﻿0. 
  C. 
  Marsh 
  — 
  The 
  Stylinodontia. 
  145 
  

  

  " 
  The 
  Edentate 
  Mammals 
  are 
  evidently 
  an 
  American 
  type, 
  

   and 
  on 
  this 
  continent 
  attained 
  a 
  great 
  development 
  in 
  numbers 
  

   and 
  size. 
  No 
  Eocene 
  Edentates 
  have 
  been 
  found 
  here, 
  and, 
  

   although 
  their 
  discovery 
  in 
  this 
  formation 
  has 
  been 
  announced, 
  

   the 
  identification 
  proves 
  to 
  have 
  been 
  erroneous. 
  In 
  the 
  

   Miocene 
  of 
  the 
  Pacific 
  coast, 
  a 
  few 
  fossils 
  have 
  been 
  discov- 
  

   ered 
  which 
  belong 
  to 
  animals 
  of 
  this 
  group, 
  and 
  to 
  the 
  genus 
  

   Moropus. 
  There 
  are 
  two 
  species, 
  one 
  about 
  as 
  large 
  as 
  a 
  

   tapir, 
  and 
  the 
  other 
  nearly 
  twice 
  that 
  size. 
  This 
  genus 
  is 
  the 
  

   type 
  of 
  a 
  distinct 
  family, 
  the 
  Moropodidm. 
  In 
  the 
  lower 
  

   Pliocene 
  above, 
  well-preserved 
  remains 
  of 
  Edentates 
  of 
  very 
  

   large 
  size 
  have 
  been 
  found 
  at 
  several 
  widely-separated 
  local- 
  

   ities 
  in 
  Idaho 
  and 
  California. 
  These 
  belong 
  to 
  the 
  genus 
  

   Morotheriwm, 
  of 
  which 
  two 
  species 
  are 
  known. 
  East 
  of 
  the 
  

   Pocky 
  Mountains, 
  in 
  the 
  lower 
  Pliocene 
  of 
  Nebraska, 
  a 
  large 
  

   species 
  apparently 
  of 
  the 
  genus 
  Moropus 
  has 
  been 
  discovered. 
  

   The 
  horizon 
  of 
  these 
  later 
  fossils 
  corresponds 
  nearly 
  with 
  beds 
  

   in 
  Europe 
  that 
  have 
  been 
  called 
  Miocene. 
  In 
  the 
  Post-Plio- 
  

   cene 
  of 
  North 
  America, 
  gigantic 
  Edentates 
  were 
  very 
  numerous 
  

   and 
  widely 
  distributed, 
  but 
  all 
  disappeared 
  with 
  the 
  close 
  of 
  

   that 
  period. 
  These 
  forms 
  were 
  essentially 
  huge 
  sloths, 
  and 
  

   the 
  more 
  important 
  were 
  Megatherium, 
  Mylodon, 
  and 
  Megal- 
  

   onyx." 
  * 
  ■* 
  * 
  

  

  "It 
  is 
  frequently 
  asserted, 
  and 
  very 
  generally 
  believed, 
  that 
  

   the 
  large 
  number 
  of 
  huge 
  Edentata 
  which 
  lived 
  in 
  North 
  

   America 
  during 
  the 
  Post-Pliocene 
  were 
  the 
  results 
  of 
  an 
  

   extensive 
  migration 
  from 
  South 
  America 
  soon 
  after 
  the 
  eleva- 
  

   tion 
  of 
  the 
  Isthmus 
  of 
  Panama, 
  near 
  the 
  close 
  of 
  the 
  Tertiary. 
  

   No 
  conclusive 
  proof 
  of 
  such 
  migration 
  has 
  been 
  offered, 
  and 
  

   the 
  evidence, 
  it 
  seems 
  to 
  me, 
  so 
  far 
  as 
  we 
  now 
  have 
  it, 
  is 
  

   directly 
  opposed 
  to 
  this 
  view. 
  No 
  undoubted 
  Tertiary 
  Eden- 
  

   tates 
  have 
  yet 
  been 
  discovered 
  in 
  South 
  America, 
  while 
  we 
  

   have 
  at 
  least 
  two 
  species 
  in 
  our 
  Miocene, 
  and, 
  during 
  the 
  depo- 
  

   sition 
  of 
  our 
  lower 
  Pliocene, 
  large 
  individuals 
  of 
  this 
  group 
  

   were 
  not 
  uncommon 
  as 
  far 
  north 
  as 
  the 
  forty-third 
  parallel 
  of 
  

   latitude, 
  on 
  both 
  sides 
  of 
  the 
  Pocky 
  Mountains. 
  In 
  view 
  of 
  

   these 
  facts, 
  and 
  others 
  which 
  I 
  shall 
  lay 
  before 
  you, 
  it 
  seems 
  

   more 
  natural 
  to 
  conclude, 
  from 
  our 
  present 
  knowledge, 
  that 
  the 
  

   migration, 
  which 
  no 
  doubt 
  took 
  place, 
  was 
  from 
  north 
  to 
  

   south. 
  The 
  Edentates, 
  finding 
  thus 
  in 
  South 
  America 
  a 
  con- 
  

   genial 
  home, 
  flourished 
  greatly 
  for 
  a 
  time, 
  and, 
  although 
  the 
  

   larger 
  forms 
  are 
  now 
  all 
  extinct, 
  diminutive 
  representatives 
  of 
  

   the 
  group 
  still 
  inhabit 
  the 
  same 
  region." 
  * 
  * 
  * 
  

  

  " 
  The 
  Edentates, 
  in 
  their 
  southern 
  migration, 
  were 
  probably 
  

   accompanied 
  by 
  the 
  horse, 
  tapir, 
  and 
  rhinoceros, 
  although 
  no 
  

   remains 
  of 
  the 
  last 
  have 
  yet 
  been 
  found 
  south 
  of 
  Mexico. 
  

  

  