﻿140 
  THE 
  EXTINCT 
  BATRACHIA, 
  REPTILIA 
  

  

  The 
  accompanying 
  cut 
  is 
  a 
  restoration 
  of 
  the 
  typical 
  species 
  of 
  the 
  genus, 
  and 
  may 
  he 
  

   compared 
  with 
  those 
  of 
  the 
  genera 
  preceding 
  and 
  following. 
  Like 
  the 
  others, 
  it 
  is 
  derived 
  

   from 
  a 
  great 
  number 
  of 
  broken 
  fragments 
  which 
  have 
  been 
  arranged 
  and 
  attached. 
  On 
  

   one 
  side 
  the 
  dermal 
  sutures 
  have 
  been 
  omitted 
  for 
  clearness 
  sake. 
  

  

  The 
  structure 
  of 
  the 
  sternum 
  appears 
  to 
  be 
  identical 
  with 
  that 
  of 
  Osteopygis. 
  

  

  It 
  may 
  be 
  added 
  that 
  the 
  genus 
  Euclastes, 
  Cope, 
  was 
  established 
  on 
  the 
  cranium 
  of 
  a 
  

   turtle, 
  which 
  will 
  perhaps 
  be 
  found 
  to 
  enter 
  either 
  this 
  genus 
  or 
  Osteopygis, 
  in 
  either 
  of 
  

   which 
  cases 
  it 
  will 
  have 
  priority 
  of 
  publication. 
  

  

  TROPLEURA 
  SOPITA, 
  Leidy. 
  

  

  Chelone 
  snpita, 
  Leidy, 
  Cretac. 
  Rept. 
  N. 
  Amer. 
  Smiths, 
  contr. 
  xii., 
  104. 
  Osteopygis 
  s., 
  Cope, 
  Pr. 
  A. 
  N. 
  S., 
  Phila., 
  

   1868, 
  147. 
  

  

  This 
  species 
  is 
  indicated 
  by 
  two 
  marginal 
  hones, 
  part 
  of 
  a 
  costal, 
  half 
  a 
  femur, 
  a 
  tarsal 
  and 
  two 
  phalanges, 
  which 
  

   lay 
  in 
  close 
  proximity 
  in 
  a 
  block 
  of 
  the 
  Timber 
  creek 
  Limestone 
  taken 
  from 
  the 
  quarry 
  of 
  Barclay 
  Edwards, 
  near 
  

   Harrisonville, 
  Salem 
  county, 
  N. 
  J. 
  The 
  original 
  specimen, 
  several 
  marginal 
  bones 
  of 
  one 
  individual, 
  are 
  in 
  the 
  

   State 
  Collection 
  of 
  New 
  Jersey, 
  while 
  the 
  specimens 
  also 
  described 
  and 
  figured 
  by 
  Leidy 
  in 
  the 
  Cretaceous 
  Keptiles, 
  

   I 
  can 
  scarcely 
  refer 
  to 
  the 
  same 
  species. 
  

  

  The 
  principal 
  evidence, 
  however, 
  on 
  which 
  this 
  species 
  rests, 
  is 
  a 
  partially 
  complete 
  carapace 
  and 
  plastron, 
  with 
  

   some 
  limb 
  bones 
  from 
  the 
  marl 
  excavations 
  at 
  Birmingham, 
  N. 
  J. 
  ; 
  and 
  for 
  which 
  the 
  Academy 
  of 
  Natural 
  Sciences 
  is 
  

   indebted 
  to 
  Judson 
  Gaskill, 
  one 
  of 
  the 
  proprietors. 
  The 
  portions 
  preserved 
  are 
  the 
  first, 
  third, 
  fourth, 
  seventh 
  to 
  

   caudal 
  marginal 
  bones 
  of 
  one 
  or 
  both 
  sides; 
  the 
  front 
  vertebral, 
  with 
  numerous 
  costals 
  and 
  the 
  hyo- 
  hypo, 
  and 
  frag- 
  

   ments 
  of 
  epi- 
  and 
  xiphisternal 
  elements. 
  

  

  The 
  specimen 
  is 
  of 
  about 
  the 
  same 
  size 
  as 
  that 
  on 
  which 
  Osteopygis 
  emarginatus, 
  ficm 
  the 
  same 
  place 
  is 
  chicliy 
  

   based, 
  and 
  the 
  anterior 
  marginal 
  bones 
  are 
  similar 
  in 
  proportions 
  to 
  those 
  of 
  the 
  latter, 
  and 
  not 
  so 
  broad 
  in 
  relation 
  

   to 
  their 
  length 
  as 
  in 
  0. 
  platylomus. 
  In 
  some 
  other 
  respects 
  it 
  approaches 
  nearer 
  the 
  otter, 
  which 
  seems 
  to 
  stand 
  

   rather 
  between 
  it 
  and 
  the 
  0. 
  emarginatus. 
  

  

  The 
  front 
  marginals 
  are 
  of 
  about 
  the 
  same 
  length 
  as 
  those 
  of 
  the 
  O. 
  platylomus, 
  but 
  are 
  very 
  much 
  thinner 
  and 
  

   lighter. 
  The 
  external 
  margin 
  of 
  the 
  first 
  is 
  convex 
  and 
  continuous, 
  with 
  a 
  marked 
  CDncavity 
  of 
  the 
  nuchal 
  bone, 
  

   which 
  is 
  slighter 
  in 
  0. 
  platylomus, 
  and 
  is 
  wanting 
  in 
  0. 
  emarginatus. 
  The 
  posterior 
  part 
  of 
  the 
  first 
  is 
  of 
  increased 
  

   thickness, 
  while 
  the 
  second 
  is 
  still 
  more 
  rapidly 
  heavier. 
  They 
  have 
  no 
  groove 
  on 
  the 
  inner 
  inferior 
  edge, 
  but 
  a 
  wide, 
  

   shallow 
  one 
  externally. 
  This 
  is 
  weak 
  on 
  the 
  third 
  ; 
  the 
  external 
  face 
  of 
  the 
  fourth 
  exhibits 
  a 
  slight 
  continuation 
  of 
  

   it 
  ; 
  the 
  same 
  face 
  of 
  the 
  fifth 
  is 
  regularly 
  concave. 
  The 
  superior 
  face 
  of 
  the 
  seventh 
  is 
  gently 
  concave, 
  and 
  the 
  inferior 
  

   more 
  strongly 
  convex. 
  The 
  edge 
  of 
  the 
  eighth 
  is 
  slightly 
  everted, 
  while 
  the 
  more 
  posterior 
  are 
  flat. 
  The 
  rib-pits 
  are 
  

   % 
  round 
  conic, 
  those 
  from 
  the 
  ninth 
  posteriorly 
  not 
  completed 
  above, 
  from 
  the 
  thinness 
  of 
  the 
  bones. 
  The 
  edges 
  of 
  the 
  

   posterior 
  bones 
  are 
  not 
  prolonged 
  within 
  that 
  dermal 
  sutural 
  groove. 
  The 
  intermarginal 
  dermal 
  grooves 
  are 
  more 
  

   indistinct 
  in 
  this 
  species 
  than 
  in 
  others, 
  or 
  at 
  least 
  are 
  so 
  in 
  the 
  three 
  specimens 
  I 
  have 
  seen. 
  The 
  costo-marginal 
  

   suture 
  is 
  not 
  visible 
  either 
  on 
  the 
  fourth 
  or 
  any 
  more 
  anterior 
  marginal 
  bone. 
  

  

  Length 
  of 
  edge 
  of 
  nuchal 
  marginal, 
  

  

  Length 
  of 
  first 
  marginal. 
  

  

  Width 
  of 
  " 
  

  

  Width 
  of 
  fourth 
  " 
  above 
  (greatest) 
  

  

  Width 
  of 
  " 
  " 
  below 
  (median) 
  

  

  Length 
  of 
  " 
  " 
  

  

  III 
  

  

  Lin 
  

  

  4 
  

  

  (i 
  

  

  2 
  

  

  9.6 
  

  

  1 
  

  

  9.6 
  

  

  2 
  

  

  

  1 
  

  

  2.5 
  

  

  ■2 
  

  

  11.2 
  

  

  