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  THE 
  EXTINCT 
  BATRACHIA, 
  REPTILIA 
  

  

  This 
  genus 
  was 
  established 
  on 
  a 
  species, 
  represented 
  by 
  a 
  single 
  imperfect 
  cranium, 
  

   procured 
  by 
  Thomas 
  Heritage 
  from 
  his 
  marl 
  excavations, 
  near 
  Hurfftown, 
  in 
  Camden 
  

   Co., 
  N. 
  J. 
  The 
  matrix 
  in 
  which 
  it 
  is 
  preserved 
  is 
  very 
  similar 
  to 
  that 
  near 
  Vincentown, 
  

   in 
  which 
  the 
  cranium 
  of 
  the 
  Thoracosaurus 
  neocaesariensis 
  was 
  discovered, 
  being 
  a 
  coarse, 
  

   granular 
  limestone. 
  

  

  The 
  physiognomy 
  of 
  this 
  large 
  turtle 
  in 
  the 
  obliquely 
  expanded 
  zygomata 
  and 
  short 
  

   muzzle 
  is 
  like 
  the 
  Pleurodire 
  genera 
  Podocnemis 
  Wagl. 
  among 
  recent 
  Chelonia, 
  and 
  Bo- 
  

   thremys 
  Leidy, 
  of 
  the 
  same 
  age, 
  among 
  extinct 
  forms. 
  Its 
  completely 
  over-arching 
  tem- 
  

   poral 
  fossae 
  add 
  to 
  the 
  impression 
  of 
  its 
  affinity 
  to 
  the 
  former 
  genus, 
  but 
  on 
  inspection 
  of 
  

   the 
  vomer, 
  it 
  is 
  found 
  to 
  be 
  as 
  in 
  the 
  true 
  Cheloniidae, 
  largely 
  developed 
  on 
  the 
  palatal 
  

   surface 
  between 
  the 
  o. 
  o. 
  maxillaria, 
  and 
  to 
  extend 
  to 
  a 
  posteriorly 
  situated 
  nareal 
  open- 
  

   ing. 
  Though 
  this 
  element 
  is 
  unossified 
  in 
  the 
  Chelonioid 
  types 
  of 
  Pleurodira, 
  Peltoce- 
  

   phalus 
  and 
  Podocnemis, 
  it 
  is 
  well 
  developed 
  in 
  the 
  family 
  Chelydidae, 
  (Agassiz) 
  and 
  the 
  

   peculiarity 
  of 
  the 
  cretaceous 
  species 
  might 
  still 
  exist 
  in 
  this 
  suborder. 
  As 
  it 
  is 
  a 
  mat- 
  

   ter 
  of 
  much 
  interest 
  to 
  determine 
  the 
  precedence 
  in 
  time 
  of 
  the 
  two 
  suborders 
  of 
  the 
  Che- 
  

   lonians, 
  I 
  have 
  taken 
  pains 
  to 
  remove 
  the 
  matrix 
  from 
  the 
  orbital 
  and 
  nasal 
  cavities, 
  so 
  as 
  

   to 
  determine 
  the 
  structure 
  of 
  the 
  pre-frontal 
  bone. 
  As 
  I 
  have 
  elsewhere 
  pointed 
  out, 
  this 
  

   sends 
  downward 
  a 
  column 
  to 
  the 
  vomer, 
  either 
  vertically 
  or 
  directed 
  obliquely 
  inwards, 
  

   in 
  all 
  the 
  Cryptodira, 
  while 
  in 
  the 
  Pleurodira 
  the 
  column 
  is 
  wanting. 
  

  

  The 
  diagnosis 
  will 
  be 
  as 
  follows 
  : 
  That 
  of 
  the 
  Bothremys 
  a 
  Hydraspid, 
  which 
  has 
  fur- 
  

   nished 
  the 
  only 
  other 
  cranium 
  from 
  the 
  same 
  formation, 
  is 
  introduced. 
  It 
  also 
  has 
  the 
  

   vomer 
  osseous 
  extensively 
  in 
  contact 
  with 
  the 
  maxillaries 
  on 
  the 
  palatine 
  surface. 
  

  

  bothremys, 
  Leidy. 
  

  

  Posterior 
  nares 
  separating 
  vomer 
  from 
  o. 
  o. 
  palatina 
  ; 
  premaxillary 
  margin 
  concave, 
  

   involute 
  ; 
  alveolar 
  profoundly 
  concave, 
  vomerine 
  surface 
  a 
  sulcus 
  ; 
  nasal 
  meatus 
  floored 
  

   in 
  front. 
  

  

  EUCLASTES, 
  Cope. 
  

  

  Maxillaries 
  and 
  palatines 
  separated 
  throughout 
  by 
  the 
  prolonged 
  vomer 
  ; 
  posterior 
  

   nares 
  opposite 
  palatal 
  front 
  margin 
  of 
  orbits 
  ; 
  premaxillary 
  margin 
  projecting 
  beak-like 
  ; 
  

   alveolar 
  face 
  little 
  concave, 
  vomer 
  forming 
  a 
  central 
  ridge. 
  Floor 
  of 
  nasal 
  meatus 
  perfo- 
  

   rate 
  for 
  hook 
  of 
  mandible. 
  

  

  While 
  Bothremys 
  had 
  an 
  inferior 
  mouth 
  and 
  projecting 
  muzzle, 
  as 
  in 
  the 
  modern 
  Hy- 
  

   draspidcs, 
  the 
  nostrils 
  of 
  the 
  Euclastcs 
  were 
  superior 
  and 
  behind 
  the 
  short 
  projecting 
  beak. 
  

   The 
  orbits 
  arc 
  not, 
  as 
  in 
  the 
  Macrochelys 
  of 
  the 
  Mississippi, 
  far 
  anterior 
  and 
  reduced 
  in 
  

  

  