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  THE 
  EXTINCT 
  BATRACHIA, 
  REPTILIA 
  

  

  The 
  following 
  section 
  of 
  the 
  exposure 
  at 
  Pea 
  Shore, 
  will 
  give 
  the 
  best 
  idea 
  of 
  its 
  

   character. 
  

  

  Fig. 
  55. 
  

  

  5' 
  5' 
  3 
  

  

  Of 
  

  

  p 
  © 
  

  

  00 
  

   <rt- 
  O 
  

  

  CO 
  

  

  o 
  

  

  

  CD 
  

  

  to 
  

  

  Or 
  

  

  

  ^ 
  The 
  regularity 
  of 
  the 
  beds 
  as 
  exposed 
  for 
  some 
  

   distance 
  along 
  the 
  line 
  of 
  the 
  Camden 
  and 
  Amboy 
  

   P. 
  E,, 
  and 
  their 
  S. 
  E. 
  dip, 
  apparently 
  similar 
  to 
  

   that 
  of 
  the 
  Cretaceous 
  beds 
  above 
  them, 
  has 
  seemed 
  

   to 
  confirm 
  the 
  supposition 
  of 
  authors 
  as 
  to 
  their 
  

   horizon. 
  I 
  believe, 
  however, 
  that 
  they 
  really 
  be- 
  

   long 
  to 
  a 
  much 
  later 
  age 
  than 
  the 
  bed 
  No. 
  1, 
  and 
  

   are 
  really 
  of 
  a 
  Pliocene 
  period, 
  and 
  older 
  than 
  the 
  

   stratified 
  drift. 
  Two 
  reasons 
  have 
  a 
  strong 
  bearing 
  

   on 
  the 
  question. 
  A 
  large 
  part 
  of 
  the 
  cranium 
  of 
  

   a 
  horse 
  — 
  Equus 
  fraternus 
  of 
  Leidy 
  — 
  was 
  found 
  by 
  

   the 
  workmen 
  just 
  above 
  the 
  Unio 
  bed, 
  and 
  twenty 
  

   feet 
  below 
  the 
  top 
  of 
  the 
  clay, 
  evidently 
  in 
  place. 
  

   The 
  underlying 
  bed 
  of 
  coarse 
  red 
  sand, 
  is 
  in 
  all 
  

   apparent 
  respects 
  identical 
  with 
  the 
  material 
  of 
  a 
  

   stratum 
  which 
  underlies 
  the 
  soil 
  over 
  the 
  country 
  

   5 
  and 
  6 
  miles 
  to 
  the 
  eastward 
  of 
  Pea 
  Shore, 
  e. 
  g., 
  

   the 
  town 
  of 
  Haddonfield, 
  which 
  rests 
  unconform- 
  

   ably 
  on 
  the 
  Ripley 
  division 
  of 
  the 
  Cretaceous. 
  

   It 
  does 
  not 
  exist 
  on 
  the 
  surface, 
  so 
  far 
  as 
  I 
  could 
  

   ascertain 
  from 
  an 
  examination 
  on 
  one 
  line, 
  between 
  

   these 
  points. 
  It 
  may 
  be 
  the 
  same 
  bed. 
  

  

  That 
  this 
  bed 
  is 
  synchronous 
  with 
  our 
  Post- 
  

   pliocene, 
  is 
  doubtful, 
  from 
  the 
  marked 
  difference 
  

   presented 
  by 
  the 
  Unios, 
  when 
  compared 
  with 
  

   those 
  now 
  existing. 
  The 
  Helices 
  of 
  the 
  Post- 
  

   pliocene 
  are 
  identical 
  with 
  the 
  living 
  species, 
  viz 
  : 
  

   H. 
  major, 
  H. 
  tridentata, 
  H. 
  dentifera, 
  etc., 
  are 
  

   associated 
  with 
  Tapirus, 
  Dicotyles, 
  Equus, 
  etc., 
  

   in 
  cave 
  deposits. 
  The 
  Unionida?, 
  Lea 
  remarks, 
  

   have 
  the 
  heavy 
  teeth 
  of 
  one 
  type 
  of 
  the 
  genus, 
  

   H 
  with 
  the 
  light 
  thin 
  shells 
  of 
  another 
  type, 
  and 
  are 
  

   all 
  distinct 
  from 
  the 
  living. 
  An 
  older 
  age 
  than 
  

   Postpliocene 
  is, 
  therefore, 
  indicated. 
  

  

  