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  THE 
  EXTINCT 
  BATRACHIA, 
  REPTILIA 
  

  

  If 
  the 
  coracoid 
  found 
  near 
  them 
  belongs 
  to 
  the 
  same 
  skeleton, 
  the 
  body 
  was 
  remarkably 
  slender, 
  and 
  the 
  fore- 
  

   limbs 
  possessed 
  comparatively 
  little 
  power. 
  

  

  From 
  the 
  clays 
  below 
  the 
  upper 
  bed 
  of 
  Cretaceous 
  Green 
  Sand 
  at 
  Hornerstown, 
  Mon- 
  

   mouth 
  Co., 
  N. 
  J. 
  Discovered 
  by 
  Jno. 
  G. 
  Miers. 
  

  

  BAPTOSAURUS 
  FRATERNUS, 
  Marsh. 
  

   Ilalisaurus 
  fratemus, 
  Marsh, 
  Amer. 
  Jour. 
  Sci. 
  Arts, 
  1869, 
  397. 
  

  

  This 
  species 
  is 
  established 
  on 
  an 
  anterior 
  dorsal 
  and 
  two 
  posterior 
  dorsal 
  vertebra?, 
  found 
  not 
  far 
  from 
  each 
  other, 
  

   and 
  probably 
  part 
  of 
  the 
  same 
  series. 
  They 
  are 
  about 
  the 
  same 
  size 
  as 
  those 
  just 
  described, 
  and 
  have 
  many 
  points 
  of 
  

   resemblance 
  to 
  them, 
  but 
  differ 
  in 
  having 
  the 
  centra 
  less 
  depressed 
  and 
  less 
  elongate. 
  The 
  anterior 
  dorsal 
  has 
  the 
  zy- 
  

   gapophyses 
  less 
  expanded, 
  and 
  their 
  articular 
  face 
  more 
  nearly 
  vertical 
  than 
  the 
  corresponding 
  parts 
  in 
  the 
  previous 
  

   species. 
  It 
  has 
  also 
  indications 
  of 
  a 
  small 
  hypapophysis, 
  which 
  in 
  form 
  and 
  position 
  resembles 
  somewhat 
  that 
  of 
  Mo- 
  

   sasaarus. 
  The 
  neural 
  spine 
  is 
  compressed, 
  of 
  moderate 
  height, 
  and 
  directed 
  slightly 
  forwards. 
  The 
  posterior 
  dorsals 
  

   have 
  the 
  centra 
  considerably 
  less 
  depressed 
  than 
  the 
  anterior 
  dorsals, 
  and 
  the 
  neural 
  arch 
  rests 
  upon 
  the 
  anterior 
  two- 
  

   thirds 
  of 
  the 
  centrum. 
  The 
  diapopophyses 
  pass 
  off 
  horizontally, 
  their 
  upper 
  flat 
  surface 
  being 
  nearly 
  in 
  the 
  same 
  

   plane 
  as 
  the 
  floor 
  of 
  the 
  neural 
  canal. 
  At 
  their 
  extremities 
  there 
  is 
  an 
  articular 
  face 
  which 
  is 
  subtriangular. 
  These 
  

   vertebrae 
  are 
  all 
  much 
  more 
  depressed 
  than 
  those 
  of 
  Liodon 
  Iwvis, 
  Owen, 
  or 
  L. 
  validus, 
  Cope, 
  and 
  indicate 
  an 
  animal 
  

   smaller 
  than 
  either 
  of 
  those 
  species, 
  probably 
  twenty-five 
  or 
  thirty 
  feet 
  in 
  length. 
  The 
  remains 
  were 
  found 
  near 
  Hor- 
  

   nerstown, 
  New 
  Jersey, 
  by 
  Mr. 
  Meirs, 
  at 
  the 
  same 
  locality 
  as 
  those 
  described 
  above. 
  

  

  The 
  preceding 
  description 
  is 
  quoted 
  from 
  Marsh, 
  loc. 
  cit. 
  A 
  vertebra 
  probably 
  of 
  this 
  species 
  is 
  in 
  the 
  Museum 
  

   of 
  the 
  Academy 
  Natural 
  Sciences. 
  

  

  HOLCODTJS, 
  Gibbes. 
  

   HOLCODUS 
  ACUTIDENS, 
  Gibbes. 
  

  

  On 
  Mosasaurus, 
  Smithsonian 
  Contributions, 
  1851 
  9: 
  Tab. 
  Leidy, 
  Cretaceous 
  Reptiles, 
  p. 
  118, 
  Tab. 
  X, 
  fig. 
  17. 
  

  

  Cretaceous 
  formation 
  of 
  Alabama 
  and 
  Mississippi. 
  

  

  POLYGONODON, 
  Leidy. 
  

   Proceed. 
  Acad. 
  Nat. 
  Sci., 
  Phila., 
  1856. 
  221. 
  

  

  This 
  genus 
  is 
  only 
  known 
  from 
  teeth. 
  These 
  are 
  of 
  remarkable 
  and 
  elegant 
  form, 
  

   and 
  could 
  scarcely 
  have 
  pertained 
  to 
  animals 
  which 
  presented 
  any 
  close 
  affinity 
  to 
  Mosa- 
  

   saurus. 
  Their 
  cutting 
  edges 
  are 
  equally 
  developed 
  and 
  acute 
  on 
  both 
  anterior 
  and 
  pos- 
  

   terior 
  aspects, 
  and 
  separate 
  equal 
  faces. 
  The 
  facets 
  are 
  better 
  defined 
  than 
  in 
  any 
  other 
  

   genus. 
  There 
  are 
  two 
  species, 
  as 
  follows 
  : 
  

  

  Facets 
  six 
  inner 
  and 
  seven 
  outer. 
  p. 
  vetus. 
  

  

  Facets 
  four 
  or 
  five 
  inner 
  and 
  outer. 
  p. 
  rectus. 
  

  

  POLYGONODON 
  VETUS. 
  Leidy. 
  

   Loc. 
  Cit,, 
  1856, 
  221 
  ; 
  Cretaceous 
  Reptiles, 
  tab. 
  IX., 
  12-13. 
  

  

  Cretaceous 
  Green 
  Sand 
  of 
  New 
  Jersey. 
  

  

  