﻿AND 
  AYES 
  OF 
  NORTH 
  AMERICA. 
  207 
  

  

  Lines. 
  

  

  Depth 
  ball, 
  10.4 
  

  

  Width 
  " 
  11 
  

  

  " 
  cup, 
  12.6 
  

  

  Depth 
  " 
  11. 
  

  

  Length 
  base 
  neurapophysis, 
  1?. 
  

   In 
  profile 
  the 
  base 
  has 
  a 
  very 
  slight 
  obliquity 
  looking 
  upwards. 
  

   From 
  the 
  Rotten 
  Limestome 
  of 
  Alabama; 
  discovered 
  by 
  E. 
  R. 
  Showalter, 
  M. 
  D. 
  

  

  LIODON 
  VALIDITS, 
  Cope. 
  

  

  Macrosaurus 
  validus, 
  Cope, 
  Proc. 
  Boston, 
  18G9. 
  Nectoportheus 
  validus, 
  Cope, 
  Proc. 
  A. 
  N. 
  Sci., 
  Phil. 
  1868, 
  p. 
  181. 
  

   Leidy, 
  Cretac. 
  Rept. 
  74-75; 
  Tab. 
  VII, 
  19, 
  20, 
  III 
  1-2. 
  

  

  This 
  species 
  is 
  represented 
  by 
  two 
  cervical 
  and 
  four 
  dorsal 
  vertebrae 
  of 
  one 
  individual, 
  and 
  a 
  large 
  dorsal 
  of 
  another, 
  

   in 
  the 
  Museum 
  of 
  the 
  Academy; 
  the 
  former 
  associated 
  with 
  numerous 
  fragments, 
  including 
  part 
  of 
  an 
  os 
  quad- 
  

   ratum, 
  from 
  L. 
  T. 
  Germain, 
  Burlington 
  Co., 
  N. 
  J. 
  Two 
  dorsal 
  vertebrae 
  of 
  a 
  large 
  individual 
  in 
  the 
  Museum 
  of 
  Rut- 
  

   ger's 
  College, 
  submitted 
  to 
  me 
  by 
  Prof. 
  Cook; 
  several 
  vertebrae 
  with 
  broken 
  quadrate 
  and 
  other 
  bones 
  and 
  teeth, 
  in 
  my 
  

   private 
  collection, 
  from 
  near 
  Barnesboro, 
  Gloucester 
  Co., 
  N. 
  J. 
  ; 
  a 
  similar 
  series 
  with 
  portions 
  of 
  the 
  cranium 
  from 
  the 
  

   same 
  locality, 
  in 
  Cabinet 
  of 
  N. 
  J. 
  State 
  Geol. 
  Survey, 
  and 
  a 
  number 
  of 
  vertebras 
  in 
  the 
  collection 
  of 
  Prof. 
  Marsh, 
  of 
  

   Yale 
  College, 
  further 
  establish 
  its 
  characters. 
  

  

  The 
  quadrate 
  bone 
  is 
  highly 
  peculiar, 
  as 
  above 
  pointed 
  out. 
  The 
  posterior 
  descending 
  hook 
  of 
  the 
  proximal 
  ex- 
  

   tremity 
  is 
  quite 
  short, 
  and 
  is 
  marked 
  by 
  an 
  obtuse 
  ridge 
  which 
  passes 
  forwards 
  and 
  disappears 
  immediately 
  above 
  the 
  

   pit 
  alongside 
  the 
  meatus. 
  What 
  especially 
  characterizes 
  this 
  species 
  and 
  genus, 
  and 
  allies 
  it 
  to 
  Clidastes, 
  is 
  the 
  pres- 
  

   ence 
  of 
  a 
  strong 
  longitudinal 
  angular 
  ridge, 
  which 
  extends 
  from 
  the 
  usual 
  external 
  angle 
  of 
  the 
  proximal 
  extremity, 
  

   which 
  becomes 
  here 
  a 
  process, 
  separating 
  the 
  outer 
  aspect 
  of 
  the 
  quadratum 
  into 
  two 
  entirely 
  distinct 
  planes; 
  one 
  that 
  

   of 
  the 
  meatus, 
  the 
  other 
  that 
  of 
  the 
  ala. 
  

  

  Two 
  separate 
  opistliotic 
  bones 
  accompany 
  these 
  remains, 
  which 
  were 
  mixed 
  up 
  with 
  those 
  of 
  the 
  M. 
  depressus. 
  The 
  

   vertebrae 
  of 
  the 
  two 
  species 
  were 
  easily 
  separated. 
  The 
  quadrate 
  bone 
  also 
  was 
  identified 
  by 
  one 
  accompanying 
  the 
  

   vertebrae 
  of 
  M. 
  validus 
  in 
  my 
  own 
  collection. 
  I 
  could 
  not 
  so 
  readily 
  assign 
  the 
  opisthoties 
  to 
  the 
  proper 
  species. 
  I 
  

   have 
  assigned 
  them 
  here, 
  because 
  their 
  glenoid 
  cavities 
  apply 
  much 
  more 
  readily 
  to 
  the 
  quadrate 
  bone 
  of 
  the 
  M. 
  

   validus 
  than 
  of 
  the 
  M. 
  depressus. 
  As 
  compared 
  with 
  the 
  same 
  bones 
  of 
  three 
  Mosasaurus 
  dekayi, 
  they 
  present 
  three 
  

   marked 
  characteristics. 
  First, 
  they 
  are 
  relatively 
  much 
  shorter; 
  second, 
  the 
  distal 
  anterior 
  process 
  which 
  fits 
  within 
  

   the 
  squamosa], 
  is 
  much 
  more 
  prolonged; 
  third, 
  the 
  inferior 
  of 
  the 
  two 
  faces 
  to 
  which 
  the 
  squamosal 
  is 
  applied, 
  is 
  a 
  

   continuation 
  of 
  the 
  general 
  inferior 
  plane 
  of 
  the 
  bone; 
  in 
  M. 
  mitchillii 
  it 
  is 
  a 
  different 
  plane, 
  like 
  a 
  rabbet. 
  It 
  may 
  

   be 
  added, 
  that 
  the 
  glenoid 
  cavity 
  is 
  narrower 
  and 
  deeper. 
  

  

  Four 
  teeth 
  from 
  Barnesboro, 
  indicate 
  marked 
  characters. 
  They 
  are 
  much 
  compressed, 
  as 
  in 
  L. 
  mitchillii, 
  and 
  the 
  

  

  posterior 
  cutting 
  edge 
  is 
  well 
  developed 
  and 
  forms 
  the 
  narrowed 
  extremity 
  of 
  an 
  elliptic 
  section- 
  The 
  anterior 
  ridge 
  

  

  less 
  developed. 
  In 
  three 
  crowns 
  there 
  is 
  no 
  trace 
  of 
  the 
  unequal 
  division 
  by 
  these 
  edges, 
  as 
  in 
  Mosasaurus 
  sp. 
  One 
  

  

  probably 
  from 
  the 
  premaxilla 
  is 
  more 
  abruptly 
  recurved 
  than 
  in 
  the 
  others, 
  with 
  base 
  rather 
  expanded 
  inwards. 
  The 
  

  

  distinguishing 
  character 
  of 
  these 
  teeth, 
  which 
  separates 
  it 
  from 
  L. 
  mitchillii, 
  is 
  the 
  abruidant 
  longitudinal 
  fluting 
  and 
  

  

  striation 
  of 
  the 
  enamel. 
  The 
  grooves 
  are 
  deeper 
  and 
  shallower, 
  coarser 
  at 
  the 
  base; 
  the 
  striae 
  are 
  fine, 
  contiuuous 
  and 
  

  

  rugose. 
  These 
  are 
  not 
  seen 
  in 
  L. 
  mitchillii. 
  The 
  general 
  form 
  of 
  the 
  crown 
  is 
  short, 
  broad 
  at 
  the 
  base 
  and 
  well 
  

  

  curved 
  posteriorly 
  and 
  inwards. 
  

  

  Lines. 
  

   Elevation 
  of 
  crown 
  and 
  pedestal, 
  21 
  

  

  " 
  " 
  alone, 
  16 
  

  

  Antero-posterior 
  diameter 
  do. 
  at 
  base, 
  12 
  

  

  The 
  lateral 
  element 
  of 
  the 
  atlas 
  is 
  represented 
  from 
  the 
  inner 
  side 
  in 
  Fig. 
  48, 
  No. 
  3. 
  The 
  anterior 
  termination 
  

   of 
  the 
  inferior 
  ala, 
  and 
  the 
  articular 
  face 
  for 
  the 
  centrum, 
  are 
  as 
  in 
  M. 
  mitchillii. 
  The 
  inner 
  articular 
  face 
  is 
  divided 
  

  

  