to do even the best descriptive work. Suppose a man to be standing before some complex geological phenomenon. The whole intricate interlocking story is engraved upon the retina of his eye with more than photographic accuracy. The image on the retina is absolutely the same in the eye of this experienced geologist and that of a child.. Yet if the child be asked to state what he Traning of a Geologist—Van Hise. 157 sees, his statements will be of the most general kind and may be largely erroneous. The experienced geologist with a know- ledge of the principles of physics and chemistry and biology interprets the phenomena imaged in terms of these subjects. The engraving on his retina is the same as that of a child, but his brain perceives the special parts of the picture of interest to him in their true proportions. He understands what is im- portant, what is unimportant. He must select and record the things which are important. If he attempted to record all that imaged in his eye, a notebook would be filled with the phen- omena to be described at a single exposure, and yet half the story would not be told. Good descriptive work is discrimina- tive. Good descriptive work picks out certain of the facts as of great value, others of subordinate value, and others of no val- ue for the purposes under consideration. How then can this dis- discrimination be made. How can the facts be selected which are of service? Only by an insight into the causes which may have produced the phenomena. Without this insight to some ex- tent at least a description is absolutely valueless. So far as the geologist has such insight, his description is valuable. It is frequently urged in opposition to the above that, ‘If a person has theories in reference to the phenomena which he observes his descriptions will be erroneous; he will be biased by his theories.’ Unfortunately in many cases this is so; but just so far as it is true, the man fails of the qualities which make a successful geologist. One’s theories undoubtedly con- trol in large measure the selection of the phenomena which are to be noted, and the wisdom of the selection is a certain cri- terion of the grade of the geologist. But whatever the facts selected for record, the statement of them should be absolutely unbiased by the theories. Invariably, good practice requires that the statement of facts and the explanation of these facts shall be sharply separated. Doubtless each geologist who is lis- tening has at different times had different ideas about the same locality, or while away from a locality a new idea has come as to the meaning of the phenomena there observed. Upon re- turning to the old locality with the new idea, additional obser- vations of value have been made, But all the statements of facts at the previous visits should be found to be absolutely true. In so far as they are untrue, the geologist fails of accuracy, the 158 The American Geologist. Reptermber rae first fundamental of observation. If the previous observations are found to be largely erroneous, the man who made them has small chance to become a good geologist. The difference be- tween bad observation and good observation is that the former is erroneous; the latter is incomplete. Unfortunately in many cases not only are the observations recorded by many men ab- solutely false, but they are so intertwined with the theories of the author that one is unable to discriminate between what is intended to be fact and what is advanced as opinion. It is needless to say that the case of such a man is hopeless; that there is no possibility that he shall ever become a geologist. I conclude, therefore, that in order to have a standing in the future, even as a descriptive geologist, one must interpret the phenomena which he observes in the terms of the princi- ples of astronomy, physics, chemistry, mineralogy, and biology. If my statement thus fat be true, the outline of the training of a man hoping to become a professional geologist is plain. Such a man should take thorough and long courses in each of the subjects of astronomy, physics, chemistry, mineral- ogy, and biology. This means that a large part of the train- ing of a geologist is the study of the sciences upon which geology is founded. If a man who hopes to be a geologist is wholly lacking in a knowledge of any of the basal sciences, this defect he can probably never make good. Even if he so desires, the time cannot be found. Moreover, chemistry, phys- ics, mineralogy, and biology are laboratory sciences and can be satisfactorily handled only in the laboratory. If the fun- damental work in the basal subjects has been done in the col- lege or university, one may keep abreast of their progress dur- ing later years , but in order to do this, the basal principles must have, become living truths to him while a student. If a person- al illustration be allowable, during the past five years, in order to handle the problems of geology before me, I have spent more time in trying to remedy my defective knowledge of physics and. chemistry and in comprehending advances in. these sciences since I was a college student than I have spent upon current papers in geology, and with, I believe, much more profit to my work. If one has a working knowledge of the basal sciences and lacks training in some branch of geology, this defect he may, remedy, for he has the foundation upen eS Se Tcl Training of a Geologist—Van Hise. 159 which to build. But if he lacks knowledge of the primary principles of the basal sciences he is likely to be a cripple for life, although this is not invariably the case. There are con- spicuous instances where lack of early training in the basal sciences has been largely remedied by unusual ability and in- dustry, but this has been most difficult. We should see to it that the young men trained in our colleges and universities, upon whom we place the degree of Doctor in Geology, are not crippled by the necessity of making good in later life defec- tive basal training. Any university which gives a man the degree of Doctor in Geology with a defective knowledge of the basal sciences is wronging the man upon whom the degree is conferred; for this man has a right to expect that his courses shall have been’so shaped as to have given him the tools to handle the problems-which will arise in his chosen profession. It is not necessary that all of the basal work shall be done before a man begins his life work, but at least a large part of this work should have been done before a man is given the certificate that he can do the work of a professional geologist. But in any case studies in the basal sctences should not cease when the professional degree is granted. Continued studies not only in the basal subjects but in cognate branches and even those far removed from science should continue through life. The geologist finds that however broad and deep his studies are in basal and cognate subjects, that he is continually limited by lack of adequate knowledge of them. In recent years it has been a moot question in colleges and universities as to when specialization should begin, rather implying that when specialization begins broadening studies should cease. And, indeed, it is upon this hypothesis that most of the discussion upon this subject has been carried on. Some have held that specialization should not begin until late in the college course, or even rather late in a postgraduate course. Others have held that one should early direct his studies to special subjects which he expects to pursue, and give coniparatively little time to other subjects. The argument for this latter course is that competition is now keen, and if a man keeps in the race he must begin to specialize early. It appears to me that both of these answers are inadequate. My answer to the question is that specialization should begin early, 160 The American Geologist. PeprSmDer isis but that broadening studies should not be discontinued. This rule should obtain not only through the undergraduate course, but in the postgraduate work and during professional life. The specialized work will be better done because of the broad grasp given by the other subjects. The broadening studies will be better interpreted because of the deep insight and knowledge of a certain narrow field. Thus each will help the other. No man may hope for the highest success who does not continue special studies and broadening studies to the end of his career. But is it held that a geologist lacking an adequate working knowledge of basal studies cannot perform useful service? No, the domain of geology is so great, the portion of the earth not geologically mapped and the structure worked out issovast, the ore and other valuable deposits. which have received no study are so numerous, that there is an immense field for the application of well-established principles. In geology, as in engineering and other applied sciences, there is an opportunity for many honest, faithful men to perform useful service to the world even if their early training and capacity are not all that could be desired. But even the application of old principles to new areas will be well done in proportion as the geologist has training in the basal sciences, and to the man who com- bines with such training talent must necessarily be left the ad- vancement of the philosophy of geology. The philosophy of ge- ology, the inner meaning of phenomena, was the paramount consideration to Hutten and Lyell and Darwin. To them facts were useful mainly that they might see common factors, the great principles which underlie them, or in other words, gener- alization. To correctly generalize in geology involves the capa- city to hold a vast number of facts in the mind at the same time; to see them in their length and breadth and thickness; to see them at the same time as large masses and as composed of parts, even to the constituent mineral particles and the ele- ments ; to see the principles of physics and chemistry and min- eralogy and biology interlacing through them. Only by hold- ing a multitude of facts and principles in one’s mind at the same time can they be reduced to order under general laws. Failure thus to hold in one’s mind a large number of facts and principles leads to lack of consistency. Often in a single Training of a Geologist—Van Hise. 161 book, or a single chapter, or on the same page, or even in the same paragraph or sentence, are contained ideas which are exclusive of one another. They are not seen by the writer to be exclusive of one ancther because he is so lacking in a com- mand of the principles of the basal sciences that he is not aware of the antagonism. Major Powell once said to me, ‘The stage of the development of the human mind is measured by its capacity to eliminate the incongruous.’ If this hard criterion were rigidly applied, it would follow that many of our pro- fession have not passed the youthful stage. The man who can insert in the same treatise, chapter or page incongruous ideas saves an immense amount of cerebral tissue for himself. Such a man cai write on through chapters and books, and not find . it necessary to go back, adjust and interrelate the various parts. here is no action and reaction between the multitude of ideas. The writer has the easy task of holding in his mind at any one time but a few data. He is in delightful and happy uncon- sciousness of the fact that many of his statements destroy one another. But the man who sees the phenomena and principles of geology in all their complex relations, tries to express the parts of them he is considering in proportion to one another, and to place his fragment of the science of geology in prop- er relations to other departments of geology and other natural sciences, has a task before him requiring great mental effort. He must see and understand in three dimensions. At every point he must see the lines of cause and effect radiate and con- verge upon the phenomena he is considering from many other phenomena and principles. Of course all fail to do this com- pletely in reference to any complex problem. All fail to reach the ultimate truth. To do so would require infinite capacity. But in so far as success would be attained, the effort must ‘be made. In preportion as one can hold many facts and prin- ciples and see their interrelations, he will be able to advance the philosophy of geology. This is the work which burns the brain. And his results he must express in language, the chief means of communicating ideas and relations. Yet language is linear. By figures, models, maps and other illustrations, wisely used, one may to an important degree remedy the defects of linear language. Yet language and illustration, even where used 162 The American Geologist. BeptemiDeh noes to the best advantage, but poorly convey one’s ideas. Most conscientious writers require as much or more time to put a complex subject into words and illustrations ready for publi- cation as they do in working out the results. sut upon the other side, and in favor of expression in lan- guage, it should be remembered that there is action and reaction between one’s ideas and the attempt to express them in words and illustrations. The necessity for expression in language is often a wonderful clarifier of ideas. The ideas are improved by the attempt at expression, and the expression is continually improved as the ideas are enlarged. That the difficulty as to expression does not apply to geology alone is well illustrated by the vast amount of labor Charles Darwin spent in putting into the linear form of language the most revolutionary work of the time, “The Origin of Species.’ It seemed as if the intricately interrelated facts of life were of * Missouri Geological Survey, vol. x, p. 128. ; A Editorial Comment. 193 the Iowan ice-epoch, and that would make it five times the period elapsed since the final retirement of the ice. Post-glacia! time has been computed in various ways, and it has been pretty nearly unanimously agreed that post-glacial time does not ex- ceed 10,000 years, and probably amounts to ahout 8,000 years. . Accepting the lower term, the age of the Lansing man is found to be near 40,000 years. These time-ratios, however, are tentative, as given by Chamberlin, and may require consid- erable modification. ’ From a study of the interglacial gorge running through the west part of the city of Minneapolis, the -vriter calculated that about 15,000 years were required for its excavation by the Mississippi river.* It was supposed to have been formed immediately prior to the Wisconsin epoch and after the Iowan. On that supposition the close of the Iowan epoch was approxi- mately 23,000 years ago. If 8,000 years be added to this for the duration of the Iowan (which is probably too small an ai- lowance) the commencement of that epoch, which may be as- sumed to be about coeval with the Lansing skeleton, was about 31,000 years ago. If, however, the interglacial Mississippi gorge at Minneapolis was excavated at some earlier interglacial epoch, say the Buchanan (pre-Iowan) or the Aftonian (as suggested by Mr. Upham) it antedates the Iowan loess, and cannot serve as a factor in any calculation as to the age cf the Lansing skeleton. It will require, therefore, considerable further and careful examination of the loess sheets of Iowa, and of their relations to the till-sheets, as well as the marginal features ec! the till- sheets themselves, to enable anyone to fix with any certainty the age of the Lansing skeleton more exactly than is above in- dicated. That it dates from glacial time, at some remote point in the complex history of that age, is about all that can be affirmed from the present state of knowledge of the drift de- posits. | It remains to call attention to a newspaper story which af- firms that formerly a cemetery of the Fort Leavenworth pene- tentiary was located at or near this place, and that the skeleton is but one of numerous others that could probably be found in the immediate vicinity if sufficient exploration should be under- *An approximate interglacial chronometer, AM. GEOL., vol. x, p. 69 and 302, 1892. 194 The American Geologist. Sentra bate taug taken. It is not at all likely that the four geologists who niade the recent joint examination, and who are supposed to be ex- pert in the detection of all irregularities in the ground and all such variations that would be implied in the existence of a modern burial at this place, would have failed to observe the disturbance which such a burial would have produced. Again, on the authority of Mr. Long it appears that such former burial place was at a distance of three miles from the place at which this skeleton was found. Still the same imputation can be brought against this skele- ton as against numerous other alleged human relics discovere«l in glacial or pre-glacial deposits, viz.: no scientist was present at the time of discovery to vouch for the fact and to verify the place and the surroundings of the skeleton. N. H. W. MONTHLY AUTHOR’S CATALOGUE OF AMERICAN GEOLOGICAL LITERATURE ARRANGED ALPHABETICALLY, AMI, H. M. Esquisse géologique du Canada; materiaux pour servir a la prep- aration d’un chronographe géologique, Quebec, pp. 66, 1902. BARBOUR, E. H. (C. R. Eastman and). Synopsis of the Missourian and Permo-Carboniferous fish fauna of Kansas and Nebraska. (Science, vol. 16, p. 266, Aug. 15, 1902. Abstract.) e BARON, J. F. P. Some geological notes in Honduras, Central America. (Science, vol. 16; p. 264, Aug. 15, 1902. Abstract.) BELL, ROBERT. ) An outline of Idaho geology and of the principal ore deposits of Lemhi and Custer counties, Idaho. (Proc. Internat. Min. Cong., 1901, pp. 64-80.) BROADHEAD, G. C. The New Madrid earthquake. (Am. Geol., vol. 30, pp. 76-88, Aug. 1302.) ; BROOKS, A. H. (and G. B. RICHARDSON, A. J. COLLIER and W. ‘Cc. MENDENHALL). Reconnaissances in the Cape Nome and Norton Bay regions, Alaska, in 1900. U.S. G.oS., pp. .222; pis. 17, Washington, 190i CALVIN, S. The Geology and Geological resources of Iowa. (Proc. Inter- nat. Min. Cong., 1901, pp.. 52-56.) a ee Author's Catalogue. 195 CLARKE, J. M. Report of the state Paleontologist, [N. Y.] 1901. Bull. 52, N. Y. State Mus., pp. 419-693, Albany, 1902. CLARKE, J. M. (R. RUEDEMANN and DD. LUTHER) Contact lines of Upper Siluric formations on the Brockport and Medina quadrangles. (Bull. 52. N. Y. St. Mus., Rep. State Pal., pp. 517-523.) CLARKE, J. M. George Bancroft Simpson. (Bull. 52, N: Y. State Mus., Rep. St. Paleontologist, pp. 457-460.) ’ CLARKE, J. M. Preliminary statement of the paleontologic results of the areal survey of the Olean quadrangle. (Bull. 52, N. Y. St. Mus., Rep. St. Pal., pp. 524-528.) CLARKE, J. M. The indigene and alien faunas of the New York Devonic. (Bull. 52, N. Y. St. Mus., Rep. St. Pal., pp. 664-672.) CLARKE, J. M. A new genus of; paleozoic brachiopods, Eunoa, with some consid- erations therefrom on the organic bodies known as Discinocaris, Spathiocaris and Cardiocaris. ( Bull. 52, N. Y. St. Mus., Rep. St. Pal., pp. 606-615.) CLELAND, H. F. The landslides of Mt. Greylock and Briggsville, Mass. (Jour. Geol., vol. 10,-pp. 513-518, July-Aug., 1902.) CLEMENTS, J. MORGAN. The Vermilion district of Minnesota. (Science, vol. 16, p. 261, Aug. 15, 1902. Abstract.) CLEMENTS, J. MORGAN. Ellipsoidal structure in the pre-Cambrian basic and intermedi- ate rocks of the lake Superior region. (Science, vol. 16, p. 260. Aug. 15, 1902. Abstract.) COLEMAN, A..P. Nepheline syenites and other syenites near Port Coldwell, On- tario. (Am. Jour. Sci., vol. 14, pp. 147-156, Aug., 1902.) COLLIER, A. J. (A. H. BROOKS, G. B. RICHARDSON, W. C. MENDENHALL and). Reconnaissances in the Cape Nome and Norton Bay regions, Alaska, in 1900. U.S) G. S., pp. 222, pls. 17; Washington, 1901. CRAWFORD, J. : List of the most important volcanic eruptions and earthquakes in western Nicaragua within historical time. (Am. Geol., vol. 30, pp. 111-113, Aug., 1902.) CROSS, WHITMAN. The development of systematic Petrography in the nineteenth century. (Jour. Geol., vol. 10, pp. 451-500, July-Aug., 1902.) 196 The American Geologist. eeprom her, tee DAVIS, “WW. M. Systematic Geography. (Science, vol. 16, p. 266, Aug. 15, 1902. Abstract.) DAVIS, W. M. Terraces of the Westfield river, Mass. (Am. Jour. Sci., vol. 14, pp. 77-95, Aug. 1902.) EASTMAN, C. R. (and E. H. BARBOUR). Synopsis of the Missourian and Permo-Carboniferous fish fauna of Kansas and Nebraska. (Science, vol. 16, p. 266, Aug. 15, 1902. Abstract.) EASTMAN, E.R. Some hitherto unpublished observations of Orestes St. John on Paleozoic fishes. (Am. Nat., vol. 36, pp. 653-659, Aug., 1902.) EASTMAN, C. R. Phylogeny of the Cestraciont group of sharks. (Science, vol. 16, p. 267, Aug. 15, 1902. Abstract.) EASTMAN, Cc. R. The Carboniferous fish fauna of Mazon creek, Illinois. (Jour. Geol., vol. 10, pp. 535-541, July-Aug., 1902.) ECKEE; E.G. The quarry industry in southeastern New York. (20th Rep. N. Y. State Geol., 1900, pp. 1438-176.) EMERSON, B. K. Two cases of metamorphosis without CRU RIES (Am. Geol., vol. 30, pp. 73-76, Aug., 1902.) EMERSON, B. K. Holyokeite, a purely feldspathic diabase from the Trias of Mas- sachusetts. (Jour. Geol., vol. 10, pp. 508-512, July-Aug., 1902.) FAIRCHILD, H. L. Pleistocene geology of western New York. (20th report, N. Y. State Geol., 1900, pp. 105-139.) FARRINGTON, O. C. Meteorite studies, I. Field Col. Mus., Geol. Ser., vol. 1, pp. 284- 315, May, 1902. FARRINGTON, O. C. The meteorites of northwestern Kansas. (Science, vol. 16, p. 2cyv, Aug. 15, 1902.’ Abstract.) GRABAU, A. W. Geological excursions in the Pittsburg coal region. (Science, vol. 16, pp. 274-276, Aug. 15, 1902.) HALL, C. WW. The Geology of Minnesota. (Proc. Int. Min. Cong., 1901, pp. 165-171.) HATCHER, J. B. Origin of the Oligocene and Miocene deposits of the great plains. (Am. Phil. Soc. Proc., vol. 41, pp. 113-132. April, 1902.) “se. ae Author's Catalogue. 197 HAWORTH, EF. Geology and mining interests of Kansas. (Proc. Internat. Min. Cong., 1901, ppv. 196-200.) HERRICK, C. L. Applications of geology to economic problems in New Mexico. (Proc. Internat. Min. Cong., 1901, pnp. 61-64.) HILL, ROBT. T. Geography and Geology of the Black and Grand prairies, Texas. 21 Ann. Rep. U. S. G. S., 1899-1900, Part 7, pp. 666, pls. 71 Wash- ington, 1901. HITCHGOCK, C. H. The Mohokea caldera. on Hawaii. (Science, vol. 16, p. 260, Aug. 15, 1902. Abstract. HOBBS, W. H. A new meteorite from Algoma, Kewaunee county, Wisconsin. (Science, vol. 16, p. 260, Aug. 15, 1902. Abstract.) HUNTINGTON, ELLSWORTH. The great canyon of the Eunhrates river. (Science, vol. 16, p. 265, August, 1902. Abstract.) : IHERING, (von) H. On the molluscan fauna of the Patagonian Teritary. (Proc. Am. Phil. Soc., vol. 41, pp. 132-137.) : KEYES, C. R. Geographical age of certain gypsum deposits. (Am. Geol., vol. 30, pp. 99-103, Aug., 1902.) LOUDERBACH, G. D. General geological features of Nevada, and their relationships to the prevailing economic deposits. (Proc. Internat. Min. Cong., 1901, pp. 200-207.) LUTHER, D. D. Stratigraphic value of the Portage sandstones. (Bull. 52, N. Y. State Mus., Ren. St. Pal., pp. 616-631.) LUTHER, D. D. (J. M. CLARKE, R. RUEDEMANN ang). Contact lines of the Upper Siluric formations on the Brockport and Medina quadrangles. (Bull. 52, N. Y. St. Mus., Rep. St. Pal., pp. 517-523.) MARBUT, C. F. Development of the Southeastern Missouri Lowlands. (Science, vol. 16, p. 262, Aug. 15, 1902. Abstract.) MENDENHALL, W. C. (A: H. BROOKS, A. J. COLLIER, G. B. RICHARDSON and). Reconnaissances in the Cape Nome and Norton Bay regions, Alaska, in 1900. U. S. G. S., pp. 222, pls. 17, Washington, 1901. MERRIAM, JOHN C. Triassic Ichthyopterigia from California and Nevada. Univ. of Cal., Dept. Geol. Bull., vol. 3, pp. 63-108, pls. 5-18, June, 1902. MOSELENY., EE. Submerged valleys in Sandusky bay. . (Science, vol 16, p. 265, Aug: 15, 1902. Abstract.) 198 The American Geologist. Sep Rem BSE ares MOORE, CHAS. J. The formation of the Leadville mining district. (Proc. Internat. Min. Cong., 1901, pp. 175-179.) MOORE, CHAS. J. The formation of the Cripple Creek mining district, Teller coun- ty, Colorado. (Proc. Internat. Min. Cong., 1901, pp. 87-91.) OGILVIE, J. H. An analcite bearing camptonite from New Mexico. (Jour. Geol., ’ vol. 10, pp. 500-507, July-Aug., 1902.) O’HARRA, C. C. Black Hills ore deposits. (Proc. Internat. Min. Cong., 19301, pp. 97-100.) PEARSON, H. W. A nebulo-meteoric hypothesis of Creation. pp. 38, Duluth, 1902. PRESTON, H. L. Niagara meteorite. (Jour. Geol., vol. 10, pg. 518-520, July-Aug., 1902.) x PROSSER, C. S. . Richard Burton Rowe. (Am. Geol., vol. 30, pp. 128-130, Aug., 1902.) RICHARDSON, G. B. (A. H. BROOKS, A. J. COLLIER, W. C. MENDENHALL and). Reconnaissances in the Cape Nome and Norton Bay regions, Alaska, in 1900. U. S. G. S.; pp. 222, pls. 17, Washington, 1901. RUEDEMANN, R. (J. M. CLARKE and D. D. LUTHER). Contact lines of Upper Siluric formations on the Brockport and Medina quadrangles. (Bull. 52, N. Y. St. Mus., Rep. St. Pal., pp. 517-523.) RUEDEMANN, RUDOLF. The Grapolite (Levis) facies of the Beckmantown formation in Rensselaer county, N. Y. (Bull. 52, N. Y. St. Mus., Rep. St. Pal., pp. 544-575.) RUEDEMANN, RUDOLF. Modé of growth and development of Goniograptus thureaui Mc- Coy. (Bull. 52, N. Y. St. Mus., Rep. Pal., pp. 576-592.) SCHRADER, F. C. (and A. C. SPENCER). The geology and mineral resources of a portion of the Copper river district, Alaska. U.S. G. S., pp. 94. pls. 18, Washington, 1901. SPENCER, A. C. The Pacific Mountain system of British Columbia and Alaska. (Science, vol. 16, p. 261, Aug. 15, 1902. Abstract.) SPENCER, A. C. (F. C. SCHRADER and). The geology and mineral resources of a portion of the Copper river district, Alaska. U.S. G. S., pp. 94, pls. 13; Washington, 1901: SPRINGER, FRANK. On the crinoid genera Sagenocrinus, Forbesiocrinus and allied forms. (Am. Geol., vol. 30, pp. 88-98, Aug., 1902.) SPRINGER, FRANK. Notice of a new Comatula from the Florida reefs. (Am. Geol., vol. 30, p. 98, Aug., 1902.) Author's Catalogue. 199 TALMADGE, JAMES E. The geology of Utah. (Proc. Internat. Min. Cong., 1901, pp. 42- 48.) UPHAM, WARREN. a Growth of the Mississippi delta. (Am. Geol., vol. 30, pp. 103- 111, Aug., 1902.) VAN INGEN, GILBERT. The Potsdam sandstone of the lake Champlain basin: notes on field work, 1901. (Rep. N. Y. State Paleontologist, 1901, pp. 529- 545. WARD, H. A. The Bacubirito meteorite. (Science, vol. 16, p. 267, Aug. 15, 1902. Abstract. WELLER, STUART. Crotalocrinus ecora (Hail). (Jour. Geol, vol. 10,. pp. 532-534, July-Aug., 1902.) WHITE, IC. The geology of the Pittsburg district. (Science, vol. 16, p. 258, Aug. 15, 1902.) Abstract. WHPFETE, I. C. : The geology of West Virginia. (Proc. Internat. Min. Cong., 1901, pp. 56-61.) WHITE, DAVID. Fossil Alga from the Chemung of New York, with remarks on the genus Haliserites, Sternberg. (Bull. 52, N. Y. St. Mus., Rep. St. Pal., pp. 593-605.) WHITE, DAVID. Stratigraphy versus Paleontology. (Science, vol. 16, p. 232, Aug. 8, 1902.) WIELAND, G. R. Cretaceous turtles, Toxochelys and Archelon, with a classifica- tion of the marine Testudinata. (Am. Jour. Sci., vol. 14, pp. 95- - 109, ‘Aue.,. 19022) WILLISTON, S. W. On the skull of Nyctodactylus, an upper Cretaceous Pterodactyl. (Jour. Geol, vol. 10, pp. 520-531, July-Aug., 1902.) WINCHELL, N. H. “ Sketch of the iron ores of Minnesota. (Proc. Internat. Min. Cong., 1901, pp. 136-140.) WORTMAN, J. L. Studies of HKocene Mammalia in the Marsh collection, Peabody Museum, Part 1, Carnivora. (Am. Jour. Sci., vols. 11-14, 1901- 1902.) WRIGHT, G. FREDERICK. Possible effects of the Glacial period upon the low levels of Central Asia. (Science, vol. 16, p. 262, Aug. 15, 1902. Abstract.) WRIGHT, G. FREDERICK. Recent Geology of the Jordan valley. (Science, vol. 16, p. 263, Aug. 15, 1902. Abstract.) 200 The American Geologist. SEDRet Vet aaee CORRESPONDENCE. Tre New Mapriv EartHouake. In his valuable and instructive article on “The. New Madrid Earthquake” in your current number, professor Broadhead makes no reference to ‘a source of information which I have regarded as of first importance, viz: Mitchill’s article in ‘Transactions of the Literary and Philosophical Society of. New York,’ Vol 1, 1815, pp. 281-307. The full title of the article is, ““A detailed Narrative of the Earthquakes which occurred cn the 16th day of December, 1811, and agitated the parts of America that lie between the Atlantic Ocean and Louisiana; and also a particular account of the-other quakings of the earth oc- casionally felt from time to time to the 23d and 30th of January, and the 7th and 16th of February, 1812, and subsequently to the 18th of December, 1813, and which shook the country from Detroit and the Lakes to .New Orleans and the Gulf of Mexico. Compiled chiefly at Washington, in the District of Columbia. By Samuel L. Mitchill, Representative in Congress, etc. (Read before the Society on the 14th of April, and the 12th of May, 1814.)” Briefer articles on then recent earthquakes in Venezuela, on the volcano and earthquake in the island of St. Vincent, on volcanoes in the Azores, and on the atmo- spheric disturbances accompanying the New Madrid earthquake, are appended on the ensuing pages 308-340. Dr. Mitchill’s article is by far the fullest contemporary account known to me. It is rendered especially valuable by the full and ex- plicit data relating to the earthquake in its eastern extension. From the data it appears that the primary shock of December 16, 1811, was destructive at Charleston and many other points in South Caro- lina, at Richmond and elsewhere in Virginia, at Washington, at Fort Duquesne (Pittsburg), at Detroit, at Fort Dearborn (Chicago), and at many other points so distributed as to indicate that the area affected by the earthquake must have reached ‘at least a million and a quarter square miles, or some two-fifths of the present area of the United States. He introduced many-original records not elsewhere published ; among others a letter from William Shaler, Esq., kinsman of the distinguished geologist of Harvard, who was descending the Missis- sippi in a flat-boat when the subsequent shock of February 7, 1812, occurred and whose craft was caught and floated up-stream ‘‘with the velocity of the swiftest horse.” Another contemporary record of value was that of Engineer Louis 3ringier, published in an early number of the American Journal of Science, whose name is misprinted “Binegler” in professor Broadhead’s article (p. 83); and it is of interest to note that Dekay’s type of Bos pallassi (now Ovibos cavifrons) was founded on a skuli thrown out of one of the earth fissures formed during the New Madrid dis- turbance. My own information relating to the earthquake was origi- nally derived from a manuscript diary, or ordinary book, kept by a grandfather residing in Barren county, Kentucky, during the period Correspondence. 201 1811-1813, where the disturbances were severe and often destructive. Unfortunately this record is no longer in existence. It was my fortune in 1891 to traverse a considerable part of what may be called the epicentral area of the New Madrid earthquake, and to trace certain of its geographic: and other effects. These include fissures in both bluffs and bottom-lands, those in the bluffs being simple chasms generally cleaving ridges or paralleling scarps, and still remaining open sometimes to depths of three to five feet; while the fis- sures in the bottom-lands are usually marked by banks of gravel erupt- ed from earlier Columbia deposits beneath the Port Hudson clays, some of these gravel banks being fifty to one hundred feet wide, hundreds of yards long, and three to ten feet high. Still more striking, of course, are Reelfoot lake, east of the river, and the “sunk country,’ which replaces a river system (Whitewater) on the west; but to my mind the most impressive phenomenon of all is the lifted country lying athwart the valley of the great river a few miles below New Madrid. This area may be likened to a low elliptical dome, springing from the western shore of Reelfoot lake and the eastern border of the sunk country; it measures some twenty miles in width from east to west, and thirty or forty miles in transverse diameter ; its hight, estimated from the elevation above the river in comparison with the hight of banks above and below, may be twenty or twenty- five feet. The various phenomena still traceable on the ground have been repeatedly described in lectures; and an abstract of one of these, under the title “A Fossil Earthquake,’ was published in Bull. Geol. Soc. Am., Vol. 4, 1892, pp. 411-414. W. J. McGee. Washington, D. C., Aug. .14, 1902. PERSONAL AND SCIENTIFIC NEWS. Mr. H. O. Woop has been appointed assistant in mineralogy and petrography at Harvard University for the coming acade- mic year. Mr. T. T. Reap, E. M. (—’o2 School of Mines, Columbia University) has been appointed instructor in mining and met- allurgy in the University of Wyoming. Mr. Wm. C. PHaten, M. S., of Gloticester, Mass., has been appointed an aid in the Department of Geology in the U. S. National Museum at Washington. Mr. Phalen is a graduate of the Massachusetts Institute of Technology and was for two years engaged in teaching in the School of Mines, Socorro, New Mexico. He comes to the Museum under the civil service regulations, and will have immediate charge of the petrographic collections. WISCONSIN GEOLOGICAL AND NaAturAL History Survey. Dr. Samuel Weidman, assisted by Mr. W. D. Smith, is engaged in mapping a district in the north central part of the state. The rocks of this area are of Pre-Cambrian and Cambrian age, 202 The American Geologist. ROP GRRE ia the former consisting of granites, gneisses, nepheline syenytes, quartzytes and slates, and the latter of Potsdam sandstone. The district is crossed by the boundary of the driftless area and Dr. Weidman has been able to differentiate several drift deposits lying outside of, and earlier than, the terminal mor- aine of late Wisconsin age. It is hoped that a report on this district in the north central part of the state, to be issued as a bulletin of the Survey, will be ready within a year. In the meantime a report on the soils of the district is being pre- pared for the Annual Report (for 1902) of the State Board of Agriculture. Dr. E. R. Buckley, now state geologist of Missouri, be- gan the preparation of a report on the road materials of Wis- consin while connected with the Wisconsin Survey, and it is expected that this report will be issued shortly. Professor N. M. Fenniman, of the University of Colorado, has prepared a report on the lakes of Wisconsin and their phys- iographic features, which is now in press. Professor U. S. Grant, of Northwestern University, is en- gaged in a study of the lead and zinc deposits of the south- western part of the state, where there is a revival of mining interest. A preliminary report on these deposits will be pre- pared during the coming fall and winter. COLUMBIA UNiversrry Notes: = Professor J. F2 Kemp left immediately after commencement for Wyoming, and passed a week in the study of the Rambler Copper mine and vi- cinity under the direction of Dr. David T. Day of the U. S. Geological Survey. The occurrence of the platinum group of metals with the copper lends special interest to the mine. Sub- sequently, in company with professor Wilbur C. Knight of the University of Wyoming, trips were made to the titaniferous magnetite at Iron Mountain and into the Leucite hills. Pro-~ fessors Knight and Kemp plan a joint paper upon the latter. many new data having been accumulated regarding the struc- tural geology of the Leucite hills. The regular work of the second session in field geology for students in the Columbia School of Mines was conducted last year at Marquette, Michigan, by professor Grabau, owing to the illness of professor Kemp. This year it was given by professor Kemp at Bingham Canyon, Utah, during the week beginning July 13. A geologic map of the region around the principal mines was prepared by a class of fifteen, and observations were also made underground. In connection with this each pair of students will make a petro- graphical and chemical examination of the different rocks and ores found in the field. Every courtesy was extended to the party by the officials of the United States Mining Company, where headquarters were established, and by others in the camp. . LIBRARY Eek. THEY rs UNIVERSITY of ILLINOIS \ Io it THE AMBRICAN GEOLOGIST, VoL. XXX. PLATE IV. CAVATION. HENRY A. WARD. pad —UBRARY Bee a OF THE UNIVERSITY of ILLINOIS ; 1D 4 which was given to the world in 1795. This work was evidently intended by its author to consist of four parts, though prior to his death in 1797 only two parts had been 216 The American Geologist. October, 1902. fully completed and published, and it is in the second part that he refers to the transport of erratics by ice*. The manuscript of a portion of the third part, for over forty years in the possession of the Geological Society of London, has re- cently been published (1899) by the council of the society, with Sir Archibald Geikie as editor. Geologists of the present day, however, learn also of Hut- ton’s views through his friend and biographer, John Play- fair, in the “Illustrations of the Huttonian Theory of the Earth,” published in 1802. Playfair therein voices the opin- ion of Hutton concerning glaciers when he says that “for the removing of large masses of rock, the most powerful en- gines without doubt which nature employs are the glaciers, those lakes or rivers of ice which are formed in the highest valleys of the Alps, and other mountains of the first order. Before the valleys were cut out in the form they now are, and when the mountains were still more elevated, huge fragments of rock may have been carried to great distances ; and it is not wonderful if these same masses, greatly diminished in size, and reduced to gravel or sand, have reached the shores or eve:, the bottom of the ocean.” This original suggestion concerning the transportation of the erratic blocks of Switzerland by glaciers, at a time of great extension of ice in the Alps, apparently passed out of mind, however, till some thirty years later. Venetz and Charpentier were first to resume this study of glacial work in tracingé the dispersal of crystalline rocks of the central Alps, over the great Swiss plain to the Jura mountains; f but it remained for another to comprehend the full significance of the conditions observed, and to evolve investigations which led to the recognition of the Ice age, with its supremely im- portant bearing upon geology, and the antiquity of man. Jean Louis Rudolph Agassiz is the man who is universally recognized as the founder of glaciology. Agassiz was born in Switzerland in 1807, rose to distinction by his scientific work in Europe previous to 1846, when he came to the United States. Two years later he was elected professor of zoology and geology at Harvard University, and made *Theory of the Earth, Part 2, pp. 174. 218. +Sehweizer Gesell. Verhandl, 1834, p. 23. Ann. des Mines VIlll, 1835, p. 219. Leonhard and Bronn, Neues Jahrb, 1837, p. 472. ‘ Glacier Work.—Scott. 217 this country his home till his death in 1873. Two of his most important contributions to glaciology are ‘‘Etudes sur ies gla- ciers” (1840) and “Systeme Glaciare”’ (18477). It is inter- esting to note in connection with the work of Agassiz in Eu- rope that he believed “the great extension of ice was con- nected with the last great geological changes on the surface of the globe, and with the extinction of the large pachyderms, whose remains are so abundant in Siberia. He believed that “the glaciers did not advance from the Alps into the plains, but rather that the ice once covered all the grounds, and finally retreated into the mountains.”* He further demon- strated the identity of the conditions which obtained in Bri- tain with those of Switzerland, claiming that “not only gla- ciers once existed in the British Islands, but that large sheets of ice covered all the surface,” + and in extending his in- vestigations to America, showed that the northern part of this continent also, including the northern and eastern por- tions of the United States have been under an enormous ice mass. In the history of glaciology his researches have been most admirably supplemented by the works of Buckland, Lyell, Darwin, Archibald Geikie, James Geikie, Dana, Le Conte, Daubrée, Heim, Forbes, and many others who might be mentioned, until the literature upon the subject is not only most voluminous, but highly instructive concerning the past history of the world as indicated by present day glaciological evidence. In a comprehensive work on glaciers published twenty years ago, Prof. Shaler, of Harvard University, expressed the opinion that “Of all the elements of our understanding of the past, the knowledge of the changes of condition in the earth brought about by glaciers is clearly the most important.” = Whether this statement still remains undisputed, is perhaps open to question, yet the fact certainly holds that geology has a valuable corner stone that has been properly placed by glaciology. The reference to the history of the subject here given is extremely brief, and interested students may read with *The Founders of Geology, Geikie, A. p. 274. 7Proc. Geol. Soc., Vol. III. (1840), p. 331. tGlaciers. Shaler and Davis. 1881. 218 The American Geologist. October, 1902. pleasure and profit, “The Founders of Geology,” by Archi- bald Geikie, (1897), “Illustrations of the Huttonian Theory of the Earth,” by Playfair (1802), and “Theory of the Earth, As by James Hutton (1795). Classification. For convenience in considering this subject it may be di- vided into two general classes: glaciers of the present, and glaciers of the past. The former class may be said to include the existing glaciers of the mountainous portion of the globe, together with the polar ice sheets, while the latter class con- siders particularly the great continental glaciers. We may further distinguish broadly between the two prominent types of present glaciers, which have been termed the Alpine or mountain glaciers, and the polar ice-fields of the Greenland type.* First, the area of the polar glaciers is enormous, compared with that of the Alpine; secondly, the maximum rate of motion is much greater in polar than in Alpine glaciers; and thirdly, the economic results produced by the one are vastly different from those produced by the other. A glacier in general may be defined as a gigantic mass of ice formed from snow falling in altitudes above the snow line, and subsequently assuming a granilar form, which, as it moves by gravitation to lower levels, becomes compacted into a mass known as névé, which gradually takes ona charac- teristic blue, crystalline structure as the air is squeezed out by motion, and compression, and becomes glacier ice. The Great Aletsch and Gorner glaciers of the Swiss Alps, are typical examples of mountain. glaciers, where, as is often the case, the main ice stream is produced by the com- bination of many tributary streams. The St. Elias Alps in North America, however, furnish the grandest examples of this type (which is known as Alpine because it was first systematically studied in the Swiss Alps) from the fact that Mt. St. Elias and Mt. Logan, its giant neighbor (19.500 *Notrr.—Some authors include in their classification, glaciers of the Seandinavian type, as separate from those here given. Such a clas- sification may be preferable in some respects; the reason for not dis- tinctively including it here is, that a glacier of the Scandinavian type is defined, according to Johnson's Encyclopeda, as ‘“‘A broad sheet: of ice accumulating on a mountainous plateau,’ et cetera. ‘Therefore this type appears to find a place under ‘glaciers of the mountainous portions of the globe,’ as already stated. ee Glacier Work.—Scott. 219 feet high) are said to rise from the most thoroughly glacier covered region on the mainland of the continent. Hundreds of glaciers gather in the vicinity; the largest one of which is the Seward, the principal tributary of the Malaspina. It may further be said that North America has existing glaciers of all the known types, excepting possibly the pe- culiar Scandinavian variety. Examples of the Alpine type have been cited; the Piedmont type has several representa- tives in Alaska, one of which is the Malaspina ‘glacier. Greenland furnishes perhaps the solitary example of a conti- nental ice sheet that can be investigated; and the so-called “tide-water” glaciers are numerous both in Alaska and Green- land. Comparative size. Peary’s estimate is undisputed that about 600,000 square miles of Greenland is under a glacier of the centinental type. Many of the tongues of this glacier extending into the sea through the ice fjords are of immense proportions, being hun- dreds of miles long in some cases, and several miles broad. The Antarctic region has as yet been comparatively little explored. In a summary on the region, Dr, J. D. Murray considers that the southern pole is surrounded: by a continent of about 4,G00,000 square miles, being larger than Aus- tralia.* The land rises abruptly from the sea, having hills ranging from 3,090 to 7,000 feet in hight with some peaks that are considerably higher. ‘These are said to be covered with ice more uniformly and to a greater depth than in the Arctic region, and even at the coast, bare low lands or rocky cliffs are uncommon. The ice sheet descends from the slopes into the sea, and from it the great tabular bergs are formed, and also the immense ice cliffs which preclude satisfactory explorations into the interior’ The ice is supposed to be from 1200 to 2000 feet thick. This estimate is made chiefly from the bergs that extend from 150 to 200 feet above the water, con- sidering that ice floats with approximately nine tenths of its volume submerged. The sea is so covered with floating ice in that region that navigation is practically impossible beyond a latitude of 65 degrees. *Geog. Jour. 1894, Vol. 1. 220 The American Geologist. October, 1902, Thus it is that exploration in cold climates has, for obvious reasons, thus far been centered in the north. Lieut. Peary, as an indefatigable explorer, has of late enlarged our knowl- edge of Arctic geography.* He has shown that Greenland is an island and, further, has fixed the limits ef this enormous territory. We are led to believe, however, that the Antarctic region may soon give up its secrets, for some of the best equipped, most costly, and most. scientific expeditions ever planned have moved toward the southern pole. The two largest are those of Britain and Germany, each supported by government grants to the extent of $250,000, with additional private contributions amounting to $100,000. Two smaller expeditions are also sent out; one by the Scotch, and the other under the command of Dr. Otto Nordenskjold, a nephew of the late Baron Nordenskj6ld, the famous Arctic explorer.* These expeditions are equipped for a work or from three to six vears, and if successful, our knowledge uf the southern ice sheet will in the future, be based upon facts rather than hypotheses. The single Alpine glaciers in comparison with the polar, are smail; usually less than 25 miles long, less than three miles broad and vary from 200 to 300 feet in depth. It ts said that the Gorner glacier has an area as large as three cities the size of London, or about 350 square miles; the Great Aletsch glacier, in 1880 was somewhat over ten miles long, being the longest of the Alpine glaciers in Europe, though covering an area of less than 18 square miles. The gla- ciers of the highest peaks of the Himalayas, one of which was climbed by Conway to a height of 23,000 feet, reach an extreme length of forty miles so far as known, and ir some cases the ice is presumed to be about 1000 feet thick. ‘che glaciers of the St. Elias Alps, previously mentioned, are of size corres- ponding in general to those of the Himalayas, as the Seward, for example, whose length is fifty miles and breadth three miles at its narrowest part ;i other mountain glaciers of North America are quite comparable to those of the Alps, as for in- *See ‘“‘Northward over the ‘Great Ice’; a Narrative of Life and Work along the Shores and upon the Interior Ice Cap of Northern Greenland in the years 1886 and 1891-97. Robert E. Peary, 2 Vols. Illustrated. Fred- erick A. Stokes Co., New York, 1896. yReview of Reviews, July, 1901. New Phases of Polar Research, Cyrus C, Adams. tGeog. Jour. 1898. Russel. Glacier Work.—Scott. 231 stance, the five glaciers of Mt. Shasta; the largest of these called’) Whitney glacier, after professor J. D. Whitney, of Harvard University, has a length of about two miles, and a width of from 1000 to 2000 feet. As might be expected the glaciers found in the lati- tude of the equator are much smaller. Numerous glaciers are known to exist, however, in the Andes of Ecuador. They attain their greatest size upon the mountains of Antisana, Cayambe and Chimborazo, the latter having eleven distinct ones. Velocity of Flow. A consideration of the second point embraces the well known fact that glaciers are nearly always in motion, though under certain conditions the rate is very slow. Observations made upon glaciers in the Alps seem to show the average of the measured rates of flow is from one to three feet per day depending upon the size of the glacier, the larger moving fast- er. One of the early notes in this connection is made by Henry Thomas La Beche.* A ladder left by the geologist Horace Benedict de Saussure at Col. du Geant, in 1787, was discovered in the Mer de Glace, the continuation of the same glacier, having advanced about nine miles during the intervening forty-five years, or an average of nearly three feet per day. Observations made upon American Alpine glaciers show about the same rate of movement. The motion of the Greenland ice sheet is said to resemble an inundiation, as there appears to be a general movement of the whole mass of ice from the central regions toward the sea. Its force is concentrated largely at a few points, and to an extraordinary degree. These points are the fjords through which the annual surplus ice is carried away and dis- charged into the sea as icebergs. Danish explorers measured the velocity of seventeen glacier tongues in the ice fjords of Greenland, repeating such measurements in both cold and warm seasons, and thereby showed that the movement was not influenced by seasons. Further, glaciers which produced bergs showed a movement averaging from thirty to fifty feet per day throughout the year. The great glacier of the ice fjord of Jacobshaven *Manual of Geology, 1832. 222 The American Geologist. Optobeta mata having a breadth of nearly three miles was rated at fifty feet per day, and that of Karajak, four miles broad, at twenty- two to thirty-eight feet in twenty-four hours: * These figures show the average rate of motion to be at least ten times that of glaciers of the Alpine type. “It has been stated as an empirical rule,” says Prof. Harry Fielding Reid, + “that the velocity of glaciers in beds of uniform slope is greatest in the neighborhood of the néve-line, and diminishes as we leave it going up or down the glaciers.” He proceeds immediately to show, however, that this rule has very important exceptions. Prof. Heim + believes that the increased velocity of some Greenland glaciers near their ends, accords with the rule by consider- ing the ends as the upper part of the glacier. Prof. Reid thinks this a mistake as the ends are some distance below the neve-line, but that the real cause is due to a lack of sup- port in front, which Prof. Heim also mentions. It is consid- ered probable that the under part of these tidewater glaciers does not move as fast as the upper, otherwise the bergs would be of comparatively thin sheets instead of immense irregular masses of ice. There is a general law, however, that the flow is less be- low, than in the neve-line; this flow being equal it is stated, to the product of the average velocity, by the sectional area, by the effective density. The more rapid surface velocity often found, being thought by some authors to be due to the formation of immense crevasses which reduce the ef- fective density. Where the glacier bed is of uniform slope the velocity and flow are said to increase together, though- not necessarily in proportion. Glacier Motion.—General Theories. Glacier motion, ever since work on glaciers began, has been a subject of much interest, of careful investigation, and of keen controversy. It has engaged the attention alike of both geologists an1 physicists. De Saussure, as one of the first to consider the question, presumed that the weight of the ice *Prestwich, Geology, Vol 2, Chapter 33. +Journal of Geology, Vol. 4, 1896, p. 9183. tHandbuch der Gletscherkunde, 1885, p. 160. ee Glacier Work.—Scott. 223 might be sufficient to urge it down the slope of the valley if the sliding motion were aided by water flowing at the bottom. * Agassiz was the first to commence a series of exact meas- urements on glacier motion, in 1841, and to substitute, fol- lowing Charpentier the idea of dilitation, for the ‘“gravita- tion theory” of de Saussure. His theory was based on the idea that solid ice is always permeable to water, and contains innumerable capillary tubes. These tubes were supposed to | imbibe water during the day, subsequently freezing at night, and expanding in such a way as to distend the whole ice mass. The immense force exerted by this distention was presumed to be sufficient to propel the glacier “down the valley.” Later on, however, the theory of Agassiz was replaced by that of Forbes, or the viscosity theory. This theory sup- poses motion among the ultimate particles without rupture and is regarded as the first to explain, in a partially satis- factory way at least, the differential motion of a glacier. Faraday showed in 1850, that if two pieces of ice having throughout a temperature of 32 F. and each melting at its surface, be made to touch each other, theyl will freeze together at the point of contact, the process being known as _ regela- tion. Upon this demonstration as a _ foundation Prof. Tyndal subsequently brought forward his regelation theory of the motion of glaciers, which, in brief, supposes motion among discrete particles, by rupture, change of position, and regelation, t Croll’s Theory £ seems to be a modi- fication of Forbes’, in attempting ‘‘a physical explanation of the viscosity of ice.” Another theory that deserves mention is that of Thomson. It is based on the fact that the fusing point of ice is Jowered, and the ice promptly melted by pres- sure. Compared with Tyndal’s theory the result obtains that differential motion in the one case is by fracture, change of position, and regelation; in the other by melting, change of position, and regelation. Many other theories have been advanced from time to time, but only those of apparently most importance, have been considered. *“Voyages dans les Alpes.”’ ~ Le Conte, Elements of Geology. iCroll, Climate and Time. 224 The American Geologist. OcLOReEr ieee In reference to the Thomson * theory of liquefaction by pressure, it does not seem to the writer of this paper that such influence can enter into glacier movement in other than a very elementary way. It is proved in thermo- dynamics that where ice and water are together at the same temperature, if V,— the volume of unit mass of the mixture in the higher state, andV,= the volume of unit mass of the ; ; Bye, lags mixture in the lower state, then L=t (\ —V)-e, where (t) is the absolute temperature, or 274+0°C., and L—latent heat of unit mass in foot pounds. If we take L as latent heat of one pound of the material, and V, and V, as volumes in cubic feet of one pound or the material, then the formula holds for (p) reckoned in pounds per square foot. Now in ice water V,=.01747 V,=.01602 when * (¢)==27410'C,;. and» (p)=147 pounds per square inch, or 2116 pounds per square foot. dp Hence —— = — 278100, a constant; the quantitative dt : MOET ioe ; ; meaning of the expression—7— is, obviously, that the melting point lowers at the rate of .oo1 of a degree for an increase pressute of 278 pounds per square foot. If we consider a given glacier to be 1000 feet thick then the pressure upon one square foot at the base would be 1000 x 62.5 x .g18=57000 pounds (Approx.). At the rate then of .oor of a degree for every 278 pourds we have for the total 57000 pounds a lowering of the meiting point by only a little over two-tenths of a degree. It is true, however, that this decrease would aid slightly in producing liquefaction at the under surface of the glacier. It is generally conceded that glacier ice acts like a viscous substance, and that its motion is fundamentally due to the weight of the ice itself. It seems that there are no available experiments bearing upon the sliding of ice over its bed other than those of Hopkins. + He used a number of pieces of ice on a rough sandstone slab, and found that the movement down the slope was uniform and approximately proportional to the pressure, and to the angle of inclination, for angles *Proc. Roy. Soc. 1856-7. 7Phil. Mag. 1845,-Vol. XXVI. pp. 3-6. Glacier Work.—Scott. 225 between 1° and 10. With the sandstone polished the move- ment was observed at an angle of forty minutes. The laws of friction between solids are found to be inapplicable to the conditions of a glacier on its bed, though the angle of slope of the bed obviously is an important factor in glacier motion, and particularly so in the matter of erosion, which will be con- sidered later. The Rev. Coutts Trotter has described experiments * showing that glacier ice will shear under small forces if al- lowed sufficient time, and more recent experiments by Mugge + appear to prove that the apparent viscosity of glaciers is partly the result of shearing along the cleavage planes of the crystalline granules of the glacier ice. A study of some of the larger Swiss glaciers, by Deeley and Fletcher~ concerning glacier structure, and its bearing upon glacier motion, is interesting because it involves meth- ods somewhat different from those of their predecessors. A polariscope was used and sketches made purporting to show the character of the crystalline particles in a satisfactory way, just as they found them in the glaciers. Glacier ice had, of course, previously been regarded as a crystalline aggregate, by Heim, McConnell, Bertin, Grad, and others, the individual crystals fitting closely without the presence of a matrix. This conception is verified by Deeley and Fletcher, who further show that the optical structure of each grain is uniform, as indicated by the polariscope, but the bounding surfaces are very irregular and usually curved. The optic axes of neigh- boring grains appear to be arranged at random, and the sur- faces of the majority of the granules are seamed with exceed- ingly small furrows. The relation between these furrows or _striae and the optic axis, however, is not noted. It is believed that the stria are analogous to those seen on other crystals, and are due to the alternation of two faces of crystallization. A sketch of such striated crystals from the ice-cave of the Rhone glacier, § shows no definite direction of the striae with reference to the crystal mass, or to the neighboring crys- tals. *Proc. Roy. Soc. 1885, Vol XXXVIII, pp. 92-108. yJour. of Geol. 1895. *“Structure of Glacier Ice and its bearing upon Glacier Motion.” Geol. Mag. 1895. pp. 152-162. $Geol. Mag. (1895), Plate 156. 226 The American Geologist. October, 1902, In this connection we may note one point more concern- ing individual crystals. McConnell and Kid have indicated * that a single crystal of ice will not change its shape un- der either tension or pressure applied at right angles to the optic axis, and therefore is non-plastic. Their experiments have proved conclusively, however, that glacier ice as a whole is plastic, at a certain temperature at least, both for tensile and compressive stress. From such facts the conclusion is drawn that the ob- served viscosity must be due to an action at the interfaces of the crystals, such that their shape is altered in a way to allow them to change their relative positions. A hypothesis of this character is elaborated by Deeley and Fletcher who arrive at the conclusion that glacier grains may change their sizes and shapes under comparatively small stresses, and further that they may readily shear, or slide over each other without actual fractures occuring. A later contribution by Hobson + confirms the crystal- line structure ideas of Deeley and Fletcher just considered. He saw at Chamounix in September, 1896, without the aid a polariscope, similar phenomena to that already noted of the crystals in the ice-cave of the Rhone glacier. “The ice” he says, “was disintegrating into separate pieces of ir- regular form, each an inch or thereabouts in diameter, and fitting exactly together, with inter-locking projections and cavities, so that the structure reminded one of a toy dissect- ed map.” He also suggests that it might be possible to show the same thing by immersing glacier ice in hot water. An excellent paper on the movement, melting and interior tem- perature, of the Hintereis glacier, of the eastern Alps, was published in 1899, by Drs. Blumcke and Hess #. Movement in Zones of Fracture and Plasticity. While it may be unwise to presume to add materially to the vast amount that has been written on the cause of glacier mo- tion, it may not be entirely out of place here to make some sug- gestions that have come to the writer in connection with a study of glaciers. *“On the Plasticity of an ice-crystal,’’ McConnell. Proc. Roy. Soc. Vol. 49, p. 328. 1891. *+*Geol. Mag. 1896, p. 572. : tUntersuchungen am Hintereisferner Wissensch. Ergans L. Leit des Du. O. Alpenvereins 1 Bd. 2 Heft. —_ —" Glacier Work.—Scott. 227 Since it is reasonable to presume that motion is by no means confined to the upper or surface layers of a glacier, but has to do with the whole thickness, it is here proposed to consider the mass as divided primarily into two parts. 1. An upper zone of fracture, or crevasses. 2. A lower zone of constant plasticity. * The portion of a glacier above which the ice is under less weight than its yielding resistance is in the zone of fracture or crevasses. The first point to be considered in connectior: with this zone rests upon some interesting experiments upon ice blocks by Col. William Ludlow (1880-81) +, A. Fruhling (1885) %, C. W. Beach, A. M. Mann, and H. E. Reeves (1895) §. The results of these experiments as far as recorded show that the maximum yielding resistance of pure ice a few degrees below the freezing point, to compressive stress, is under 300 pounds per square inch. It thus appears that crevasses or cracks of any sort cannot exist below a limited depth. To determine this depth, it simply remains to cal- culate the height of a column of ice one square inch in cross section which shall have a weight of three hundred pounds and the result shows this to be not over 750 feet. It should be said here that all these experiments show a wide range of results, largely due, doubtless, to variable qual- ity of ice and temperature and rate of deformation; so that an average rather than a maximum value, as above cited, would reduce the depth limit to about one-half the value given, or 300 feet, approximately. Another point to be con- sidered, is the question as to whether the ‘ce blocks tested were of the proper dimensions to give the correct results for larger masses of this material. The specimens used by all of the experimenters, so far as is apparent to the writer. were cubes of various sizes. *This idea, and others also, embodied in this paper, have originated primarily from a study of ‘Principles of N. A. Pre-Cambrian Geology,” and ‘‘Metamorphism and ,Rock Flowage,”’ by Prof. C. R. Van Hise, Rep. U. S. Geol. Survey, 1894-95; Bull. Geol. Soc. of America, Vol. 9, pp. 269-328. +“Observations on the Crushing Strength of Ice.’’ Proceedings of the Ergineers’ Club of Phil. 1884, Vol. IV, p. 93. {Zeitschrift des Vereines deutschen Ingenieure. May 9, 1885, p. 357, §Digest of Physical Tests, 1596-97. 228 The American Geologist. Octoher: As It has been shown by Prof. Johnson * «that brittle mater- ials fail under a compressive load, by shearing on definite. angles, and that the resistance to move along these angles is composed of two parts. “First, the strength of the mater- ial to resist shearing, and second, the frictional resistance to motion along the plane.’’ Moreover, he saya, “The relation of crushing strength to relative dimensions of specimens is a very important matter. Hitherto nearly all crushing test specimens of brittle materials have a cubical form. So long as the theoretical angle of rupture was thought to be 45°, this was proper, but since this theoretical angle approaches 60°, it is evident that the height of the specimen should be at least one and one-half times the least lateral dimension, in order to allow of failure on a normal angle.” Professor Johnson gives a mathematica! demonstration ort this important conclusion, which is also verified by the results of experimental tests. It is shown in the case of some limestone blocks which were tested, that when the cubical form was used, the results were 9 per cent greater than would have been true if the specimens had been chosen of the proper hight. He says, “The wit strength of the material is no function of the size of the specimens, but only\a function of its form,’ and that “Crushing test specimens should be true prisms in form.” The work of professor Johnson did not in- clude experiments with ice specimens, yet it is noticeable that the characteristic appearance of the ruptured materials, as re- presented by half-tone cuts, appears to coincide with the de- scribed appearance of the ruptured ice blocks. It is to be regretted that no photographic representations of the broken ice specimens are given by any of the experi- menters. Since, however the more compact specimens of ice “broke suddenly with report,” it is probable that the ice behaved strictly as a brittle substance at the lower temper- atures. This being true, the apparent strength of the cubical blocks as tabulated may have been, on the whole, nearly one- tenth too high. This suggestion is made here, not so much to criticise the work referred te, upon the crushing strength of ice, as to indicate to future experimenters a possible elimination of error. *“Brittle materials: under compressive stress.’ J. B. Johnson. Di- gest of Physical Tests. 1896-97. Glacier Work.—Scott. 229 From what has been said, a reason is indicated as to why the crevasses never extend completely through the larger and deeper glaciers, although they may be immense openings at the surface. Col. Ludlow says in regard to the series of 12 inch cubes which he tested, “It was found that when subjected to pres- sure from whatever direction, the ice almost invariably re- solved itself into small vertical columns, which, when the pres- sure was continued, buckled slightly and compressed, until in several cases, under a further increase of pressure, the block exploded with a loud report; this, however, only in the case of the better and more compact specimens. By vertical col- umns is meant columns normal to the natural surface of the ice.” * The results of Beach, Munn, and Reeves are very similar in this respect, + for they say: “Ice, when subjected to pressure, is resolved into columns whose direction is nor- mal to the surface which was in contact with the water while freezing.” . The same experimenters show, in a table, that when the temperature of the testing laboratory, as well as that of the ice-block tested, were well below 32°F., viz., 21.2°F. for the laboratory, and 12.2°F. for the ice block, the specimen always “broke suddenly” and usually with report, but when the tem- perature of the laboratory and test blocks were but a few de- grees below 32°F., many of the specimens “gave way grad- ually.” These results indicate an inherent tendency in ice masses to rupture along planes normal to the natural surface of the ice, and also to exhibit brittleness under conditions where the temperature is well below 32° F. They further show that the _breaking of ice at a low temperature is of the nature of a shock. Prof. Russell has observed in connection with glaciers, that the formation of cracks which later open as crevasses is attended by rumbling noises and sharp crashes, with vibrations of the ice-mass as though an earthquake wave acted upen tt. = Gravity, the dominant force in glacier motion, acting to urge forward the ice mass accomplishes the greatest movement *Proceedings of Eng. Club of Philadelphia, cit. 7Digest of Physical Tests, cit. tGlaciers of North America. Professor I. C. Russell, 1897, p. *8. 230 The American Geologist. October, 1902. in the central portions of the surface, since the friction between the mountain sides and the ice particles is greater than that between the ice particles themselves. This active mechanical stress results in a differential motion of the ice mass which is of the nature of both plane and torsional shear. The stress is great enough to overcome the strength of the solid and the ice vields by snapping asunder, thus forming a miniature crevasse. The mechanical stress may also be aided more or less in the formation of cracks, by the factor of contraction which tends to take place in the ice as the temperature de- creases. The surface layers are especially susceptible to this. influence, since the temperature of the air above the ice is like- ly to be at times far below the freezing point. Furthermore cracks once started would not be nearly filled at once with water from below, as is frequently the case with lake ice, * but would, so long as mechanical stress and contraction con- tinue open wider and deeper, finally resulting in vast impas- sable chasms. ; If the ice travels over a very uneven bed, as is often the case with Alpine glaciers, some portions become engulfed, while the upper parts slide over them, and here the forma- tion of immense crevasses is greatly augmented. Evidence is plentiful to show, however, that the upper portion of nearly all glaciers is traversed by fissures or crevasses, regardless of angle of slope, or volume of the ice mass. These fissures beginning as very small cracks will increase in size until a more equable slope is reached, or,a rise in temperature occurs, when there is at once a tendency for the crevasses to close, and the ice regains its former solid condition by regelation. Again and again are repeated the before mentioned processes of rupture by mechanical strain and contraction, with sub- sequent repair by pressure and regelation and thus the glacier ice in the zone of fracture moves onward down the slope. The movement of ice in this zone would be expected to comply with observed conditions, viz.: a more rapid rate in summer than in winter, and a greater movement by day than by night. During the time when the temperature of the air in contact with the ice is falling, the resistance to the onward moving force of gravity is increased, and contraction of the *“Toe Ramparts.” E.-R. Buckley and C. R. Van Hise. Trans. of the Wis. Academy of Sciences, Arts, and Letters, Vol. 13. —— Glacier Work. Scott: 231 ice mass is also taking place, while during periods of rising temperature, the surface of the ice becomes more mobile, and the mass moves forward more easily under mechanical stress. The limit to which crevasses extend, as already pointed out, doubtless depends chiefly upon the weight of the super- ‘incumbent ice, though it is also probable that different con- ditions of stress may exert some influence; and, further, microscopic fractures might exist where macroscopic ones are not discernible, and so under certain conditions through- out a limited thickness below the zone of fracture, what might be called an intermediate belt of combined fracture and plastic- ity exists. Here under certain conditions of temperature, and acting pressures in the ice mass itself, the ice might either fracture, or move as a plastic substance. Siwdden pressures, or the low- ering of the temperature, or both, would produce fracture, when reverse conditions would cause the ice to behave like wax. It is probable that combined forces in this space may be largely responsible for the fact that the movement of any given point in.a glacier may vary from day to day, or hour to hour, because folding and thrusting of the ice would naturally occur, which, in turn, would make its influence felt on the observed surface ice above. And, further, a valley hav- ing a particularly irregular contour, would have such an effect upon the movement of ice in this space, as to augment the formation of crevasses and irregularly directed chasms in the zone above. This accords with Russell’s statement that “The ice of glaciers is also broken along planes more or less inclined to their surfaces. Movement takes place along these cracks, and produces thrusts, analogous to the over-thrusts, or under-thrusts, sometimes seen in rocks that have been folded and broken. In fact, the counterpart of many of the structural features observed in rocks, such as faults, folds, joints, contortions, etc., may be observed in the ice of glaciers.” Mention has been made by various writers of the movement upward in portions of some glaciers, as, for example, where Prof. Pfaff noted in one of the reservoirs of the Aletsch glacier, where the surface slope was 9’, that the direction of motion made an angle of about 40° with the horizontal. Some *Gjaciers of North America, 1897, p. 11. 232 The American Geologist. October, tite authorities have doubted the validity of such observations, but it does not seem improbable that they were quite correct nevertheless. In the zone of constant plasticity, to be consider- ed, the direction of flow would naturally be in the direction of least resistance, so that if a land barrier were interposed in the natural path of movement, or the slope of the bed were re- versed in direction, the resultant of the two pressure com- ponents might readily force the ice upward and raise the mass above it. It is even possible that a large mass of the lower portion of the glacier would pass into the zone of fracture, carrying with it the morainic debris from the bed beneath, which in time would be extruded from the central portion of the ice wall at its melting terminus. It has been suggested that the comparatively rapid rate of motion of the Arctic glaciers may be due in part to the pre- sence of infra-glacial material; it would appear, however, that its aid is ‘small, and the rapid rate of flow is! to be more partic- ularly attributed to the great amount of ice in the zone ot constant plasticity. Here the movement would be chiefly in this zone rather than in the zone of fracture. It would be relatively rapid because of its increased mobility, carrying for- ward the whole ice mass, as an inundation, as previously not- ed. The power to erode is at the same time relatively in- creased, since the kinetic energy of the moving mass is pro- portional to the square of the velocity, and thus the production of ground moraine is greatly augmented, but does not become great enough to cause stagnation of the glacier. 'ce which is at such depth that the weight of the super- incumbent mass exceeds its yielding strength, or its ultimate strength, is im the sone of constant plasticity. This depth, as shown on previous pages, would be variable, though so far as present experiments indicate, would not be less on the aver- age than 300 feet. In this zone the weight above is great enough to mash the ice and render it like soft wax, and toward the bottom of the larger glaciers the very slight increase in temperature resulting from the pressure, as shown elsewhere in this paper, doubtless aids in producing a condition of pure viscosity. This condition precludes at once the existence of cavities of any sort for the ice would flow in the path of least resistance, and immediately close them. Glacier Work.—Scott. 233 Viscosity is defined as tangential force per unit area divided by shear per unit time, and so the conditions for viscosity are here of the best. The force, due to pressure is enormous, and while the time is indeterminate, the shear re- sistance is certainly small for ice masses as shown by experi- ment. The modulus of elasticity is low * as would be expect- ed, so that any small detormation produces permanent strain, resulting *in a rearrangement of crystalline aggregates, if not indeed of the crystal molecules themselves. Thus it is obvious that in the zone of plasticity, continuous deformation of the ice mass results from the pressure exerted upon it, which pressure consists of both a vertical and a horizontal component. ‘Minerals deformed in the zones of flowage,” says Van Hise, “show no interspaces under the microscope, but their remarkable shapes, undulatory extinction, and granulation in polarized light give evidence of their change of form.” + And again ‘deformation may be partly ac- complished by the rearrangement of the mineral particles with respect to one another.” Such changes in ice crystals are apparently well exempli- fied by the studies of Deeley and Fletcher, mentioned previous- ly. Furthermore it seems entirely probable that the ice in this zone is assisted in its movement as a viscous mass through the prime agencies of continuous solution and recrystallization. The great pressure exerted in this zone, which is at the same time widely variable in magnitude and direction because of the opening and closing of crevasses and irregular movements in the zone of fracture, together with temperature effects, is obviously a cause for a state of interior strain in the ice mass. It has been shown by Barus § _ that the work done in strain- ing certain materials is largely potentialized, and, further, that in the case of glass || the release from strain occurred through the process of crystallization. Van Hise {| also says concerning rock materials, that “as soon as a state of strain is produced, the processes of solution and recrystallization set to *See Smithsonian Tables. 7Principles cit. p. 696. tPrinciples, cit. p. 694. §The mechanism of sclid viscosity, by Carl Barus. Bull. U. S. Geol. Survey, No. 94, 1892. || The Compressibility of Liquids, by Carl Barus. Bull. U. S. Geol. No. 92, 1892. {Metamorphism of Rocks and Rock Flowage. Bull, of the Geol. Soe. of America, Vol. 9, p. 300. 234 The American Geologist. Oetober, a work to adjust the minerals.” Such a conception applied to ice necessarily precludes the possibility of obtaining a measure ot the straining, because the strain is continuously obliterated by solution and recrystallization. Yet it is easily shown that mechanical stresses in the ice mass are constantly operative, and a condition of strain it seems must inevitably exist. Again it has been shown that in general, in the process of recrystallization under condition of saturation, there is always a growth of large crystals “at the expense of the smaller ones. This fact is due, as pointed out by Ostwald, * to the phenomenon of surface tension which exists on the boundary surfaces between solids and liquids. These surfaces are reduced in size by the tension, with the re- sulting enlargement of individual crystals, the process heing augmented, as is well known, by pressure and increase in tem- perature.. Now for a given volume of the substance it is eas- ilv seen that the surfaces of the crystals are inversely as their diameters, whence it appears that an increase in the size of the crystals, through the reduction of surface tension liberates energy as heat. It is difficult to estimate the amount of heat thus set free in the case of ice, but it would seem that this heat, be it great or small in amount, will aid the pressure in increas- ing further the rapidity of crystal growth. The particular point of interest here is the possible appli- cation of these principles in explanation not only of the movement of the ice mass, but also of the well known fact that crystals of glacier ice increase in size in passing from the néve line toward the terminus of the glacier. If this assump- tion concerning solution and recrystallization be true of the zone of plasticity, the premises relating to the movement in the zone of fracture do not preclude its application there also, to a greater or less extent. Indeed it is probable that an in- crease in size of crystals takes place where the forces of rup- ture, solar energy, and regelation, are in active operation. It is also logical to suppose that partial recovery from a state of strain where the deforming pressure is relieved, means partial recrystallization, in which case the bounding surfaces might in consequence be irregular and curved and the optic axes arranged at random, as instanced by Deeley and Fletcher, already quoted. *Foundations of Analytical Chemistry. W. Ostwald. Glacier Work.—Scott. 235 It should be said that possibly too few recorded experi- ments are available upon the properties of ice, and glacier ice in particular, for one to be able to reason in a perfectly logical manner concerning its behavior under the conditions extant in a glacier. It seems well, however, to consider what ex- perimental results are given, remembering that conjecture alone must account for certain phenomena of a glacier, since some portions are quite as inaccessible even as the inner por- tion of the earth’s crust. Such consideration leads to the as- sumption of the zones of fracture, and constant plasticity, together with the movements therein. Recorded observations appear to verify the reasoning, and to conform to a theory of glacier motion, which may include to some extent the causes of movements and deformation of the earth’s crust. The scope of this paper cannot include a presentation of such a theory in detail, and only a suggestion of certain prin- ciples is here attempted. It is believed by the writer, however, that a further study of the properties of glacier ice, including tensile and compressive strength, with proper curves to show the relation between strength and temperature, together with careful examination under the microscope and polariscope of the crystalline structure of different parts of a glacier should be made. Further, the more prevalent use of the camera for the pur- pose of illustrating important features of scientific interest connected with glaciers, cannot fail to be commendable, and possibly may aid greatly in settling disputed questions. That photographic work is possible at the present time under al- most any circumstances likely to be met with in glacier study is well known, and is most admirably evidenced by the eight hundred photographic reproductions in Peary’s book on the Arctic region, Advance and Retreat of Glaciers. Early observation upon glaciers appeared to indicate an advance or a retreat with reference to the line of lower limit, corresponding with variations in precipitation and tem- perature of the air. Enlargement apparently took place in cold rainy periods of years, and diminution in the warm and dry. A report by Prof. Forel (1886) * shows that there ap- *Arm. Jour. of Science, Vol. 32, 1886. p. 77. 230 The American Geologist. October, 1902, peared to be such periods in connection with the glaciers of the Alps, viz., enlargement from 1800 to 1815, diminution from 1815 to 1830, enlargement from 1830 to 1845, diminution from 1845 to 1875, and enlargement from 1875 onward. These periods are quoted by one of the text-books, yet it will be noticed that they are remarkably regular, and it would seem that sufficient study had not been given to the subject to war- rant these conclusions. At a’ later date Prof. Forel * states that the periodicity of glacial variations is much longer than was formerly believed to be the case. “It is possible.” he says, “that the cycle of variation is 35 to 50 years.” Beginning with 1850 or 1855 the glaciers steadily decreased up to 1875. At that time they apparently began to increase again in the Mont Blanc region. In.a summary by Dr. H. F. Reid + concerning glaciers in 1899, the following statements are made: “Swiss Alps—As we approach the end of the century the advance of a number of glaciers which began in 1875 has gradually died out. Only one glacier was known to be ad- vancing in 1899; nine were doubtful, and fifty-five were cer- tainly or probably retreating.” = “Ttalian Alps.—Eight glaciers show retreat and two ad- vance. The glaciers of the French, Swedish and Norwegian Alps are either stationary, or show a slight retreat. Photo- graphs of the small Kiagtut glacier of Greenland show a re- treat of several hundred meters between 1876 and 1899. The Victoria glacier near Lake Louise, Alberta, is retreating, and the [llecellewaet shows an average retreat since 1887 of about 15.8 meters per year. In Russian Asia the glaciers are re- treating, while in the Himalayas the condition is more or less uncertain. It is ee that the majority are stationary or advancing slightly.” In the volume published by the cr S. Geol. Survey on “Ex- plorations in Alaska” § it is shown that the Alaskan glaciers were formerly much more extensive than now, and show evidence of continued retreat. It is also indicated that Alaska was never under a continental ice sheet as was the eastern *Am. Jour. of Science, Vol..144, 1892, p. 342. y7Jour. of Geology, Vol. 9, 1901. pp. 250-254. tFrom report of Prof. Forel. gsTwentieth Annual Report U. S. Geol. Survey, Part 7, 1898. Glacier Work.—Scott. 237 part of North America: In a recent Russian report, on the glaciers of the Caucasus mountains, of thirteen glaciers ob- served, all were retreating; those on the northern slope at.the rate of 66 feet per year, those on the southern, at 75 feet per year. ‘ . Line of Lower Limit. The line of lower limit of glaciers varies of course with the geographical location. In the Alps where the line, of perpetual snow is fixed at about 7500 feet above sea level, the line of 32° is about 2000 feet; and the line of lower limit, about 5000 feet below the snow line. In some parts of the Arctic Region the 32 line is at an altitude of 3500 feet. In Norway, the line of lower limit is about 4000 feet below the 32° line. In Chili glaciers touch the sea level at 46° 40’ south latitude. The line of lower limit of perennial snow is about 2000 fect above the sea level in the Mt. St. Elias region, where so many glaciers become united in the great Malaspina glacier of the Piedmont type. This glacier has an average breadth of 20 to 25 miles, and an area of about 1500 square miles, or about midway between the states of Rhode Island and Delaware. This remarkable glacier will again be mentioned in connection with the subject of moraines. Glacial Drainage. Most of the Alpine glaciers are drained principally by streams issuing at their ends from beneath. It is worth noting that a feature of Greenland glaciers is that the char- acter of drainage does not coincide with the drainage common to Alpine glaciers. “It is the rare exception,” says Salisbury, of Greenland glaciers,” that a visible stream of any size issues from beneath a glacier at its end.”+ The water that without doubt issues from the glaciers, passes through or under debris, rather than over it. The sides of a glacier, it is said, rarely rest against the valley, but usually have a stream between the ice wall and the side of the gorge. Very few streams are found on the ice surface, as the water plunges into the crevasses soon after formation. Occasionally englacial drainage takes place, and the water may issue in a great stream from the céntre of a mass of ice at its *Le Conte, text-book. 7Jour. of Geology, 1896. 238 The American Geologist. Octeber, 190E end, and further,these streams sometimes contain silt which must have been raised from the bottom of the glacier. Stratification. Some observations on the stratification of glaciers have been made, though it is said that a correct observation of this phenomenon is very difficult. Prof. Heim* gives some atten- tion to stratification, and Prof. H. F. Reid also gives a theory concerning it. } He says, “In order that the general volume of the glacier should be preserved we must have below the néve-line, where there is melting, a component of the motion toward the surface, and this component is strongest where the melting is greatest; i. e., it gets larger as we descend the dissipator. Above the névé-line this is reversed.” The move- ment of a glacier is so related to its formation and surroundings that stratification is probable, though it seems that a thin layer of debris is almost absolutely necessary to determine the surfaces of separation. Drawings made by Agassiz show such layers as he found them in the Unteraar glacier + and they appear to be true surfaces of stratification. In some instances it is observed that rock material falling upon the snow in the cirque is car- ried along the under part of the glacier, reappearing at the surface near the terminus. Debris layers in the Sierra Nevada glaciers are cited by Prof. Russell§ as separating successive strata. ‘The parts of strata formed at a distance from rocky slopes have very little dust blown upon them, and consequent- ly when they reappear at the surface in the upper regions of the dissipator the stratification is but slightly, 1f at all, indicated by dust bands. The strata should be well defined at the lower end, but the large amount of debris on the surface and in the crevasses, would make them difficult to recognize.” || A controversy existed between Agassiz and Forbes in 1841, as to the meaning of banded structure seen on the surface of glaciers. The former contending that such structure marks the outcrop of strata, while the latter believed it to be a peculiarity of glacier ice, and independent of stratification. *Gletscherkunde. jJour. of Geology, 1896, Vol. 4, pp. 917 to 928. tSysteme Glaciare, p. 260, Atlas, plate 5. §$The glaciers of U. S. 5th Ann Rep. U. S. Geol. Surv. 1883-4. ||Mechanies of Glaciers. H. F. Reid. Jour. of Geol. 1896. Vol. 4. — ee Db Sin CR TONIC Ty ti SI[BAO BIULDING seeefeee | talG [eee | “131.1098 (deiq) winjnj}uepe uniperaqdg . ioe eee ij erardis meets | (dead) wmnwusid unyound aPetug eshale ier see lie lpi tes “98.01 (eg) sn}eou [ snostpoorfeH co) | ISG QTiat|": ‘Sild (Avg) BAT Deds19d BlNPIUUIRIAG | sees) ere a| ene] cece wese| eons Ae A Sok Eis eRe cama ote pra e in, inal 6 is. teiTehele ddvip. | | (s1aorD) B1BISOO B}eUIOI[e BlNpruUTeisV. PIRSSON; HS: WASHINGTON). A quantitative chemico-mineralogical classification and nomen- elature of igneous rocks. (Jour Geol., vol. 10, Sept.-Oct., 1902, pp. 555-690.) DAVIS, W. M. Systematic geography. (Proc. Am. Phil. Soc. vol. 41, April, 1902, pp. 235-259.) : . DOUGLASS, EARL. A Cretaceous and Lower Tertiary section in South Central Montana. (Proc. Am. Phil. Soc., vol. 41, April, 1902, pp. 207-224, plate.) GILBERT, G. K. John Wesley Powell (portrait). (Science, vol. 16, Oct. 10, 1902, pp. 561-567.) GORDON, REGINALD. Bones of a Mastodon found. (Science, vol. 16, Oct. 10, 1902, p. 594.) HAYES, C. W. The Southern Appalachian coal field. (22 Ann. Rep., U. S. G. S., 1900-1901, part 3, pp. 233-263, 1902.) HAYES, C. W. The coal fields of the United States. . (22 Ann. Rep., U. S. G. S., 1900-1901, part 3, pp. 1-24, 1902.) ROMEY, E70: A visit to Martinique and St. Vincent after the great eruptions of May and June, 1902. (Am. Mus. Jour., vol. 2, Oct., 1902, pp. 57- 63, 2 pls.) HOVEY, E::.0. Martinique and St. Vincent; a preliminary report upon the eruptions of 1902. (Bull. Am. Mus. Nat. Hist., vol. 16, pp. 333-372, pls. 33-51, Oct 11, 1902.) IDDINGS, J. P. (and W. CROSS, L. V. PIRSSON, H. S. WASH- INGTON). A quantitative-chemico-mineralogical classification and nomen- clature of igneous rocks. (Jour. Geol., vol. 10, Sept.-Oct., 1902, pp. 555-690.) JEFFERSON, MARK S. W. Limiting width of meander belts. (Nat. Geog. Mag., vol. 13, Oct., 1902, pp. 373-384.) 332 The American Geologist. November tee JOHNSON, A. N. (H. F. RIED and). Second report on the highways of Maryland. (Md. Geol. Sur., vol. 4, pp. 95-202, pls. 6, 1902.) KUNZ, GEO. F. The production of precious stones in 1301. (U. S. G. S., Min. Res., 1901, pp. 56.) LEONARD, A. G. Geology of Wapello county. (Iowa Geol. Sur., vol. 12, pp. 4389- 499, 1902.) LEVERETT, FRANK. Glacial formations and drainage features of the Erie and Ohio basins. Mon. XLI, U. S. G. S., pp. 802, pls. 26, Washington, 1901.) MORSE, E. S. Observations on living Brachiopoda. (Mem. Bos. Soc. Nat. Hist., vol. 5, No. 8, pp. 313-385, pls. 39-61, July, 1902.) NEWSOM, J. F. (J. C. BRANNER and). The Phosphate rocks of Arkansas. (Bull. Ark. Ex. Sta., No. 74, pp. 60-123, 1902.) . PENFIELD, S. L. Solution of problem in crystallography by means of graphical methods based upon spherical and plane trigonometry. (Am. Jour. Sci., vol. 14, Oct. 1902, pp. 249-284.) PIRSSON, L. V. (and W. CROSS, J. P. IDDINGS, H. S. WASH- INGTON). A quantitative chemico-mineralogical classsification and nomen- clature of igneous rocks. (Jour. Geol., vol. 10, Sept.-Oct., 1902, pp. 555-690.) REID, H. F. (and A. N. JOHNSON). Second report on the highways of Maryland. (Md. Geol. Sur. vol. 4, pp. 95-202, pls. 6, 1902.) RIES, HEINRICH. Report on the clays of Maryland. (Md. Geol. Sur.; vol. 4, pp. 203-505, pis. 52, 1902.) REIS, HEINRICH. Occurrence of glass-pot clays in the United States. (@ Cre Sie G. S., Min. Res., 1901, pp. 17.) ? SCOTT, A. C. A brief summary of glacier work. (Am. Geol., vol. 30, Oct., 1902, pp. 215-262.) ~*~ SPENCER, J. W. On the geological and physical development of Antigua; of Guadeloupe: of Anguilla, St. Martin, St. Bartholomew, and Som- brero; of the St. Christopher chain and Saba banks; of Dominica, with notes on Martinique, St. Lucia, St. Vincent, and the Grena- dines; of Barbadoes, with notes on Trinidad. (Extracted from the Quart. Jour. Geol. Soe. (London), vols. 47 and 48, 1901 and 1902.) Author's Catalogue. 333 UPHAM, WARREN. Primitive man and his stone implements in the North Ameri- can loess. (Am. Ant., vol. 24, Sept.-Oct., 1902, pp. 413-420.) UPHAM, WARREN. The fossil man of Lansing, Kansas. (Rec. of the Past, vol. 1, pp. 272-275, Sept., 1902.) UPHAM, WARREN. Primitive Man in the Ice Age. (Bibliotheca Sacra, vol. 59, pp. 730-7438, Oct., 1902.) WARD, HENRY A. On Bacubirito or the great meteorite of Sinaloa, Mexico. (Am. Geol., vol. 30, Oct., 1902, pp. 203-211.) WASHINGTON, H. S. (and W. CROSS, J. P. IDDINGS, L. V. PIRS- SON). A quantitative chemico-mineralogical classification and nomen- clature of igneous rocks. (Jour. Geol., vol. 10, Sept.-Oct., 1902, pp. 555-690.) WHITE, I. C. Lists of fossils from the lower half of the Conemaugh form- ation near Morgantown, West Virginia, collected in 1870 by Dr. John J. Stevenson and identified by F. B. Meek. (Am. Geol., vol. 80, Oct., 1902, pp. 211-215.) WHITEAVES, J. F. On the genus Trimerella, with descriptions to two supposed new species of that genus from the Silurian rocks of Keewatin. (Ot. Nat., Oct., 1902, pp. 189-1438, 2 plates.) WILLIS, BAILEY. Paleozoic Appalachia, or the history of Maryland during Pat- eozoic time. (Md. Geol. Sur., vol. 4, pp. 23-93, pls. 12, 1902.) WOODWORTH, J. B. The Atlantic coast Triassic coal field. (22 Am. Rep., U. S. G. S., 1900-1902, part 3, pp. \25-53.) CORRESPONDENCE. SxetcH or Dr. FrENzEL. In my mail of a few days ago I found the following letter from Dr. Beck of the Bergakademie of Freiberg Saxony. “—* “To my sorrow I must send you sad news from Saxon Freiberg. Our old and loved D. Phii. Frenzel died on the 20th of August of a cancerous tumor of the stomach. (Kresbartige Magenverhartung). He was confined to his bed only eight days though he was weakened for a longer period. A few days before his death he became chief officer of the smelting office laboratory.” * * “he left his family, a widow and two daughters, in comfortable circumstances.” 334 The American Geologist, ‘November, 1902 This sad news of the death of one of the greatest of all mineralo- gists is particularly so to the writer who made his acquaintance in Frei- berg in the early summer of 1866—36 years ago. He was recommended to me as the specia! protegé of the great Brei- thaupt who in that year delivered his last course of lectures at the Bergakademie. I was attracted to the delicate, intelligent looking In- lander and soon a warm friendship grew up between us which only death has dissolved. Frenzel was the son of a Freiberg miner who lived anc supported a family, as so many others have done and are doing, on twenty to twenty-five cents a day. His early experiences were of the extremest poverty; but when he was old enough his father sent August to the excellent Bergschule which the Saxon government under Von Beust had established to educate the children of the miners. Showing unusual ability and docility he rapidly made himself a favor- ite, and easily won for himself a scholarship in the Bergakademie itself. At a very early period in his course he attracted the attention of the great mineralogist, Breithaupt, who called on him frequently for assistance in arranging new collections of minerals, and determining their species. Following his illustrious master he soon achieved phenomenal success in this direction even equalling his preceptor in the latter’s opinion. But the way was hard, the father died and he must contribute to the support of his mother whom he tenderly loved. August was unfit for the hard work of a miner. His skin was at this time sallow, and his face cadaverous; a Chinese-like intimation of a de- sultory beard, and a very thin and unhealthy moustache adorned a head set upon narrow shoulders and a flat chest. His hands were cold to the touch and he suffered frequently from headaches and other bodily ail- ments. Yet when the exigencies of his favorite science of mineralogy required it he would tramp over hill and dale with tireless energy and industry, leaving far in the rear those vastly more robust than he. At this period, when we were both students, he an Inlander and I an Aus- lander at Freiberg, I knew him to determine correctly three well crystal- lized minerals behind his back with eyes bandaged, by the sense of touch alone. When his course was completed and his final examinations had been brilliantly passed, he was offered a subordinate post inthe smelting laboratory, at a very small salary; and accepted ruefully because he had never cared for chemistry, while devoted to mineralogy. In spite of this however, he brought a true scientific mind, and a sense of high honor to the task before him. He applied himself with the same diligence to metallurgical chemistry from a sense of duty, that he had consecrated to mineralogy from pure love of that science, and after some set-backs such as the loss of parts of his right digits through an explosion, (immediately following which accident, he learned to write admirably with the left hand), he attained a high standing among his colleagues. He was commended, if my mem- ory serve me, for his report on the extent of damage to vegetation through the volatile products of the smelting works of the Mulda. He even succeeded in discovering what he took to be a new element and Correspondence. . 335 _ isolating a small portion of its oxide. Owing to certain stringent rules of the German official scientific research offices whereby all the dis- coveries of a subordinate inure to his superior, Frenzel sent the present writer several grams of this isolated new element and the latter offered it at a meeting of the Chemical Section of the A. A. A. S. in Phila., 1884, asking that a committee be named by the president of the section to investigate the material and report on its elementary character. The offer was not accepted and the material was returned to its discoverer. In 1886 science was startled by the announcement that Prof. Winkler of the Freiberg Mining Academy had accomplished for Germany what de Boishaudran eleven years before had effected for France, the dis- covery of a new clement; and following the example of his French col- league, he named it after his country—‘Germanium” as the former had bestowed the name of “Gallium” on his newly found simple body. Whether or not this was the material found by Frenzel and. communi- cated to me under so many safeguards, I do not know, but the co- incidence 1s a curious one. In spite of the handicap of his straitened circumstances Frenzel had already secured a valuable collection of minerals by purchase, ex- change, and exploration before the end of 1870. This was increased and finally sold for quite a large sum, when another collection was begun and at last also disposed of. With his professional duties and cares and the correspondence and labor incident to the prosecution of his studies in his beloved mineralogy, one would have thought his days sufficiently full; but quite unexpectedly he developed a taste for zoology in the de- partment of ornithology, and more specially in the order of Psittaci (paroquets), and contributed several interesting papers beautifully il- lustrated with colored plates of love birds, to the zoological journals of Germany. While Prof. Credner was chief geologist of the geological survey of Saxony, Frenzel issued his mineralogical dictionary of Saxony. His name wil! be found here and there in Dana’s and other standard mineralogies but not to the extent that.is due his profound knowledge of structural, determinative, and chemical mineralogy, and had he been able to devote his time to these branches he would have probably become pre-eminent in them. He had a gentle, affectionate disposition and a high sense of honor. For many years he made me the confidant of his most secret trials, and aspirations ; and called upon me to share his joy at his triumphs. I have now a small silver medal which he won as a prize at the Bergschule. It is about as large as an old Saxon thaler.and has engraved upon it simply “Dem Fleisse.” This he insisted upon giving me when I had exceeded his anticipations in mastering the difficulties in crystallography in which he was instructing me. It is the conscientious, thorough, high toned, industrious men of his type which have made his Fatherland great in science. May we in this country have many like him. PERSIFER FRASER: 330 The American Geologist. ’ November, 1902 PERSONAL AND SCIENTIFIC NEWS. Mr. P. S. Smiry, M. A., has been appointed Assistant in Geology at Harvard University. Dr. J. P. Ippincs, of Chicago University, has been elected a foreign member of the Scientific Society of Christiania. Mr. E. C. Ecker, of the New York survey, has been ap- pointed to a position on the United States Geological Survey. Dr. A. R. C. Sotwyn for many years director of the Canadian Geological Survey, died Oct. 19, at his home in Vancouver, B. C., at the age of 78 years. Mr. R. G. McConneE LL, of the Canadian Geological Sur- vey has spent the past season on the Canadian Yukon river, and is elaborating at Ottawa his notes and maps preparatory to his official report. Dr. R. A. DaAry, geologist of the Canadian Commission, in locating the Canadian international boundary, recently re- turned to ‘Ottawa, having spent the season along the boundary line east from the Okanagan river. Pror. W. H. Hormes, of the United States National Mu- seum, was appointed by the secretary of the Smithsonian In- stitute, S. P. Langley, to be director of the Bureau of Eth- nology. Prof. Holmes is one of the foremost ethnologists in the United States. CoLtuMBIA UNIvERsIty.—New courses have _ recently been established in paleontology, viz.: Phylogeny of some group of invertebrates, involving the principles and methods of the Hyatt school; Invertebrate faunas of geologic hori- zons of North America, and a course in stratigraphy over a wide area directed to some single horizon, based on the fore- going course. The last will involve original research, with field work. The department has opendd with a largely in- creased list of students. Dr. C. H:. Gordon, SUPERINTENDENT OF THE CITY Scuoors of Lincoln, Nebraska, has been appointed instructor in geology and geography in the University of Nebraska. Dr. Gordon retains his position at the head of the city schools and will, for the present, carry one course in petrology, and dur- ing the spring semester one in geography, the latter designed especially for teachers or those having teaching in view. In addition to this work he will also, during the spring semester, repeat his course of lectures on school supervision and man- agement given last year. MMERICAN CEOLOGIST. Vou. XXX. DECEMBER, 1Igoz. No. 6. [STUDIES FROM TIIE DEPARTMENT OF GEOLOGY, UNIVERSITY OF NEBRASKA.] NEW BRYOZOA FROM THE COAL MEASURES OF NEBRASKA.* By G. EB. Conpra, PH. D., Lincoln, Neb. PLATES XVIII-XXV. I. Introduction, In the summer of 1896, at the suggestion of professor E. H. Barbour, the writer began a study of the fossil Bryozoa of the state. Since that date an abundance of material, re- presenting over fifty species, has been collected, classified and described. This paper is only a part of a complete unpub- lished report in which both new and old species are described. Professor Barbour, Miss Carrie A. Barbour and Messrs. W. H. H. Moore, and E. C. Woodruff have assisted in the col- lecting. The illustrations were drawn by the writer, Mr. E. O. Ulrich and Mrs. G. E. Condra. The writer is indebted to Messrs. E. O. Ulrich and R. S. Bassler for valuable assistance. Specimens sent to Mr. Ulrich for. verification were returned with helpful notes. My es- pecial thanks and gratitude are due professor Barbour whose kind and stimulating assistance has made this publication possible. Il. Descriptions of species. Fistulipora carbonaria var. nebrascensis »n. var. Pl. XVIII. Figs. 1, 2. Zoarium large, massive; form irregular. A specimen collected at Louisville is fifteen by eleven by four and one-half centimeters in size, * Read before the Nebraska Academy of Science, January 25, 1902. 338 The Amencan Geologist. December ag being the largest specimen of the genus yet found in the state. The surface is rendered irregular by large mastoid-like projections and by elevated maculae which are not very different from monticules. Macu- lae 5mm. apart, with fair elevation, surrounded by apertures slightly larger than the average, Zooecia average 0.28 mm. in diameter being much smaller than in typical specimens of the species; the lunarium is more prominent. Tabulae a little farther apart; the interstitial ves- icles vary more in size, This is a well marked variety and could be described as a new species. It may be a coral. Type in the museum of the University of Nebraska, Lincoln, Nebraska. Position and locality: Coal Measures; Louisville, Nebraska. Cyclotrypa (?) barberi U/rich n. sp. PRS VILL Rigs 3-85 The following description was furnished the writer by Mr. E. O. Ulrich, the author of the species. “Zoarium ramose dividing at rather long intervals; branches sub-cylindrical, commonly from 7 to 12 mm. in diameter, but reaching 20 mm. in Texas specimens referred to the species. Maculae rather small, 5 or 6 mm. apart; zooecial apertures subcircular, nearly direct, separated by interspaces averaging a little less in width than their diameters, arranged in moderately regular rows, nine or ten in 5 mm.; peristomes ring-like carrying, on the side opposite the lunarium, which is distinguished only by its slightly greater elevation and comparative smoothness, seven to ten small per- forated pustules. Similar pustules are scattered amoag the much smaller granules covering the depressed interspaces. Here and there, especially in the maculae, a small pore of uncertain functions may be observed. Internal structure as shown in the accompanying illus- trations. Named in honor of Mr. Manly D. Barber, of DeKalb, Illi- nois, from whom the first specimens seen of this well marked and widely distributed species were received. The generic position of C. barberi is uncertain, and we may add, so is that of a large proportion of the Fistuliporidae. The family requires thorough revision, and until that is attempted it would be, to say the least, unwise to create generic groups.” This is the first published description of the species, though its specimens are common in the collection of E. O. Ulrich, who not only gave the name, but has placed specimens in the National Museum ° under the above name. The species is quite readily distinguished from associated Fistuli- porae (to which genus it may belong) by its ramose form of growth. Kigs. 3-8 were drawn by E. O. Ulrich. Position and locality: Coal Measures; De Kalb, Illinois; Bartles- ville, Indian Territory; Kansas City, Missouri; Pomeroy, Kansas; Texas; Louisville, Weeping Water, Nehawka, Cedar Creek, South Bend, Dawson, Table Rock, Roca, and Plattsmouth, Nebraska, being plentifully represented in the exposures across the Platte river from New Bryozoa from Nebraska.—Condra, 339 Louisville. Type specimens in the museum of the University of Ne- braska, Lincoln, Nebraska, and in the collection of E. O. Ulrich. Meekopora prosseri Ulrich n. sp. Pl. XVIII. Fig. 9; P}. XIX, Figs. 1-6. “Zoarium bifoliate, forming palmate fronds or frequently dividing branches 8 to 4o mm. wide, 1 to 2 mm. thick; edges of branches nonporiferous, subacute; zooecia opening on both faces of fronds, comparatively small, ovate, very slightly oblique, directed dis- tally, separated by interspaces as wide or wider than their longer di- ameter, arranged in rather regular intersecting series, about eleven in 5 mm.; peristome thick, highest on the lower or lunarial side; inter- spaces, like the maculae, which are rather large and occur at intervals of 4 or 5 mm., concave and covered by minute granules: This fine species is related to M. clausa Ulrich, a characteristic fos- sil of the Chester group, but is readily distinguished by its wider fronds, smaller zooecial apertures, and thicker interspaces. The types of the species were collected some years ago by Prof. Charles S. Prosser (Ohio State University) and submitted to the author for determination and description.” d The above description and Figs. 1, and 3-7 were sent to the writer by E. O. Ulrich, the author of the species. Nebraska specimens agree with this concise description, to which a few notes are here added. Zoaria usually fragmentary, rarely over 10 cm. high, generally 4 or 5 cm., one to three mm. thick; apertures 0.16 by 0-2 mm. across, eleven to thirteen in 5 mm. Diaphragms few, wanting in some tubes; vesicles numerous, arranged more or less in series, not very different in size in different parts of the zoarium, sometimes quite filled by a deposit near the surface. There are two forms of growth, one with narrow, and the other with wide branches. Position and locality: “Coal Measures; near Grenola, Elk County, Kansas” (Ulrich) ; Dawson, Table Rock, Bennett and Roca, Nebraska. Quite plentifully represented at these places, especially at Dawson in the railroad cuts about one-half mile west of the B. & M. depot. Professor E. H. Barbour secured the first specimens collected in the - state at Roca, in 1896. Type specimens in the collection of E. O. Ul- rich, and in the museum of the University of Nebraska, Lincoln,, Nebraska. Batostomella leia n. sp. Pl. XIX. Figs. 7-10. The zoarium consists of slender irregularly branching stems sup- ported by a basal expansion. Branches circular in section, 3 to 5 mm, in diameter, surface smooth, without spines. Cell apertures subcircu- lar, quite regular in size, 0.14 to 0.16 mm. across, twelve to thirteen in 5 mm., not arranged in regular vertical or diagonal series. Interspaces. 340 The American Geologist. Deeembety aoe: smooth, wider than the zooecial apertures; thickened interspaces or small areas without apertures occur on the surface of the zoarium placed about 2 mm. apart. Zooecia quite vertical in the axial region and then bend slowly outward to the surface where they are not yet direct; walls thin in the immature region, thickened in the periphery; by vertical sections, narrow cortical and wide axial regions are shown. Tubes in the axial region, subcircular in section; walls 0.02 mm. thick. Owing to the thickened walls in the outer portions, the zooecial cavi- ties decrease slightly in size mear the apertures. Acanthopores quite numerous, not long, small and large, generally small, forming in sec- tions, irregular circles about the zooecia, ten to fifteen in a circle; they do not in any way form divisional lines in the zooecial walls; a few acanthopores, 0.06 mm. in diameter, occur at the angles of the cells; small acanthopores 0.02 to 0.04 mm. in diameter. Tabulae scarce, ab- sent in most zooecia. Mesopores few and small. On account of the even cylindrical surface, few zooecia, and wide interspaces, this species is not apt to be confused with any of the as- sociated species of Rhombopora. The interspacial areas, I to 2 mm. apart, when present, will also serve in its identification. On account of the few large acanthopores resembling those of R. lepidodendroides Meek, the specimens may be confused with that species. Other char- acters enumerated will amply serve for distinction. It is clearly dis- tinct from all described species of Batostomella. Few specimens have been collected. One was sent to E. O. Ulrich who pronounced it new and a member of the genus Batostomella. The name is suggested by the even surface. Type specimens in the museum of the University of Nebraska, Lincoln, Nebraska. Position and locality: Coal Measures; South Bend, and Bennett, Nebraska. Stenopora heteropora n. sp. Pl. XX. Figs. 1, 2. Zoarium massive; surface with clusters of elevated apertures larger than the average; clusters 1.5 mm. across, 4 or 5 mm, apart. Aper- tures polygonal or rhomboidal, more or less in series about the clus- ters, 0.24 to 0.4 mm. across, average 0.26 to 0.3 mm., fourteen or fifteen in 5mm. Interspaces thin, 0,05 to 0.06 mm. wide. Zooecia about 3 mm. long, at first horizontal, and then with a quick curve, they pass direct to the surface; tubes polygonal, average diameter 0.27 mm., walls thin, usually not more than 0.02 mm. thick; near the surface they increase in thickness equal to that of the interspaces. Diaphragms thin, 5 to 8 in each tube, about 0.26 mm. apart in the straight portion of each tube. Acanthopores few, of medium size, located at the cell angles. The line of division between the adjacent zooecia is quite plain. The writer knows of no species of the genus more closely related to Aniso- trypa. The nearest related species is S. rudis Ulrich from which this dif- fers mainly in zoarial form. The zoarium of that species consists of New Bryozoa from Nebraska.—Condra. 341 hollow, irregular branches, while this species is massive. The walls, in section, resemble those of S. cestriensis Ulrich, but show smaller acanthopores and plainer diyisional lines between the adjacent zooecia. The main points of specific importance are to be found in the varying sizes of the zooecial apertures and in the form of the zoarium. Type specimens in the museum of the University of Nebraska, Lincoln, Nebr. Position and locality: Coal Measures, South Bend, Nebraska. Stenopora distans n. sp. Pl: XX. Figs. 3-5. Zoarium an expanded crust, consisting of a single layer of zooecia, supported by a wrinkled epitheca; thickness 2 to 3 mm., width variable, average about 3 mm.; surface spinulose when not worn, with low ‘moaticules, or smooth. Apertures subcircular, not in regular lines, un- equal in size, 0.25 mm. in diameter, fifteen or sixteen in 5 mm. Inter- spaces thick, with rounded surface, unequal in width, sometimes 0.15 mm. or more wide. Zooecia 2 to 3 mm. long, quite straight throughout the entire length; walls quite thick throughout the length of each tube, not plainly moniliform; zooecial tubes subcircular in section, of un- equal diameters, varying from 0.16 to 0.28 mm. Large acanthopores occur at some of the cell angles; acanthopores 0.1 to 0.12 mm. in diameter, of regular form, circular in section, slightty more than half as numerous as the zooecia; small and less regular acanthopores, 9.03 to 0.05 mm. in diameter, occur in the walls between the large acantho- pores; their number varies from about Io to I5 surrounding each zo- oecium. Diaphragms thin, three to seven in each tube, irregularly dis- posed. Mesopores small, usually not more than 0.07 mm. in diameter, irregular in section, one-third to one-half as ‘numerous as the zooecia. To a limited extent, this species resembles S. spinulosa Rogers, in having similar though less numerous large acanthopores which are not disposed as they are in that species. The wide interspaces and the varying sizes of the zooecia serve as the main specific characters. The diaphragms are also of use in separating it from related species. Type specimens in the museum of the University of Nebraska, Lincoln, Ne- braska. Position and locality: Coal Measures; Louisville, Nebraska. Stenopora (?) polyspinosa pn. sp. (Provisional.) Pl. XX. Figs. 6-10. Zoarium ramose consisting of subcylindrical branches with di- ameters of 4 or 5mm. Bifurcations far apart, with small angles. Sur- face smooth, except for numerous small and a few large acanthopores which project on the interspaces as low, blunt spines; the former give the surface a papillaceous appearance. Zooecial apertures subcircular, not arranged in series, 0.25 to 0.3 mm. in diameter, thirteen in five mm. Interspaces average 0.07 or 0.08 mm. wide. The zooecia ascend from the vertical axis of the branch, curve, and then pass in nearly a straight line to the cortical portion, where the walls thicken quickly, 342 The American Geologist. TRCCPEEREE, ia and then continue direct to the surface. Walls, in the immature por- tion, very thin, 0.02 mm. thick; not moniliform; in the cortical por- tion they are evenly thickened and finely laminated. The small acan- thopores are 0.04 to 0.07 mm. in diameter and more numerous than in other species collected in the state; they form in sections one com- plete series about each zooecium, with twelve to twenty in a series; at places, two or more incomplete rows are observed. A few large acanthopores occur at the angles of some of the zooecia. The zooecial cavity is about equal in diameter throughout. Diaphragms, few in number, not more than one to each zooecium, generally placed at the inner border of the mature portion of each tube which is I to 1.5 mm. thick. Mesopores small, irregular in form, about one-fourth as nu- - merous as the zooecia. The writer is-in doubt about the systematic position of this species. It may belong to Stenopora, Batostomella or Rhombopora. When someone establishes the limits of these genera, it can be correctly placed. Rhombopora crassa Ulrich has a thicker cortical portion, no large acanthopores, and the zooecia are not vertical in the axial region. There are not enough large acanthopores to place it with R. lepido- dendroides Meek: also, other characters, such as the zoarial form and quick transition from the immature to the mature region, make it dis- similar. The apertures are not like those of most species of Batosto- mella, but the walls, mesopores, and small acanthopores resemble to a degree the same of that genus. The apertures, acanthopores and mesopcres as a whole seem to be nearer those of Stenopora than to either of the other genera. The species may be a Rhombopora related to R. crassa and R. lepidodendroides. Further, it may be a peculiar form of an old growth of the latter. Type specimens in the museum of the University of Nebraska, Lincoln, Nebraska. Position and locality: Coal Measures; South Bend, Nebraska.- Fenestella cyclofenestrata n. sp. Pl. XXI. Figs, 1-3. Zoarium a reticulate expansion apparently of large size; of a num- ber of incomplete zoaria, each over 4 cm. across. Branches straighi or slightly flexuous, average width 0.25 mm., twelve to fourteen in 5 mm., 0.35 mm. wide immediately below bifurcations which are far apart and with very acute angles; reverse face evenly and slowly rounded, smooth or faintly striated; the obverse shows a broad, evenly elevated area 0.07 to 0.I mm. across; spines not observed to be present. Frequently the area is more elevated and appears as a broad carina. Dissepiments on the reverse face, as wide as long, over one-half as wide as the branches, on a level with the latter, much expanded terminally; they and the branches slope evenly to the fenestrules; not much depressed and strong on the obverse. Fenestrules on the reverse, circular or subcircular, modified by the terminally expanded dissepiments, average 0.2 mm. long, about twelve in 5 mm.; a little longer and less wide on the opposite face. New Bryozoa from Nebraska.—Condra. 343 Zooecia in two regularly alternating ranges (sometimes three for a short distance below a bifurcation). The two ranges are widely separated by the broad area. Apertures circular or subcircular, usually two, rarely three to each fenestrule, 0.08 mm. across, 0.12 mm. across including the peristome, with the peristome slightly less than their own diameter apart, twenty-four in five mm. These specimens are not apt to- be confused with any of the de- scribed species. The reverse face resembles, to a degree, that of F. conradi Ulrich, but is of smaller proportions and without perforated nodes. The circular to subcircular fenestrules, wide area or carina, and rather robust appearance serve to distinguish the specimens from related species. Some authors would classify this species with the genus Polypora. The name is suggested by the circular fenestrules of the reverse face. Type specimens in the museum of the University of Nebraska, Lincoln, Nebraska. Fosition and tocality: Coal Measures; Bennett, Nebraska. Quite plentifully represented at that locality, being found in a thin layer of impure limestone, in the creek bed, about two miles below town. Fenestella spinulosa n. sp. PSI Mies) 4,15. Zoarium a fan-shaped expansion, commonly found fragmentary. One complete abnormal zoarium, resembling Ptilopora in its mode of growth, is 4 cm. high by 3 cm. wide. Its main branches are 0.28 to 0.30 mm. in diameter and give rise, from their sides, at very acute angles, to smaller branches, 0.2 to 0.25 mm. wide; also, the latter may originate by bifurcation. Branches of normal zoaria, on the reverse, straight, cylindrical, faintly striated or granulose, 0.28 mm. wide, vary- ing some in distance apart, usually about their own diameter apart, about nine or ten in 5 mm. ‘The obverse face has a rounded carina, quite well elevated, bearing a row of conical spines 0.07 to 0.I mm. in “iameter at their bases in young growth, averaging 0.25 mm. distance from apex to apex, usually two to each fenestrule, disposed so that one occurs near the end of each dissepiment and one between; they about equal one series of zooecial apertures in number. In older _growth the spines are larger, and quite obscure the apertures. Dissepiments on the reverse, straight, cylindrical, with very little terminal expansion, not much depressed, average width one-third that of the branches; depressed on the obverse face. Fenestrules rectang- ular, vary in size, 0.35 to 0.45 mm. long by 0.2 to 0-3 mm. wide; not so regular on the obverse, only slightly modified by the zooecial apertures, nine and one-half to ten in 5 mm. Zooecia small, in two alternating ranges, about two times their own diameter apart, subcircular, in some specimens pustuliform, others have faint peristomes, project little into the fenestrule, nineteen or twenty in 5 mm. 344 The American Geologist. Sco te ae The species is nearest related to F. sevillensis Ulrich, from which it is not readily distinguished if the reverse face is viewed, except with worn specimens when the smaller zooecia show. The zooecia are larger than those of F. parvipora n. sp. The distinguishing features are the large spines on a carina. The obverse face is not very apt to be confused with other species. F. limbata Foerste has more promin- ent apertures and smaller proportions. Type specimens in the museum of the University of Nebraska, Lincoln, Nebraska. Position and locality: Coal Measures; Roca and Dawson, Ne- braska. This is a common fossil in the Warner quarry one mile east of Roca. a Fenestella parvipora n. sp. Pl. XXI. Figs. 6. 7. Zoarium an expanding foliar net work of medium size. Branches on the reverse, straight to sinuous, convex, finely striated if worn, more than their own diameter apart, average diameter 0.24 mm., nine or ten in 5 mm.; bifurcations at distances of 2 to 4 mm. Obverse face subcarinate; the carina is represented by a line on which occur very small nodes; nodes scarcely discernible, 0.04 mm. at bases, 0.15 to 0.2I mm. apart. Dissepiments straight, long, cylindrical, about one-third as wide as the branches, not much depressed on the reverse face; depressed on the obverse. Fenestrules oblong, quite large for the size of the branch- es, average 0.5 to 0.55 mm. long, 0.31 mm. wide; the narrowest are 0.28 mm.; seven and one-half in 5 mm. Zooecia small, in two alternating ranges, three or four to each fen- estrule. Apertures very small, circular, pustuliform with rounded subconial peristomes, 0.09 mm. across including the peristome, face obliquely outward, more than their own diameter apart, 25 in 5 mm. This species resembles F, sevellensis Ulrich in having a similar re- verse face, but is distinct on account of the number, size and disposi- tion of zooecia. It is not apt to be confused with another member of the genus. F. gracilis n. sp. has a definite carina with larger spines, larger apertures and very different fenestrules. The writer knows of no species of the genus with as small zooecia and zooecial apertures. Type in the museum of the University of Nebraska, Lincoln, Ne- braska. Position and locality: Coal Measures; Roca, Nebraska. Fenestella gracilis n. sp. ‘Pl XXI. Figs. 8, 9. Zoarium a regular foliar expansion of large size as indicated by numerous incomplete specimens. Branches on the reverse, about equal in size, straight or slightly flexuous, spread little when bifurcating, appear cylindrical, with longitudinal striae; average width 0.25 mm., nine to twelve in 5 mm. The obverse face has a straight carina, 0.07 mm. wide, with rounded summit, bearing a row of sharp, conical New Bryozoa from Nebraska.—Condra. 347 small spines with diameters of 0.07 mm. and placed at distances of 0.22 mm. Dissepiments slightly expanded terminally, depressed some on each face, slightly on the reverse, 0.1 to 0.13 mm. wide in the middle, wider in older growth. Fenestrules quite regular in form, subrect- angular, vary some in dimensions with different conditions of growth, modified little by zooecial apertures, average 0.65 mm. long by 0.25 mm. wide, long for the width, about six in 5 mm. A larger form has longer fenestrules. Zooecia in two alternating straight ranges. Apertures with fairly prominent peristomes, about their own diameter apart, set close in against the carina, facing outward, four and rarely five to each fenes- trule, twenty-three to twenty-five in 5 mm. The species resembles F. ‘dentata Rogers but is not so robust. That species has eight branches in 5 mm., each being 0-4 mm. in diameter, The fenestrules average 0.9 mm. long by 0.3 mm. wide, with four in 5 mm. This species has more and smaller nodes as well as twenty-three to twenty-five instead of eighteen zooecia, for each range, in 5 mm. The fenestrules are shorter. Type in the museum of the University of Nebraska, Lincoln, Nebraska. Position and locality: Coal Measures; Roca, Nebraska. Fenestella polyporoides n. sp. Pl, Xe, Figs:6, ‘7. Zoarium a strong reticulate expansion. Several specimens each 3 or 4 cm. high have been found. Branches robust, cylindrical, striated on the reverse, straight or flexuous, flexures bending to and away from the dissepiments, 0.35 to 0.4 mm. wide, 0.5 mm. below a bifur- cation, six in 5 mm. The obverse face has a well developed carina 0.1 mm. across, somewhat flexuous, bearing a row of prominent nodes 0-5 to 0.6 mm. apart. Dissepiments expanded terminally about one- half as wide as the branches. Another form has smaller dissepiments and larger fenestrules; fenestrules subelliptical to subquadrangular, large in typical specimens, 0.9 to 1.05 mm. by 0.4 mm. inside measure- ment, eight in I cm. Zooecia in two or three ranges, sometimes three for a short dis- _tance below a bifurcation, four or five in each range to the fenestrule, seventeen or eighteen in 5 mm.; apertures circular, 0.13 mm. across including the peristome, a little more than their own diameter apart, project very little into the fenestrule. The species is related to F. kansanensis Rogers and F. dentata Rogers; F. burlingtonensis Ulrich differs in the size of the nodes, but has as many apertures. Specimens sent to E. O. Ulrich were pro- nounced by him members of the genus Polypora. However, the writer is inclined to place them with the fenestellas. The main specific char- acters are found in the resemblance to the polyporae and in the large dimensions. 348 The Amencan Geologist. December, 2005: Position and locality: Coal Measures; Roca and Plattsmouth, Ne- braska. Fenestella conradi var. compactilis x. var. Pl Re aes. a 2s Zoarium a very thick compact foliar expansion supported by a stalk and root-like processes. The best specimen secured is 4 cm. high by 2 em. wide; the root-like supports are I to 2 mm, in diameter. Branches straight or slightly flexuous, unusually thick from obverse to reverse, close set, quite regular in form and size, average 0.35 mm. wide, 0.4 mm. below and 0.3 mm. immediately above a bifurcation, nine or nine and one-half in 5 mm.; reverse face smooth, without nodes, slightly smaller than the obverse, but not the difference noted in typi- cal specimens of the species; striations show on the stalk and for a short distance out on the branches, especially when worn. Median carina of the obverse face not very prominent, rounded, straight or slightly flexuous, with small spines or nodes placed in two faint rows. Fenestrules on the reverse, circular, slightly elliptical in young por- tions of the zoarium, 0.25 to 0.35 mm. across at the surface, much contracted and mearly obliterated deeper in the frond, eight and one- half or nine in 5 mm., a little longer and less wide on the opposite face. Zooecia in two alternating ranges. Apertures circular, peristome faint or wanting, two and never three to each fenestrule, encroach slightly on the fenestrule, eighteen in 5 mm. This variety may prove a distinct species. F. sp. (?) differs in mode of growth. Also the keels and reverse faces are dissimilar; the rounded irregular keel which at places shows two rows of small nodes brings to mind F. binodata n. sp. Type-specimens in the museum of the University of Nebraska, Lincoln, Nebraska. Position and locality: Coal Measures; South Bend and Roca, Ne- braska. Fenestella sp (?) Pl. XXII. Figs 3-5. Zoarium a regular rapidly or slowly expanding net work. The larg- est specimen, not complete, is 3.75 cm. high by 2.5 cm. wide. Branches rigid or flexuous, much the wider on the obverse face, narrowly rounded and thin on the reverse being 0.16 to 0.24 mm. wide, nine or ten in 5 mm. Carina quite prominent, thin, varying with the growth, about 0,06 mm. across at the top where it appears sinuous bearing a row of flattened nodes; nodes 0.1 mm. long by 0.06 mm. wide at the base, 0.2 to 0.3 mm. apart from apex to apex. Dissepiments on the obverse, not constant in character, about 0.15 mm. wide, depressed, expanded terminally, modifying the fenestrules; on the reverse, slightly smaller, long and without much terminal ex- pansion, on a level with and of the same character as the branches. New Bryozoa from Nebraska.—Condra. 349 Fenestrules usually subcircular or elliptical on the obverse; larger -on the reverse where they may be subquadrate and sometimes hex- agonal, about as wide as long, average 0.4 mm. wide, decreasing in width towards the obverse face where they are 0.35 mm. long by 0.26 mm. or less wide; nine or nine and one-half occur in 5 mm.; except for the projecting apertures, they are subcircular or subelliptical on the obverse face. Zooecia in two alternating ranges, of medium size. Apertures cir- . cular, two to each fenestrule, one placed at the end of each dissepiment with one between, a little «more than their diameter apart including the not very definite peristome, project slightly into the fenestrule; eigh- teen to twenty in 5 mm. The affinities of this species are with F. conradi Ulrich and F. con- radi var. compactilis n. var. It differs from the former ia having eigh- teen or twenty instead of twenty-three zooecia in 5 mm., two instead of two or three apertures to the fenestrule and a different character of fenestrule. On the reverse face, the branches are relatively much smaller compared with the obverse. The thin keel is also a distinctive feature. It differs from the new variety in mode of growth, char- acter of keel, and in having a very different reverse face. The species is not apt to be confused with the latter. Type specimens in the mu- seum of the University of Nebraska, Lincoln, Nebraska. Position and locality: Coal Measures; South Bend and Nehaw- ka, Nebraska. ‘The first specimen was collected at South Bend by Prof. E. H. Barbour, 1896. Fenestella subrudis n. sp. Pl. XXTI. Figs. 10,11. Zoarium a foliar expansion of unknown size. Branches on the re- verse, broadly rounded, granulo-striated, slight sinuous, quite closely approximated, 0.35 to 0.45 mm. wide, eight in 5 mm-.; on the obverse, they are subcarinate and finished by a small carina which may be smooth or have inconspicuous nodes; carina 0.06 mm. across; ‘nodes, if present, feebly elevated; a flattened area or face extends on each side of the carina down to. the broadest part of the branch; these areas, slightly concave, are modified by the zooecial apertures. “ Dissepiments on the reverse, short, wide, expanded terminally, narrowly rounded, not much depressed, 0.15 to 0.2 mm. wide; they vary more in size and are faintly striated on the opposite face. Fenestrules elliptical to elongate-elliptical; average on the reverse, 0.5 to 0.55 mm. long by 0.24 mm. wide, slightly larger on the severse, six in 5 mm. Zooecia in two alternating ranges. Apertures circular, of medium size, 0.13 mm. across with peristome, a little more than their own di- ameter apart including the peristome, three to each fenestrule, seven- teen or eighteen in 5 mm. The nearest related species is F. missour- iensis Rogers which is not very dissimilar. 350 The American Geologist. December, t0Ge- The writer sent a specimen, as a new species, to E. O. Ulrich, who made the following comment: “Related to F. rudis Ulrich, but more delicate. The present form is practically the same as an abundant Chester species to which I have applied the manuscript name F. sub- rudis.” The writer has used the very suggestive name proposed by Mr. Ulrich. Type in the museum of the University of Nebraska, Lin- coln, Nebraska. Position and locality: Coal Measures; between Weeping Water and Nehawka, Nebraska. Fenestella binodata 2, sp. Pl eet Figs. 12513. Zoarium a reticulate expansion of unknown size. No complete zoaria have yet been found; one nearly complete is 3 cm. high; an- other specimen shows the zoarium at its inception where the numer- ous bifurcations give it a rapid expanse. Fragments from farther out in the frond have straight or flexuous loosely approximated branches. Branches on the reverse, slightly flexuous in the older parts, nearly straight in the periphery, stout, rounded, finely striated or smooth; deep from the reverse to the obverse face, 0.35. to 0.4 mm. wide, six to eight in 5 mm. Carina a blunt ridge, 01 to .I4 mm. across, bearing two rows of conical or laterally compressed nodes alternately placed; nodes at their bases, 0.1 mm, long, 0.06 mm. wide, placed 0.27 mm. apart from apex to apex in each series and 0.15. mm. distant from the nearest node or spine in the alternating series. Dissepiments on the reverse, of the same character as the branches, expanded terminally, slightly elevated or depressed, average 0.2 mm. wide and 0.22 mm. long, slightly less wide and faintly striated on the opposite face. Fenestrules usually subelliptical to oblong, vary in size, about the same size and form on both faces, slightly modified by zooecial aper- tures, 0.6 to 0.7 mm. long by 0.35 mm. wide, six or six and one-half in 5 mm. Zooecia in two subalternate ranges, not laterally disturbed as with F. conradi Ulrich. Apertures circular, with thin peristome on the side of the fenestrule, inner border set in against the carina with the aper- tures facing out or obversely, three or four to each fenestrule, may or may not be placed at the ends of the dissepiments, eighteen to twenty in'5 mm. What may be a variety has smaller dimensions. This species is related to, but is very distinct from F. ovatipora Rogers which has no keel but has a raised area without spines. It has ovate apertures, four to each fenestrule with four fenestrules in 5 mm. This species is nearer F. conradi var. compactilis n. yar. which may have a slightly binodate appearance, but is distinct on account of the character and number of apertures to the fenestrules, the longer fenestrules, and the more definite binodate arrangement of the larger nodes. The reverse faces are very dissimilar. There is some resem- blance to F. remota Foerste, which has a more regular and New Bryozoa from Nebraska.—Condra, 351 finer growth, a less binodate appearance and a larger number of aper- tures. The principal characters of this species are found in the double row of alternating nodes on a broad carina and in the robust appear- ance. Type specimens in the museum of the University of Nebraska, Lincoln, Nebraska. Position and locality: Coal Measures; South Bend, Weeping Water, and Roca, Nebraska. Polypora bassleri zn. sp. Pl. XXII. Figs. 8,9; Pl. XXIII, Fig. 1. Zoarium and expanding growth of medium size; branches not very straight, narrowly or evenly rounded on the reverse resembling, when narrow, P. submarginata Meek; evenly rounded on the reverse, with small or large spines distributed among the apertures about as in P. spinulifera Ulrich; spines located on thin zigzag ridges between the ranges or on a fairly even surface; about five branches occur in 5 mm., each having an average diameter of 0.7 mm., 0.8 to 0.9 mm. just below a bifurcation. Dissepiments on the obverse, one-half as wide to as wide as long, about 0.35 mm. wide, broadly rounded, expanded terminally. Fenes- trules elliptical to oblong, average 0.9 to 1.0 mm. long by 0.4 wide on the obverse, with four in 5 mm., larger on the reverse face. Zooecia in three to six, usually closely placed alternating ranges, commonly four above a bifurcation; five, rarely four, sometimes six, in each range to the fenestrule. Apertures circular, 0.11 mm. across, one and one-half diameters apart, nineteen or twenty in 5 mm. with peristomes around the apertures of the lateral ranges; zooecia of the other ranges with peristomes or open into small depressions between the zigzag lines which may separate the ranges; apertures usually less than their own diameter apart from those in the adjacent or alternat- ing ranges. This species resembles P. approximata Ulrich, but is structurally different. The growth in one form is more diffuse the reverse face of which resembles smaller P. submarginata Meek. In fact some of the specimens commonly referred to that species belong here. The other form of growth is nearer P. approximata and P. spinulifera. The ranges of zooecia are more crowded in old than in young growth. Little area or space is left between the alternating ranges. P, approximata Ulrich is more robust and differs structurally. The name is given in honor of Mr. R. S. Bassler who has rendered the writer valuable assistance. Type specimens in the museum of the University of Nebraska, Lincoln, Nebraska. Position and locality: Coal Measures; Louisville, Weeping Water, Nebraska. Polypora reversipora np. sp. P). XXIII Fig..2-5:% Zoarium a flat foliar expansion of large size. Branches on the re- verse, stout, flexuous, bending into and away from the dissepiments, 352 The Amencan Geologist. Decenees narrowly or slowly rounded, sides facing the fenestrules flattened, surface covered with granules 0.05 mm. across; a few circular acces- sory pores are present on this face; pores placed near the ends of the dissepiments, sometimes scattered over the surface, 0.14 mm, in diam- eter; branches close, average 0.7 to 0.8 mm, wide, 0.9 mm. just be- low a bifurcation, five in 5 mm.; obverse face quickly rounded, with large nodes along the center which cause it to appear thin; nodes read- ily observed by the unaided eye, irregular in form and size, 0.15 mm, wide by 0.3 mm. long at their bases, elevated, 0.4 to 0.5 mm. apart from apex to apex, in one regular row in young specimens, or in ir- regular rows in old forms. Dissepiments on the reverse, short, granulose; much depressed and thinner on the opposite face. Fenestrules of the reverse, elliptical, 0-9 mm. long by 0.5 mm. wide, smaller deeper in the frond; on the ob- verse face, less regular, longer, narrower, 1. to 1.1 mm. long by 0.3 to 0.4 mm. wide, four in 5 mm. Zooecia in four or five, sometimes six, alternating ranges. Aper- tures subcircular, 0.9 to 0.11 mm. across, one to one and one-half di- ameters apart; lateral ranges have thin peristomes; the middle ranges are quite obscured by the large nodes while the lateral ranges are not easily seen on account of the depth and the flattened surface. No Coal Measure species has the apertures more obscured; sixteen occur in 5 mm., with four in each range to the fenestrule, This species is related to F. ulrichi n. sp., but is less robust and structurally different. The accessory pores of the reverse face serve as the basis for the name. Type specimens in the museum of the University of Nebraska, Lincoln, Nebraska. Position and locality: Coal Measures; Table Rock, Nebraska. The first specimen of the species was collected by Mr. H. H. Moore, 1900, Polypora ulrichi 72. sp. Pl. XXIII. Figs. 6-10. Zoarium a reticulate expansion of large size; branches on the re- verse, stout, rigid, rounded; sides facing the fenestrules rounded or flattened, granulose; granules in faint lines. Branches average 0.9 mm. in width, 1.25 mm. just below and 0.75 to 0.8 mm. immediately above a bifurcation, six to eight in 1 cm.; obverse subcarinate, especial- ly in young unworn specimens, with a row of large cylindrical nodes along the middle of the branch, nodes usually in a straight line, 0.5 to 0. 7 mm. apart, 0.15 to 0.21 mm. in diameter, with blunt apices, larg- er and less regularly disposed in old forms. Dissepiments depressed, subcarinate, thin and short on the obverse; larger, some wider, not much and sometimes not at all depressed, stout, one-third to two-thirds as wide as the branches, expanded term- inally, and faintly granulose on the reverse. Fenestrules on the reverse, subelliptical, 1.15 to 1.38 mm. long by 0.4 to 0.5 mm. wide, six to seven in I cm., not quite so long on the reverse. Zooecia quite large, in four to seven alternating ranges, us- New Bryozoa from Nebraska.—Condra. 353 ually five or six, six or seven for a short distance below, and four for a short distance above a bifurcation. Apertures of medium size, circular, with thin peristome incomplete on the lower and inner mar- gins, nearly twice their own diameter apart, sixteen or seventeen in 5 mm., usually five in each range to the fenestrule. This species differs from P. nodocarinata Ulrich in having much larger and fewer nodes which are not distributed as they are in that species ; ‘the zoarium is more robust. The zooecial apertures are of a different character. The subcarinate appearance of the - branches calls to mind P. submarginata Meek, though the two species are very distinct. P. bassleri n. sp. is less robust but resembles some in the disposition of zooecia and to a degree on the reverse faces. Type specimens in the museum of the University of Nebraska, Lincoln, Nebraska. The name is given in honor of E. O. Ulrich, the American author- ity on Paleozoic Bryozoa, whose literature and other assistance have been of inestimable value to the writer. Position and locality: Coal Measures; Table Rock, Falls City, and Bennett, Nebraska. The first specimen of the species was collected by Miss Carrie A. Barbour at Table Rock, rIcco. Polypora remota n. sp. Pl. XXIV. Figs.1. 2 Zoarium an evenly spreading net-work, 3 cm. high by 2 cm. wide, growing from a small stalk. Branches cylindrical, about their own diameter apart, evenly convex on both faces, smooth except for the zooecial apertures and fine striae, loosely joined, bifurcating at regular intervals of about 5 mm., 0.7 mm. wide, one mm. wide just below a bifurcation, seven in I cm. Dissepiments thin, cylindrical, depressed on each face, few in num- ber, pass direct or at an angle from one branch to the other, average width 0.25 mm. Fenestrules few, long, not very different in size and form; by in- side measurement, they are 2.5 long by 0.7 to 0.8 mm. wide; three to three and one-half in 1 cm. Zooecia in four to six alternating ranges. The usual number is -five, with six before, and four immediately above a_ bifurcation; apertures circular, small, 0.08 to 0.10 mm. in diameter, 0.13 mm. across including the peristome, pustuloid with peristome, four to five times their own diameter apart longitudinally, five or six to the fenestrule, twelve to thirteen in 5 mm. This species is not far removed from the genus Thamniscus, the bifurcations being about one-half as numerous as the dissepiments. Polypora gracilis Prout seems to be the closest related species. That species has a less regular growth and nine instead of twelve or thir- teen apertures in 5 mm, Also, it has spines while this species is smooth. The very thin and slender dissepiments are of specific im- portance. No other Coal Measure Polypora of as large dimensions 354 . The American Geologist. December sate has dissepiments so thin. The name is given on account of the dis- tance the apertures are apart in the series. Type in the museum of the University of Nebraska, Lincoln, Nebraska. Position and locality: Coal Measures; Louisville, Nebraska. Thamniscus pinnatus 2. sp. PI. XXIV. Figs. 3-8. Zoarium a flabellate frond varying much in size; one complete specimen collected at Roca, is 3 cm. high, and 4 cm. wide; all other zoaria found are smaller and average higher than wide; the base is subcircular from which a stalk ascends to support the frond. The main branches (sometimes one branch) ascend in a zigzag manner, giving off short pinnae or lateral branches at the bends and bifurcate at distances of from 4 to 10 mm. Another form of growth is less zigzag in character. It is more like T. octonarius Ulrich, but has been pronounced distinct by the author of that species. Branches subcircular to subelliptical in section, wider than thick, especially at a distance from the stalk, I or 2 mm. in width, more than their own diameter apart; form and size vary in different regions and with the condition of growth; the obverse face is more convex than the reverse. The pinnate branches divide with rounded angles. Pinnae alternately places, about 2 mm. apart on each margin of the branch, I mm. apart longitudinally along the branches between the bifurcations, usu- ally about I to 1.5 cm. long. Zooecia increase rapidly in number of ranges, from three, four or five, to seven or eight, and infrequently nine between the bifurcations. Apertures small, 0.07 mm. in diameter, circular, pyriform in worn specimens, arranged in definite longitutinal series, and quite regular diagonal series; fifteen occurring in 5 mm. longitudinally, four and one- half in I mm. diagonally; in some well preserved specimens they are placed on faint oblique ridges. The branches divide with rounded angles, but the ranges of zooe- cia separate with acute angles with a wedge-shaped area between. Peristome, in perfect specimens, horse-shoe-shaped, elevated, lifted into a small spine on each side of the aperture. On the lower side of the aperture the peristome widens to wholly or partially surround a sub-oval depression which, in perfect specimens, is .14 mm. wide by .18 mm. long. This species is related to T. octanarius Ulrich, but has more prom- inent apertures and a much more diffuse growth. The figures repre- sent two types of growth and what may be two distinct species, yet the writer prefers, for the present at least, to place them under the same name. One form is less pinnate and more like Ulrich’s species. Type specimens in the museum of the University of Nebraska, Lin- coln, Nebraska. Position and locality: Coal Measures; Bennett, Roca and Daw- son, Nebraska. Plentifully represented at Bennett. New Bryozoa from, Nebraska.—Condra. 355 Thamniscus palmatus 2. sp. (Provisional.) PE SXV. Hig 9; Zoarium a small palmate expansion, II mm. wide and 12 mm. high, supported by a circular base from which ascends a short dividing stalk which divides into primary and secondary branches; branches about 0.65 mm. wide, quite straight, evenly convex, nearly in a plane, about their own diameter apart, bifurcate with rounded acute angles; no dissepiments or fenestrules are present. Zooecia extend from the sides of the branches and seem to show prominent projecting apertures, 0.2I to 0.25 mm. apart, with thirteen occurring in 5 mm. Worn portions of the zoarium show them ar- ranged in three to five ranges. Owing to its mode of growth, no oth- er described bryozoan is apt to be confused with this species. As yet only one specimen has been secured. It was sent to E, O. Ulrich who pronounced it of strange and peculiar growth, and expressed his regrets that the obverse face did not show. Type in the museum of the University of Nebraska, Lincoln, Nebraska. Position and locality: Coal Measures; Roca, Nebraska. Cystodictya anisopora n. sp. Pl. XXV. Figs. 1-5. Zoarium a bifurcating stipe, 0.8 mm. thick, I. to 1.25 mm. or more wide between the bifurcations, 1.6 mm. wide just below a bifurcation, subelliptical in section; one margin is sharp and the other rounded resembling, to a degree, the same of C. inequimarginata Rogers. Bi- furcations not numerous, at wide angles. ‘ooecial apertures in four or five linear series on each face of the zoarium, usually five, subcircular to elliptical, elevated on the side of the wider margin when perfect, vary in size in the different series, about 0.14 mm. wide by 0.18 to 0.2 mm. long in the row nearest the wide margin, smallest in the row nearest the narrow margin, about twice their own diameter apart longitudinally, (More in the fifth range) closer laterally. The first range has seven apertures in 5 mm., the third eight and the fifth nine and one-half; no longitudinal ridges are present; apertures in well preserved specimens sometimes on prominent transverse ridges, except the less prominent apertures of the fifth range, which are near the narrow margin. The apertures of this range are located between the small ends of the transverse ridges and alternate with the apertures of the fourth range. The transverse ridges are higher, when present, and broader near the wide margin and decrease in width and elevation towards the narrow margin. Zooecia of the two faces of the zoarium separated, by a definite mesotheca, lie close together against the latter dnd are incompletely separated from each other by vesicular tissue. The main body of each zoarium is vertical, from which a vestibule or neck curves quickly to the surface. 356 The American Geoiogist. Decesier, (aaa This species is related to C. inequimarginata Rogers, but is more robust and shows, when perfectly preserved, transverse ridges. There are four and usually five instead of three or four longitudinal series of apertures, also seven instead of ten large apertures occur in 5 mm, in the range nearest the broad margin. The name is based on the unequal apertures. Type specimens in the museum of the University of Nebraska, Lincoln, Nebraska. Position and locality: Coal Measures; Roca and Ashland, Ne- braska. Cystodictya lophodes n. sp. Pi KOXN,.. (Biers: (6.17. Zoarium a bifurcating stipe, subcircular or slightly elliptical in sec- tion, width I. to 1.1 mm. between bifurcations, 1.5 mm. or more at bifurcations; angle of bifurcation wide. Nonporiferous margins nar- row, equal or about equal in width. Zooecial apertures in linear series between longitudinal ridges. Ridges 0.2 mm. apart. Four or five, rarely three, subalternate ranges of apertures occupy each face of the zoarium. The number is increased to five or six below each bifurca- tion. Apertures elliptical, rather large, 0.12 to 0.14 mm. wide by 0.18 mm. long, about twice their own diameter apart longitudinally, about the same distance apart in each range, do not differ much in size, eight in 5 mm. longitudinally in each range, open into trough-like depres- sions between the longitudinal ridges, with or without peristomes. Vesicular tissue composed of small irregular vesicles is closely packed about the zooecia. The species is distinguished from C. anisopara n. sp. by having more equal apertures, no transverse ridges and equal margins. Also, the zooecial apertures open between longitudinal ridges instead of be- ing elevated on the oblique ridges as they are in perfect specimens of that species. Type specimens in the museum of the University of Nebraska, Liacoln, Nebraska. Position and locality: Coal Measures; Roca, Nebraska. Description of Plates. PICA bE SOvaniae Fistulipora carbonaria var. nebrascensis n. var. 1. Surface enlarged. *2 Tangential section, drawn to a scale of I mm. Cyclotrypa (?) barberi Ulrich n. sp. 3. Surface ealarged, X 22. 4. Specimen outlined, natural size. 5. Transverse section, X 22. 6. Transverse section, near the center of the stem. 7. Vertical section of a small branch, X 12. *Observe the milliméter scale which is used for most drawings. New Bryozoa from Nebraska,—Condra. Surface enlarged. Meekopora prosseri Ulrich n. sp. Specimen outlined, natural size. PLATE. XIX, Meekopora prosseri Ulrich n. sp. Surface enlarged, x 6. Tangential section of an old example, X 30. Transverse section of a young specimen, X 18. ‘Tangential section, < 18. Vertical section, * 18. Section representing basal parts of zooecial tubes, x 6. Botostomella leia n. sp. Specimen cutlined, natural size. Portion of the surface enlarged. Tangential section. . Vertical section. PLATE XX. Stenopora heteropora n. sp. Vertical section. Tangential section from deep in the zoarium. Stenopora distans n. sp. Surface enlarged. Tangential section from near the surface. Vertical section. Stenopora (?) polyspinosa n. sp. (Provisional). Specimen outlined, natural size. Outline of transverse section. Surface enlarged. Tangential section. Vertical section. PEATE. X XI. Fenestella cyclofenestrata n. sp. Portion of reverse face of young growth enlarged. Portion of reverse face of older growth enlarged. Obverse force of small branch. Fenestella spinulosa n. sp. Portion of reverse face enlarged. Portion of obverse face enlarged. Fenestella parvipora n- sp. Portion of obverse face, enlarged less than in Fig. 7. Portion of reverse face enlarged, scale to the left. Fenestella gracilis n. sp. Portion of reverse face enlarged. Portion of obverse face enlarged, 357 358 The American Geologist. Decent aan Fenestella subrudis n. sp. 10. Portion of reverse face enlarged. 11. Portion of obverse face enlarged. PLATE XXII. Fenestella conradi var. compactilis n. var. I. Reverse face. 2. Portion of obverse face enlarged. Fenestella sp. (?) Portion of reverse face, enlarged. Portion of reverse face of irregular growth. ~% Portion of obverse face, enlarged. Ee AR w Fenestella polyporotdes n. sp. 6. Portion of reverse face enlarged. 7. Portion of reverse face of worn specimen enlarged. Polypora bassleri n. sp. q 8. Outline, portion of reverse face of diffuse growth. 9. Portion of obverse face of diffuse form enlarged. PLATE XXIII. I. Portion of obverse face, regular form of old growth. Polypora reversipora n. sp. 2. Reverse face, outlined. 3. Portion of reverse face enlarged. 4. Transverse section of branches. 5. Portion of reverse face enlarged. Polypora ulrichi n. sp. Reverse face, outlined. Portion of reverse enlarged. Portion of obverse enlarged. Profile of a branch. Io. Transverse section of a branch, 2 FON D PLATE XXIV. Poilypora remota n. sp. 1. Portion of obverse face enlarged. 2. Horizontal section, enlarged. Thammiscus pinnatus n. sp. Outlined reverse face of one form of growth, natural size. Outlined reverse face, natural size. Outlined reverse face, natural size. Outlined reverse face of form most like T. octonarius. Portion of obverse face enlarged. 8. Horizontal section, enlarged. WANA Y Thamniscus palmatus n. sp. (Provisional) 9. Reverse face. PLATE XVIII. E AMBPRICAN GEOLOGIST, VOL. XXX. is mi he hy ae eh 4 ? a THE AMERICAN GEOLOGIST, VoL. XXX. PEATE OSS iF. pr. Pode LIBRARY > ; Bi: ij iF aot RHE Sot ES. UNIVERSITY of ILLINOIS — THE AMBPRICAN GEOLOGIST, VOL. XXX. PLATE XX. seein ely, Wiawenoreas hay Cs Chey orn Ba ieee, LIBRARY As Oe Aa 05. THE eae hear es UNIVERSITY oF ILLINOIS Se PLATE XXI. THE AMERICAN GEOLOGIST, VOL. XXX. ee EN aw of Agnes Satire # pg dthitids, Tee cue ses Mathai a farts ace or erebabheeess PUATH ooh THE AMERICAN GEOLOGIST, VoL. XXX. Bite. ae * . : ; aA te oy Shae a . si LIBRARY Bye NES Se a OF THES le -. = UNIVERSITY of ILLINOIS THE AMERICAN GEOLOGIST, VOL. XXX. PLatE XXIII Cob OoCOo CcococooTCca jPe Ce © Re ey ey at pS ee we Buy 0 aim eee (Seis) PeEeSeOsco X ° THE AMERICAN GEOLOGIST, VOL. XXX. PLATE XXIV. UNIVERSITY of ILLINOIS. i THE AMERICAN GEOLOGIST, VOL. XXX. PLATE XXV. LIBRARY ~ Se Oe nH beee | "UNIVERSITY of ILLINOIS © Ye Ba ie eras rags ee te rane ay UNIVERSITY of ILLINOIS — eee ae Ce Ware eros ei a ; . Ls iy s n ¢ ” 4 he a) . f * ' P « ‘ = : - ‘ a : 7 . om ' } > ‘ < — « - s ‘ a > 5 A ‘ n , ’ *. . Ne ; , 1 rn * * i < * nS om ™ aN Pl < THE AMERICAN GEOLOGIST, VOL. XXX. MUNFORDVILLE SCOTTSVILLE © g CS (949 BOWLING GREEN PLATE XXVI. GEOLOGICAL MAP OF SOUTH CENTRAL KENTUCKY By Avg.¥. Foerste SCALE CLLIITITTIT) MILES NEW ALBANY OR CHATTANOOGA SHALE RESTING ON DEVONIAN LIMESTONE 3 SILURIAN ORDOVICIAN OUTCROPS OF FOWLER LIMESTONE —— New Bryozoa from Nebraska.—Condra. 359 Thamniscus sevillensis Ulrich. to. Reverse face of a diffuse form. PLATE XXV. Cystodictya antsopora n. sp. 1. Outline of specimen, natural. size. 2. Enlarged branch. 3. Transverse section of a branch. 4. Vertical section. 5. Oblique tangential section. Cystodictya lophodes un. sp. 6. Outline of specimen, natural size. 7. Enlarged branch. WHE CINCINNATI ANTICLINE IN SOUTHERN KENTUCKY. By Auc. F. FOERSTE, Dayton, O. PLATE XXVI. CONTENTS. A. The Cincinnati anticline. HSE SMELT Crone tee caees cane ccc oceaisesc gricte hen soesonsvuscenscsesdepsuusecssdeensetecsees 359 Ets existence in early Devonian times. ............0.0. secscoccscereees 359 B. The Silurian east of the anticline in southern Kentucky. Fishing creek; Forbush creek; Little Cub creek.... ..... ...... 361 C. The southern extension of the Devonian along the anticline. NOMIC Att PUES CONG a cescece cscs conscccs snencestuccscesacennseecoencaus¥erwsasse 362 Louisville; southern Ohio; along the crest of the antic- line; along the western flank at Pegram in Tennessee; along the eastern flank on Fishing creek in Kentucky New Albany or Chattanooga Black shale...............---... 364 D. The Ordovician east of the anticline in Kentucky. Pesaro MC TO GIT bl Olas. -civevscur arene seccns! docuaiceatsksacscescow-unece sees 364 Fishing creek; Forbush creek; Little Cub creek............ 364 NEGORAAINE TOL DELON vee scnnsdescsssaaeficessecarcs appear as yet to be sufficient. Moreover, the arguments in fa- vor of the existence of the anticline in later Ordovician times or during the Silurian period do not seem as yet to be alto- gether conclusive. However, the presence of this fold in early Devonian times may be definitely established by means of the evidence now at hand. This evidence consists in the presence of Silurian strata along the flanks of the anticline and in their absence along the crest. In consequence, the later Devonian deposits rest directly upon Ordovician strata along the crest of the anticline, but upon Silurian formations along its flanks. This evidence is found in south central Kentucky and in north- ern Tennessee. In central Kentucky, the Devonian rests on Silurian form- ations, along the western flank of the anticline, as far east as Loretto and Raywick in the western part of Marion county. East of these localities for a distance of 40 miles, as far as Stanford in the western part ‘of Lincoln county, the Devonian rests directly upon the Ordovician. Southeast of Stanford, however, near Neals Creek church, the Silurian is exposed, and from this point eastward and northward along the eastern flank of the anticline, the Devonian rests again upon the Silur- ian. In northern Tennessee, the most eastern exposures of Si- lurian rocks along the western flank of the Cincinnati anticline occur several miles west of Lafayette in Macon county. Thence eastward for a distance of more than 50 miles, both along the northern border of the Central Basin of Tennessee and along the Cumberland river, the Devonian rests directly upon the Ordovician. The most western exposures of Silurian rocks along the eastern flank of the anticline occur near the mouths of Little Cub and Forbush creeks in Wayne county, Kentucky. The areas within which the Silurian strata are absent, be- tween Loretto and Stanford, and between Lafayette and Little Cub creek, lie along the crest of the present Cincinnati anti- cline. The absence of the Silurian in these areas may be ac- counted for most readily by assuming that the anticline existed at least before the deposition of the later Devonian formations now found in place. Whether the anticline existed already in Anticline in Southern Minnesota.—F oerste. 301 Silurian times, so that Silurian formations were never de- posited along its crest, or whether the anticline originated at a later date, the absence of Silurian strata being due to sub- sequent removal by erosion, must be determined by other ev- idence. The western boundary of the area within which Silurian strata are absent is necessarily conjectural between Raywick and Lafayette. Recent operations within the oil field near Glasgow, however, have suggested the presence of Silurian strata immediately beneath the New Albany or Chattanooga Black slate. B. Tue SILURIAN EAST OF THE ANTICLINE IN SOUTHERN KENTUCKY. The distance between -Neals Creek church and Little Cub creek is much less than that between Raywick and Lafayette and the determination of the eastern boundary of the area within which Silurian strata are absent is assisted both by the numerous exposures between Stanford and Liberty, at which the Devonian rests directly upon the Ordovician, and also by the recent discovery of Silurian strata about 5 miles west of Somerset, along Fishing creek. This discovery was made by Prof. Arthur M. Miller of the State College of Kentucky. The exposures occur on both sides of Fishing creek, chiefly north of the bridge, for a distance of about 2 miles, and along a branch flowing north of the home of V. L. Gossett and entering Fishing creek from the west. The Silurian here is 17 feet thick. North of the bridge, the lower 7 feet are massive, have a bluish color, and are very fine-grained, without a trace of fossils. Lithologically they resemble very much the lower part of the Clinton as exposed Ddetween Bardstown and Raywick, west of the anticline in cen- tral Kentucky. Similar rock occurs at the base of the Clinton in many parts of Garrard and Madison counties, east of the anticline. Above this massive rock cccur Io feet of dis- tinctly bedded limestone. At the top of this section, a layer about 1 foot thick contains large crinoid beads, such as are characteristic of the Clinton, numerous specimens of a coral identified provisionally as Enterolasma calycula, and one epecimen each of Dalmanella elegantula, Calymmene Vog- desi, and Whitfeldella cylindrica subquadrata. The Whit- 362 The American Geologist. December, 1902, fieldella is characteristic of the Osgood formation. A slight unconformity is believed to exist between the Clinton and the Osgood formations, an intermingling of fossils occurring at the base of the Osgood. A greater thickness of the Osgood beds is seen at numerous points farther up the creek but no measurements were recorded. Near the mouth of Forbush creek, the Clinton is 14 feet thick, and is overlaid by the layer containing large crinoid beads and also the Whitfieldella. The Osgood is a foot and a half thick. The Whitfieldellas are common at a poor exposure near the home of William Richardson. Just below the mouth of Little Cub creek, the Clinton is 16 feet thick. Crinoid beads and Whitfieldellas are very com- mon in the layer immediately above. The Osgood formation is 17 feet thick and is formed of the following beds in ascend- ing order: limestone, 3 feet 4 inches; green clayey shale, 2 feet 6 inches; clayey limestone, 2 feet; greenish clayey shale, about 9 feet. C. THE SOUTHERN EXTENSION OF THE DEVONIAN ALONG THE ANTICLINE, The Devonian in the area occupied by the Cincinnati anti- cline consists of limestone overlaid by black slate. Devonian limestone.-—At Louisville, the Devonian lime- stone may be divided into two formations; the lower or Jef- fersonville limestone, about 20 feet thick; and the upper or Sellersburg bed, 15 feet thick. According to Edward M. Kin- dle,* the Jeffersonville limestone may be traced southward into Kentucky, but the Sellersburg bed has not been seen south of Louisville. The Sellersburg bed corresponds most nearly to the Hamilton of New York, while the Jeffersonville lime- stone is most nearly equivalent to the Corniferous or Onon- daga limestone. In Ohio, the Hamilton has been identified as far south as Delaware and Franklin counties. The Corniferous, however, may be traced farther south, to the western part of Pickaway county. *B. M. KINDLE. The Devonian and Lower Carboniferous Faunas in southern Indiana and central Kentucky. Bulletin of American Paleontology, No. 12,1899. + Geol. Sur. of Ohio Rep. of Progress in 1870, pp. 285-286. Antichine in Southern Minnesota.—Foerste. 363 It seems, therefore, that along both flanks of the Cincinnati anticline the Corniferous extends farther south than the Ham- ilton. It is probable that most of the Devonian limestones be- tween the Ohio river and central Kentucky belong to the Cor- niferous. However, no attempt has been made as yet to keep separate the faunas belonging to different horizons and to de- termine their geological position accurately. It is possible therefore that other horizons, above or below the Corniferous may be present, especially at those localities where the Devo- nian limestone has a thickness of 20 feet or more. Devonian limestone is frequently. exposed on the crest of the Cincinnati ‘anticline between Loretto and Stanford, and also along the many branches of Rolling Fork, and in the vicinity of Moreland and McKinney. It is absent however on the crest of the anticline along the Cumberland river and in northern Tennessee. The probable southward extension of the Devonian limestone is indicated on the accompanying map as well as our present knowledge will permit. The. Devonian limestone extends farther south along the flanks of the anticline than along its crest. *In Tennessee, Devonian limestone occurs at the bridge west of Pegram, about 18 miles west of Nashville. At the thickest part of the section 11 feet of Corniferous are over- laid by 1 foot of Hamilton. On a recent visit to the area along Fishing creek, east of the crest of the Cincinnati anticline in Kentucky, in company with Prof. Arthur M. Miller, Devonian limestone was dis- covered outcropping for a distance of about 7 miles along the creek. The most southern outcrop detected occurred along the branch separating the farms of Mrs. Al Loval and Sol Jones. Here the limestone is 3% inches thick and is overlaid by coarse sandy material, half an inch thick. About a quarter of a mile northward, along the Sulphur Spring branch, the Devonian is 234 feet thick; it consists, in descending order, of coarse sandstone, 6 inches; fine grained bluish limestone, 1 foot 9 inches; and brecciated rock, 4 to 6 inches. A mile and a half northward, just above John Freeman’s house, the De- vonian limestone is 4 feet thick; most of it is white and cri- noidal, containing Cyathophylloid corals and large Spirifers. 304 The American Geologist. December, 19 A short distance northward, just above the home of Taylor Brock, the Devonian is 12 feet thick; at the top the rock is cherty ; just beneath it contains Cyathophylloid corals ; near the base 5% feet of the rock is massive and finegrained. A short distance northward, just below the mouth of Coldwater branch, the Devonian is 17 feet thick, consisting in descending order of brecciated brownish rock, 9 inches; white limestone, 1 foot; thin limestone layers, 21% feet; massive limestone, 77/, feet; cherty limestone, 2% feet; and finegrained limestone, 3 feet. The Devonian was traced 3 miles above the mouth of Cold- water branch, and is said by the natives to occur 2 miles farther northward, in the vicinity of Adams mill. At a number of localities fossils are not uncommon. Among these a specimen of Amphigenia suggests the Cornif- erous age of the rock. It is a pedicle valve, 8.4 cm. long, 4.3 cm: wide at a point about */, of the length of the shell from the beak, and 2.6 cm. deep; the sides are strongly compressed so that the shell appears more elongate than most of the spec- imens referred to Amphigenia elongata. The cast of the spon- dylium is distinctly shown. The specimen was found at the Sulphur Spring locality. It is possible that the sandy layer, 3 inches thick, at the base of the black shale on Forbush creek corresponds to the sandstone at the top of the Devonian at its most southern ex- posures on Fishing creek. New Albany or Chattanooga Black Shale.—East of Fish- ing creek, along the road leading from Somerset west across the iron bridge and passing the house of V. L. Gossett, the New Albany or Chattanooga Black shale is 46 feet thick. It decreases gradually in thickness westward. At Burksville it is 30 feet thick; at Martinsburg, 22 feet; west of the crest of the anticline it varies considerably and irregularly in thick- ness, from 28 feet as a maximum to 4 or 5 feet, and occasion- ally is absent altogether. The Devonian along Fishing creek probably rests upon Osgood strata. D. THE ORDOVICIAN EAST OF THE ANTICLINE IN SOUTHERN KENTUCKY. The Richmond formation.—Along the branch north of the home of V. L. Gossett, 27 feet of Ordovician rock are exposed ee es oe er Anticline in Southern Minnesota.—Foerste. 305 below the Clinton. It is chiefly a clayey section with occasion- al layers of harder clayey limestone. The lower 2 feet of the exposure contain Streptelasma rusticum (= corniculum of most authors). The largest specimen found was 8 cm. long. In Ohio, Indiana, and north central Kentucky this species was common in the Richmond epoch, occurring even in the lowest parts of the group. It has not however been discovered in the Lorraine. This suggests the Richmond age* of the Ordovi- cian exposures along Fishing creek. The other fossils found, Hebertella sinuata, Pterinea demissa, and Byssonychia radi- ata, are found both in the Richmond and in the Lorraine epochs. ; At the mouth of Forbush creek, the Clinton is underlaid by a bluish clayey Ordovician rock, 21 feet thick, containing poorly preserved specimens of Coluwmmnaria. This fossil is common at certain levels in the Richmond formation in Ken- tucky and Indiana, but apparently is absent in most of the Lorraine. Possibly some of the beds in Nelson and Marion counties, Kentucky, which contain Columnaria may be re- ferred to the top of the Lorraine. At the mouth of Little Cub creek, the Clinton is underlaid by clayey Ordovician rock, 19 feet thick, in which no fossils were found. The reference of the Ordovician rocks immediately beneath the Clinton, along Fishing creek, and at the exposures men- tioned along the Cumberland river, to the Richmond is there- fore merely provisional. The total thickness of rock along the upper course of the Cumberland river to be referred to the Richmond is unknown. The Lorraine formations——The next lower rock consists of thin bedded clayey calcareous material, in some places ‘changing to a thin bedded sandy limestone, without fossils. At the bend north west of Thomas branch, the exposure of this bed is 22 feet thick. On the western side of Horse shoe bottom, it measures 28 feet. The total thickness is unknown. Beneath the thinbedded rock occurs a massive clayey cal- careous rock, usually about 10 feet thick. At the most north- ern point on the river, northwest of Thomas branch, this bed contains Heterospongia subramosa (identified by E. O. UI- rich), and a large form of Platystrophia lynx. The Platystro- *JOoHN M. NICKLES. The Geology of Cincinnati. Journal, Cincinnati Sac. Nat. Hist., vol. xx, No. 2. 1902. 306 The American Geologist. December, a yue, phia is fully as large as the form of Platystrophia lynx which is characteristic of the Mount Auburn bed in the upper third of the Lorraine as defined by John M. Nickles. The form most characteristic of the Mount Auburn bed has a hinge line con- siderably shorter than the greatest width of the shell. The bed contains also a second form, with a hingeline equaling or exceeding the greatest width of the shell. This form occurs not only in the Mount Auburn bed, but also in the overlying Warren bed, and in the underlying Corryville bed. It is this more widely distributed form of Platystrophia lynx which oc- curs in the massive bed along the Cumberland. Both forms are confined to the upper half of the Lorraine in Ohio, Indi- ana, and Kentucky; they do not occur in the Richmond. Hence the massive bed is identified as Lorraine. Heterospongia sub- ramosa occurs both in the Richmond and in the upper Lor- raine in Marion county, Kentucky. Below the massive bed occurs a clayey calcareous rock which often forms high steep bluffs at the river’s edge. It contains the same form of Platystrophia lynx as the massive bed immediately above, but the form occurs in vastly greater numbers, being occasionally abundant at all levels; usually however they are common only at lower levels and are much less common or even absent in the upper third of this bed. The bed is referred to the upper half of the Lorraine. Its total thickness is unknown. Northwest of Thomas branch only the upper 17 feet of this bed are exposed. Farther down the river, however, occur sections in which this bed equals and exceeds. 50 feet in thickness. Below the Platystrophia beds occur a series of less clayey layers, often consisting of fairly well bedded-limestone. Two miles above Rowena, at the beginning of the high cliffs on the north side of the river just below Masons branch the lime- stone contains Orthorhynchula linneyi. This species seems to occur also in the same limestone southeast of the Horseshoe bottom, half a mile east of Difficult creek. This form is char- acteristic of the Fairmount bed in the lower half of the Lor- raine. Hence the limestone along the Cumberland, in which the Orthorhynchula is found is identified with the lower Lor- raine. This limestone contains more numerous and a greater variety of fossils than any other part of the Ordovician sec- tion along the crest of the anticline in southern Kentucky. Anticline in Southern Minnescta.—F oerste. 307 The Cumberland sandstone.—In 1877, Prof. N. S. Shaler gave the name Cumberland sandstone* to a series of rocks along the Cumberland river. No section is described. Typi- cal exposures are said to be located above Burksville, in Cum- berland county, and thence the sandstone extends in?a narrow area up the Cumberland to the southwestern border of Pul- aski county, and down the river to the southern edge of Ken- tucky. The sandstone is stated to range considerably in thick- ness, and to attain thicknesses of 50 and even 100 feet. It is described as finegrained, commonly of greenish color, and en- tirely barren of organic remains. It is a difficult matter to determine what an author intend- ed to include under any term when no section is described and when no locality is mentioned at which the rock occurs typically, with the practical exclusion of other rocks to which the same description might readily apply. Under these cir- cumstances it must be assumed that the rock which topograph- ically is most conspicuous, and which geographically has the same general extension must have been the rock designated. The most conspicuous rock of Ordovician age between Burksville and Pulaski county, and the one which has the most general extension is the series consisting of the Platy- strophia bed, the Heterospongia bed, and the overlying thinbed- ded clays of clayey limestones. These are all referred here to the Lorraine. While the Platystrophia bed frequently con- tains fossils, these fossils are often absent in the upper part of the beds, or are very inconspicuous, owing to the fact that they never weather out of the clayey matrix, so as to be read- ily detected, but are seen only as cross-sections, where the rock has broken across the fossil, due to scaling in consequence of weathering. While these cross-sections could be readily de- tected if the rock were closely examined, they might readily escape attention during a more hasty survey, especially dur- ing a rapid reconnaissance of the territory along a large river in a sparsely inhabited country, designed for the study of only the more striking economic features. The rock identified as Richmond at Forbush and Little Cub creeks does not occur at the other exposures visited farth- er down the river. * Geological Survey of Kentucky, 1877, vol. iii, New Series; consult also, 24th Report, Indiana Survey, pp. 57 to 60, 368 The American Geologist. December, 1902. The Fowler limestone,* occurring at various localities be- tween Fowlers Landing and Burksville, usually is located higher up, above the steeper parts of the cliffs which are with- . in easy reach of persons landing from a skiff. Moreover the Fowler limestone and the overlying Ordovician rock usually weather away more readily than the underlying section, so that they are less frequently exposed, and rarely form any con- spicuous part of the cliff sections. The writer is therefore of the opinion that the major part of the rock designated as the Cumberland sandstone by Prof. N. S. Shaler must have been of Lorraine age, and if any part of the Richmond is to be included under this name this is due rather to accident than to the original intention of the author. The Richmond localities at Forbush and Little Cub creeks, and the Fowler limestone and overlying beds near Burksville are altogether too inconspicuous parts of the river sections along the Cumberland to have given rise to this name. The writer is even more convinced that most of the beds in Casey, Marion, Boyle and Lincoln counties belong to the Lorraine. In the western part of Marion county, and in Nel- son county, less than 30 feet of Richmond beds have been identified in any section. The unfossiliferous beds in the vicinity of Lebanon belong to the Lorraine. This is also the horizon of the unfossiliferous beds at Moreland. On the eastern side of the anticline, in the vicinity of the Clinton outcrops, it is almost certain that both Richmond and Lorraine rocks have been included under the name of Cumber- land sandstone. Near Concord, east of Maysville on the Ohio river, the Richmond exceeds 164 feet in thickness. West of Spencer, on the railroad east of Mount Sterling, about 50 miles southwest of Concord, the Richmond is about 62 feet thick. At the base, Streptelasma rusticum is common, Twelve feet above the base, Rhynchotrema capax and Strophomena planumbona occur. Twenty feet below the top, Strophomena sulcata was found. The top of the beds containing the form of Platystrophia lynx with a long hingeline occurs 46 feet be- neath the base of the Richmond. The intervening rock is al- most unfossiliferous, but stratigraphically belongs to the top *AuGc. F. ForERSTE. Silurian and Devonian limestones of Tennessee and Kentucky. Bull. Geol. Soc. of Am., vol. xii, 1901. Antichine in Southern Minnesota.—F oerste. 309 of the Lorraine. Even if the Richmond continues to decrease southward in Madison, Garrard and Lincoln counties it is probably not entirely absent in any of these counties although fossils may be extremely difficult to find. It was only by ac- cident that the fossils in the Richmond west of Spencer were discovered. Even in the immediate neighborhood of Spencer the beds at the same horizon failed to reveal any fossils. It is therefore extremely probable that in the immediate vicinity of the Clinton outcrops in Madison, Garrard and Lincoln coun- ties, the upper part of the rock included by various authors in the Cumberland sandstone belongs to the Richmond, while ‘the sections at a greater distance consist chiefly or entirely of the top of the Lorraine. . E. Tue Satupa or MADISON BED. The bed described as the Madison bed* in the Indiana reports forms the top of the Richmond section. It includes all the material overlying the coral beds, the latter forming the base. These beds usually consist of large numbers of Colum- naria alveolata, Columnaria halli, and Calopoecia cribiformis. The name Madison bed has been utilized also by other writ- ers for other beds. To these authors must be conceded the priority of usage. It is therefore considered desirable to change the name of the beds at the top of the Richmond, hith- erto called the Madison beds; the same Saluda bed is therefore introduced, taken from Saluda creek, 6 miles south of Han- over, Indiana. While the coral bed is practically absent along Saluda creek, the section nevertheless is sufficiently distinct to enable any one to draw the line between the nearly unfossil- iferous base of the Saluda bed and the richly fossiliferous beds of the Richmond immediately beneath. While the name - may be taken from another locality, the typical exposures must ever remain those at Madison, since nature in distribut- ing her most typical exposures has not always followed the laws of geological nomenclature. * 21st Annual Rep. Indiana Survey, 1897. 370 The American Geologist. Der enoee sae ON SOME JURASSIC FOSSILS FROM DURANGO, MEXICO. By DouUGLAS WILSON JOHNSON, New York. While making an examination for coal in certain form- ations west of Mapimi, state of Durango, Mexico, Edgar F. Tuttle, E. M., secured a few fragments of ammonoids which were sent to the Geological Department of the Columbia Uni- versity. These fossils were given to the writer for identifi- cation, and the following notes are offered regarding their occurrence and age. : Quoting from Mr. Tuttle’s letter, the fossils were found at San Pedro del Gallo, a town about fifty miles west of Mapimi, occurring in limestone near an underlying bed of bituminous and calcareous shale. This shale is exposed over a considerable area, and consists of alternate thin layers of the bituminous and limy material, the former sometimes be- coming quite thick, and where exposed by shallow wells, smelling perceptibly of the bituminous matter. The town of Gallo is situated at the western border of the area over which the shales are exposed, (the area being some four thousand feet across the strike), near the contact with the limestone band in which the fossils occur, The whole formation has a westerly dip. The fossils are few and fragmentary, Of the four ammonoids sent by Mr. Tuttle one fragment is too poorly preserved to admit of identification. The costae are simple, broad and rounded, and show uncertain evidence of terminating in nodes along the ventro-lateral angle, while even more uncertain is the possible occurrence of nodes mid- way between this and the umbilical angle. The writer can find no type to which the apparent features of this fragment correspond, and is inclined to regard it as a new species, al- tho it is too badly worn and broken to be determined with certainty. Another fragment, well preserved as to detailed features, but too small to show distinctive characters, is evidently one of the Perisphinctidae, possibly Perisphinctes potosinus Cas- tillo and Aguilera, described from Rancho Alamitos, Sierra de Catorce, San Louis Potosi.* The costae are compressed and ***Pauna Fossil de la Sierra de Catorce. San Louis Potosi,’’ por Antonio del Castillo y Jose G. Aguilera. Boletin del Instituto Geologico de Mexico, Num. 1, p. 31, lam. xvii, fig. 1; lam. xxiv, fig. 2. ‘ Mexican Jurassic Fossils —Johnson. 371 prominent, and directed obliquely forward. Bifurcation takes place in some of the costae at least, two or three of them showing the beginning of the division just where the shell was broken. . A fairly good impression of one of the medium sized Per- isphinctidae corresponds closely with the specimen which Cas- tillo and Aguilera described from Tutotepec, Distrito de Huan- chinango, Puebla, and compared with Perisphinctes balderus Oppel.* Various fragments from Catorce, San Louis Potosi, were also supposed to belong to this species. Our specimen shows the trifurcations in the last whorl mentioned by Cas- tillo and Aguilera, has the same (or possibly one less) num- ber of costae on this last whorl, while the costae on the first whorls are more marked than those in the last. In size of shell they agree closely. The characters of the ventre are not shown. Both our specimen and those of Castillo and Aguilera differ from the figures of Ammonites (Perisphinctes:) balder- us Oppel by Loriol} in that the trifurcations of the costae are absent in the latter. The last specimen is a portion of the outer whorl of Per- isphinctes mazapilensis Castillo and Aguilera.{ The type spec- imens were described from Arroyo de los Alamitos, Sierra de Catorce, San Louis Potosi; and Sierra de los Tajos 0 Zuloaga, Mazapil, Zacatecas. Our specimen shows some twelve cos- tae, all regularly bifurcate except two, in which the posterior branch of the bifurcation suffers a new bifurcation a little above the point of the first one. Jn respect to this occurrence the two sides of the whorl are not symmetrical, the costa on the one side being thus trifurcate, while its continuation on the opposite side is bifurcate. As a result the succeeding for- ward costae are no longer opposite, but alternate, the two ’ branches of the bifurcated costa on the one side passing over the ventre, not to reunite as usual in an opposite costa, but one branch passing to a costa slightly behind the proper posi- tion of such an opposite one, while the other passes to the adjacent costa slightly in front of such position. This contin- ues until a trifurcation on the opposite side re-establishes the * Idem., p. 24, lam. xi, fig. 1. + Mem. Soc. Paleont. Susise, vol. v. p. 94, pl. xv, fig. 7 et 8. t Bol. Inst. Geol. Mex., Num. 1, p. 23, lam. x. 372 The American Geologist. BecemBer, Tl usual order. The entire shell must have been about 125 mm. in diameter. In none of the specimens are the sutures shown. The above named fossils are referred to the Upper Jur- assic by Castillo and Aguilera. This points to the presence of Upper Jurassics limestones and bituminous and limy shales near San Pedro del Gallo, state of Durango, Mexico. In the Bosquejo Geologico de México* it is stated that the Upper Jurassic and Cretaceous series occurs in the north-central part of the state of Durango, being fossiliferous in the vicinity of the town of Gallo, but that lack of data would not permit the classification (separation) of this formation. It is believed that the town of Gallo here referred to, and shown on the map about fifty miles slightly southwest of Mapimi, is the same as the San Pedro del Gallo from which our fossils come. The abbreviation of such names is usual, and Mr. Tuttle himself speaks of the town simply as Gallo in one place in his. letter. On the geological map of Mexico published in 1889 under the direction of professor Castillo, a small portion of the map in the vicinity of Gallo is colored blue, indicating Jurassic at this point. In the revised edition of this map, however, “re- formada con nuevos datos en 1891, 1892 y 1893,” no Juras- sic is shown at this point at all, Cretaceous alone being repre- sented. It would appear that the “new data” led to the rejec- tion of the idea of the Jurassic’s occurring in this locality. If such is the case, the present note may serve to confirm the correctness of the older map in this regard: Palaeontological Laboratory, Columbia Umversity, November 18, 1902. * Bol. Inst. Geol. Mex., Nos. 4, 5 y 6, p. 20.) eo a a a ms New Species of Cladodus.—Hay. 373 DESCRIPTION OF A NEW SPECIES OF CLADODUS (C. FORMOSUS) FROM THE DEVONIAN OF COLORADO. By O. P. Hay, New York. This species is based on a single specimen which was col- lected in the year 1900 by Mr. Whitman Cross of the U. S. Geological Survey. It was found in the Ouray limestone of the Needle Mountain quadrangle, at the northwest edge of Lime mesa, which is on the south slope of the Needle moun- tains, in western Colorado. Dr. George Girty, who has de- scribed the invertebrate: fossils of this formation, informs us (U. S. Geol. Surv. 20th Ann, Rept., pt. 11, 1900, p. 35.) that it belongs to either the late middle or early upper Dewonian. The fossil is borne on a piece of limestone which was found loose on a ledge of the Ouray limestone; but there are no higher formations at that part of the mesa, as I am informed by Mr. Cross; hence its origin is unquestionable. As to the character of the fauna of this formation, Dr. Gir- ty informs me through Mr. Cross that it is a clearly defined Devonian fauna, containing no Lower Carboniferous forms. Fig.1. Cladodus Formosus. Hay, X2. The tooth is firmly imbedded in a hard limestone, the an- terior face being exposed; and I have not ventured to remove it. Consequently, the character of the posterior face is un- known. The tooth (Figure 1, X 2) is of median size. The hight of the principal cusp, measuring from the lower line of the base, is 10.5mm. The base from one extremity to the other equals 15mm. Seen from the front the extremities of the base are narrow. In the midline the base is rather deeply sinuated; while between the sinus and the extremities the outline is convex. From the base spring the large median cusp and two pairs. of small lateral cusps. The width of the principal cusp, 374 The American Geologist. December, 1902. at the notch between it and the inner lateral cusps, is 4.5mm. The lateral outlines are nearly straight to the smooth round- ed tip. There is a very gentle sigmoid flexure. The anterior face is rather strongly convex, becoming flattened toward the base, and at length somewhat excavated. The lateral edges appear to be sharp. The anterior face is occupied by sharp cost, about 20 at the base and about 10 just below thei tip. The costz near the outer border of the base of the large cusp disappear soon in the edges of the cusp. The costz all come down low on the base of the tooth. The lateral cusps are small, conical, and rather slender. The inner pair are somewhat the larger. All are ornamented with a few sharp coste. 3 From Cladodus girtyi Hay, of the Coal-measures of Color- ado, this species differs especially in the shorter lateral cusps. C. concinnus Newb. of the Cleveland shales of Ohio, has the median cusp higher than the length of the base of the tooth. C. intercostatus has on each side of the anterior face a strong ridge running parallel with the cutting edge. Dr. Eastman has suggested a resemblance of this new species to some varieties of C. springeri, especially with some forms of it from Russia. The latter species belongs to the Lower Carboniferous, and it is quite unlikely that it. will oc- cur as low down as the middle Devonian. Most of the speci- mens of C. springeri possess several cusps on each side of the main cusp, and the base lacks the median sinus. Dr. Eastman kindly informs me that C. primigenius, of the De- vonian of Russia, has also several cusps on each side of the main one, and that the latter is slenderer, and the base not so sinuate. American Museum of Natural History, New York, Oct. 10, 1¢02. tIBRARY ° GORI ea S aaa ee UNIVERSITY of ILLINOIS of , b 3 . 5 ; ly ee 1 ‘f nat ' . y i) i . * r } 7 7, ’ 2 | 4\ The AMERICAN GEOLOGIST, VOL. XXX. PLATE XXVIII. Topography of Howard Co., Ia.—Calvin. 375 CONCRETE EXAMPLES FROM THE TOPOGRAPHY OF HOWARD CoO., IOWA. By S. CaLvin, Iowa City, Ia. PLATE XXVII. With reference to the distribution of geological formations, the location of Howard county, Iowa, is one of unusual inter- est. Along the Upper, lowa, or Oneota river, in Albion town- ship, the county possesses, topographically, some of the char- acteristics of the Driftless Area, an area from which it is sep- arated by a comparatively narrow- marginal zone of Kansan drift. The margin of the lowan drift passes through the north- eastern part of the county, and so northeast of a certain def- inite line which can be easily traced, the country is rolling Kansan drift covered with loess; while by far the larger part of the county—the part lying southwest of the line referred to—belongs to the level or gently undulating, uneroded, loess- less Iowan plain. One of the interesting geological features of this region is the absence of the Niagara limestone or any representative of the Silurian system, for here the Devonian overlaps upon the shales and shaly limestones of the Ordovic- ian. But it is with the topography of the county that this pa- per will specifically deal. What Norton calls the loess margin or loess moraine of the Iowan drift passes through the northeast part of Howard and divides the county into two very distinct topographic areas, each of which is again divided into smaller areas according to the extent to which glacial deposits are developed. The line separating the two principal areas passes from Minnesota into lowa near the northwest corner of section 11, Forest City ‘township, from which point it bends to the west and then turns nearly due south, traversing the eastern edge of section 10. After passing into section 15 the line makes an abrupt bend to the east, passes through the northern part of section 14, whence, veering southward, it maintains, with some minor de- flections and sinuosities, a general southeasternly course until it leaves the county a few rods south of the northeast corner of section 36, Albion township. The area north and east of this line is comparatively small; only about 22 square miles, all told, are here included; but within this limited space there is 376 The American Geologist. December eat more of topographic interest than in all the rest of the county. On one side of this line is an old, leached, oxidized and deep- ly eroded drift overlain by loess; on the other side the surface is occupied by a young, unaltered, uneroded drift upon which there is no loess, but large granite bowlders, of types wholly absent from the northeastern part of the county, give character to long vistas of gently undulating plain. The small north- eastern area may be called the Loess-Kansan, the larger area to the southwest is the Jozwan. The Loess-Kansan Area—Leaving out of consideration for the present the valley of the Upper Iowa or Oneota river, the Loess-Kansan area presents a series of rounded hills separated by ravines which have been cut in the surface of a sheet of drift by flowing water. All the topographic features of the region—the hills, ravines and even the deep stream valleys— are due to the carving and shaping effects of ordinary sur- face drainage. Outside the river valley, the topography is a direct product of the run-off of the ordinary storm waters. The underlying drift, as already intimated, is what has been called in recent geologic literature the Kansan. The surface of this ancient glacial deposit, by reason of long exposure to rains and other meteorologic agents, was deeply trenched, and the sculpturing resulted in producing, on a small scale, a ma- ture type of erosional topography (Fig. 1, Pl. XXVIT). At the time of maximum development of the ice sheet which deposit- ed the comparatively recent Iowan drift, the carved surface of the old Kansan till which lay exposed outside the border of the Iowan ice, was covered with a thin veneer of the fine clay called loess. This loess was moulded over the inequalities of the eroded Kansan surface. The deposit was doubt- less thicker in some places than in others, but, after all, the thickness was practically uniform, the variations being no greater than would be found in a mantle of snow laid down in comparative quiet upon an uneven surface. And thus it was that by the deposition of the loess the characteristics of the old topography were not veiled or obscured to any note- worthy extent. The hills and ravines remained during and after the process of loess deposition in the same relative posi- tions and with the same relative hights. It is true that some minor features of the present topography are due to trenches Topography of Howard Co., Ia.—Calvin. 377 cut in the recently deposited loess, but in general the amount of erosion since the loess was laid down as a comparatively thin mantle over the trenched surface of ancient Kansan, is so small as to be scarcely appreciable. For a measure of the amount of erosion that has taken place since the period of loess deposition we may turn to the Iowan plain, for in the matter of age the Iowan drift is contemporaneous with the main body of the loess of this part of the Mississippi valley. The fact is, that with very few and very unimportant exceptions, ‘the sur- face of the younger drift remains practically as the glaciers left it. Over ninety-nine per cent. of its area and more, the erosion of the surface, from the withdrawal of the Iowan ice to the occupation and cultivation of the territory by the white man, would have to be expressed by zero. Except in some trifling and unimportant details, therefore, the topography of the Loess-Kansan region is not due to erosion of the loess, but is controlled by surface forms which had been developed long before any loess was deposited. All deep cuts for roads or railways or for whatever purpose made, in Loess-Kansan areas of Iowa, whether in Howard county or in other portions of the state, show that the present loess surface is essentially parallel with the old eroded surface of the Kansan till. At the risk of seeming to indulge in unnecessary reiteration it may be stated that all field evidence is overwhelmingly in favor of the view that the topography of Loess-Kansan areas —such topography as is shown in figure I—is fundamentally pre-loessial. The loess did not level up the surface as some have supposed. Over the greater part of the area in which it is distributed it has not been eroded to any appreciable ex- tent since it was laid down. Its thickness and general rela- tions to the surface have never been very different from what they are to-day. A marked departure from the type of topography gener- ally prevailing ip the Loess-Kansan area of Howard county is found in the charmingly picturesque valley of the Upper Iowa or Oneota river. This valley is a deep trench cut into the indurated rocks.. In some of its characteristics it resembles the valleys of the Driftless Area. The topography of the greater part of the northeastern division of Howard county is post-Kansan in age. It was developed, as already noted, 378 The American Geologist. December, 190 by erosion of the drift surface during the long intervals be- tween the retreat of the Kansan ice and the deposition of the loess. On the other hand the valley of the river is older than the Kansan; it is preglacial. There are no indications that this ‘part of Iowa was ever occupied by the more ancient ice sheet that, over the major portion of the state, preceded the Kansan ; but that the valley was deep and open almost as it is to-day when the ice of the Kansan stage was melting, is attested by terraces of rusty Buchanan gravel at various points along the stream. A concrete illustration of these old gravels, deposited by floods from the melting Kansan ice and rising not more than twenty or twenty-five feet above the level of the water in the present channel, is found south of the bridge at Flor- enceville, near the center of section 10, Albion township. The Iowan Area—The Iowan area embraces much the larger part of Howard county. There was a time, however, when the whole county, and practically the whole surface of _ Iowa, presented an appearance topographically like the north- eastern part of Albion township. At a date very recent com- pared with the age of the Kansan drift, glacial conditions re- curred; a new ice sheet coming from the northwest flowed over the eroded Kansan surface, obliterating the old erosional topography as far as it went, distributing new and fresh ma- terial, and leaving the surface, when the ice melted, in the form of plain with long, low, sweeping undulations. Con- structive work of glacier ice in spreading out and piling up morainal detritus, was the potent factor in developing the re- sulting topography. Erosion was in no way concerned. Eros- ion has had practically no effect in modifying the ice-moulded surface of the Iowan drift since the disappearance of the Iow- an ice. Iowan glaciers covered all of Howard county except the few square miles of the Loess-Kansan area already described. The Iowan ice advanced to what is now the ,boundary line be- tween the two topographic areas of the county, and there stopped. On one side of that line the topography is old, on the other side it is young. Along the boundary line there is usually a great thickening of the loess; and as ordinarily seen from the Iowan plain the margin is marked by a series of hills which, from a distance, present the appearance of a terminal Topography of Howard Co., Ia.—Calvin. 379 moraine (Fig.2,Pl.X XVII). From the summit of the marginal ridges the observer looks in one direction upon a tumultuous series of erosionally developed and well rounded hills and ridges (Fig. 1, Pl. XX VII); in the other direction the land- scape is an uneroded plain stretching away to an uninterrupted horizon, as level as a sea (Fig. 3, Pl. XX VII). The typical characteristics of the Iowan plain are best il- lustrated on the broad, flat divides between the drainage cour- ses. The region having its center at the southeast corner of Saratoga township, may be cited as a concrete example of the ideal Iowan plain. But all portions of the county lying south- west of the [owan-Loess boundary, and not immediately ad- jacent to streams, present the type of topography illustrated in figure 3. The surface is everywhere a plain slightly modified by elevations and depressions. As intimated above, such ine- qualities and irregularities as are present are due to the man- ner in which the drift material was arranged by the action of the lowan glaciers, and not to any subsequent shaping or carv- ing by drainage waters. Drainage is as yet imperfectly devel- oped. There are in fact no drainage channels in the inter- stream areas. The storm waters simply flow off along broad, shallow, concave sags or so-called sloughs, the surfaces of which gradually blend into the low, broadly rounded swells which constitute the higher and better drained portions of the surface. The permanent streams of the Iowan area, in the south- western three-fourths of the county, flow in shallow depres- sions broadly concave from side to side, the margins of the depressions blending imperceptibly into the general [owan plain. This is the condition presented by the Wapsipinicon and Little Wapsipinicon in Wayne township and by Crane creek in Saratoga, Howard and Paris townships. These ill defined valleys, however, are all in a sense remnants of a pre- Iowan, even of a pre-Kansan, topography which has been modified by deposits of drift. The streams are simply follow- ing ancient valleys which are almost completely filled. Along all these streams there are beds of ferruginous, oxidized Bu- chanan gravels which show that here were drainage courses when the Kansan ice was melting. The gravels rest on Kan- san drift with which the old valleys, probably preglacial, were 380 The American Geologist. Pecenthek tas partly filled, and are in turn overlain by Iowan drift. The gracefully curving surfaces of valleys and uplands are sprink- led with Iowan bowlders. Nearly all the streams of this south- western area have their origin within the limits of the county, and they are practically branchless so far as development of tributary channels is concerned. Broad “sloughs,” in place of eroded creek beds, serve to collect the waters from the ad- jacent slopes. While the main drainage courses seem to have been largely determined by the position of preglacial valleys, the post-lowan streams have accomplished very little in the way of erosion. They have neither valleys nor flood plains. in the ordinary sense. They run in simple shallow trenches cut only a few feet below the level of the surface on which they began to flow after the withdrawal of the lowan ice. The facts bearing on the relative age of the Kansan and Iowan stages of glaciation, presented by the topography of the county we are considering, are consistent with all the facts which may be gathered from other portions of the state. The Kansan drift is deeply eroded; it was deeply eroded before the loess was deposited upon it. Taking the state as a whole, the entire Kansan surface, with the exception of a small undissect- ed plateau here and there on the divides, was similarly trenched and carved by erosive agents. Mature erosional top- ography, with reliefs ranging from fifty to 200 feet, was devel- oped by water carving of the drift surface, before the loess period began. Since the time of the loess, since the withdraw- al of the Iowan ice, the erosion of the surface of the lowan drift is too small to be measured, too small for relative numer- ical expression. The erosion of the old drift surface in the inter-Kansan-Iowan interval was certainly many hundreds of times as great as the erosion of the Iowan surface in all post- Iowan time. If any other measure of the relative age of the two drift sheets of Howard county be applied, the same aston- ishing results are reached. In the valley of the Turkey river at New Oregon, for example, there is a terrace of old, altered, rusty Buchanan gravel deposited when the Kansan ice was waning. About a mile above New Oregon there are young terraces of sand and fine gravel of late Iowan age, as fresh as if the material had been deposited by last season’s floods. The same thing occurs at scores of places. At Iowa City, in the Topography of Howard Co., Ila.—Calvin. 381 valley of the Iowa river, there is a bed of old, rotted, ferru- -ginous Buchanan gravel about thirty feet above the present water level. Down in the valley—the difference in hight be- ing a measure of the erosion which took place in the interval— there are extensive terraces of perfectly fresh sands which were deposited when the Iowan ice was melting a few miles farther up the stream. Whether comparisons be made on the leaching and segregation of the limy constituent of the two drifts, on the ferrugination and oxidation of the surface, on the rotting or decay of the: surface bowlders, or whatever the ‘test employed may be, the changes wrought by time in the Iowan are too near to zero for satisfactory numerical expres- ‘sion ; the changes in the Kansan are astonishingly great. If it should be claimed that the Kansan is a hundred times as old as the Iowan, I know of no facts at present that would dis- prove the claim. If some one should estimate the age of the Kansan as fifty times as great as that of the Iowan, I should be compelled to acknowledge that the estimate is very conserv- ative. Description of Plate XXVIII. Figure 1. View in the Loess-Kansan area, aortheastern part of How- ard county, Iowa, showing the type of topography developed by pre- _ loessial erosion of the ancient Kansan driit. Figure 2. The loess margin or loess moraine at the border of the Iowan drift in section 26, Albion township, Howard county, Iowa. The level space in the foreground is a part of the Iowan plain. Figure 3. A typical portion of the Iowan plain in section 7, Oak Dale township, Howard county, Iowa. GEEST. By W.J. MCGEE, Washington, D.C. - (From the Eleventh Annual Report, U.S.G.S., Part 1, pp. 277-280, 1889-90. ] Despite its extent and its accessibility, the superficial man- tle of rock débris has received comparatively little attention; it was too common to inspire the enthusiasm of research in the local student, and like the drift, of a generation past, was by many regarded only as an annoying obstacle to investigation of the underlying rocks. Yet within recent years many Amer- ican chemists and geologists have found it a worthy subject of study. Hunt has well elucidated the conditions of its or- 382 The American Geologist, DeCeinee, eae igin, and has seen within it a recerd of chemic activity vary- ing through the ages with changes in atmospheric conditions and climate; Pumpelly has seen within it a possible source of vast xolic deposits; Julien has ably set forth the influence of the humus acids in decomposing rocks and producing soils, and has, like Hunt, seen within the products a record of var- iable activity in the rock destruction and considerable changes in the climate of the earth during the geologic periods; Hil- gard, Shaler and others have investigated the products of rock decay as the most important source of soils; Chamberlin and Salisbury have made a classic study of the origin and physical composition of the residuary clays and loams of a definite ter- ritory and Russell has summarized the work of his predeces- sors, pointed out that the products of rock decay vary in vol- ume with the latitude, and inferred that they represent secu- larly constant activity in the rock-destroying process. The local characteristics of the extensive mantle of rock debris within this country have also been set forth by a score of ge- ologists in half the states of the Union. Perhaps because of its universality in many lands and its prevalence in nearly all, the product of rock decay has no commonly accepted appellation. Pumpelly indeed groups the phenomena as “residuary products of a secular disintegra- tion’ ;* Chamberlin and Salisbury combine them as “residu- ary products” ;+ and Russell speaks of “residual clay,” “res- idual deposits,” “residua,” ete ;{ but the expressions are man- ifestly employed as descriptive terms rather than specific appellations. Broadhead designates such material as “local drift,’’§ and Kinahan applies the term “meteoric drift’’;|| but these expressions, too, are employed rather in a descriptive than in a denotative way, and moreover they are misleading in that, where typically developed, the materials are not drift- ed. Many varieties of rock débris indeed have descriptive names ;—‘‘adobe,” ‘gumbo’ (applied to disintegrated Cre- taceous and Tertiary shales as well as to a Pleistocene depos- it), etc., are common terms in this country; “terra rossa’’ 1s * Am. Jour. Sci., 3d Ser., vol. 17, p. 135. + Sixth Ann. Rep. U. S. Geol. Survey, 1885. p. 230. + U. S. Geol. Survey Bull. 52, pp. 13, 23, and elsewhere. § Geol. Surv. Mo., 1874, pp. 64, 98, and elsewhere. || Jour. of the Royal Geol. Soc. of Ireland, 2d ser., vol. 4, part 3, pp.115-1214 ; Geest.—McGee. 383 equally well known in southern Europe; ‘“regur’’ is the com- mon name of a prevailing soil, and “laterite” the accepted designation for a peculiar ferruginous phase of the prevailing product of rock decay in peninsular India; and the “black earth” of Ukraine and ‘‘chernojem” of the Ural region are well known; but the group into which these phenomena fall is singularly nameless, alike among the students and the tillers of the earth. The product of modern river action is everywhere recog- nized by some form of its classic appellation, alluvium; the distinctive but ever-varying deposit first studied on the banks of the Rhine has come to be known in all civilized lands by its original provincial name, loess; the assemblage of glacial de- posits is everywhere known by the simple Anglo-Saxon des- ignation, drift——and only less widely by its British synonym, till; the foundation upon which all these categories of super- ficial deposits rest is universally recognized as rock, and a score of subordinate divisions are named by every school boy ; yet the most extensive category of superficial deposits, of the phenomena lying nearest to man, is without a general name though many of its subdivisions are named—for here civilized man has imitated the savage, who names the members of a class but feels no need of a name for the class itself. It is the more singular that the widespread products of rock decay should remain without distinctive appellation since at one period in the growth of geologic science such a desig- nation was proposed and found its way into geologic litera- ture. Early in the present century J. André De Luc clearly discriminated, first the solid rocks of the earth and the un- consolidated materials by which these rocks are mantled, and second, (a) the immediate products of rock decay in situ and (b) the débris transported and redeposited by streams. For the former portion of the superficial mantle he adopted the provincial designation for ‘earth’ in Holland and northern Germany (‘‘geest’’*), and for the transported materials of all kinds he adopted the term “alluvium.”+ Soon after, De Luc’s term came into use by geologists in this country; and by twe of the foremost among them, Amos Faton and T. Romeyr * Abrege Geologique, Paris, 1816, p. 121. TiDid.,; ps 112. 384 The American Geologist. ae nice he Beck, the unconsolidated mantle of superficial deposits was divided into the proper unmodified soil, called geest, and that which has been conveyed from a distance by water and exists in thick beds, called ‘‘alluvium.’* Both Eaton and Beck pointed out that in extent and volume the geest far exceeds alluvium. But they lived in an age of speculation; the alluvial deposits -offered an attractive subject for reflection and the thoughts of domestic and foreign geologists were concentrated upon them; cataclysms and deluges were in all men’s mouths and minds, and before the pendulum of current thought had swung to mid position there came the glacial theory to once more distract attention from an iherently important subject; and the simple taxonomy and definite nomenclature of the pioneer geologists were forgotten in the race for knowledge concerning other and subordinate classes of deposits. The provincial term adopted by De Luc and introduced into American literature by Eaton and Beck is in itself mean- ingless, and is thus an unobjectionable denotative term ; it meets a manifest need of the tongue; it has never been supplanted ; it has a definite place in literature, and it seems well to restore it. REVIEW OF RECENT GEOLOGICAL LITERATURE. United States Geological Survey, Twenty-first Annual Report to the Secretary of the Interior, 1899-1900, iz seven parts. CHARLES D. Waccott, Director. Part VII. Geography and Geology of the Black and Grand Prairies, Texas, with detailed descriptions of the Cretaceous Formations and special reference to Artesian Waters. By Ropert T. HILL. Pages 666; with 71 plates (including seven folded, maps, profiles, etc., in a pocket of the cover), and 80 figures in the text. Washington, 1901. The region here reported comprises about 50,0c0 square miles, mostly in east central Texas, and thence extending into the southern part of the Indian Territory. Its southern end is at Austin, and thence it reaches north and northeast to the common corner of Texas, the Indian Territory, and Arkansas. The chief rock formations of the sur- face, chalky sands, marls, clays, and limestones, range from the begin- ning to the end of the Cretaceous period. They are almost horizontal, * Geol. Survey of the County of Albany, 1820, p. 31; Cf. Geol. and Agl Survey, Rensselaer County, 1821. p. 23. Review of Recent Geological Literature. 385 but have prevailingly a slight dip to the southeast, toward the Gulf coast, somewhat exceeding the average surface slope, which declines from about 1,500 feet at the west to 400 feet at the east above the sea level. From paleontologic studies of this development of the Cretaceous system in Texas, Mr. Hill finds it “divisible into two great groups or series, each of which ia turn is composed of many beds of rock. The lower of these series begins with the Trinity sands and ends with the Denison beds, and has been named the Comanche series, after the town of Comanche, where the writer, when a boy, first studied these form- ations. The upper series begins with the Woodbine formation and ex- tends through the Navarro beds; this has been termed the Gulf ser- ies. Each of the series represents a complete cycle of sedimentation and is initiated by an arenaceous littoral terrane.’ A running summary of the fifteen formations making eee: Lower and Upper Cretaceous series, aggregating together about 4,500 feet in thickness, is given as follows: ‘The lowest Cretaceous formation (1) resting on the Paleozoic rocks and outcropping at the surface in the belt’ of Western Cross Timbers consists of loose beds of friable sand (locally called pack sand), with a few pebbles at its base (the Trinity sands). These sands pass upward into (2) light-colored arenaceous clays and marls in which alternating layers or beds of firm limestone of varying texture and thickness gradually appear. The marls and limestones are the Glen Rose beds. Another thick bed (3) of pack sand (the Paluxy sands) succeeds the Glen Rose beds. The outcrop of the Paluxy sands is covered with timber. Above the Paluxy sands are (4) clays alternating with thin limestones, usually accompanied by vast numbers of fossil oysters. . These, the Walaut beds, pass up- ward into (5) white chalky limestones (the Comanche Peak beds), which are very fossiliferous and which usually constitute lower slopes of the escarpment of flat-topped mesas or plains. The Comanche Peak beds are distinguishable from the succeeding bed (6) of white chalky limestone (the Edwards limestone) only by the superior hardness of the latter, which is the rock of the numerous flat-topped buttes of the western border of the Grand Prairie and in which, at least south of the Brazos, are numerous beds of flint. The limestone, which is not very thick along the section under consideration, is succeeded to the east by another group of beds making, the surface formations of the dip plains of the Grand Prairie between the western scarp rock and the Eastern Cross Timbers and consisting of alternations of marls and indurated layers of limestone. The lowest beds of this group consist of (7) darker-colored clays (the Kiamitia clays) containing great quantities of another fossil oyster. Above these appear more bands of limestone strata (8) of a chalky white color, alternating with clays (the Duck Creek formation) in which huge ammonites a foot or more in diameter are found. Near the top of these alternations of maris is a group (9) of whitish limestone beds (the Fort Worth limestone) in which limestones and marls alternate with great regularity. Fort 386 The Amenican Geologist. Recembets aan Worth is built on this formation. Above the Fort Worth limestone are beds (10) known as the Denison beds, which are mostly composed of clays, with frequent hard layers of impure limestone. These have ferruginous colors, such as chocolate, brown, and red, instead of the whitish lines which mark the preceding formations, The Denison beds pass into the western border of the Eastern Cross Timbers, where they are succeeded by another. sandy timber-covered formation (Gane the Woodbine, consisting of loose brown sand somewhat resembling the Trinity sands lying at the base of the whole section, but differing in particulars which are elsewhere described. In the upper part of these sands thin layers of blackish bituminous clay begin to alternate with the sand. Gradually the sand decreases and the clay increases until the latter makes the entire formation (12), the Eagle Ford. With the initiation of these black clays prairie lands again appear. The clays finally pass upward into a great formation of chalky lime- stone (13), the Austin chalk. This formation, upoa which the city of Dallas is located, is some 500 feet thick. The chalk in turn passes upward into marly clays of great thickness, consisting in their lower part of unctuous, laminated, lighteblue and yellow clays (14) which are known in Texas as ‘joint clays,’ and which we shall call the Tay- lor marl. These clays underlie the main Black Prairie for a distance east of the longitude of Dallas. The whole of the Black Prairie east of the Austin chalk is composed of soft, unconsolidated beds, but those above the Taylor marl are characterized by sandy layers, alternating with the clays, and especially by minute specks of glauconite. The sands and clays of this character, which constitute the final formations of the Cretaceous, are found along the eastern margin of the Black Prairie and may be called the Navarro beds (15). The Navarro beds are blacker and more arenaceous than the Taylor marl. The small laminz of glauconitic sand in the Navarro beds give to them a green- ish-yellow color in places. There are also some thin indurated bands of glauconitic sandstone and chalk marl in their upper portion.” After the detailed descriptions of all these Cretaceous formations, the following generalized observations of their physical or lithologic characters in relation to the stratigraphy and fossil faunas are stated: “The paleontologic zones persist in horizontal extent regardless of changes in lithologic nature of the matrix. “The beds vary in lithologic composition aloag horizontal lines toward or away from original shore lines of deposition. “Similar lithologic character diagonally transgresses time horizons. ... Thus it is that everywhere at the base of the Cretaceous system there is a continuous bed of sand, which, when considered as a form- ation, transgresses much of the range of Cretaceous time.” The flowing wells of this region vary in depth from 100 to 3,330 feet; and they also vary greatly in their water pressure, from those of feeble flow, as a gallon per minute, to spouters of seven hundred times as great supply. In 1897 the number of flowing wells report- ed in this great district was 458; and the reports showed 506 other wells Review of Recent Geological Literature. 387 reaching horizons of artesian water, from which it did not rise so far as the surface. W. U. The Evolution of the Northern Part of the Lowlands of Sowtheast- ern Missourt. By C. F. Marsut. The University of Missouri Studies, Vol. I, No. 3. Pages viii, 145-207; with six plates (one being a folded map on the scale of three miles to an inch). Colum- bia, Mo., July, 1co2. Price, $1.25. An area of about 2,500 square miles is described in this memoir, including the lowlands west of the Mississippi on both sides of the northeastern part of Crowley ridge, and of its continuation, beyond a space of interruption, by the Benton ridge. The geologic formations, in descending order, comprise Recent alluvium, of great extent, form- ing the surface of the lowlands; Pleistocene loam aad loess; Lafayette gravels, sands, and clay, referred to the closing part of Tertiary time; and Paleozoic rocks, limestones and sandstone, of Trenton and Cal- ciferous age. After the Lafayette period, the country was uplifted, and the Lafayette deposits were greatly eroded. This time of uplift seems to’ the reviewer to be correlative with the principal part of the Ice age farther north. During the later depression of the land, which seems to me referable to the closing part of the Ice age, being indeed the cause of its decline, “the mantle of Loess was deposited over the uneven surface, filling the valleys and building the land up nearly to ‘its level before the preceding erosion. Then followed uplift and erosion to the present condition of the country. Late in the history of the re- gion slight oscilations occurred producing terraces, but they were not sufficient in amplitude to interrupt the continuity of the cycle.’ Erosion after the deposition of the loess reached much deeper than the present lowlands, and they have been subsequently built up to their -present levels with sandy alluvium. A very interesting and complicated history of the stream changes is traced during the vast work of erosion in the thick deposits of the valley drift, and during the recent upbuilding of the alluvial tracts. In this greatest watercourse of our continent, the volume of modi- fied drift very far exceeded its deposits in the Connecticut and Merri- mack valleys of New England, where this part of the drift was earliest studied; but the conditions of its deposition, in the closing stages of the Glacial period, and of its speedily ensuing re-excavation, leaving remnants as plains and terraces, or in the Mississippi valley as long and wide ridges, above the alluvial bottomlands, were of the same character in both regions, and are our most important records of Late Glacial and Postglacial time. Professor Marbut has well supplemented, for this region about the north end of the Crowley ridge, the description of its continuation more than a hundred miles south into Arkansas, which was given by Call and Salisbury in the second volume of the Annual report of the Arkansas Geological Survey for 1889. The deposition of sediments in the lower Mississippi valley derived from the waning northern ice- sheet was evidently of vast amount; their erosion in southeastern 388 The American Geologist. DI BCOMDEL yee Missouri reached to depths below the present streams; and in recent time the Mississippi, Ohio, and other rivers have partially refilled the valleys along the flat lowlands. W. U. Mineral Resources of South Dakota: including Mineral Wealth of the Black Hillis, by Cleophas C. O’Harra; and Mineral Building Ma- terial, Fuels, and Waters of South Dakota, with Production for z9o0o, by JAMEs E. Tovp, South Dakota Geological Survey, Bulletin No. 3, J. E. Topp, State Geologist. Pages 136, with 31 plates and 4 figures in the text. Vermillion, S. D., 1902. Professor O’Harra, of the State School of Mines, Rapid City, pre- sents a report, in 80 pages, with 21 plates, on the ores and associated minerals of the Black Hills. The gold product of this district, begin- ning with $10,000 in 1875, has mainly increased, with some fluctuation, to a maximum of about $7,000,000 in 1901. The aggregate in the twenty- seven years is estimated to slightly exceed $100,000,000. It is expected that during many years to come the gold output will continue of increas- ing amount. ; Tin mining, begun in 1884, but prosecuted irregularly and unprofit- ably, has yielded in total possibly 50,000 pounds of this metal. “In the minds of many mining men the failure to profitably work the tin deposits in the past was due in great part to unwise management and not to the low grade o7 the ore. In view of this belief some effort is now being made to reopen old mines, and possibly by careful avoidance of extravagant methods some of the more favorable deposits may yet yield fair returns.” The geologic resources of other parts of the state are described by Prof. Todd, including building stones, cements and clays, lignite, ete. Numerous beds of lignite, varying in thickness up to a maximum of about 10 feet, occur in the Laramie formation in the northwest corner of the state; but they have been only slightly worked, being far from railways. They are similar to the lignite deposits of the same Laramie age in North Dakota, which are very extensive and have been long mined. Natural gas has been encountered by artesian wells at Pierre and in a large adjoining region. It occurs in such amount that it is used for lighting the city of Pierre, and as fuel of many stoves and several steam engines. Mune Lie Martinique and St. Vincent, a preliminary report on the eruptions of 1902. E. O. Hovey. (Extract from the Bulletin of the American Museum of National History, vol. 16, pp. 333-372, pls. 33-51, Oct. 11, 1902, Author’s edition.) This admirable account of the late volcanic eruptions in the lesser Antilles is lucidly illustrated by half-tone reproductions of photo- graphs taken mainly by the author. The final report which is to fol- low this will contain the author’s “extended arguments, and the elab- oration of many interesting details, together with the results of mi- croscopical and chemical studies yet to be made on the ejecta of the eruptions of both volcanoes.” Review of Recent Geological Literature. 389 Mr. Hovey considers that the loss of life at Martinique was mainly due to a cloud of hot steam carrying sulphur gases (SO2z and H.S) and charged with angular particles of ash and dust which rolled over and enveloped St. Pierre with hurricane velocity prevailing for several minutes on the morning of May 8 last. Other causes of death were, (1) blows from falling stones which had been hurled out from the volcano, (2) crushing beneath’ falling walls and various objects (one man was found with his back broken by a sign which had fallen from over a store front), (3) burns due to hot stones and dust, (4) burns caused by steam alone, aad (5) by steam mingled with dust, (6) cre- mation in burning buildings, (7) nervous shock, (8) suffocation from lack of respirable air, and, perhaps, (9) lightning. “No autopsy was made on any of the thousands of victims of the disaster on Martinique although men capable of performing such operations had the opportunity of making. them within a very few hours after the eruption; hence there is no sure way of determining whether poison- ous gases other than those mentioned played any part in the destruc- tion of life.” A similar statement is made by Mr. Hovey respecting St. Vincent. The examination made by Dr. Hovey does not warrant, in his judgment, the idea that any new or strange forces or gases need to be called in to account for the phenomena attending the eruption of Mt. Pelee, or the destruction of St. Pierre and its people. He also discredits the idea of independent mud volcanoes situated at the heads of the gorges that radiate from Pelee. The mud flows that descended these gorges are secondary products of the eruption. Heavy rains accompanied and followed the eruption. These waters, enter- ing the hot cinders, and the streams being dammed by the ashes that had enveloped the country, furnished steam sufficient to throw off the surface layer that enveloped them, and allow the flow of large volumes of mud and hot muddy water. The volcanoes of Mt. Pelee and Soufriere of St. Vincent showed a sympathetic. action, and this was more manifest in the later eruptions of September. It is evident that the American Museum of Natural History, through the wise initiation of president Morris K. Jessup, is to con- tinue this investigation and terminate it by the publication of a final complete report, which, if this preliminary report is an earnest of what may be expected, is likely to be thorough and satisfactory.—N. H. W. Syllabus of a course of lectures in elementary geology, JOHN C. BRANNER. pp. 369. Second edition. Stanford University. 1902. Price $2.75, postpaid. The science of geology is here systematized and classified, and its data and literature by references and foot-notes are brought into reach of any student. The fwadamental conceptions are illustrated by many fine engravings, mostly new, and the discussions consist almost wholly in a grouping of the secondary and subordinate branches in paragraphed sections and subsections. Throughout the volume are numerous blank pages designed for additional notes and references. 390 The American Geologist. December, 1902. It thus is intended to be a complete compend and vade mecum for ready use by lecturers and writers and for the independent student who desires to investigate any geological subject—at least so far as the same may have been already investigated and published by others, N. H. W. Bidrag till Kannadomen om Trilobiternas Byggnad. af, Joh. Chr. Moberg [Aftryck ur geol. foren i Stockholm férhandl Bd. 24. H. 5, 1902. ] From a fine example of Nileus armadillo Dal. the author is en- abled to show the point of attachment of the muscles of the antenne, hypostome, epistome, and several limbs of this species. He also re- marks upon the nature of the compound eyes which have 3-4,000 facets. In this connection he takes exception to the opinion of the late G. Lindstr6m that the “macule”’ on the hypostome carry organs of vision, and that the earlier Olenide were blind. ; Dr. Moberg compares the system of radiating canals ia front of the eyelobes and glabella in the Conocoryphide with the liver im- pressions in Limulus, and refers to the presence of these radiating im- pressions in Elyx and Harpides, and even in the Olenide. He re- marks on the importance of an organ which is plain in a few blind forms, but has left no trace in the majority of the trilobites. Considerable space is given to the description of a problematical organism apparently related to the graptolites. The paper is illustra- ted by one text figure, and a plate showing the head of Nileus arma- dillo and the problematical graptolite. G. F. M. Animals before man in North America, their lives and times. By Frep- ERIC A. Lucas, Nov. 1902, pp. 1-291, 6 full page illustrations ard 64 text figures. Appleton & Co., Price $1.25 net. A year ago, Mr. Lucas presented in popular form some of the as- certained facts of “Animals of the past” as they probably appeared in the flesh, and of their habitations. This book has been well re- ceived and is now supplemerted by the one cited above. In the ear- lier work, the author dealt with extinct vertebrates, and these were described in groups according to affinity or association. In the present account both invertebrates and vetebrates are treated ard the species are arranged chronologically, but not strictly so, thus enabling the writer to more readily keep alive the interest of the reader. About 80 pages are devoted to introductory matter and the invertebrates, while the balance of the book treats of the vertebrates with which Mr. Lucas is ertirely familiar. Some of the chapter headings are “How the history of the past is read,’ “The era of invertebrates,” “Great salamamders and their associates,’ “Dragons of sea and air,” etc. Mr. Lucas, among American scientific men, stands nearly alore as an author endeavoring to popularize some of the many intensely interesting facts concerning the geological antiquities dug out of the earth by paleontologists. How successful his books are to be with —————— Authors Catalogue. 391 the general public, time alone will demonstrate, but from the stand- point of accuracy of statement, Mr. Lucas’ account is as good as present knowledge and one author can make it. It may be that in the future, the great popular books‘on scientific subjects will be pre- pared by a symposium of specialists, and then edited by some master teacher as John Fisk or John Lord. To the average reader, the vertebrates will long remain as the most wateresting forms of extinct life because of their resemblance to animals familiar to him, or because of their greater complexity of structure and size. In the chapter “Dragons of sea and air,’ the reader is told of fishes 20 feet long, turtles that weighed in the flesh about 2 tons, sailing reptiles having spread of wings 20 feet across and which in life did not weigh more than 25 pounds, and of a Di- nosaur having 1600 teeth. On page 229 we.are told that Brontosaurus had two pounds of brain, to twenty tons of flesh, and on page 163 that man has about the same weight of brain to one hundred pounds of total mass. In the chapter entitled “The rise of the mammals,” a short but in- teresting account of the Titanotheres is given with two good drawings of heads of the oldest and most recent species as they appeared in the flesh. Another interesting chapter is the one entitled ‘The life of yesterday” in which the reader is told of the derivation, and migration of such familiar brutes as the horse, mastodon, mammoth, bison, bear, etc. The typography and printing are excellent, but the small cost of the book prevents elaborate illustrations and but few new figures are added. However, all of the illustrations are from good to passable excepting: ore designated ‘Devonian fishes” which has been badly mutilated in cutting down the plate made for Hutchison’s book; “Creatures of other days.’’ A slip of the pen occurs on page 92 where Postdam sandstone of Cambrian time is used in place of Catskill sand- store of the Upper Devonian. Ges MONTHLY AUTHOR’S CATALOGUE OF AMERICAN GEOLOGICAL LITERATURE ARRANGED ALPHABETICALLY, ADAMS, C. C. Postglacial origin and migrations of life of the Northeastern United States. II. (Jour. Geog., vol. 1, Oct. 1902, pp. 352-357.) AMI, H. M. Bibliography of the late George Mercer Dawson. (Can. Rec. Sci., vol. 8, No. 8, July, 1902, pp. 503-516.) 392 The American Geologist. Deena ea ANON. The Mississippi river. (Jour. Geog., vol. 1, Oct., 1902, pp. 374- 378.) BAKER, MARCUS. In memory of John Wesley Powell. (Science, vol. 16, Nov. 14, 1902, p. 788.) BEEDE, J. W. New fossils from the Upper Carboniferous of Kansas. (Kans. Univ. Sci. Bull., vol. 1, Sept., 1902, pp. 147-154, plates.) BEEDE, J. W. Variation of the Spiralia in Seminula Argentia (Shepard.) Hall. (Kan. Univ. Sci. Bull., vol. 1, Sept., 1902, pp. 155-157, pl. 6.) BELL, ROBT. Geological map of the Dominion of Canada (western sheet. No. 783) scale 50 to inch. Ottawa, 1902. BEYER, S. W. Mineral production of Iowa for 1901. (Iowa Geol. Sur., vol. 12, pp. 39-61.) . BREWER, W. H. John Wesley Powell. (Am. Jour. Sci., Nov., 1902, vol. 14, pp. 377-382.) BROWN, ROBT. M. Gaspee point: a type of cuspate foreland. (Jour. Geog., vol. 1, Oct., 1902, p. 343.) BUCHAN, J. S. Some notes on Mount Royal. (Can. Rec. Sci., vol. 8, No. 8, July, 1902, pp. 517-525.) CALVIN, S. Iowa Geological Survey, vol. 12. Anual Report 1901, with accom- panying papers, pp. 511, 11 plates, 6 maps, Des Moines, 1902. CROSBY, W. O. Origin and relations of the auriferous veins of Algoma, (western Ontario). (Tech. Quart., vol. 15, June, 1902, pp. 161-180.) CROSBY, W. O. A study of hard-packed sand and gravel. (Tech. Quart., vol. 15, pp. 260-264, Sept. 1902.) DALE, T. NELSON. Structural details in the Green Mountain region and in eastern New York [second paper]. (Bulletin, U. S. G. S., No. 195, pp. 29, 4 plates, Washington, 1902.) ‘ DALL, W. H. In memory of John Wesley Powell. (Science, vol. 16, Nov. 14, 1902, \p. 783.) DAVIS, W. M. River terraces in New England. (Bull. Mus. Comp. Zool., Geul. Ser., vol. 5, No. 7, p. 347, Oct., 1902) ——— Author's Catalogue. 393 DEAN, BASHFORD. The preservation of muscle-fibres in sharks of the Cleveland shale. (Am. Geol., vol. 30, Nov., 1902, pp. 273-278.) FISHER, C. A. Discovery of the Laramie in Nebraska. (Am. Geol., vol. 30, Nov., 1902, pp. 315-316.) : FRAZER, PERSIFOR. Sketch of Dr. Frenzel. (Am. Geol., vol. 30, Nov., 1902, pp. 333- BaD.) G. H G. John Wesley Powell. (Nat. Geog. Mag., vol. 13, p. 393, Nov., 1902, portrait.) GILMAN, D. C. In memory of John Wesley Powell. (Science, vol. 16, p. 784, Nov., 14, 1902.) GIRTY, GEO. H. On the Upper Permian in western Texas. (Am. Jour. Sci., vol. 14, pp. 363-368, Nov., 1902.) HARRIS, W. T. in memory of John Wesley Powell. (Science, vol. 16, Nov. 14, 1902, p. 786.) HATCHER, J. B. Discovery of a Musk-ox skull (Ovibos cavifrons) in West Vir- ginia. (Science, vol. 16, Oct. 31, 1902, p. 707.) HATCHER, J. B. A correction of Prof. Oshorn’s note entitled: New vertebrates of the Mid-Cretaceous. (Science, vol. 16, Nov. 21, 1902.) HAWORTH, E. Mineral Resources of Kansas. 1900 and 1901 Univ. Geol. Sur. of Kans., Bulletin, pp. 78, Lawrence, 1902. AlEL; B.. F. The Terlingua quicksilver deposits. Univ. Tex. Min. Sur., pp. 74, Austin, 1902. HOVEY, E."O: Observations on the eruptions of 1902 of La Soufriére, St. Vin- cent, and Mt. Pelée, Martinique. (Am. Jour. Sci., vol. 14, pp. 319- 350, Nov., 1902.) LANGLEY, S. P. In memory of John Wesley Powell. (Science, vol. 16, Nov. 14, 1902, p. 782.) PEE. 1. Canyons of southeastern Colorado. (Jour. Geog., vol. 1, Oct. 1902, pp. 357-370.) LEONARD, A. G. Report of the Assistant State Geologist [Iowa] 1901. (lowa Geol. Sur., vol. 12, pp. 28-32.) 304 The American Geologist. December sa LEONARD, A. G. Geology of Wapello county. (Iowa Geol. Sur., 1901, vol. 12, pp. 441-499.) LYMAN, BENJ. SMITH. Accounting for the depth of the Wyoming Buried valley, (Pre. Acad. Nat. Sci., Phil. June, 1902, pp. 507-509.) LYMAN, BENJ. SMITH. Lodel creek and Skippack creek. (Proc. Acad. Nat. Sci., PhiL., Dec. 1901, pp. 604-606.) LYMAN, BENJ. SMITH. The original southern limit of the Pennsylvania anthracite beds. (Trans. Am. Inst. Min. Eng., N. Y. and Phil., Meeting, 1902.) MACBRIDE, T. H. Geology of Cherokee and Buena Vista counties, with notes on the limits of the Wisconsin drift as seen in northwestern Iowa. (Geol. Sur. Iowa, 1901, vol. 12, pp. 305-353.) McGEE, W. J. In memory of John Wesley Powell. (Science, vol. 16, Nov. 14, 1902, p. 788.) MORLEY, E. ‘L. Submerged valleys in Sandusky bay. (Nat. Geog. Mag., vol. 13, Nov. 1902, p. 398.) NORTON, W. H. Report on Artesian wells, 1901. (Iowa Geol. Sur., vol. 12, pp. 33-34.) RATHBUN, — In memory of John Wesley Powell. (Science, vol. 16, Nov. 14, 1902, p. 783.) REID, JOHN A. The igneous rocks of Pajaro. (Bull. Univ. Cal., Geol. Dept., vol. 3, pp. 173-190, Nov., 1902.) SARDESON, F. W. The Carboniferous formations of Humboldt, Iowa. (Am. Geol, vol. 30, Nov. 1902, pp. 300-312.) SAVAGE, T. E. Geology of Henry county. (lowa Geol. Sur., 1901, vol. 12; pp. 239-302.) SHERWOOD, GEO. H. The Sequoia, a historical review of biological science. (Supple- ment io Am. Mus. Jour., vol. 2, Nov., 1902, pp. 28.) SHIMEK, B. The loess of Natchez, Miss. (Am. Geol., vol. 30, Nov. 1902, pp. 279-299.) SMITH, E. A. (AND T. H. ALDRICH) The Grand Gulf formation. (Science, vol. 16, Nov. 16, 1902, pp. 835-837.) ‘ ——— Author's Catalogue. 395 ‘UDDEN, J. A. Geology of Jefferson county. (Iowa Geol. Sur., 1901, vol. 12, pp. 355-437.) ‘WALCOTT, C. D. In memory of John Wesley Powell. (Science, vol. 16, Nov. 14, 1902, p. 785.) WHITFIELD, R. P. Notice of a new genus of marine Algae, fossil in the Niagara shale. (Bull. Am. Mus. Nat. Hist., vol. 16, pp. 399-400, pl. 53, Nov. 3, 1902.) WHITLOCK, H. P. Guide to the mineralogic collections of the New York State Mu- ‘seum. Bull. No. 58, New York State Museum, pp. 147, Albany, 1902. WILDER, FRANK A. Geology of Webster county. (lowa Geol. Sur., 1901, vol. 12, pp. 63-235.) WILSON, A. W. G. Some recent folds in the Lorraine shales. (Can. Rec. Sci., vol. 8, July, 1902, p. 525-531.) WILLISTON, S. W. An arrowhead found with bones of Bison occidentalis Lucas in western Kansas. (Am. Geol., vol. 30, Nov. 1902, pp. 313-315.) CORRESPONDENCE. ADDITIONS TO THE LIST OF NICARAGUA VOLCANIC ERUPTIONS IN HIS- ‘TORIC TIME. On reviewing the list of volcanic eruptions ard earth quakes in Nicaragua—mailed to you on 28th Juwae 1902—I fear that I -overlooked a few important ones—as follows: 1609. Momotombo, in violent action accompanied by severe earth- quakes, lasting for several days, covering to a depth of several feet with ejecta the ancient city of Leon, then the capital of Nicaragua, at the N. W. base of the volcano, an the western margin of lake Man- agua: The capital was removed to the present site about 40 miles to the S. of W. and about 18 miles from the Pacific ocean: Fragments of records of this eruption also of the marriage there in 1608 of thie cacique of the Ameriques were in the archives of the “Palacio Epis- copale” in the present city of Leon in 1890. 1648. Strong earthquakes in western Nicaragua, doing much dam- age to the than new city of Leon, killing several persons and injuring ‘many: These earthquages were probably from Momotombo. 1651. Earthquakes very violent in western Nicaragua. 1663. Earthquakes in series, very violent, destroying houses and lives that were near to volcano Momotombo and westward to the Pa- cific; also violent about the city of Granada on western side of lake Nicaragua: The cause of that series of earthquakes also elevated the bed of the Rio San Juan, the outlet of the waters of lake Nicaragua, 396 The American Geoiogist. Degeneres so as to afterwards (unto the date of fhis letter) prevent the naviga- tion of that river by vessels of size sufficient to transport cargoes be- tween Cadiz, Spain, and Granada, at the west margin of lake Nicaragua, also between Cuba aad Granada. Nicaragua: Ayon’s “History of Nicaragua”—(the only reliable history of the country published) tells, Vol. 2, chap. vi, pp. 6465, of a “ship that was in the lake Nicaragua during the several earthquakes of 1663, that had come loaded with merchandize from Cuba; that after the earthquakes and rise of the bed of San Juan river, near its exit from lake Nicaragua, never succeeded — in getting out of the lake—altho endeavoring to do so several times.” It is probable that transportation of ships across Nicaragua would have ceased—for a month or so—until the elevation of about one- fourth of the length of the bed of the Rio San Juan had been dredged to a proper or to its former depths. No fissures are to be found in,. across, or near that river. J. CRAWFORD. ‘WorK OF THE CoRNELL SUMMER ScCHooL oF FieLp Geotocy. Dur- ing the four past summer seasons, Prof. G. D. Harris of Cornell University has conducted a series of geological expeditions which have been very beneficial to the students who have taken the work and also been the means of adding rot a little to the accurate knowl- edge of New York stratigraphy. Thoroughly believing in field work for beginners as well as for advanced students, professor Harris owns and keeps in repair two gasoline launches that the best service possible may be given to the expeditions. By this means the party has (1) access to all the var- ious water-ways of the state, (2) means for transporting camp mater- ials, fossils, &c., and (3) a means of travel free of charge. Two classes of students have availed themselves of the oppor- tunities, viz., beginners in geology who wish to see: the country and learn how detailed work is done, and those more advanced, graduate students, instructors, &c., who have wished to apply themselves to: some particular problem and work it to completion. For the latter class all the machinery of the department is at hand. Camp _ is. pitched to stay till the field work on such particular problems is done. The beginners are given tramps over the region until they are fa- miliar -with the topography, and then they are asked: to help in the detailed work. If this program seems unfair to the beginning class, it is only necessary to state that the beginners of one season become the producers of the next. ; The first trip was in 18909. Professor.Harris took five men ia one of his launches on a four week’s trip through the different water- ways of the state. In Icoo permanent camp was pitched at Trenton Falls and side trips were taken to lake Champlain and through the Mohawk valley via the Erie canal. It was during this season that a new fauna was fownd in the Calciferous of the Mohawk valley. Dr. H. F. Cleland, now professor of geology at Williams, described this new fauna in Bulletin No. 13 of “Bulletins of American Pal- eontology”. A topographic map of the region was made by Mr. A. Correspondence. 307 €. Veatch now on the U. S. Geological Survey, which also appeared in the same publication. In 1901, with headquarters in the Helderberg Mts., three side trips were taken, viz, lake Champlaia, as far as Plattsburg, down the Hudson to Rondout, and the Erie canal back to Ithaca. The major part of the detailed work of this season was done in the Champlain valley. Mr. P. E. Raymond, now fellow in geology at Yale, worked out the Crown Point section and during last year published the results as No. 14 “Bulletins of American Paleontology”. He also during that summer began work on the Chazy limestone on Valcour island. In 1902 camp was again in the Helderbergs. Mr. Raymond con- tinued his work on the Chazy of Valcour island. The Bryozoa he sent to Yale where he is now working on them, and his other mater- ial he sent to Cornell where he expects to work again in the near future. : In the Helderbergs, six weeks were spent in a detailed study of the geology of the region. Spirit level lines were run by professor Harris from the newly established bench mark at East Berne (U. S. G. S.) around through all the sections studied in detail, to the N. Y. State Survey triangulation station on top of Countryman hill, a distance of at least 12 miles. All lines were run in duplicate. The exact hight of each contact line in each section can now be referred to mean ocean level. Extensive collecting and minute stratigraphic work at Country- man hill and Indian Ladder sections occupied the major part of the time of the more advanced workers. Miss Mignon Talbot, now working over her material at the State University of Ohio, spent with aids about six weeks on the Country- man Hill section, while the writer with more or less assistance spent an equal amount of time on the geology of Indian Ladder; the mater- ial collected, he is working up at Cornell. The combined work will shortly appear in printed form. The last three weeks of the season were spent at Oriskaay falls. Professor Harris made a detailed topographic map of the region on a scale of I in. to 500 feet, and the section was carefully worked by Mr. Joviano Pacheco, who had charge of the Water Lime group, and Me. Joviano Pacheco, who was responsible for the Lower Helderberg rocks. : Mention too should be made of the trip on foot from New Salem to Oriskany Falls in company with Dr. H. F. Cleland whereby we quite carefully worked a number of sections through the Helderberg formations, noting variations in thickness, lithological characters, and faunas. This trip made a connecting link between the work at the Helderbergs and Oriskany Falls. A Bulletin will be forthcoming on the Oriskany Falls section. On the way back to Ithaca, stops were made at Manlius and Union Springs. CuHas. E. SmirnH. 398 The American Geologist. Deccrtet Toe PERSONAL AND SCIENTIFIC NEWS. Tue Haypen Memortat Mepat for 1902 was conferred by the Philadelphia Academy of Natural Science on Sir Arch- ibald Geikie. Pror. J. F. Kemp Anp Dr: E. O. Hovey were recently elected respectively chairman and secretary for 1903 of the section of geology and mineralogy of the New York Academy of Sciences. NATURAL GAS was developed recently by a well at Heath- field, Sussex, England, the capacity being fifteen million cubic feet per day. This is situated 46 miles from London, and the gas is derived from the Kimmeridge clays. Pror. A. W. Grapau, of Columbia University, on Nov. i9 gave a public address at the College of Physicians and Surgeons, New York, on “‘Tllustrations of the law of Tachy- genesis, or acceleration of development.” Dr. F. A. WILpER late of the lowa survey has recently been appointed state geologist of North Dakota and professor of geology at the State University. The survey is an adjunct to the department of geology in the State University, located at Grand Forks. GEOLOGICAL SOCIETY OF WASHINGTON. At the meeting on November 12th the following program was presented: “Ti- tanic iron ore from Wyoming,’ Waldermar Lindgren; “Min- eral vein formation in Yellowstone Park,’ W. H. Weed; “A reconnaissance in the Mt. McKinley region, Alaska,’ Alfred H. Brooks. THE AMERICAN ASSOCIATION FOR THE ADVANCEMENT OF ScIENCE will hold its fifty-second annual meeting at Washing- ton, D. C., Dec. 27 to Jan. 3. The “affiliated societies” number twenty-two and they will hold meetings at Washington the same week. Section E, (Geology) of the Association will’ hear the‘ addréss.of> Prot. W., M-- Davis, "et aG@ami bridge, Mass., who will also preside over the Section. The The Geological Society of America will be presided over by Prof. N. H. Winchell, Minneapolis, who will give the annual presidential address. This society will meet in the hall of the United States Geological Survey. Prof. Winchell will discuss the question: Was Man in America in the Glacial period? Mr. R. A. Buatir died at his home in Sedalia, Mo., on the 18th of October. He had not been in good health for 6 months and finally, after an illness of something like two: weeks, died. He was about 60 years old. Personal and Scientific News. 399 Tor over 25 years he spent nearly all his leisure in studying the rocks of central Missouri, particularly the beds of the Bur- lington and the Chouteau limestone. He made a large col- lection of fossils, but generously gave them away. His cous- in, Sam Miller of Cincinnati, Ohio, described and figured many of the fossils found by Mr. Blair. He was a good collector and probably collected more Chouteau fossils ‘than anyone else. He was a member of the State Board of Mines and Geology from 1889-1890. His wife died in rgo1. He leaves one daughter, Miss Jessie Blair. G. Cc. BROADHEAD. Proressor W. H. Hopss recently presented (Oct. 20) a paper to the New York Academy of Sciences which was ac- companied by a wealth of detailed observations on the geol- ogy of Manhattan island, condensed as follows by the secre- tary, Dr. E. O, Hovey: In his introduction the author called attention to the unusual oppor- tunities now offered for studying the geology of Manhattan island through the numerous great engineering projects now being carried forward. The waterways surrounding Mashattan island are deep cafi- ons, with a depth of nearly 200 feet in the East river and 300 feet or more in the North river, now partly filled with drift deposits the amount depending on the velocity of the tidal currents. In 1865 Stevens advanced the theory that the river channels were along lines of faults (‘‘longitudinal and transverse fractures”). New- berry regarded the East river as the lowest reach of the Housatonic river before it discharged its waters into the Hudson, which was then the outlet of the Laurentian series of lakes, and he considered the Harlem river with Spuyten Duyvil creek a smaller tributary of the Hudson. Dana believed that the relatively easy solution of certain beds of limestone determined the position of the river channels. This view of Dana’s has been supported by Kemp and Merrill, while Gratacap re- jects the theory advanced by Stevens. Professor Hobbs finds that no correspondence can be established between the directions of the belts of limestone or dolomyte and of the New York water front, except within the stretch from Kingsbridge to Macomb’s Dam bridge. Along this line too the observed facts -point to the occurrence of a narrow strip of limestone dropped down between nearly vertical faults. The sections of the Harlem river which are furnished by the bridges across it show clearly that it is not a sim- ple erosion valley resulting from cutting by the stream, The bed of the stream is marked by sudden changes of level, and the Harlem seems to have chosen its course quite independently of the position of ridges of the harder gneiss. Under the East river limestone has been found at but two localities——under the channel east of Blackwell’s island and in one of the drill holes underneath the Manhattan pier of 400 The American Geologist. DSCEmAVETy East river bridge No. 3. The limestone east of Blackwell’s island is enclosed between parallel fault walls, and appears to have been dropped down along them. The numerous occurrences, however, of gneiss and gneiss only along, in and under the East river leave little doubt that the main portion of the bed is composed thereof. Regarding the bed rock beneath the North river, comparatively little is known, but the origin of its channel is sufficiently accounted for by its position along the contact of the Newark system with the crystal- lines. This contact seems surely to be a fault-border on account of its markedly rectilinear extension, the great scarp of basalt, the much inferior position of the newer terranes, and the borings along the route of the proposed tunnels of the Pennsylvania, New York and Long Island railroad company. The author holds that the directions of the channels of Spuyten Duyvil creek and Harlem and East rivers have been determined largely by lines of jointing and displacement. Manhattan island borders di- rectly upon the Newark area, in which the existence of a network of faults. has been established by the work of several observers, and the network probably extends beyond the limits of the area. The strik- ing rectilinear outlines of the island, especially of the northern half of it, and its topographic development are favorable to the view that it represents an orographic block left standing between dowzathrown strips of the crust. The rectilinear gorge of the upper Harlem between Washington Heights and Fordham Heights is continued, so far as its western wall is concerned some two and a half miles south of the river. It is parallel to the direction of the scarp of the Palisades, and of the Hudson. Besides the cross fractures indicated by the different parts of the Harlem river, which were pointed out by Stevens, several other cross fractures on and about Manhattan island were pointed out by the same author. Dana also considered that the Manhattanville cross valley was formed by a cross fracture. A considerable number of faults have been definitely established. Their directions correspond in general to the elements in the courses of the river channels. The ex- ceptions to this rule are the fissures in the East river east and west of Blackwell’s island. The author cited a number of faults which have been disclosed by numerous borings and tunnels and in closing called attention to the fact that the buried rock surface in the lower part of the city (south of Twenty-third street), as well as that below the area of the Harlem flats (north of One Hundred Tenth street and east of Eighth avenue) is characterized by the most abrupt changes of level. In his opinion the area of these portions of the island represent orographic blocks depressed by faults, reefs of gneiss and limestone rising along the Harlem area, while reefs of gneiss alone characterize the southern district. Professor Hobbs’ paper was discussed briefly by professors Kemp, Dodge and Stevenson, and it was evident that the author’s theory would not be accepted without considerable further investigation. INDEX TO VOL. A American Association for the Ad- vancement of Science, 398. American Institute of Mining En- gineers, 272. An arrowhead found with bones of Bison, occidentalis in western Kansas, S. W. Williston, 313. Animals before man in North America, their lives and times, F. A. Lucas, 390. Artesian waters of Texas, R. T. Hill, 384. p Asiatic Russia, G. F. Wright, 327. B Bain, H. Foster, Western Interior coal field, 124; (fl Bell, Robert, Canadian Geological Survey, 1901, 64. Beyer, S. W., 71. Bidrag till Kannedomen om _Trilo- biternas Byggnad. J. C. Moberg, 390. Black and Grand Prairies, Texas, R. PSE, B84. Blair IR. AL) 398. Branner, J. Ke Syllabus of course of lectures, 388. Brief summary of glacier work, A. Ce SCO, 210. Brigham, A. P. (G. K. Gilbert and) An Introduction to Physical Ge- ography, 123. Broadhead, G. C. The New Madrid earthquake, 76. Buckley, E. R., 202, Clays and clay industry of Wisconsin, 329. Cc Calvin, S., Concrete exainples from the topography of Howard cou:- ty, Iowa, 375. Carboniferous coal in Arizona, E. T’. Dumble, 270. Carboniferous formations of Hum- boldt, Iowa, F. W. Sardeson, 300. Cincinnati