﻿X68 
  THE 
  EXTINCT 
  BATRACHIA, 
  REPTILIA 
  

  

  ridge-like 
  and 
  other 
  elevations 
  between 
  them. 
  On 
  some 
  portions 
  of 
  the 
  surface 
  they 
  assume 
  a 
  longitudinal 
  direction. 
  

   A 
  portion 
  of 
  the 
  margin 
  is 
  rather 
  abrupt 
  and 
  thick. 
  Thickness 
  of 
  bone, 
  one 
  inch 
  from 
  margin 
  less 
  than 
  nearer 
  the 
  

   same; 
  greatest 
  thickness, 
  6 
  lines. 
  

  

  APPENDIX 
  TO 
  THE 
  TESTUDINATA. 
  

  

  Lembonax, 
  Cope. 
  

  

  Established 
  on 
  the 
  remains 
  of 
  a 
  marine 
  turtle 
  which 
  presents 
  the 
  peculiarity 
  of 
  a 
  regu- 
  

   lar 
  continuous 
  inner 
  margin 
  of 
  the 
  hyo- 
  and 
  hyposternal 
  bones, 
  without 
  radiating 
  processes 
  

   for 
  intercalation 
  with 
  that 
  of 
  the 
  opposite 
  side, 
  or 
  emargination 
  for 
  the 
  median 
  fontanelle. 
  

   It 
  follows 
  either 
  that 
  there 
  is 
  no 
  fontanelle, 
  or 
  that 
  the 
  fontanelle 
  is 
  continuous 
  to 
  the 
  

   xiphisternals, 
  in 
  either 
  case 
  differing 
  from 
  Chelone 
  and 
  Puppigerus. 
  The 
  hypo-xiphister- 
  

   nal 
  suture 
  is 
  transverse, 
  as 
  in 
  Emydidse, 
  for 
  a 
  portion 
  of 
  its 
  length 
  nearest 
  the 
  median 
  line 
  ; 
  

   or 
  this 
  element 
  having 
  transverse 
  parallel 
  sutural 
  outlines 
  may 
  be 
  intercalated 
  between 
  

   hyo- 
  and 
  hyposternals, 
  as 
  in 
  Pleurosternum, 
  though 
  this 
  I 
  consider 
  altogether 
  improbable. 
  

   The 
  suture 
  for 
  the 
  episternals 
  oblique, 
  and 
  not 
  squamosal, 
  as 
  in 
  Chelone 
  and 
  Chelydra, 
  

   but 
  by 
  shallow 
  gomphosis 
  ; 
  the 
  anterior 
  inner 
  margin 
  of 
  the 
  hyosternal 
  retreating 
  outwards 
  

   a 
  little, 
  and 
  leaving 
  space 
  apparently 
  for 
  mesosternum: 
  the 
  hyo-hyposternal 
  suture 
  by 
  

   fine 
  deep 
  gomphosis 
  ; 
  hyo-xiphisternal 
  by 
  shallow 
  coarse 
  gomphosis. 
  

  

  The 
  common 
  neck 
  of 
  the 
  scapulo-procoracoid 
  bone 
  is 
  short, 
  and 
  more 
  like 
  an 
  Emydoid 
  

   than 
  a 
  Chelonioid. 
  

  

  On 
  the 
  whole, 
  there 
  is 
  reason 
  to 
  suspect 
  that 
  this 
  form 
  is 
  more 
  nearly 
  related 
  to 
  Che- 
  

   lydra 
  than 
  to 
  Chelone. 
  

  

  Lembunax 
  polemicus, 
  Cope. 
  

  

  Spec. 
  nov. 
  

  

  The 
  sternum 
  presents 
  a 
  longitudinal 
  angle 
  on 
  each 
  side, 
  leaving 
  the 
  median 
  plane 
  portion 
  of 
  the 
  sternal 
  bones 
  

   rather 
  narrow, 
  as 
  in 
  species 
  of 
  Chelone. 
  The 
  angle 
  is 
  slight, 
  the 
  surface 
  rounded. 
  The 
  inner 
  face 
  of 
  the 
  hyosternal 
  

   is 
  strongly 
  radiate-ridged 
  towards 
  the 
  inner 
  anterior 
  angle, 
  and 
  the 
  inner 
  face 
  of 
  the 
  margin 
  serate; 
  the 
  posterior 
  por- 
  

   tions 
  of 
  the 
  margin.are 
  slightly 
  roughened. 
  The 
  inner 
  margin 
  of 
  the 
  hyposternal 
  is 
  regular, 
  smooth, 
  and 
  thinned 
  ob- 
  

   tusely; 
  it 
  is 
  without 
  radiating 
  ridges. 
  

  

  The 
  external 
  surface 
  is 
  smooth, 
  without 
  sculpture. 
  

  

  The 
  sternum 
  has 
  been 
  small 
  for 
  the 
  size 
  of 
  the 
  animal, 
  judging 
  by 
  indications 
  furnished 
  by 
  the 
  scapular 
  glenoid 
  

  

  cavitv- 
  No 
  portions 
  of 
  the 
  carapace 
  are 
  preserved. 
  

  

  M. 
  M. 
  

  

  Antero-posterior 
  length 
  hyosternal, 
  .24 
  

  

  Width 
  do. 
  to 
  longitudinal 
  angle, 
  .136 
  

  

  Antero-posterior 
  extent 
  hyposternal, 
  .1525 
  

  

  Width 
  do. 
  to 
  angle, 
  .155 
  

  

  Long 
  diameter 
  extremity 
  scapulo-procoracoid, 
  .115 
  

  

  Do. 
  neck 
  of 
  do., 
  -098 
  

  

  Do. 
  distal 
  extremity 
  scapula, 
  -059 
  

  

  This 
  species 
  was 
  derived 
  from 
  the 
  Eocene 
  marl 
  of 
  New 
  Jersey, 
  where 
  excavated 
  by 
  the 
  Farmingdale 
  and 
  Squankum 
  

   Marl 
  Company, 
  to 
  the 
  Director 
  of 
  wbich, 
  A. 
  J. 
  Smith, 
  I 
  am 
  indebted 
  for 
  the 
  specimens 
  on 
  which 
  the 
  present 
  identifi- 
  

   cation 
  are 
  based. 
  

  

  