﻿292 
  KEPORT 
  UNITED 
  STATES 
  GEOLOGICAL 
  SUSVEY. 
  ^ 
  

  

  ular 
  manner 
  we 
  have 
  collected 
  specimeus 
  from 
  Washiugtoa 
  County 
  to 
  

   Fort 
  Lamed, 
  a 
  distance 
  of 
  150 
  miles. 
  The 
  fossil 
  plants 
  are 
  usually 
  ob- 
  

   tained 
  from 
  thin 
  layers, 
  or 
  strata, 
  extending 
  in 
  a 
  horizontal 
  position 
  

   along 
  a 
  ravine 
  or 
  around 
  a 
  hill. 
  They 
  may 
  occur 
  at 
  several 
  places 
  in 
  

   tlie 
  same 
  vicinity, 
  but 
  usually 
  without 
  any 
  connection. 
  They 
  are 
  found 
  

   at 
  all 
  depths 
  in 
  the 
  Dakota, 
  from 
  within 
  35 
  feet 
  of 
  the 
  Permian 
  to 
  

   within 
  40 
  feet 
  of 
  the 
  Fort 
  Hays 
  limestone. 
  The 
  numerons 
  indications 
  

   show 
  that 
  the 
  trees 
  must 
  have 
  grown, 
  on 
  islands 
  near 
  the 
  shore-line, 
  and 
  

   that 
  the 
  leaves 
  were 
  imbedded 
  in 
  the 
  marine 
  sediment 
  immediately 
  

   after 
  dropping. 
  Worm-borings 
  are 
  also 
  found 
  in 
  the 
  same 
  strata 
  with 
  

   the 
  leaves. 
  The 
  contrast 
  between 
  this 
  fossil 
  flora 
  and 
  the 
  plants 
  of 
  the 
  

   older 
  formations 
  is 
  very 
  strong, 
  while 
  its 
  resemblance 
  to 
  those 
  now 
  liv- 
  

   ing 
  is 
  equally 
  remarkable. 
  The 
  interest 
  attached 
  to 
  this 
  numerous 
  vari- 
  

   ety 
  of 
  modern 
  plants 
  is 
  enhanced 
  by 
  the 
  fact 
  that 
  in 
  the 
  earlier 
  forma- 
  

   tions 
  no 
  Dicotyledons 
  are 
  found, 
  the 
  Conifers 
  which 
  come 
  down 
  from 
  the 
  

   Devonian 
  age 
  being 
  the 
  highest 
  type. 
  But 
  in 
  our 
  Dakota 
  and 
  the 
  

   corresponding 
  age 
  in 
  Em^ope, 
  we 
  have 
  a 
  sudden 
  influx 
  of 
  new 
  types 
  

   covering 
  nearly 
  all 
  the 
  forms 
  now 
  living. 
  These 
  are 
  "the 
  first 
  known 
  

   of 
  the 
  great 
  modern 
  group 
  of 
  Angiosperms," 
  " 
  and 
  the 
  ordinary 
  fruit- 
  

   trees 
  of 
  the 
  temperate 
  zones," 
  " 
  distributable 
  not 
  in 
  a 
  single 
  one, 
  but 
  in 
  

   all 
  of 
  the 
  essential 
  groups 
  of 
  vegetable's 
  living 
  at 
  our 
  time."* 
  This 
  sud- 
  

   den 
  appearance 
  of 
  the 
  full 
  type 
  of 
  modern 
  vegetation 
  will 
  be 
  more 
  appar- 
  

   ent 
  on 
  examination 
  in 
  detail. 
  Professor 
  Lesquereux, 
  in 
  his 
  Cretaceous 
  

   Flora, 
  describes 
  one 
  hundred 
  and 
  thirty-two 
  species, 
  distributed 
  among 
  

   seventy-two 
  genera 
  and 
  twenty-three 
  orders, 
  of 
  which 
  one 
  hundred 
  and 
  

   seven 
  species 
  of 
  nineteen 
  orders 
  and 
  fifty-two 
  genera 
  are 
  dicotyledo- 
  

   nous 
  plants. 
  Of 
  these, 
  more 
  than 
  one-half 
  have 
  been 
  collected 
  in 
  Kan- 
  

   sas, 
  and 
  about 
  twenty 
  of 
  the 
  new 
  species 
  were 
  described 
  by 
  Professor 
  

   Lesquereux 
  from 
  specimens 
  discovered 
  by 
  the 
  writer. 
  To 
  these 
  are 
  to 
  

   be 
  added 
  twenty-six 
  new 
  species 
  described 
  by 
  the 
  same 
  author 
  in 
  a 
  re- 
  

   cent 
  bulletin 
  (VII 
  of 
  jS'o. 
  5, 
  second 
  series) 
  of 
  Hayden's 
  reports. 
  Addi- 
  

   tions 
  to 
  these 
  are 
  constantly 
  being 
  made. 
  There 
  are 
  nine 
  species 
  of 
  

   Conifers, 
  five 
  of 
  poplar, 
  six 
  of 
  willow, 
  eight 
  of 
  oak, 
  six 
  of 
  platanus 
  or 
  

   buttonwood, 
  seven 
  of 
  sassafras, 
  fiveof 
  magnolia, 
  two 
  of 
  fig, 
  one 
  of 
  palm, 
  

   and 
  two 
  of 
  cinnamon. 
  The 
  last 
  four 
  were 
  probably 
  hardy 
  species 
  of 
  

   their 
  kinds. 
  Still 
  they 
  indicate 
  a 
  warmer 
  climate 
  than 
  now 
  exists. 
  

   When 
  we 
  recollect 
  that 
  at 
  the 
  period 
  of 
  their 
  growth, 
  this 
  part 
  of 
  the 
  

   country 
  was 
  nearly 
  on 
  a 
  level 
  with 
  the 
  ocean, 
  and 
  the 
  dry 
  land 
  was 
  

   composed 
  principally 
  of 
  a 
  lew 
  islands, 
  the 
  variance 
  of 
  the 
  climate 
  is 
  

   easily 
  explained. 
  

  

  Taking 
  Professor 
  Lesquereux's 
  list 
  of 
  Dicotyledons 
  we 
  find 
  56 
  per 
  cent, 
  

   of 
  his 
  genera 
  are 
  identical 
  with 
  those 
  now 
  living 
  east 
  of 
  the 
  Rocky 
  

   Mountains, 
  in 
  the 
  temperate 
  zone 
  of 
  the 
  United 
  States. 
  To 
  this 
  must 
  be 
  

   added 
  24 
  per 
  cent, 
  which 
  are 
  apparently 
  identical, 
  represented 
  by 
  Fop- 
  

   iilifes^ 
  BetuJites, 
  Acerites, 
  JS'eguncMdes, 
  Lauro2)hiUu7n, 
  &c. 
  Of 
  the 
  remain- 
  

   ing 
  20 
  per 
  cent, 
  some, 
  like 
  the 
  fig 
  and 
  cinnamon, 
  are 
  now 
  living 
  in 
  the 
  

   tropics, 
  while 
  a 
  few 
  are 
  probably 
  extinct 
  genera. 
  

  

  This 
  feature 
  of 
  resemblance 
  to 
  living 
  vegetation 
  is 
  increased 
  by 
  the 
  

   examination 
  of 
  specific 
  forms. 
  At 
  first 
  Lesquereux 
  was 
  disposed'^(like 
  

   all 
  paleontologists 
  who 
  find 
  familiar 
  forms 
  in 
  an 
  unexpected 
  geological 
  

   age) 
  to 
  say 
  that 
  all 
  the 
  species 
  were 
  extinct, 
  but 
  in 
  his 
  later 
  writings, 
  

   after 
  exchauging 
  opinions 
  with 
  the 
  best 
  floral 
  paleontologists 
  of 
  Europe, 
  

   he 
  has 
  been 
  led 
  to 
  chauge 
  his 
  opinion 
  on, 
  at 
  least, 
  one 
  species. 
  In 
  nam- 
  

   ing 
  a 
  new 
  sassafras 
  he 
  honored 
  me 
  by 
  calling 
  it 
  *S'. 
  mudgei. 
  By 
  a 
  com- 
  

  

  * 
  Lesquereux. 
  

  

  