. . LIBRARY . . Connecticut Agricultural College. VOL i..D...3.3.A CLASS NO 3..3.0. COST... S..iLt. DATE ,\-^irsZ>...4 190..5... DEPARTMENT OF THE INTERIOR MONOGRAPHS United States Geological Survey VOLUME XLVIII Part II.-PL^TES. WASHINGTON GOVERNMENT PRINTING OFFICE 1905 Digitized by the Internet Archive in 2009 with funding from Boston Library Consortium IVIember Libraries http://www.archive.org/details/statusofmesozoicOOward UNITED STATES GEOLOGICAL SURVEY CHARLES D. WALCOTT, Director STATUS MESOZOIC FLORAS OF THE UNITED STATES BY LESTER F. WARD with the collaboration op William M. Fontaine, Arthur Bibbins, and G. R. Wieland I'art II.-i^LATES. O WASHINGTON government printing office 1905 038"^. LIST OF THE PLATES. Plate. Coniferous plants from the Trias of Arizona i-iil Sketch map of the Little Colorado Vallej', Arizona, and adjacent regions iv Sketch map of the Buck Mountain region and Cow Creek Valley, Douglas County, Oreg v Jurassic liverworts and ferns from Oregon. vi Jurassic ferns from Oregon vii-xiv Jurassic ferns and Equiseta from Oregon xv Jurassic cycads from Oregon xvi-xxviii Jurassic cycads and Williarasonias from Oregon xxix Jurassic Gingkos from Oregon ; xxx-xxxiii Jurassic Gingkoacese and Taxacese from Oregon xxxiv Jurassic conifers from Oregon xxxv,xxxvi Miscellaneous Jurassic plants from Oregon xxxvii Jurasso-Cretaceous plants from Oregon and Alaska j xxxviii Jurasso-Cretaceous ferns from Cape Lisburne, Alaska xxxix-XLiii Jurasso-Cretaceous cycads and Gingkoacese from Cape Lisburne, Alaska XLiv Jurasso-Cretaceous conifers from Alaska, Montana, and California _ XLV Jurassic cycads from Wyoming xlvi-lxiii Sketch map showing fossil localities of the Shasta formation of California lxiv Ferns from the Shasta formation of California and Oregon lxv-lxvi Cycads from the Shasta formation of California and Oregon lxvii Cycads and conifers from the Shasta formation of California and Oregon Lxviii Conifers and dicotyledons from the Shasta formation of California and Oregon Lxix Cycadean trunk from the Shasta formation of California _ lxx . Ferns from the Kootanie formation of Montana lxxi Equiseta and cycads from the Kootanie formation of Montana Lxxii Cycads and conifers from the Kootanie formation of Montana and the Lakota formation of South Dakota Lxxiir Exposure of the Potomac formation on Ontario avenue, Washington, D. C. lxxiv Exposure of the Potomac formation on Kansas avenue, Washington, D. C lxxv Exposure of the Potomac formation on Sixteenth street, Washington, D. C. lxxvi Exposures of the Potomac formation at Terra Cotta, D. C Lxxvii Exposures of the Potomac formation at Freestone, Virginia Lxxvm Exposures of the Potomac formation on Back Lick Run, Virginia lxxi.x Map of the Potomac terrane in Maryland, the District of Columbia, and adjacent parts of Virginia lxxx VI LIST OF THE PLATES. Plate. Cycad trunk and silieiBed wood from the Potomac of Maryland. lxxxi Trunks of cycads early discovered in the Potomac of Maryland lxxxii-lxxxvi Group of cycads in the Museum of the Woman's College of Baltimore Lxxxvii View of the Link Gulch with the Link cycad in place lxxxyiii Group of cycads in the Museum of the Woman's College of Baltimore Lxxxix Cycadeoidea marylandica xo-xcii Cycadeoidea Tysoniana xciii Cycadeoidea McGeeana xciv Cycadeoidea Fontaineana xcv-xcviii Cycadeoidea Goucheriana xcix Cycadeoidea Uhleri c Cycadeoidea Bibbinsi ci-civ Cycadeoidea Fisherje cv Cycadeoidea Clarkiana cvi Fossil plants from the Potomac of Virginia, the District of Columbia, and Maryland cvii-cxix PLATE I. PLATE I. Triassic Flora of Arizona. Akaucarites shinabumpbnsis Ward n. sp -. U. S. GEOLOGICAL SURVEY MONOGRAPH XLVIIl PL. I CONIFEROUS PLANTS FROM THE TRIAS OF ARIZONA. PLATE II. PLATE II. Triassic Flora of Arizona. Page. Figs. 1, 2. Araucarites shinarumpensis Ward n. sp - 30 U. S. GEOLOGICAL SURVEY MONOGRAPH XLVIII PL. CONIFEROUS PLANTS FROM THE TRIAS OF ARIZONA. PLATE III. PLATE III. Triassic Flora of Arizona. Akaucarites monilifer Ward n. sp Figs. 1,2. Views of the outer surface of the resinous bodies found in the interior of silicified stumps. ., . Fig. 3. View of the interior of one of the same split longitudinallj- through the center. Fig. 4. View of a cross section of one of the same. Fig 5. View of a piece of the wood from the interior of a stump with three of t!ie resinous bodies attached to it, showing their moniliform arrangement. U. S. GEOLOGICAL SURVEY MONOGRAPH XLVIII PL. CONIFEROUS PLANTS FROM THE TRIAS OF ARIZONA. PLATE IT. PLATE IV. Sketch map of tbe Little Colorado Valley, Arizona, and adjacent regions. PLATE V. PLATE V. Page. Sketch map of the But-k Mountain region and part of the Cow Creek Valley, Douglas County, Oieg. , . 47 PLATE VI. MON XLVUI — VOL 2 — 05 2 PLATE VI. Jurassic Flora of Oregon. Page. FiCi. 1. Marchantites ekectus (Bean) Sew.? 53 Fig. 2. Enlargement of Fig. 1, X 2. Fios. 3-9. DicKSONiA oREGONENSis Font. n. sp 55 Fig. 4. Pinnule of Fig. 3 enlarged, X 2. Fig. 6. Pinnule of Fig. 5 enlarged, X 2. Fig. 7. Portion of Fig. 5 slightly enlarged. Fig. 9. Pinnule of Fig. 8 enlarged, X 2. , U. S. GEOLOGICAL SURVEY MONOGRAPH XLVIII PL. VI JURASSIC LIVERWORTS AND FERNS FROM OREGON. PLATE VII. , PLATE VII. Jurassic Flora of Oregon. Figs. 1-10. Dicksonia obegonensis Font. n. sp Fig. 3. Pinnule of Fig. 2 enlarged, X 2. Figs. 6-8. Enlarged sterile pinnules showing nervation, X 2. Fig. 9. Enlarged fertile pinnules showing a sorus, X 2. Fig. 10. Fertile pinnule showing one sorus somewhat more enlarged than Fi; U. S. GEOLOGICAL SURVEY MONOGRAPH XLVIII PL. VII JURASSIC FERNS FROM OREGON. PLATE VIII. PLATE VIII. Jurassic Flora of Oregon. Page. Figs. 1-3. Coniopteris hv.menophylloides (Brongn.) Sew --. 59 Figs. 2, 3. Enlarged pinnules of Fig. 1 showing sori, X 2. Figs. 4-1 1 . Thyrsopteris MuRR.4Y.iN.i (Brongn. ) Heer ...'..._ 61 Fig. 5. Enlarged pinnule of Fig. 4, X 3. Fig. 6. Enlarged pinnule of Fig. 4, X 2. Fig. 8. Enlarged pinnules of Fig. 7, X 2. Fig. 10. Enlarged pinnule of Fig. 9, X 4. Fig. 11. Enlarged pinnule of Fig. 9, X 2. Figs. 12-1.5. Folypodiuji oreoonense Font. n.sp.._ 63 Fig. 13. Enlarged pinnule of Fig. 12, X 2. Fig. li. Portion of a pinnule of Fig. 12 X 4. U. S. QEOLOQICAL SURVEY MONOGRAPH XLVIII PL. VIM JURASSIC FERNS FROM OREGON. PLATE IX. PLATE IX. Jurassic Flora of Oregon. Page. Figs. 1-S. Polypodium okboonensb Font. n. sp 63 Fig. 2. Enlarged pinna of Fig. 1, X 2. Figs. 4, 5. Enlarged pinnules of Fig. 3, X 2. Fig. 8. Enlarged pinnule of Fig. 7, X 2. U. S. GEOLOGICAL SURVEY MONOGRAPH XLVIII PL. IX JURASSIC FERNS FROM OREGON. PLATE X PLATE X. Jurassic Flora of Oregon. Page. Figs. 1-7. Poi.vpodium orbgonense Font. n. sp 63 Fig. 3. Enlarged pinnules of Fig. 2, X 2. Fig. .5. Portion of a pinnule of Fig. 4 enlarged to show the sori, X 2. Fig. 6. Enlarged sterile pinnule showing the nervation, X 2. Fig. 7. Enlarged fertile pinnules showing a sorus, X 2. Figs. S-12. Cladophlebis vaccensis VA'ard n. sp... 66 Fig. 9. Enlarged pinnule of Fig. S. X 2. Fig. 11. Enlarged pinnule of Fig. 10, X 2. U. S. GEOLOGICAL SURVEY MONOGRAPH XLVIII PL. X JURASSIC FERNS FROM OREGON. PLATE XI PLATE XI. Jurassic Flora of Oregon. Page. Figs. 1-7. Cladophlebis denticul.4ta (Brongn. ) Nath 68 Fig. 2. Enlarged pinnule of Fig. 1, X 3. Fig. 4. Enlarged pinnules of Fig. 3, X 2. Fig. 7. Enlarged pinnule showing the nervation. Figs. 8-10. Cladophlebis iiaiburnensis (L. & H. ) Brongn 71 Figs. 9, 10. Enlarged pinnules of Fig. 8, X 2. Figs. 11, 12. Cladophlebis acutiloba (Heer) Font. n. comb 72 Fig. 12. Enlarged pinnule of Fig. 11. Figs. 13-15. Cladophlebis pecopteroides Font. n. sp 73 Figs. 14, 15. Portions of Fig. 13 enlarged, to show the nervation. U. S. GEOLOGICAL SURVEY MONOGRAPH XLVIII PL. XI JURASSIC FERNS FROM OREGON. PLATE XII. PLATE XII. Jurassic Flora of Oregon. Page. Figs. 1-3. Sclekopteris oregonensis Font. n. sp 74 Fig. 2. Enlarged pinna of Fig. 1, X 3. Fig. 3. Enlarged pinnules of Fig. 1, X 3. Figs. 4-8. Ruffordia G. 117 Ficis. 2, 3. Encephalartopsis '. oregonensis Font. n. sp 117 Fig. 3. Pen drawing of Fig. 2. Fig. 4. Cycadeospermum okegonense Font. n. sp IIS Fig. 5. Cycadeospermum ovatum Font. n. sp '. IIS Fig. 6. Williamsonia oregonensis Font. n. sp IIS Fig. 7. Williamsonia ? sp. Font. (Bract, No. 1) 119 Figs. 8,9. Williamsonia ? sp. Font. (Bract, No. 2a) 119 Fig. 9. Enlargement of Fig. 8, X 2. Fic. 10. Williamsonia ? sp. Font. (Bract, No. 2b) 119 Figs. 11,12. Williamsonia ? sp. Font. (Bract, No. 2c) 119 Fig. 12. Enlargement of Fig. 11, X 2. U. S. QEOLOQICAL SURVEY MONOQRAPH XLVIII PL. XXIX JURASSIC CYCADS AND WILLIAMSONIAS FROM OREGON. PLATE XXX. PLATE XXX. Jurassic Flora of Oregon. Figs. 1-7. Ginkho niGiiATA (Brongii.) Heer . Fig. 2. Pen drawing of part of Fig. 1 to sliow norviition, natural size. Fig. 5. Pen drawing of Fig. 4, natural size. Fig. 7. Pen drawing of Fig. 6, natural size. Figs. 8-12. GrNKGO Huttoni (Sternb.) Heer Fig. 9. Pen drawing of Fig. 8, natural size. Fig. 11. Pen drawing of Fig. 10, natural size. U. S. GEOLOGICAL SURVEY MONOGRAPH XLVIII PL. XXX JURASSIC GINGKOS FROM OREGON. PLATE XXXI. PLATE XXXI. Jurassic Flora of Oregon. Page. Figs. 1-3. Ginkgo Huttoni (Sternb.) Heer 123 Fig. 3. Pen drawing of Fig. 2, natural size. Figs. 4-8. Ginkgo Huttoni Magnifolia Font. n. var 124 Fig. .5. Pen drawing of a portion of Fig. 4, natural size. Fig. 7. Pen drawing of a portion of Fig. 6, natural size. U. S. GEOLOGICAL SURVEY MONOGRAPH XLVIII PL. XXXI JURASSIC GINGKOS FROM OREGON. PLATE XXXII. PLATE XXXII. Jurassic Flora of Oregon. Page. Figs. 1, 2. Ginkgo Huttoni magnifolia Font. n. var 124 Fig. 2. Pen drawing of Fig. 1, natural size. Figs. 3-S. Ginkgo lepida Heer 125 Fig. 4. Pen drawing of Fig. 3, natural size. Fig. 7. Enlargement of Fig. 6, X |. U. S. GEOLOGICAL SURVEY MONOGRAPH XLVIII PL. XXXII JURASSIC GINGKOS FROM OREGON. PLATE XXXIII. PLATEXXXIII. Jurassic Flora of Oregon. Page. Figs. 1-19. Ginkgo sibiriga Heer 125 Fig. 4. Enlargement of Fig. 3, X S. Fig. 6. Enlargement of Fig. 5, X f. Fig. 10. Enlargement of Fig. 9, X |. Fig. 13. Enlargement of Fig. 12, X 2. Fig. 1.5. Enlargement of Fig. 14, X 2. Fig. 17. Enlargement of Fig. 16, X 2. Fig. 19. Enlargement of Fig. IS, X 2. U. S. GEOLOGICAL SURVEY MONOGRAPH XLVIII PL. XXXIII JURASSIC GINGKOS FROM OREGON. PLATE XXXIV. PLATE XXXIV. Jurassic Flora of Oregon. Pasre. Figs. 1-12. Ginkgo sp. Font., aberrant forms of leaves 127 Fig. 2. Enlargement of Fig. 1 , X 2. Fig. 4. Enlargement of Fig. 3, X 2. Fig. 6. Enlargement of Fig. 5, X 2. Fig. 8. Enlargement of Fig. 7, X 2. Fig. 10. Enlargement of Fig. 9, X 2. Fig. 12. Enlargement of Fig. 11, X 2. Figs. 13,14. Pikenicopsis ? sp. Font ' 128 Fig. 14. Pen drawing of Fig. 13, natural size. ■ Figs. 1.5-17. Taxites zamioides (Leek.) Sew ... 129 Fig. 1(3. Enlargement of Fig. 15. U. S. GEOLOGICAL SURVEY MONOGRAPH XLVIII PL. XXXIV JURASSIC GINGKOACE^E AND TAXACE/€ FROM OREGON. PLATE XXXV. PLATE XXXV. Jurassic Flora of Oregon. Page. Figs. 1-3. Taxite.s za.mioides (Leek.) Sew - - 129 Fig. 2. Enlargement of part of Fig. 1, X 3. Figs. 4-8. Brachvphyllum mamillare Brongn .-. 130 Fig. 5. Enlarged portion of Fig. 4, X 2. Fig. 7. Enlargement of Fig. 6, X 2. Fig. 9. .\kaucarites ? sp. Font, (cone scale) - - 131 FiG.s. 10-17. PiNL's NoRDENSKioLDi Hcer. - - - - 131 Fig. 11. Pen drawing of Fig. 10, natural size. Fig. 13. Pen drawing of Fig. 12, natural size. Fig. 1.5. Pen drawing of one of the leaves shown in Fig. 14, natural size. Fig. 17. Pen drawing of Fig. 16, natural size. U. S. QEOLOQIGAL SURVEY MONOGRAPH XLVIII PL. XXXV JURASSIC CONIFERS FROM OREGON. PLATE XXXVI PLATE XXXVI. Jurassic Flora of Oregon. Page. Figs. 1, 2. Cyclopitys oregonensis Font. n. sp 132 Fig. 2. Enlargement of Fig. 1, X S. Figs. 3-8. Sphenolepidium oregonense Font. n. sp _ 133 Fig. 4. Enlargement of Fig. 3, X 2. Fig. 7. Enlargement of the principal branch shown in Fig. 6, X 2. Fig. 8. Enlargement of the cone and twig to which attached sho%vn in Fig. 6, X 2. Figs. 9-12. Samaropsis ? oregonensis Font. n. sp , 134 Fig. 10. Enlargement of Fig. 9, X 3. Fig. 12. Enlargement of Fig. 11, X 3. FiQ. 13. Male ament of conifer 135 U. S, GEOLOGICAL SURVEY MONOGRAPH XLVIII PL. XXXVI JURASSIC CONIFERS FROM OREGON. PLATE XXXVII. PLATE XXXVII. Jurassic Flora of Oregon. Page. Figs. 1,2. Yuccites hettangensis Sap. ? 135 Fig. 2. Pen drawing of a portion of Fig. 1, natural size. Figs. 3, 4. Undetermined leaf, No. 1 136 Fig. 4. Pen drawing of one of the leaves of Fig. 3, natural size. Figs. 5, 6. Undetermined leaf, No. 2 136 Fig. 6. Pen drawing of a portion of Fig. .5, natural size. Figs. 7, 8. Cakpolithus olallensis Ward n. sp 137 Fig. 9. Carpolithus Bucklandii Willn. ? 138 Figs. 10, 11. Carpolithus OREGONENeis Font. n. sp . 139 Fig. 12. Carpolithus elongatus Font. n. sp 139 Fig. 13. Carpolithus douglasensis Font. n. sp 139 U. S. GEOLOGICAL SURVEY MONOGRAPH XLVIII PL. XXXVII MISCELLANEOUS JURASSIC PLANTS FROM OREGON. PLATE XXXVIII. PLATE XXXVIII. Jurasso-Cretaceous Floras. Page. Figs. 1 , 2. Dicksoxia oregonensis Font. ? 148 Fig. 2. Enlargement of Fig. 1, X 2. Figs. 3, 4. Thyrsopteris Murrayak.4 (Brongn.) Heer ? 148 Fig. 4. Enlargement of Fig. 3. Figs. 5, 6. Cladophlebis vaccensis Ward 149 Fig. 6. Enlargement of Fig. 5, X 2. Figs. 7,8. Ctexis sulcicaulis (Phill.) Ward ? 149 Fig. 8. Enlargement of Fig. 7, X 3. Figs. 9, 10. Ctenopiiylluji ? sp. Font. n. sp. ? 149 Fig. 10. Enlargement of Fig. 9. Figs. 11, 12. Podozamites lanceolatus minor (Schenk) Heer ? ISO Fig. 12. Enlargement of Fig. 11. Figs. 13,14. Otozamites orego.mensis Font. n. sp 150 Figs. 1.5-18. Taxites zamioides (Leek.) Sew 151 Fig. 16. Enlargement of Fig. 15, X 2. Fig. 18. Enlargement of Fig. 17, X 2. Figs. 19,20. Pterophyllum alaskense Font. n. sp 152 Fig. 20. Portion of Fig. 19, enlarged, X 2. Fig. 21. Sagenopteris alaskensis Font. n. sp - - 152 U. S. QEOLOQICAL SURVEV MONOGRAPH XLVIII PL. XXXVIII JURASSO-CRETACEOUS PLANTS FROM OREGON AND ALASKA. PLATE XXXIX. PLATE XXXIX. Jurasso-Cretaceous Flora of Cape Lisburne, Alaska. Page. Figs. 1,2 Dicksonia Saportana Heer 15.5 Fig. 2. Enlarged portion of Fig. 1, X 3. Figs. 3-6 Onychiopsis psilotoides (Stokes & Welib) Ward n. comb 1.55 Fig. 4. Enlarged portion of Fig. 3, X 3. Fig. 6. Enlarged pinnule of Fig. 5, X 3. Figs. 7, 8. Ci.adophlebis vaccensis Ward 157 Fig. 8. Enlarged portion of Fig. 7, X 3. Figs. 9-11. Cladophlebis alata Font 158 Fig. 10. Enlarged portion of Fig. 9. X 3. Fig. 11. Two pinnules of Fig. 9, enlarged to .show the teeth, X 2. U. S. GEOLOGICAL SURVEY MONOGRAPH XLVIII PL. XXXIX JURASSO-CRETACEOUS FERNS FROM CAPE LISBURNE, ALASKA. PLATE XL. PLATE XL. Jurasso-Cretaceous Flora of Cape Lisburne, Alaska. Page. Figs. 1-9. Cladophlebis al.ata Font 158 Fig. 2. Enlarged portion of Fig. 1, X 2. Fig. 4. Enlarged portion of Fig. 3, X 2. Fig. 6. Enlarged portion of Fig. 5, X 3. Figs. 8, 9. Enlarged pinnules of Fig. 7, X 2. U. S. GEOLOGICAL SURVEY MONOGRAPH XLVIII PL. XL JURASSO-CRETACEOUS FERNS FROM CAPE LISBURNE, ALASKA. PLATE XLI. P L A T E X L I . Jurasso-Cretaceous Flora of Cape Lisburne, Alaska. Faee. Ci,Aunpiii,EBi!S HuTTONi (Duiik.) Foiit. n. comb - - 161 Fig. 2. Portion of Fig. 1 enlarged, X i- Fig. 3. Pinnule of Fig. 1 enlarged, X 2. F'ig. -J. Pinnule of Fig. 1 enlarged and restored X -3. Fig. Ft. Portion of Fig. 1 enlarged and restored Xi- U. S. QEOLOQICAL SURVEY MONOGRAPH XLVIII PL. XLI JURASSO-CRETACEOUS FERNS FROM CAPE LISBURNE, ALASKA. PLATE XLII. PLATE X L T I . ,lui!Ass()-Ci!KrAci:()i's Floka of Capk IjISburnr, Alaska. Hiiee. Pkis. 1-3 Ci.AiiciiMii. Kills lli'iToNi ( 1 )unU. ) I' i"it ■ H- coiiili Kil Kifl. 2. ICiiliirficd pinmilc of Kig. 1, X 2. Fig. 3. Portion of Fig. 1 onliiiged and restoied, X 3. U. S. GEOLOGICAL SURVE MONOGRAPH XLVIII PL. XLII JURASSO-CRETACEOUS FERNS FROM CAPE LISBURNE, ALASKA. PLATE XLIII. PLATE XLIII. Jurasso-Cretaceous Flora of Cape Lisburne, Alaska. Pape. Fios. 1-7. Ci..4DOPHLBBis HuTTONi (Dunk.) Font. a. comb 161 Fig. 2. Portion of Fig. 1 enlarged, X 2. Fig. 3. Pinnule of Fig. 1 restored and slightly enlarged. Fig. 5. Enlarged pinnule of Fig. 4, X 2. Fig. 6. Pinnule of F^ig. 4 restored and slightly enlarged. U. S. GEOLOGICAL SURVEY MONOGRAPH XLVIII PL. XLIII JURASSO-CRETACEOUS FERNS FROM CAPE LISBURNE, ALASKA. PLATE XLIY PLATE XLIV. Jurasso-Cretaceous Flora of Cape Lisburne, Alaska. Page. Fig. 1. PoDozAMiTEs GRANDiFOi.ius Font. ? 167 Fig. 2. Baiera gracilis (Bean) Bunb. 168 Figs. 3, 4. Ginkgodium ? alaskense Font. n. sp 168 Fig. 4. Outline sketch of Fig. 3 showing tlie plan of neivation, natural size. Figs. 5, 6. Ginkgo digitata (Brongn.) Heer 170 Figs. 7, 8. Ginkgo Huttoni magnifolia Font. 'L 170 U. S. GEOLOGICAL SURVEY MONOGRAPH XLVIII PL. XLIV JURASSO-CRETACEOUS CYCADS AND GINGKOACE/E FROM GAPE LISBURNE, ALASKA. PLATE XLV. PLATE XLV. Jurasso-Cretaceous- Flora of Alaska, Montana, anu California. Page. Figs. 1-5. Nageiop.sis i.ongifoi.i.\ Font. ? from the Jurasso-Cretaceous of Cape Lisbunie,.\laska 171 Fig. 4. Enlarged portion of Fig 3, X 3. Fig. 6. BKACUYPiiyLLUM ? Storrsii AVard n. sp 176 Figs. 7,8. Sequoia Reichenbachi (Gein.) Heer from the Jurassic or Lower Cretaceous of Mon- tana - - - 177 Fig. 8. Enlarged portion of Fig. 7. Figs. 9-11. Sequoia Fairbanksi Font. n. sp. from the Juras.so-Cretaceous of Slate Spring-'^, Cali- fornia - - - — 178 U. S. QEOLOQICAL SURVEY MONOGRAPH XLVIII PL. XLV JURASSO-CRETACEOUS CONIFERS FROM ALASKA, MONTANA, AND CALIFORNIA. PLATE XL VI. PLATE XLVI. JcRASsic Cycads from THE Freezeout Hills, Wyoming. Page. CycADELLA WYOMiNGENSis Ward 183 View of one side and part of the base of the trunk consisting of Nos. 500.88, 500.513, and 500.525 of tlie museum of the University of Wyoming. U. S. GEOLOGICAL SURVEY MONOGRAPH XLVIII PL. XLVI JURASSIC CYCADS FROM WYOMING. PLATE XLVII. PLATE XL VII. Jurassic Ctcads from the Freezeout Hills, Wyoming. Page. Figs. 1, 2. Cycadell.\ Knowltoniana Ward 1S5 Side views of the fragments Nos. .500.9-1 and 500.498, respectively, of the museum of the Univei-sity of Wyoming. Fig. 3. Cycadella Reedii Ward 182 Side view of the small trunk No. 100.239 of the museum of the University of Wyoming. Fig. 4. Cycadella compressa Ward 186 Side and top view of the small trunk No. 100.264 of the museum of the University of Wyoming. PLM^E XLVIIL PLATE XLVIII. Jurassic Cycads from the Freezeout Hills, Wyoming. Page. Cycadella compressa Ward 1S6 Fig. 1. Side and top view of the small trunk No. .500.503 of the museum of the University of Wyoming. Fig. 2. Side view of the small trunk No. 100.22S of the museum of the Univereity of Wj-oniing. U. S. GEOLOGICAL SURVEY MONOGRAPH XLVIII PL. XLVIII CENTIMETERS I JURASSIC CYCADS FROM WYOMING. PLATE XLIX. PLATE XLIX. JlTRASSIC CyCADS FROM THE FrEEZEOUT HiLLS, WyOMIXG. Page. Cycadella JIRASSICA Ward _. 1S6 View of the surface of the segment resulting from the union of the fragments Nos. 100.2(M and 500.507 of the museum of the Unirersity of Wyoming. U. S. GEOLOGICAL SURVEY MONOGRAPH XLVIII PL. XLIX JURASSIC CYCADS FROM WYOMING. PLATE L. PLATE L. Jurassic Cycads from the Feeezeout Hills, Wyoming. Pago Cycadella nodosa Ward 187 Side view of the trunk No. 500.509 of the museum of the University of Wyoming. U. S. GEOLOGICAL SURVEY MONOGRAPH XLVIII PL. L i..^'> -^^ A^. /^'^^ I AJ' CENTIMETERSI JURASSIC CYCADS FROM WYOMING. PLATE LL PLATE LI. Jurassic Cycads from the Freezeout Hills, Wyoming. Page. Cycadella nodosa Ward - - 18" Side \-ipw showing also part of the base of the trunk No. lOU.L'Ob of the museum of tlie University of Wyoming. U. S. GEOLOGICAL SURVEY MONOGRAPH XLVIII PL. LI CENTIMETERS I JURASSIC CYCADS FROM WYOMING. PLATE LII. P L A T E L 1 1 . Jurassic Cycads from the Freezeout Hills, Wyoming. Page. Flo. 1 . Ctcadella nodosa Ward. 187 Side view of the small trunk No. 100.229 of the museum of the University of Wyoming. Fius. 2-4. Cycadella cirrata Ward.. 188 Fig. 2. Side view of the triangular section resulting from joining Nos. .500.178 and .500.422 of the museum of the University of Wyoming. Figs. 3, 4. Views of the internal structure shown in the fractures of Nos. 500.422 and 500.136, respectively, of the museum of the University of Wyoming. U. S. GEOLOGICAL SURVEY MONOGRAPH XLVIII PL. Lll JURASSIC CYCAD8 FROM WYOMING. PLATE LIII. PLATE LIII. Jurassic Cycads from the Freezeout Hills, Wyoming. Page. CvcADELLA ciRRATA Ward _ ] S8 View of the internal structure shown in the tangential fracture of the fragment No. 100.245 of the museum of the University of Wyoming. PLATE LIT. PLATE LIV. Jurassic Cycads from the Freezeout Hills, Wyoming. Page. Cycadella exogena Ward 1S9 Fh;. 1. View of the tangential fracture of the trunk No. .500..514 of the museum of the University of Wyoming. Figs. 2, 3. Views of the radial fractures of the two fragments Nos. .500.41(3 and .500.174, respec- tively, of the museum of the Univei-sity of Wyoming, showing the cxogenou.s struc- ture and woodv wedges. PLATE LV. PLATE LV. Jurassic Cycads from the Freezeout Hills, Wyoming. Page. Cycadella ramentosa Ward - 191 Fig. 1. Side view of the trunli No. 100.214 of the museum of the University of Wyoming. Fig. 2. 'S'iew of the rough radial fracture of the fragment No. 100.201 of the museum of tlie Uni- vei'sitv of Wvoming. U. S. GEOLOGICAL SURVEY MONOGRAPH XLVIll PL. LV JURASSIC CYCADS FROM WYOMING. PLATE LVI. PLATE L V I . Jurassic Cycads from the Freezeout Hills, Wyoming. Page. Cycadella contracta \Tard. 192 Fig. 1. Side view of the imperfect trunk No. 100.218 of tlie museum of the University of W\'omii)g. Figs. 2, 3. Views of the outer and inner surfaces, respectively, of tlie small trunk Nu. 1(X1.241 of the museum of tlie University of Wyoming. U. S. GEOLOGICAL SURVEY MONOGRAPH XLVIII PL. LVI I CENTIMETERS I JURASSIC CYCADS FROM WYOMING. PLATE LTII. PLATE LVII. Jurassic Cycads from the Freezeout Hills, Wyoming. CiCADELLA JEJUNA Ward - 194 Side view of the trunk consisting of Nos. .500.5L5 and 500.491 of the museum of the Universitj' of Wyoming. PLATE LVIII. PLATE LVIII. Jurassic Cycads from the Freezeout Hills, Wyoming. Page. Cycadella CREPiDAEiA Ward - 195 View of the best presei-ved side of die tiunl:, consisting of Nos. 100.202, 100.215 and 100.230 of the museum of the University of Wyoming. U. S. GEOLOQIOAL SURVEY Monograph xlvim pl. lviI JURASSIC CYCADS FROM WYOMING. PLATE LIX. PLATE LIX. Jurassic Cycads from the Freezeout Hills, Wyoming. Page. Cycadeli.a crepidaria Ward - - 195 \'ie\v tif one side of tlie trunk No. 100.203 of the jiuiseum of the Univei-sity of Wyoming. U. S. GEOLOGICAL SURVEY MONOGRAPH XLVIII PL. LIX JURASSIC CYCADS FROM WYOMING. PLATE LX. PLATE LX. Jurassic Cycads from the Freezeout Hills, Wyoming. Page. Cycadei.i.a crepidaria Ward 195 View of the convex side of tlie trunk Xo. 100.226 of the museum of tlie University of Wyoming U. S. GEOLOGICAL SURVEY MONOGRAPH XLVIII PL. LX JURASSIC CYCADS FROM WYOMING. PLATE LXI. PLATE LXI. Jurassic Cycads from the Freezeout Hills, Wyoming. Page Cycadei.la Knightii Ward 197 View of the convex side of the trunk No. 500.6S7 of the museum of the University of Wyoming. U. S. GEOLOGICAL SURVE MONOGRAPH XLVIII PL. LXI JURASSIC CYCADS FROM WYOMING. PLATE LXII. PLATE LXII. Jurassic Oycads from the Freezeout Hills, Wyoming. Page. Figs. 1-3. Cycadella ramentosa Ward 191,200,201,202,203 Fig. 1. Hypothetical form of irond. Fig. 2. Transverse section of young frond, X 25. Fig. 3. Transvei-se section of ramental eliafl', X 6.5. Fig. 4. Wii.i.iamsonia gigas (L. & H.) Carr. (introduced for comparison). . 201,204 U. S. GEOLOGICAL SURVEY MONOGRAPH XLVIII PL. LXII JURASSIC CYCADS FROM WYOMING. PLATE LXIII. PLATE LXIII. Jurassic Cycads from Wyoming. Page. Fig. 1. Cycadella kamentosa Ward 200, 201 , 202 Trans veree section of young frond, X 25. Fig. 2. Cycadella utopiensis Ward. 204 U. S. GEOLOGICAL SU«VEY MONOGRAPH XLVIII PL. LXIII JURASSIC CYCADS FROM WYOMING. PLATE LXIV. PLATE LXIV. Page. Sketch map of the Shasta foruiatiou of CaUfomia yieldiug fossil plauts - 221 U. S. GEOLOGICAL SURVEY MONOGRAPH XLVin PL. LXIV SKETCH MAP SHOWING- FOSSIL LOCALITIES OF THE SHASTA FORMATION NORTHERN CALIFORNIA Scale PLATE LXT. PLATE LXV. Flora of the Shasta Formation. Page. FlC. 1 . DiCKSONIA PACIIVPHYLLA Foilt. 11. sp 224 Figs. 2-4. Thvrsopteris rarinervis Font, t 22.5 Figs. .5-8. Cladophlebis parva Font •. 1 22.5 Figs. 9-11. Cladophlebis Browniana (Dunk. ) Sew _ 226 Figs. 12-14. Cladophlebis falcata Font 227 Figs. 15, 16. Cladophlebis Ungeri (Dunk. ) Ward n. comb 228 Figs. 17-21. Cladophlebis alata Font. '. . 229 Figs. 22,23. Matonidium Althausii (Dunk.) Ward 230 Figs. 24-29. Gleichenia Nokdenskioldi Heer 231 Figs. .30-3.5. Sagenopteris Mantelli (Dunk.) Schenk 233 Figs. 36-38. Sagenopteris orbgonbnsis Font. n. roiub 23.5 Figs. 39, 40. Sagenopteris elliptica Font 236 Figs. 41-45. S.-vgenopteris nervosa Font, n.sp 237 Fig. 4G. Sagenopteris ? sp. Font 238 Flu. 47. IIausmannia '( californica Font, n.sp - 23S U. S. QEOLOQIOAL SURVEY MONOGRAPH XLVIII PL. LXV FERNS FROM THE SHASTA FORMATION OF CALIFORNIA AND OREGON. PLATE LXVI. PLATE LXVI. Flora of the Shasta Formation. Page. Figs. 1-4. Angiopteridium canmorense Dn. ?.. -. 239 Figs. 5-7. Angiopteridium strictinerve Font 240 Figs. 8-10. Angiopteridium strictinerve latifolium Font 241 Fig. 11. Gleichenia ? Gii.bert-Thompsoni Font. n. sp 232 Figs. 12, 13. Ctenopteris integrifolia Font - 242 Fig. 13. Enlargement of Fig. 12. Fig. 14. Eqdisetum texense Font. ?. - 243 Fig. 15. Dioonites Dunkerianus (Gopp.) Miq .-. - - 243 Figs. 16, 17. Dioonites Buchianus (Ett.) Born - - 244 U. S. QEOLOQICAL SURVEY MONOGRAPH XLVIII PL. LXVI FERNS FROM THE SHASTA FORMATION OF CALIFORNIA AND OREGON. PLATE LXVII. PLATE LXVII. Flora of the Shasta Formation. Page. Figs. 1-3. Dioonites Buchianus abietinus (Gijpp. ) Ward n. comb 250 Fig. 4. Dioonites Buchianus rarinervis Font. ? 251 Figs. 5, 6. Nii.sonia Stantoni Ward n. sp 251 Fig. 7. Nilsonia californica Font -. 252 Fig. 8. Nilsonia sambucensis Ward n. sp 254 Fig. 9. Pterophyllum ? lowryanum Ward n. sp 254 Fig. 10. Ctenophyllom latifolium Font. ? 255 U. S. GEOLOGICAL SURVEY MONOGPAPH XLVIII PL. LXVII CYCADS FROM THE SHASTA FORMATION OF CALIFORNIA AND OREGON. PLATE LXVIII. PLATE LXVIII. Flora of the Shasta Formation. Page. Fig. 1 . Zamites arcticus Gopp 256 Figs. 2,3. Zamites tenuinervis Font 257 Fig. 4. Cycadeospermum californicum Font. n. sp 257 Figs. 5-7. Cephalotaxopsis ramosa Font. ? 258 Fig. 8. Cephalotaxopsis rhttidodes ? Ward n. sp 258 Figs. 9-12. Nageiopsis longifolia Font. ?. 259 Fig. 13. Nageiopsis latifolia Font. ? 260 Fig. 14. Abietites ellipticus Font 260 Figs. 15, 16. Abietites macrocarpus Font - 261 Fig. 17. Abietites * sp. Font, (immature cone) 262 U. S. GEOLOGICAL SURVEY MONOGRAPH XLVIII PL. LXVIll CYCADS AND CONIFERS FROM THE SHASTA FORMATION OF CALIFORNIA AND OREGON. PLATE LXIX. PLATE LXIX. Flora of the Shasta Formation. Page. Figs. 1-3. Pinus shastbnsis Font. n. sp 262 Figs. 4, S. Sequoia Reichenbachi (Gein. ) Heer 263 Fig. 6. Sequoia ambigua Heer 264 Fig. 7. Sphenolepidium Sternbergianum (Dunk. ) Heer 264 Fig. S. Saliciphyllum pachyphyllum Font. n. sp. 265 Fig. 9. Saliciphyllum californicum Font. n. sp 266 Fig. 10. POPULUS ? RiCEi Font. n. sp 266 Fig. 11. Prote^phyllum californicum Font. n. sp 267 Figs. 12-14. Menispermites californicus Font. n. sp 268 Figs. 15-17. Sapindopsis oregonensis Font. n. sp 26S Fig. 18. AcAciiEPHYLLUM ELLiPTicuM Font. n. sp 269 Fig. 19. Acaci.!ephyllum pachyphyllum Font. n. sp 270 U. S. GEOLOGICAL SURVEY MONOGRAPH XLVIII PL. LXIX r i CONIFERS AND DICOTYLEDONS FROM THE SHASTA FORMATION OF CALIFORNIA AND OREGON. PLATE LXX. PLATE LXX. Flora of the Shasta Formation. Vase. Cycadeoidea Stantoni Ward n. sp 276 View of the best preserved side. PLATE LXXI PLATE LXXI. Flora of the Kootanie Formation. Page Figs. 1—4. Dicksonia montanensis Font. n. sp 286 Fig. 2. Enlarged pinnule of Fig. 1, X 2. Fig. 4. Enlarged pinnule of Fig. 3, X 2. Figs. 5-11. Dicksonia pachyphylla Font 288 Fig. 6. Portion of Fig. 5 enlarged, X 4. Fig. 8. Enlargement of Fig. 7, X 2. Fig. 10. Portion of Fig. 9 enlarged, X 3. Figs. 12, 13. Thyrsopteris elliptica Font .~. 290 Figs. 14-20. Cladophlebis falcata montanensis Font. n. comb 291 Fig. 16. Portion of Fig. 15 enlarged, X 2. Fig. 18. Pinnule of Fig. 17 enlarged, X 2. Figs. 21-25. Cladophlebis iieterophylla Font 294 Fig. 22. Pinnules of Fig. 21 enlarged, X 2. Fig. 26. Cladophlebis constricta Font. ? 297 U. S. GEOLoaiCAL SURVEY MONOGRAPH XLVIII PL. LXXI FERNS FROM THE KOOTANIE FORMATION OF MONTANA. PLATE LXXII. PLATE LXXII. Flora of the Kootanie Formation. Page. Fi(;s. 1-11. Eqcisetlm Phillipsii (DunU. ) Brongn. 29S Fig. 9. Portion of Fig. S enlarged, X 2. Fig. 10. Portion of Fig. S enlarged, X 3 and restored. Figs. 12-14. Equisetum Lvellii Mant 301 Fig. 1-4. Portion of Fig. 13 enlarged, X 3 and restored. Fi(;s. 1.5. 16. Lycopodites ? .mont.\nensis Font. n.sp,. Z02 Fig. IG. Portion of Fig. 1.5 enlarged, X 2. Fios. 17-21, NiLSONiA ScHAUMBURGENSis (Dunk.) Natli 303 U. S. GEOLOGICAL SURVEY MONOGRAPH XLVIII PL. LXXll />,x EQUISETA AND CYCADS FROM THE KOOTANIE FORMATION OF MONTANA. PLATE LXXIII. PLATE LXXIII. Flora of the Kootanie Formation. Page Figs. 1-6. Za.mites arcticus Gopp SOU Fig. 6. Portion of Fig. 5 enlarged, X 4. Fig. 7. Cycadeospermum montanense Font. n. sp 310 Fig. 8. Cephalotaxopsis eamosa Font. ? 31 1 Fig. 9. Nageiopsis i.ongifolia Font 311 Fig. 10. Nageiopsis montanensis Font. n. sp 312 Figs. 11-14. Laricopsis longifolia l.atifolia Font. n. var 312 Flora of the Lakota Formation. Fic!. 15. (a-c). NiLsoNiA nigracollen'sis Wielaiid n. sp 319 Fig 1.5d. Thyrsopteris dentifolia Font 320 U. S. GEOLOGICAL SURVEY MONOGRAPH XLVIII PL. LXXIII CYCADS AND CONIFERS FROM THE KOOTANIE FORMATION OF MONTANA AND THE LAKOTA FORMATION OF SOUTH DAKOTA. PLATE LXXIV. PLATE LXXIV. Page. View of exposure on Ontario avenue, in rear of Lanier Heights, Washington, D. C, looking north, show- ing the Rappahannock sands of the Potomac formation resting on the crystalline rocks. From a photograph hy the United States Geological Survey, 1S92 3S2 PLATE LXXV PLATE LXXV. Page. Exposure ou Kansas avenue, between the Adams Mill road and Ontario avenue, Washington, D. C, looking east, showing the Potomac formation overlain by the Columbia bowlder clay. From a pho- tograph by the United States Geological Survey, 1892 382 PLATE LXXVI. PLATE LXXVI. Page. Exposure on Sixteentli street, opposite Crescent street, Washington, D C, looking northeast, showing hasiil lA)loiniU' c-l;iys overlain hy superficial deposits (compare section on page 386) — - 382 PLATE LXXVII. PLATE LXX VII. Page. Exposures at Terra Cotta,D. C.,in the railroad cutting looking ea-st, showing irrfgularly hedded Rappa- hannock sands inclosing clay lenses. The two views overlap nearly half their width and repi-esent about 100 feet from noi-th to south, Fig. 1 being the more northerly 383 U. S. QEOLOGICAL SURVEY MONOGRAPH XLVIII PL. LXXVII EXPOSURES OF THE POTOMAC FORMATION AT TERRA COTTA, D. C. PLATE LXXVIII. PLATE LXXVIII. Page Exposures at Freestone, Va., in railroad cutting, looking west 385 Fig. 1. North end of cut, showing Rappahannock sand with a stratum of green clay and below it on the right a lens of the same. Fig. 2. South end of cut, Rappahannock sand with large lens of green clay near the top, running out on the left. U. S. GEOLOGICAL SURVEY MONOGRAPH XLVIII PL. LXXVIII EXPOSURES OF THE POTOMAC FORMATION AT FREESTONE, VA. .# PLATE LXXTX. PLATE LXXIX. Page. Exposures on Back Lick Run 5 miles southwest of Alexandria, Va., looking east 386 Fig. 1. Cross-bedded Rappahannock sands with lenses of green clay. Fig. 2. Pure white lenticularly bedded Rappahannock sands. U. S. GEOLOGICAL SURVEY MONOGRAPH XLVIII PL. LXXIX . ^^y^ ^•^ ■MfP ^ jjl^iil^te^ tI ^^B^SHflftK' iJtiirffjtflffniBfllii Mi EXPOSURES OF THE POTOMAC FORMATION ON BACK LICK RUN, VIRGINIA. PLATE LXXX. PLATE LXXX. Page. Map showing the distribution of the formations of tlie Potomac group in Maryland, the District of Cokimbia, and adjacent parts of Virginia, with indication, by numbers, of the localities at which fossils and other objects mentioned in the text have been found 412 PLATE LXXXI. PLATE LXXXI. Maryland Potomac Cycads. Page. Ctcadeoidea maeylandica (Font.) Cap. & Solms. Side and base view of the Johns Hopkins Univer- sity Cycad, No. 1 : al.so of siUcified wood from the Potomac formation of Maryland, from a photo- graph by Tyson 41 9 (For historical account, see p. 410.) PLATE LXXXII. PLATE LXXXII. Maryland Potomac Cycads. Page Cycadeoidea marylandica (Font.) Cap. & Solms. View of Johns Hopkins Univei'sity Oycad, No. 2. from a photograph b}' Tyson. 421 (For historical account, see p. 410.) U. S. GEOLOGICAL SURVEY MONOGRAPH XLVIII PL. LXXXII TRUNK OF CYCAD EARLY DISCOVERED IN THE POTOMAC FORMATION OF MARYLAND. PLATE LXXXIII. PLATE LXXXIII. Maryland Potomac Ctcads. Page. Figs. 1-3. Group of cycads, from a photograph by Tyson (for historical account, see p. 414). Figs. 1,2. Cycadeoidea marylandica (Font.) Cap. & Solms. Fig. 1 . Side and top view of Johns Hopkins University Cycad, No. 1 . 422 Fig. 2. Side view of Johns Hopkins University Cycad, No. 3 422 Fig. 3. Cycadeoidea Bibbinsi Ward, Johns Hopkins University Cycad, No. 4 458 Fig. 4. Cycadeoidea marylandica (Font.) Cap. & Solms. View of the base of the Link trunk, No. 1481, of the museum of the Woman's College of Baltimore 422 U. S. GEOLOGICAL SURVEY MONOGRAPH XLVIII PL. LXXXIII ' '^i*^V'^^'^^fe^ *:?'«se' I I I I I I I I I I CENTIMETERS I I DECIMETERSI TRUNKS OF CYCADS EARLY DISCOVERED IN THE POTOMAC FORMATION OF MARYLAND. PLATE LXXXIT. PLATE LXXXIV. Maryland Potomac Cycads. Group ot cycads in tlie museum of tlie Johns Hopkins Univereity, Baltimore. Figs. 1,2. Cycadeoidea mahylandica (Font.) Cap. & Solms. Page. Fig. 1. Side view of Johns Hopkins University Cycad, No. ."i 422 Fig. 2. Johns Hopkins University Cycad, No. 3 423 Fig. 3. Cycadeoidea Bibbinsi Ward, Johns Hopkins Univei-sity Cycad, No. 4 458 .1 i PLATE LXXXV. PLATE LXXXV. Maryland Potomac Cycads. C'ycadeoidea Bibbinsi Ward. Page. View of tlie external surface of the fragment sent by Philip Tvson to Sir William Dawson, known as the Dawson Cvcad . - - - 459 (For historical account see p. 409.) • U. S. GEOLOGICAL SURVEY MONOGRAPH XLVIII PL. LXXXV TRUNK OF CYCAD EARLY DISCOVERED IN THE POTOMAC FORMATION OF MARYLAND. PLATE LXXXVI. PLATE LXXXVI. Maryland Potomac Cycaus. Cycadeoidea Fontaineana Ward. Page, View of the external surface of the South Carohna College Cycad 442 (For historical account see p. 411.) U. S. GEOLOGICAL SURVEY MONOGRAPH XLVIM PL. LXXXVI TRUNK OF CYCAD EARLY DISCOVERED IN THE POTOMAC FORMATION OF MARYLAND. PLATE LXXXVII PLATE LXXXVII. Maryland Potomac Cycads. Group of Cycads in the Museum of the Woman's College of Baltimore. Page. Fig. 1, 1. The Turner trunk: No. 3046, Cycadeoidea Fontaineana Ward 443 Fig. I, 2. The Tubbs trunk : No. 1 465, Cycadeoidea Blbeinsi Ward 460 Fig. 1, 3. The Wilson trunk ; No. 1479, Cycadeoidea Gouciieriana Ward 452 Fig. i, 4. The Pollv Jones trunk; No. 1427, Cycadeoidea Bibbinsi Ward 460 Fig. I, 5. The R. f. Donaldson trunk. No. 1 ; No. 1472, Cycadeoidea Tysoniana Ward 433 Fig. 1, 6. The Weston trunk; No. 1468, Cycadeoidea Bibbin.si Ward 460 Fig. 1, 7. The Dennis Butler trunk ; No. 1462, Cycadeoidea Bibbinsi Ward 460 Fig. II, 1 ■ The Robinson trunk ; No. 1487, Cycadeoidea Bibbinsi Ward 460 Fig. II, 2. The Lintliicuni fragment ; No. 1484, Cycadeoidea Bibbinsi Ward 461 Fig. 11^3- The Link trunk; No. 1481, Cycadeoidea marylandica (Font.) Cap. & Solnis 423 Fig. ii! 4. The Doisev trunk: No. 6353, Cycadeoidea Bibbinsi Ward 461 Fig. II, 5. The Reinsiiyder trunk; No. 6344, Cycadeoidea marylandica (Font.) Cap. & Solnis 424 Fig. ii!6. The Hehvig trunk; No. 3328, Cycadeoidea m-^rylandica (Font.) Cap. & Solms 424 Fig! II, 7. The R. T. Donaldson fragment. No. 3 ; No. 3324, Cycadeoidea marylandica (Font. ) C. & S . 424 Fig. u, 8. The All-Saints tmnk; No. 1466, Cycadeoidea Bibbinsi Ward 456 Fig. ii! 9. The Gray trunk; No. 6354, Cycadeoidea Bibbinsi Ward 462 Fig. ii, 10. The Smith ti-unk; No. 1482, Cycadeoidea Bibbinsi Ward 462 Fig. n, 11. The Smith fragment ; No. 1483, Cycadeoidea Bibbinsi Ward 462 Fig. Ill, 1. The Lester trunk; No. 3056, Cycadeoidea m.^rylandica (Font.) Cap. & Solms 424 Fig. mi 2. The Griffith tmnk; No. 1467, Cycadeoidea Fontaineana Ward 443 Fig. in, 3. The Clark trunk; Nos. 16.59, 1659a, Cycadeoidea McGeeana Ward 435 Fig. Ill, 4. The Crook fragment; No. 1428, Cycadeoidea marylandica (Font.) Cap. & Solms 425 Fig. \u, 5. The Can- trunk ; No. 1463, Cycadeoidea Bibbinsi Ward 463 Fig. Ill, 6. The Noah Donaldson trunk; No. 1470, Cycadeoidea Fontaineana Ward 443 Fig. Ill, 7. The Welsh trunk; No. 1464, Cycadeoidea Bibbinsi Ward 464 Fig. mi 8. The Riddle fi-agment; No. 1488, Cycadeoidea Fontaineana Ward 443 Fig. m, 9. The Hegeman trunk; No 6345, Cycadeoidea Fisiier.^;: Ward, n. sp 471 Fig. in, 10. The M. A. Donaldson trunk; No. 1471, Cycadeoidea McGeeana Ward 435 Fig. IV, 1. The Comegys fragment; No. 1658, Cycadeoidea Fontaineana Ward 444 Fig. ivi 2. The Harman trunk; No. 1426, Cycadeoidea Bibbinsi Ward 464 Fig. IV, 3. The R. P. Disney fragment. No. 1 ; No. 3348, Cycadeoidea Bibbinsi Ward 464 Fig. IV, 4. The R. P. Disney trunk, No. 1; No. 6343, Cycadeoidea marylandica (Font.) C. & S 425 Fig. ivi 5. The Harwood trunk; No. 3050, Cycadeoidea marylandica (Font.) Cap. & Solnis 425 Fig. IV, 6. The Ring fragment ; No. 1480, Cycadeoidea Bibbinsi Ward 465 Fig. IV, 7. Tlie K. P. Disney trunk, No. 2; No. 6352, Cycadeoidea Fontaineana Ward 444 Fig. IV, 8. The Snowdon fragment ; No. 3054, Cycadeoidea Bibbinsi W^ard 465 Fig. IV, 9. The R. P. Disney fragment. No. 2; No. 6348, Cycadeoidea Fontaineana Ward 444 Fig. IV, 10. The Crook fragment. No. 2: No. 1429, Cycadeoidea IT,ileri Ward 454 Fig. IV, 11. The Travers fragment; No. 1478, Cycadeoidea Bibbinsi Ward 466 Fig. IV, 12. The R.T.Donaldson fragment. No. 6; No. 3341, Cycadeoidea marylandica (Font.)C.&S. . 426 Fig. IV, 13. The Tubbs fragment; No. 1192, Cycadeoidea marylandica (Font. ) Cap. & Solms 427 Fig. IV, 14. The Morgan trunk; No. 3051, Cycadeoidea marylandica (Font.) Cap. & Solms 427 Fig. iy, 15. The Inglehart fragment. No. 1 ; No. 3325, Cycadeoidea McGeeana Ward 436 Fig. V, 1. The Cole fragment- No. 3122, Cycadeoidea Fontaineana Ward 444 Fig. v,2. The Harrison fragment ; No. 1486, Cycadeoidea marylandica (Font. ) Cap. & Solms 427 Fig. v,3. TheR.T.Donaldsonfragment,No.2; No. 1656,Cycadeoidea marylandica (Font.)C.&S. . 428 Fig. V, 4. The Giles fragment; No. 3352, Cycadeoidea Tysoniana Ward 433 Fig. V, 5. The Owens fragment; No. 3057, Cycadeoidea marylandica (Font.) Cap. & Solms 428 Fig. v',6. The R.P.Disney fragment, No. 3; No. 6350. Cycadeoidea marylandica (Font.) C.&S 428 Fig. v,7. TheR.T.Donaldsonfragment,No.7; No. 6349, Cycadeoidea marylandica (Font.)C.(kS. . 428 Fig. V, 8. The Deakins fragment ; "No. 3055, Cycadeoidea McGeeana Ward 436 Fig. V, 9. The, Luther Welsh fragment; No. 3323, Cycadeoidea McGeeana Ward 436 Fig. V, 10. The Inglehart fragment; No. 6347, Cycadeoidea Fontaineana Ward 444 Fig. V, 11. The Magi-uder fragment; No. 1489, Cycadeoidea Fontaineana Ward 445 Fig. V, 12. The R. P. Disney fragment; No. 6351, Cycadeoidea Bibbinsi Ward 466 Fig. V, 13. The Emmons fragment ; No. 3346, Cycadeoidea Fontaineana Ward 445 Fig. V, 14. The Odensoss fragment ; No. 3347, Cycadeoidea Fontaineana Ward 445 Fig. v,15. The Sinmis fragment; No. 3047, Cycadeoidea Bibbinsi Ward 466 Fig. V, 16. The AndoTson fragment; No. 6346, Cycadeoidea Fontaineana Ward 445 Fig. V, 17. The D. O. Donaldson fragment; No. 1657. Cycadeoidea marylandica (Font.) C. & S .. . 429 Fig. V, 18. The R. T. Donaldson fragment. No. 4; No. 3326, Cycadeoidea Fontaineana Ward 445 Fio. V, 19. The W. P. Disnev fragment; No. ,3349, Cycadeoidea McGeeana Ward 437 Fig. V, 20. The White fragment; No. 3068, Cycadeoidea McGeeana Ward 437 Fig. v,21. The R. T. Dimaldson fragment, No. 1; No. 1473, Cy.\cdeoidea Fontaineana Ward 445 PLATE LXXXVIII. PLATE LXXXVIII. Marit^and Potomac Cycads. Cycadeoiuea MARYLANDICA (Font. ) Cap. & Solms. Pago. View of the Link trunk, No. 1481, of the museum of tlie Woman'.s College of Baltimore, restored to its place in the Link Gulch, near Arbutus, Maiyland, also showing the exposure as seen from the west side, looking across the gulch 429 PLATE LXXXIX. Fio. I 1 Fia. I 2. Fig. I 3. Fig. 1 4. Fig. I 5. Fig. m 1. Fig. II 2. Fig. II 3. Fig. II 4. Fig. II •5. Fig. II 6 Fig. u 7. Fig. 11 8. Fig. Ill 1 Fig. Ill 2 Fig. Ill 3. Fig. Ill 4. Fig. Ill ■5 Fl.i. HI (i Fig. Ill 7 Fig. Ill fS Fig. Ill 9 Fig. hi 10 Fig. hi 11 PLATE LXXXIX. Maryland Potomac Cycads. Guoui' OF Cycads in the museum oe the Woman's College oe Baltimore. IMgc. The Whitehead ti'iink, No. 2; No. 90.51, Cycadeoidea Fontaineana Ward 44(i The Whitehead trunk, No. 1; No. EOSO, Cycadeoidea Clarkiana Ward n. sp 473 The Dearstine trunk; No. 9049, Cycadeoidea Gouchekiana Ward 452 The R. T. Donaldson trunk, No. 2; No. 90.52, Cycadeoidea Clarkiana Ward n. sp 473 The Travels trunk; No. 6356, Cycadeoidea Bibbinsi Ward 467 The R. T. Donaldson fragment, No. 9; No. 9047, Cycadeoidea McGeeana Ward 437 The Marlowe fragment. No. 2; No. 9059, Cycadeoidea Bibbinsi Ward 467 The Allen fragment, No. 1; No. 9046, Cycadeoidea marylandica (Pont.) Cap. & Solnis.. 429 The R.T. Donaldson fragment, No. 14; No. 9058, Cycadeoidea marylandica (Font.) Cap. & Solms - - 430 The David Ring trunk; No. 63.57, Cycadeoidea Bibbinsi Ward 468 The Allen fragment, No. 2; No. 9048, Cycadeoidea Bibbinsi Ward 468 The R. P. Disney fragment, No. 6; No. 6359, Cycadeoidea marylandica (Font.) Cap. & Solms - 430 The R. T. Donaldson fragment, No. 13; No. 9057, Cycadeoidea McGeeana Ward 437 The R. T. Donaldson fragment. No. 10; No. 9053, Cycadeoidea Fontaineana Ward 446 The R. P. Disney fragment, No. 5; No. 6358, Cycadeoidea marylandica (Font.) Cap. & Solms - 430 The Marlowe fragment. No. 3; No. 9061, Cycadeoidea Fontaineana Ward 446 The Travers fragment. No. 2; No. 9060, Cycadeoidea McGeeana Ward. 438 The R.T. Donaldson fragment. No. 17; No. 9065, Cycadeoidea marylandica (Font.) Cap. & Solms 430 The R. T. Donaldson fragment. No. 15; No. 9062, Cycadeoidea Fontaineana Ward... 446 The R. T. Donaldson fragment, No. 16; No. 9064, Cycadeoidea Fontaineana Ward 446 The R. T. Donaldson fragment, No. 8; No. 8319, Cycadeoidea marylandica (Font.) Cap. & Solms :- 430 The Marlowe fragment , No. 1 ; No. 9055, Cycadeoidea McGeeana Ward 438 The R. T. Donaldson fragment, No. 11; Nb. 9054, Cycadeoidea McGeeana Ward 438 The R. T. Donaldson fragment, No. 12; No. 9056, Cycadeoidea Fontaineana Ward . .. 447 PLATE XC. PLATE XC. Maryland Potomac Cycads. Pago. Thp Link trunk, Cvcadeoidea marylandica (Font.) Cap. & Solnis, No. 1481 of the museum of the Woman's College oC Baltimore - 431 PLATE XCL PLATE XGI. Maryland Potomac Cycads. Page. The Helwig tnaiik, Cycadeoidea maryi,andica (Font.) Cap. & Solms, No. 3328 of the niusnini of llie Woman's College of Baltimore _ . _ 431 U. S. GEOLOGICAL SURVEY MONOGRAPH XLVIII PL. XCI CENTIMETERS I CYCADEOIDEA MARYLANDICA. PLATE XCII. PLATE XCII. Maryland Potomac Cycads. Page. Trunk, No. 1 . of the museum of the Maryland Academy of Sciences, Cycadeoidea maeylandica (Font.) Cap. & Sohiis. Two views of opposite sides — 432 PLATE XCin. PLATE XCIII. Maryland Potomac Cycads. Page. The R. T. Donaldson trunk, No. 1, Cycadeoidea Ttsoniana Ward, No. 1472, of tlie Woman's College of Baltimore _ _ _ _ 433 . GEOLOGICAL SURVEY CYCADEOIDEA TYSONIANA. PLATE XCIV. PLATE XCIV. Maryland Potomac Cycads. CrcADEOiDEA McGeeana Ward. Page. The Clark trunk, otherwise known as the "insect nest," consisting of Nos. 1659 and 1659a of the museum of the Woman's College of Baltimore 438 PLATE XCV. PLATE XCV. Maryland Potomac Cycads. OyCADEOlDEA FoNTAINEANA Ward. Page View of the top of the Turner trunk or "Chicken trough," No. 3046 of the museum of the Woman's College of Baltimore, showing the deep cavity or "crow's nest" used as a receptacle for water for domestic fowls 447 PLATE XCTI. PLATE XCVI. Maryland Potomac Cycads. Cycadeoidea FoNTAiNEANA Ward. Page. Longitudinal section through the Griffith trunk, No. 1467 of the museum of the Woman's College of Baltimore, showing the internal structure and terminal bud 447 PLATE XCVII. PLATE XCVII. Maryland Potomac Cycads. CrCADEOlDEA FoNTAINEANA Ward. i'age. Fig. 1. The Noah Donaldson trunk, No. 1470 of the Woman's College of Baltimore 448 Fig. 2. The Cronmiller fragment, No. 1485 of the Woman's College of Baltimore 449 Fig. 3. The Griffith trunk, No. 1467 of the Woman's College of Baltimore 449 Fig. 4. Interior view of the Magruder fragment, No. 1489 of the Woman's College of Baltimore. . 449 Fig. 5. The Anderson fragment. No. 6346 of the Woman's College of Baltimore 450 PLATE XCVIII. PLATE XCVIII. Maryland Potomac Cycads.. Cycabeoidea Fontaineana Ward. Page. Fig. 1. View from above of the R. P. Disney trunk, No. 2, being No. 6352 of tlie museum of the Woman's College of Baltimore 450 Fig. 2. View of the base of the same _. 450 U. 3. GEOLOGICAL SURVEY MONOGRAPH XLVIII PL. XCVIII r I ^ - i flCENTI METERS I maw isai centimetfrs-i CYCADEOIDEA FONTAINEANA. PLATE XCIX. PLATE XCIX. Maryland Potomac Cycads. Cycadeoidea GoncHERiANA Ward. Side view of the Wilson trunlc, No. 1479 of the museum of the Woman's College of Baltimore. U. S. GEOLOGICAL SURVEY MONOGRAPH XLVIII PL. XCIX btj Wl IM ^ ^-NTIMETERS] CYCADEOIDEA GOUCHERIANA, PLATE C. PLATE C. Maryland Potomac Cycads. Gycadeoidea Uiileri Ward. Paee. Side view of the Les trunk, No. 2 oi' the museum of the Maryland Academy of Sciences _ . 455 u. s. aeoLOGiCAL survey MONOGRAPH XLVIII PL. C CENTIMETERS I CYCADEOIDEA UHLERI. PLATE CI. PLATE CI. Maryland Potomac Cycads. Cycadeoidea Bibbinsi Ward. Page. Side view of the Polly Jones tmnlv, No. 1427 of the museum of the Woman's College of Baltimore. 468 U. S. GEOLOGICAL SURVEY MONOGRAPH XLVIII PL. CI ■WMCENTIMETERSl CYCADEOIDEA BIBBINSI. PLATE CII. PLATE C 1 1 . Maryland Potomac Cycads. Cycadeoidea Bibbinsi Ward. Page. Fig. 1. Side view of the Dennis Butler trunk, No. 1462 of the museum of the Woman's College of Baltimore 469 Fig. 2. Side view of the Tubbs trunk, No. 146.5 of the museum of the Woman's College of Balti- more - - . - - 469 PLATE cm. PLATE cm. Maryland Potomac Cycads. Cycadeoidea Bibbinsi Ward. Page. View, natural size, of a radial section through tlie Smith fragment, No. 1483 of the museum of the Woman's College of Baltimore 469 U. S. GEOLOGICAL SURVEY MONOGRAPH XLVIII PL. Clll CYCADEOIDEA BIBBINSI. PLATE CIV. PLATE CIV. Maryland Potomac Cycads. Cycadeoidea Bibbinsi Ward. Page. Side view of the Gray trunk. No. 6354 of tlie museum of the Woman's College of Baltimore -169 PLATE CT. PLATE CV. Maryland Potomac Cycads. Cycadeoidea FisuERiE Ward n. sp. Page. View of the external surface of the Hegeman trunk, No. 6345 of tlie museum of the Woman's Col- lege of Baltimore 47 1 U. S. GEOLOGICAL SURVEY MONOGRAPH XLVIII PL. CV wiaia t i;^.'^ -I CENTIMETERS I CYCADEOIDEA FISHER/E. PLATE CVI. PLATE CVI. Maryland Potomac Cvcads. Cycadeoidea Clarkiana Ward n. sp. Page. View of the best preserved side of the Whiteliead trunk, No. 9050 of the museum of the Woman's College of Baltimore -..;.. 473 U. S. GEOLOGICAL SURVEY MONOGRAPH XLVIII PL. CVI I- WW toJJ!!! aw mH jNaceNTIMETERSl CYCADEOIDEA CLARKIANA. PLATE CVII. PLATE CVII. Flora of the Potomac Formation. Page Fig. 1 . Baierops7s plhripartita Font , 479 Fig. 2. Dioonites Buciiianus (Ett. ) Born . 479 Fig. 3. Feistmantelia virginica Font. n. sp 484 Fig. 4. Williamsonia ? gallinacea Ward n. sp - 48.5 FiG. 5. Cyoadeospermum obovatum Font. 485 Fig. 6. Aealia ? vernonensis Font. n. sp 492 Fig. 7. Celastrophyllum Brittonianum Hollick 493 Fig. 8. Ephedrites ? vernonensis Font. n. sp 495 Fig. 9. Populophyllum minutum Ward n. sp 499 Fig. 10. Scleropteris vernonensis Ward 501 Fig. 1 1 . Anient of a dicotyledon ? Font 515 U. S. GEOLOGICAL SURVEY MONOGRAPH XLVIII PL. CVII FOSSIL PLANTS FROM THE POTOMAC FORMATION OF VIRGINIA. PLATE CVIII. PLATE CVIII. Flora of the Potomac Formation. Page Fig. 1. DiooNiTEs Buchianus (Ett.) Born _ 479 Fig. 2. Dioonites Buchianus abietinus (G'pp ) Ward ._ 486 Fig. 3. Celastrophyllu.m alb.edomus Ward n sp 4S9 Fig. 4. Gltptostrobus brookensis angustifolius (Font. ) Kn 4S9 Fig 5. Aristolochi.ephyllum ? cellulare Ward n. sp 492 Fig. 6. Celastropiivllum Hunteri Ward - - 494 Fig. 7. Cela.stropiiyllu.m ? saliciforme Ward n. sp . 494 Fig. S. Mvrica brookensis Font .^IS Figs. 9, 10. Leptostrobus ? ovalis Ward nom. nov _ 51 Fig. 10. Enlargement of Fig. 9, X 2. Fig. 1 1 . PopuLOPHTLLUM MiNUTUM Ward n. sp 532 Fig. 12. Ginkgo 1 acetaria Ward n. sp 551 U. S. GEOLOGICAL SURVEY MONOGRAPH XLVIII PL. OVIII FOSSIL PLANTS FROM THE POTOMAC FORMATION OF VIRGINIA. PLATE CIX. PLATE CIX. Flora of the Potomac Formation. Page. Fig. 1. Aristolochi.ephyllum crassinerve Font 481 Figs. 2, 3. Menispermites tenuinervis Font. . ■ 497 Figs. 4-6. Pinus vernonensis Ward n. sp 497 Fig. 7. Potamogetophyllum vernonense Font. n. sp .- 500 Figs. 8,9. Sphenolepidium Sternbergianum densipolium Font 515 Fig. 10. Equisetum marylandicom Font 517 Fig. 11. Sequoia cycadopsis Font... 533 Figs. 12, 13. Athkotaxopsis expansa Font, 'i 535 U. S. GEOLOGICAL SURVEY MONOGRAPH XLVIII PL. CIX FOSSIL PLANTS FROM THE POTOMAC FORMATION OF VIRGINIA, MARYLAND, AND DISTRICT OF COLUMBIA. PLATE ex. PLATE ex. Flora of the Potomac Formation. * Page. Fig. 1. Glyptostkobus brookensis (Font. ) Ward. 495 Figs. 2-4. Populophyllum menispekmoides Ward n. sp 498 Fig. 5. Populus .\uriculata Ward 499 Fig, 6. Sterculia elegans Font. ? - 502 Figs. 7, 8. Thinnfeldia variabilis Font - . .502 Fig. 9. Baieropsis foliosa Font 504 Fig. 10. Celastropiiyllum brookense Font. ? , .505 Fig. 1 1 . Leptostrobus longifolius Font. 506 Fig. 12. Angiopteridium strictineeve Font 51 1 Fig. 13. Sequoia ambigua Heer - - 5.55 U. S. GEOLOGICAL SURVEY MONOGRAPH XLVIII PL. CX FOSSIL PLANTS FROM THE POTOMAC FORMATION OF VIRGINIA. PLATE CXI. PLATE CXI. Flora of the Potomac Formation. Page. Figs. 1 , 2. Zamia Washingtoniana Ward . 503 Fig. 3. Baieropsis longifolia Font 505 Fig. 4. Onyciiiopsis psilotoides (Stokes & Webb) Ward 506. Fig. 5. Sassafras eilobatum Font. ? 503 Fig. 6. Cladophleeis falcata Font 511 Fig. 7. Cladophleeis virginiensis Font 512 Fig. S. Frenelopsis ramosissima Font. 512 Fig. 9. Rogeesia angustifolia parva Font. n. var 523 Fig. 10. Saliciphyllu.\i ellipticum Font 524 Fig. 1 1 . Thyrsopteeis decdrebns Font 525 U. S. GEOLOGICAL SURVEY MONOGRAPH XLVIII PL. CXI FOSSIL PLANTS FROM THE POTOMAC FORMATION OF VIRGINIA AND MARYLAND. PLATE CXII. PLATE CXII . Flora of the Potomac Formation. page Fig. 1. Sphenolepidium Sternbergianum densifolium Font 507 Fig. 2. Dryopteris fredericksburgensis (Font. ) Kn 512 Figs. .3, 4. Quercophylldm chinkapinense Ward n. sp 513 Figs. 5, 6. Thyrsopteris crassinervis Font - 513 Fig. 7. Ctenopteris insignis Font. ? - - 521 Fig. S. Platypterygium densinerve Font. ? 521 Fig. 9. Rogeksia longifolia Font. - 523 Figs. 10, 11. Sphenolepidium Sternbergianum densifolium Font 524 Fig. 12. Ficus myricoides Hollick - - 531 Figs. 13-15. PiNUS sohista Ward n. sp - - 531 U. S. GEOLOQICAL SURVEY MONOGRAPH XLVIII PL. OXIl FOSSIL PLANTS FROM THE POTOMAC FORMATION OF VIRGINIA, MARYLAND, AND DISTRICT OF COLUMBIA. PLATE CXIII. PLATE CXIII. Flora of the Potomac Formation. Page. Fig. 1. Onychiopsis psilotohjes (Stokes & Webb) Ward 518 KiGS. 2, 3. Thyksopteris rabinervis Font 518 Figs. 4, 5. Zamiopsis insignis Font - 525 Fig. 6. Brachyphyllum crassicaule Font. 529 Figs. 7, 8. Celastrophyllum acdtidens Font 529 Figs. 9. 10. Eucalyptus rosierianus Ward n. sp. 530 U. S. GEOLOGICAL SURVEY MONOGRAPH XLVIII PL. CXIII FOSSIL PLANTS FROM THE POTOMAC FORMATION OF MARYLAND AND DISTRICT OF COLUMBIA. PLATE CXIV. PLATE CXIV. Flora of the Potomac Formation. Page. Fig. 1. PODOZAMITES PEDICELLATUS Font 532 Fig. 2. Sapindopsis variabilis Font. 532 Figs. 3, 4. Cladophlebis acuta Font. 538 Fig. 5. Cladophlebis acuta angustifolia Font, n. var 539 Fig. 6. Dyroptekis angustipinnata (Font. ) Kn 540 Fig. 7. Drtopteris parvifolia (Font. ) Kn. 541 Figs. 8, 9. Thinnfeldia marylandica Font. n. sp. 541 Fig. 10. Abietites angusticarpus Font - 556 U. S. GEOLOGtCAL SURVEY MONOGRAPH XLVIII PL. CXIV FOSSIL PLANTS FROM THE POTOMAC FORMATION OF MARYLAND. PLATE CXV. PLATE CXV. Flora of the Potomac Formation. Page. Fig. 1. Sphenolepidium Sternbergianum densifoi.iu.m Font 546 Figs. 2, 3. Abietites m.4ceocarpus Font. 548 Figs. 4, 5. Abietites marylandicus Font. n. sp 549 Fig. 6. Celastkophtlldm obovatum Font 550 Figs. 7, S. Dbyopteris heterophylla (Font.) Kn 550 Figs. 9, 10. Selaginella mary'l.4ndica Font. n. sp 553 Fig. 10. Enlargement of Fig. 9, X 3. Fig. 11. Williamsonia ? Bibbinsi Ward n. sp 554 U. S. GEOLOGICAL SURVEY MONOGRAPH XLVIII PL. CXV FOSSIL PLANTS FROM THE POTOMAC FORMATION OF MARYLAND. PLATE CXVI PLATE CXVI. Flora of the Potomac Formation. Page. Fig. 1 . Leptostrobus longifolius Font. ? 551 Fig. 2. Nageiopsis eecurvata Font. ?_ 552 Figs. 3, 4. Pecopteris vikginiensis Font. 552 Fig. 5. Acrostichopteris parvifolia Font _ 55S Fig. 6. Celastrophyllum l-4.tifoliuii Font 559 Fig. 7. Celastrophyllum ? marylandicum Font. n. sp 559 U. S. GEOLOQIGAL SURVEY MONOGRAPH XLVMI PL. CXVI FOSSIL PLANTS FROM THE POTOMAC FORMATION OF MARYLAND. PLATE CXVII PLATE CXVII. Flora of the Potomac Formation. Page. Fig. 1. Adiantites parvifolius Font. n. sp 5.58 Figs. 2, 3. Celastrophyllum obovatcm Font 560 Figs. 4, 5. Nageiopsis angustifolia Font. 560 Fig. 6. N.ageiopsis heterophylla Font 561 Fig. 7. Plantaginopsis m arylandica Font. n. sp 563 U. S. GEOLOGICAL SURVEY MONOGRAPH XLVIII PL. CXVII FOSSIL PLANTS FROM THE POTOMAC FORMATION OF MARYLAND. PLATE CXVIII. PLATE CXVIII. Flora of the Potomac Formation. Fage. Figs. 1, 2. Plantaginopsis marylandica Font. ii. sp 562 Figs. 3, 4. Prote-ephyllum dentatum Font 563 Fig. 5. Prote^phyllum Uhleri Font. n. sp 564 U. S. QEOLOQICAL SURVEY Monograph xlviii pl. cxViiI FOSSIL PLANTS FROM THE POTOMAC FORMATION OF MARYLAND. PLATE CXIX. PLATE CXIX. Flora of the Potomac Formation. Page. Fig. 1. Thyrsoptems Meek i ana Font 565 Figs. 2-4. Vitiphyllum multifidum Font 565 Fig. 5. Vitiphyllum multifidum Font 553 Figs. 6, 7. Pinites Leei Font. n. sp 570 Fig. 8. Araucarites virginicus Font 572 u. s. eeoLOQicAL survey MONOGRAPH XLVIII PL. CXIX FOSSIL PLANTS FROM THE POTOMAC FORMATION OF MARYLAND.