﻿138 
  TIIE 
  EXTINCT 
  BATRACHIA, 
  REPTILIA 
  

  

  less 
  anteroposterior 
  extent 
  between 
  the 
  groin 
  and 
  transverse 
  suture 
  than 
  in 
  the 
  species 
  of 
  Chelone. 
  Its 
  trans- 
  

   verse 
  extent 
  at 
  the 
  same 
  region 
  is 
  greater, 
  implying 
  a 
  greater 
  closure 
  of 
  the 
  sternal 
  fontanelle. 
  It 
  presents 
  on 
  its 
  

   outer 
  posterior 
  margin 
  a 
  pit 
  for 
  articulation 
  with 
  the 
  xiphisternal 
  by 
  gomphosis. 
  The 
  hyosternal 
  of 
  the 
  right 
  side 
  

   is 
  much 
  heavier 
  than 
  the 
  last, 
  and 
  has 
  a 
  bevelled 
  outer 
  anterior 
  face, 
  where 
  it 
  rises 
  steeply 
  to 
  meet 
  the 
  marginal 
  bones 
  

   of 
  the 
  carapace. 
  Its 
  sutural 
  margin 
  is 
  broken 
  away. 
  The 
  xiphisternal 
  is 
  broken 
  at 
  both 
  ends; 
  it 
  is 
  flat 
  and 
  

   rather 
  thin. 
  A 
  large 
  part 
  of 
  its 
  inner 
  margin 
  is 
  fitted 
  for 
  articulation 
  with 
  the 
  long 
  hyposternal. 
  Its 
  thin 
  outer 
  

   margin 
  is 
  contracted 
  gently, 
  nearly 
  opposite 
  the 
  middle 
  of 
  the 
  posterior 
  fontanelle. 
  

  

  There 
  are 
  no 
  distinct 
  dermal 
  sutures 
  crossing 
  these. 
  The 
  nuchal 
  marginal 
  scute 
  is 
  confluent 
  with 
  the 
  first 
  

   vertebral. 
  

  

  Measurements. 
  Ft. 
  In. 
  Lin. 
  

  

  Length 
  of 
  second 
  marginal, 
  2 
  10.2 
  

  

  " 
  eleventh 
  " 
  2 
  11.1 
  

  

  caudal 
  " 
  3 
  3.7 
  

  

  Width 
  of 
  second 
  " 
  ll 
  1 
  . 
  

  

  " 
  eleventh 
  " 
  3 
  9.5 
  

  

  " 
  caudal 
  " 
  2 
  7.2 
  

  

  " 
  sixth, 
  infer, 
  face 
  (average), 
  1 
  9. 
  

  

  " 
  last 
  vertebral, 
  2 
  4. 
  

  

  " 
  an 
  anterior 
  do., 
  2 
  2. 
  

  

  " 
  episternal, 
  2 
  5.5 
  

  

  " 
  hyposternal 
  (longitudinal), 
  2 
  4. 
  

  

  Length 
  inner 
  suture 
  episternal, 
  2 
  8. 
  

  

  " 
  free 
  rib, 
  1 
  5. 
  

  

  "Width 
  costal 
  bone 
  distally, 
  2 
  11.5 
  

  

  Length 
  carapace 
  (estimated), 
  2 
  2 
  

  

  Width 
  " 
  " 
  2 
  

  

  OSTEOPYGIS 
  EMARGINATUS, 
  Cope 
  Sp. 
  Nov. 
  

  

  Of 
  this 
  species 
  a 
  considerable 
  portion 
  of 
  carapace 
  and 
  plastron 
  were 
  discovered 
  near 
  Barnesboro, 
  and 
  deposited 
  

   in 
  the 
  Museum 
  at 
  Rutger's 
  College 
  by 
  the 
  State 
  Geological 
  Survey 
  of 
  New 
  Jersey, 
  under 
  Prof. 
  Geo. 
  H. 
  Cook. 
  

  

  It 
  is 
  near 
  the 
  0. 
  platylomus, 
  but 
  differs 
  in 
  the 
  greater 
  width 
  of 
  all 
  the 
  marginal 
  bones 
  in 
  -relation 
  to 
  their 
  

   length, 
  in 
  the 
  greater 
  prolongation 
  of 
  the 
  inner 
  edge 
  of 
  the 
  lower 
  face 
  of 
  the 
  lateral 
  marginals, 
  and 
  in 
  the 
  cylindri- 
  

   cal 
  ribs 
  and 
  rib 
  pits 
  of 
  the 
  lateral 
  marginals. 
  In 
  the 
  0. 
  platvlomus 
  the 
  rib 
  pits 
  are 
  everywhere 
  alike, 
  entirely 
  flat 
  

   and 
  longitudinal. 
  

  

  A 
  vertebral 
  osseous 
  plate 
  is 
  strongly 
  emarginate 
  anteriorly, 
  as 
  in 
  the 
  last 
  species, 
  but 
  not 
  to 
  more 
  than 
  half 
  the 
  

   depth; 
  the 
  piece 
  is 
  more 
  elongate, 
  especially 
  the 
  antero-lateral 
  or 
  short 
  sides 
  which 
  enter 
  the 
  greatest 
  width 
  twice, 
  

   in 
  the 
  platylomus 
  2| 
  times. 
  In 
  this 
  specimen 
  it 
  is 
  not 
  crossed 
  by 
  a 
  dermal 
  suture; 
  in 
  the 
  other 
  it 
  is, 
  hence 
  the 
  

   plates 
  compared 
  are 
  not 
  the 
  same, 
  but 
  probably 
  are 
  only 
  adjacent. 
  A 
  costal 
  bone 
  exhibits 
  the 
  head 
  of 
  an 
  anterior 
  rib, 
  

   which 
  has 
  a 
  strong 
  spongy 
  crest 
  on 
  its 
  anterior 
  margin. 
  The 
  anterior 
  sutural 
  margin 
  converges 
  outwardly 
  towards 
  the 
  

   posterior 
  margin, 
  which 
  is 
  parallel 
  with 
  the 
  rib 
  axis. 
  On 
  the 
  upper 
  surface 
  the 
  sutures 
  of 
  the 
  plates 
  are 
  distinct; 
  

   the 
  anterior 
  vertebral 
  is 
  very 
  divergent, 
  making 
  an 
  angle 
  of 
  45° 
  with 
  the 
  median 
  line. 
  The 
  anterior 
  suture 
  of 
  the 
  

   posterior 
  plate 
  of 
  the 
  two 
  is 
  less 
  divergent. 
  Three 
  junctions 
  of 
  posterior 
  and 
  anterior 
  vertebral 
  scute 
  sutures 
  with 
  

   the 
  costals, 
  compared 
  with 
  two 
  similar 
  junctions 
  in 
  the 
  0. 
  emarginatus, 
  show 
  that 
  the 
  former 
  come 
  together 
  at 
  a 
  

   less 
  angle, 
  and 
  are 
  therefore 
  more 
  oblique. 
  The 
  anterior 
  marginal 
  scute 
  is, 
  as 
  in 
  Chelone, 
  present 
  and 
  not 
  conflu- 
  

   ent 
  with 
  the 
  first 
  vertebral 
  as 
  in 
  O. 
  platylomus. 
  Both 
  the 
  first 
  and 
  second 
  marginal 
  bones 
  are 
  entirely 
  united 
  with 
  

   the 
  carapace: 
  in 
  the 
  0. 
  platylomus 
  but 
  the 
  inner 
  half 
  of 
  the 
  second. 
  The 
  anterior 
  vertebral 
  bone 
  widens 
  within 
  

   the 
  margin 
  as 
  in 
  other 
  species, 
  but 
  it 
  is 
  the 
  first 
  costal 
  which 
  completes 
  the 
  consolidation 
  of 
  the 
  carapace 
  anteriorly. 
  

   Both 
  second 
  and 
  first 
  marginal 
  bones 
  are 
  slightly 
  concave 
  along 
  the 
  outer 
  face; 
  both 
  are 
  convex 
  or 
  plane 
  in 
  the 
  

   species 
  before 
  described. 
  

  

  