﻿160 
  

  

  THE 
  EXTINCT 
  BATRACHIA, 
  REPTILIA 
  

  

  probably 
  in 
  contact 
  with 
  marginal 
  bone 
  till 
  maturity. 
  These 
  costal 
  bones 
  are 
  gently 
  curved, 
  and 
  with 
  longitudinal 
  

   shallow 
  grooves 
  of 
  sculpture. 
  

  

  Fig-. 
  43. 
  

  

  The 
  individual 
  of 
  which 
  the 
  greatest 
  num- 
  

   ber 
  of 
  fragments 
  is 
  preserved, 
  is 
  from 
  near 
  

   Barnesboro, 
  shows 
  that 
  the 
  reticulate 
  sculp- 
  

   ture 
  of 
  the 
  marginal 
  bones 
  at 
  the 
  bridge 
  is 
  

   distinct 
  above, 
  obsolete 
  below. 
  There 
  are 
  

   three 
  and 
  parts 
  of 
  two 
  others 
  in 
  the 
  bridge 
  

   in 
  Platemys 
  and 
  Emydoids; 
  three 
  of 
  those 
  

   of 
  P. 
  sulcatus 
  Leidy 
  are 
  known; 
  two 
  of 
  

   those 
  of 
  the 
  present 
  species 
  are 
  preserved. 
  

   Both 
  have 
  been 
  wholly 
  attached 
  to 
  the 
  plas- 
  

   tron 
  ; 
  one 
  has 
  an 
  acute, 
  but 
  not 
  thin 
  or 
  

   recurved 
  outer 
  margin; 
  the 
  other 
  is 
  strongly 
  

   obtuse. 
  All 
  three 
  of 
  those 
  of 
  T. 
  sulcatus 
  

   are, 
  according 
  to 
  Leidy, 
  thin 
  and 
  recurved. 
  

  

  Length 
  of 
  obtuse 
  marginal. 
  

   Width 
  of 
  inferior 
  face 
  

  

  In. 
  Lin. 
  

   2 
  fi 
  

   1 
  fl 
  

  

  The 
  edges 
  of 
  the 
  anterior 
  marginals 
  are 
  

   thin 
  and 
  acute, 
  not, 
  revolute 
  nor 
  notched. 
  

  

  In. 
  I 
  in. 
  

   Width 
  margin 
  of 
  median 
  vertebro- 
  

  

  marginal 
  bone, 
  1 
  8. 
  

  

  Width 
  marginal 
  scutum, 
  next 
  it, 
  2 
  (?. 
  

  

  Length 
  " 
  " 
  2 
  4.5 
  

  

  The 
  free 
  lateral 
  margin 
  of 
  the 
  hyposter- 
  

   nal 
  is 
  obtuse, 
  not 
  thickened 
  or 
  grooved, 
  

   thinning 
  a 
  little 
  near 
  the 
  suture 
  with 
  the 
  

   xiphisternal. 
  

  

  The 
  sternum 
  in 
  general 
  is 
  not 
  thick 
  in 
  

   this 
  specimen; 
  in 
  the 
  thickest 
  portion 
  of 
  the 
  

   hypo-hyosternal 
  suture 
  5 
  lines; 
  in 
  a 
  frag- 
  

   ment 
  of 
  another 
  no 
  doubt 
  larger 
  specimen, 
  7.5 
  lines. 
  The 
  mesosternum, 
  with 
  the 
  dermal 
  sutures 
  is 
  fortunately 
  pre- 
  

   served; 
  the 
  former 
  is 
  transverse 
  diamond 
  shape. 
  The 
  character 
  of 
  the 
  plastron, 
  except 
  the 
  hyosternal 
  region, 
  may 
  

   be 
  learned 
  from 
  the 
  accompanying 
  cuts 
  of 
  restorations. 
  A 
  cut 
  of 
  the 
  axillary 
  pit 
  and 
  its 
  position 
  is 
  also 
  given. 
  

  

  In 
  a 
  fine 
  specimen 
  from 
  Hornerstown, 
  for 
  which 
  I 
  am 
  indebted 
  to 
  Jno. 
  G. 
  Meirs,the 
  lateral 
  intersternal 
  bones 
  are 
  

   easily 
  seen. 
  They 
  present 
  a 
  rounded 
  interior 
  outline, 
  and 
  apply 
  to 
  an 
  equal 
  extent 
  of 
  the 
  hyo- 
  and 
  hyposternal 
  bones. 
  

   They 
  extend 
  but 
  one 
  third 
  the 
  distance 
  to 
  the 
  median 
  longitudinal 
  suture, 
  and 
  are 
  much 
  as 
  in 
  the 
  Podocnemis 
  of 
  the 
  

   Amazon. 
  Posterior 
  lobe 
  of 
  plastron 
  10.5 
  in. 
  wide, 
  between 
  inguinal 
  notches. 
  

  

  One 
  of 
  the 
  costal 
  hones 
  from 
  Tinton 
  Falls 
  exhibits 
  the 
  pit 
  for 
  the 
  inguinal 
  buttress. 
  It 
  differs 
  from 
  that 
  of 
  the 
  

   pubis 
  of 
  tlit- 
  other 
  specimens, 
  and 
  of 
  P. 
  princeps 
  and 
  P. 
  enodis 
  in 
  not 
  being 
  situated 
  on 
  an 
  elevated 
  ridge 
  or 
  pedestal. 
  

  

  