﻿372 
  Hay 
  — 
  Ages 
  of 
  Pleistocene 
  Deposits. 
  

  

  likewise 
  to 
  have 
  been 
  laid 
  down 
  rather 
  late 
  in 
  the 
  Pleisto- 
  

   cene 
  and 
  in 
  the 
  sea 
  ; 
  but 
  here, 
  as 
  along 
  the 
  Atlantic 
  coast, 
  

   there 
  is 
  a 
  lack 
  of 
  marine 
  fossils 
  and 
  an 
  abundance 
  of 
  land 
  

   animals. 
  All 
  along 
  that 
  coast, 
  down 
  to 
  salt-water 
  or 
  

   close 
  to 
  it, 
  are 
  found 
  remains 
  of 
  mastodons, 
  Elephas 
  

   columbi, 
  E. 
  imperator, 
  Equus 
  complicatus, 
  and 
  a 
  camel. 
  

   To 
  say 
  that 
  these 
  animals 
  lived 
  here 
  at 
  a 
  later 
  period 
  than 
  

   they 
  did 
  in 
  Kansas 
  and 
  Nebraska 
  is 
  pure 
  assumption. 
  

   Unless 
  the 
  further 
  assumption 
  is 
  indulged 
  in 
  that 
  these 
  

   and 
  numerous 
  other 
  species 
  and 
  genera 
  perished 
  in 
  Texas 
  

   during 
  the 
  prevalence 
  of 
  the 
  Wisconsin 
  glacial 
  conditions, 
  

   there 
  appears 
  to 
  be 
  no 
  reason 
  why 
  they 
  should 
  not 
  have 
  

   migrated 
  northward 
  as 
  these 
  glacial 
  conditions 
  relaxed; 
  

   especially 
  since 
  it 
  is 
  hardly 
  to 
  be 
  conceived 
  that 
  all 
  these 
  

   animals 
  were 
  confined 
  to 
  a 
  narrow 
  strip 
  immediately 
  

   along 
  the 
  Gulf. 
  

  

  As 
  will 
  be 
  noted, 
  the 
  writer 
  assigns 
  the 
  Sunderland 
  and 
  

   Wicomico 
  and 
  their 
  equivalents 
  to 
  the 
  early 
  part 
  of 
  the 
  

   Pleistocene, 
  but 
  not 
  to 
  the 
  earliest. 
  What 
  was 
  going 
  on 
  

   in 
  our 
  country 
  during 
  the 
  probably 
  long 
  first 
  glacial 
  

   epoch 
  is 
  not 
  known. 
  At 
  some 
  time, 
  either 
  in 
  the 
  late 
  

   Pliocene 
  or 
  early 
  Pleistocene, 
  the 
  whole 
  continent 
  appears 
  

   to 
  have 
  had 
  a 
  much 
  greater 
  elevation 
  than 
  it 
  has 
  at 
  pres- 
  

   ent. 
  During 
  that 
  time 
  the 
  courses 
  of 
  the 
  great 
  streams 
  

   appear 
  to 
  have 
  been 
  excavated 
  to 
  enormous 
  depths 
  and 
  

   sometimes 
  to 
  great 
  widths, 
  so 
  that 
  our 
  country 
  became 
  

   furrowed 
  by 
  vast 
  canyons. 
  It 
  is 
  well 
  known 
  that 
  many 
  

   of 
  our 
  great 
  rivers 
  are 
  flowing 
  at 
  levels 
  far 
  above 
  former 
  

   channels. 
  It 
  appears 
  possible 
  that 
  at 
  some 
  later 
  period 
  

   of 
  diminishing 
  altitude, 
  during 
  perhaps 
  the 
  first 
  inter- 
  

   glacial 
  stage, 
  these 
  old 
  channels 
  and 
  canyons 
  became 
  

   filled 
  up 
  completely, 
  or 
  nearly 
  so. 
  While 
  they 
  were 
  being 
  

   filled, 
  the 
  bones 
  and 
  the 
  teeth 
  of 
  animals 
  of 
  the 
  time 
  might 
  

   have 
  been 
  buried 
  in 
  the 
  deposits. 
  Still 
  later, 
  these 
  old 
  

   deposits, 
  soils, 
  sands, 
  gravel 
  and 
  stones, 
  might 
  have 
  been 
  

   partially 
  removed 
  by 
  quickened 
  currents, 
  but 
  partly 
  

   retained 
  as 
  terraces. 
  It 
  seems 
  possible 
  to 
  account 
  thus 
  

   for 
  the 
  presence 
  of 
  the 
  same 
  kinds 
  of 
  extinct 
  animals 
  in 
  

   the 
  upper 
  and 
  the 
  lower 
  terraces 
  and 
  in 
  the 
  present 
  banks 
  

   of 
  some 
  Texas 
  rivers. 
  In 
  the 
  upper 
  and 
  the 
  lower 
  ter- 
  

   races 
  are 
  found 
  well-preserved 
  remains 
  of 
  camels. 
  In 
  

   apparently 
  the 
  higher 
  lands 
  at 
  Fort 
  Worth 
  and 
  at 
  Waco 
  

   have 
  been 
  collected 
  fine 
  teeth 
  of 
  mastodons 
  of 
  the 
  genus 
  

   Gomphotherium., 
  not 
  long 
  ago 
  supposed 
  to 
  have 
  lived 
  only 
  

  

  