﻿184 
  ME. 
  C. 
  W. 
  ANDREWS 
  ON 
  THE 
  STRUCTURE 
  [May 
  1 
  897, 
  

  

  doubt 
  joined 
  the 
  outer 
  ends 
  of 
  the 
  parietals, 
  but 
  which 
  has 
  been 
  

   broken 
  from 
  its 
  union 
  with 
  them 
  and 
  crushed 
  down 
  upon 
  their 
  dorsal 
  

   surface. 
  In 
  consequence 
  of 
  this 
  dislocation 
  the 
  quadrate 
  region 
  is 
  

   much 
  fractured, 
  but 
  it 
  can 
  be 
  seen 
  that 
  the 
  squamosal 
  sends 
  down 
  a 
  

   broad 
  plate 
  which 
  is 
  closely 
  applied 
  to 
  and 
  apparently 
  fused 
  with 
  

   the 
  posterior 
  surface 
  of 
  the 
  quadrate. 
  This 
  portion 
  of 
  the 
  squamosal 
  

   terminates 
  ventrally 
  in 
  a 
  convex 
  border 
  which 
  forms 
  a 
  rounded 
  

   ridge 
  on 
  the 
  quadrate 
  a 
  short 
  distance 
  above 
  the 
  articular 
  condyle 
  

   of 
  that 
  bone. 
  This 
  ridge 
  is 
  most 
  prominent 
  internally 
  where, 
  

   between 
  it 
  and 
  the 
  upper 
  border 
  of 
  the 
  condyle, 
  there 
  is 
  a 
  deep 
  

   groove. 
  

  

  The 
  quadrate 
  (qu.) 
  itself 
  is 
  extremely 
  large 
  and 
  massive. 
  The 
  

   body 
  of 
  the 
  bone 
  is 
  concave 
  from 
  side 
  to 
  side 
  anteriorly, 
  convex 
  in 
  

   the 
  same 
  direction 
  posteriorly. 
  As 
  just 
  noted, 
  the 
  posterior 
  surface 
  

   is 
  largely 
  overlaid 
  and 
  concealed 
  by 
  the 
  squamosal. 
  The 
  distal 
  end 
  

   forms 
  an 
  extremely 
  large 
  articular 
  condyle, 
  the 
  form 
  of 
  which 
  is 
  

   shown 
  in 
  PI. 
  XII. 
  It 
  will 
  be 
  seen 
  that 
  this 
  articular 
  surface 
  is- 
  

   divided 
  by 
  an 
  oblique 
  ridge 
  into 
  a 
  smaller 
  postero 
  -internal 
  and 
  a 
  

   larger 
  antero-external 
  portion. 
  From 
  the 
  inner 
  border 
  of 
  the 
  bone 
  

   immediately 
  above 
  the 
  distal 
  condyle 
  there 
  arises 
  a 
  strong 
  process 
  

   directed 
  inward 
  and 
  forward 
  ; 
  this 
  unites 
  in 
  an 
  oblique 
  suture 
  with 
  

   the 
  backward 
  process 
  of 
  the 
  pterygoid. 
  

  

  The 
  teeth 
  call 
  for 
  no 
  special 
  notice, 
  since 
  they 
  agree 
  precisely 
  

   with 
  those 
  described 
  and 
  figured 
  by 
  Lydekker. 
  1 
  The 
  largest 
  

   specimen 
  preserved 
  is 
  probably 
  one 
  of 
  the 
  large 
  anterior 
  (3rd 
  

   or 
  4th) 
  maxillary 
  teeth 
  ; 
  its 
  total 
  length 
  along 
  the 
  outside 
  of 
  

   the 
  curve 
  is 
  23-5 
  cm., 
  length 
  of 
  crown 
  8*5 
  cm., 
  and 
  the 
  diameter 
  

   at 
  the 
  base 
  of 
  the 
  crown 
  2*8 
  cm. 
  The 
  smallest 
  complete 
  tooth 
  

   measures 
  6'2 
  cm. 
  in 
  length 
  along 
  the 
  outside 
  of 
  the 
  curve, 
  the 
  

   crown 
  occupying 
  one-third 
  of 
  the 
  length 
  ; 
  the 
  diameter 
  at 
  the 
  base- 
  

   of 
  the 
  crown 
  is 
  1*1 
  cm. 
  

  

  The 
  chief 
  measurements 
  of 
  this 
  skull 
  are 
  as 
  follow 
  : 
  — 
  

  

  cm. 
  

  

  Length 
  from 
  tip 
  of 
  snout 
  to 
  occipital 
  condyle 
  112 
  

  

  „ 
  ,, 
  „ 
  anterior 
  angle 
  of 
  external 
  nares 
  ... 
  57 
  

  

  „ 
  „ 
  ,, 
  ., 
  „ 
  internal 
  nares 
  ... 
  36 
  

   „ 
  „ 
  „ 
  binder 
  end 
  of 
  facial 
  process 
  of 
  

  

  premaxilla 
  74 
  

  

  „ 
  of 
  external 
  nares 
  5 
  

  

  „ 
  „ 
  internal 
  nares 
  6*5 
  

  

  „ 
  „ 
  posterior 
  palatine 
  vacuities 
  11 
  

  

  Width 
  of 
  skull 
  at 
  quadrates 
  (perhaps 
  slightly 
  exaggerated 
  by 
  

  

  crushing) 
  50 
  

  

  at 
  le^el 
  of 
  transpalatine 
  bone 
  48 
  

  

  at 
  middle 
  of 
  internal 
  nares 
  19 
  

  

  at 
  diastema 
  11*3 
  

  

  at 
  widest 
  part 
  of 
  premaxilla 
  12 
  

  

  „ 
  of 
  quadrate 
  articulation 
  12 
  

  

  Greatest 
  diameter 
  (transverse) 
  of 
  occipital 
  condyle 
  6*5 
  

  

  1 
  Quart. 
  Journ. 
  Geol. 
  Soc. 
  vol. 
  xlvi. 
  (1890) 
  p. 
  49, 
  pi. 
  v. 
  fig. 
  1. 
  

  

  