﻿J. 
  W. 
  HTJLKE 
  ON 
  THE 
  ANATOMY 
  OF 
  HYPSILOPHODON 
  FOXII. 
  19 
  

  

  The 
  body 
  of 
  the 
  praemaxilla 
  is 
  a 
  vertical 
  plate, 
  *45 
  inch 
  deep 
  from 
  its 
  

   nasal 
  to 
  its 
  dentigerous 
  border, 
  smooth, 
  except 
  quite 
  in 
  front, 
  where 
  

   its 
  surface 
  is 
  wrinkled. 
  From 
  each 
  end 
  rises 
  a 
  strong 
  process. 
  That 
  

   in 
  front 
  is 
  a 
  compressed 
  trihedral 
  blade 
  narrowing 
  upwards, 
  shorter 
  

   than 
  the 
  posterior 
  or 
  outer 
  process. 
  Applied 
  to 
  its 
  fellow 
  of 
  the 
  

   other 
  side 
  it 
  forms 
  the 
  lower 
  part 
  of 
  the 
  septum 
  between 
  the 
  anterior 
  

   nares. 
  Its 
  front 
  edge 
  seen 
  on 
  the 
  surface 
  of 
  the 
  snout 
  is 
  stout; 
  the 
  

   posterior 
  edge 
  is 
  thin. 
  

  

  The 
  posterior 
  or 
  outer 
  process, 
  broader 
  and 
  longer, 
  is 
  closely 
  ap- 
  

   plied 
  to 
  the 
  anterior 
  border 
  of 
  the 
  maxilla, 
  but 
  not 
  suturally 
  united 
  

   with 
  it. 
  It 
  overlaps 
  the 
  maxilla, 
  which 
  has 
  a 
  shallow 
  groove 
  for 
  its 
  

   reception. 
  The 
  dentigerous 
  border, 
  nearly 
  straight, 
  is 
  *65 
  inch 
  long 
  ; 
  

   and 
  in 
  this 
  space 
  it 
  contains, 
  I 
  think 
  in 
  separate 
  sockets, 
  five 
  mature 
  

   cylindrical 
  teeth, 
  of 
  which 
  the 
  roots, 
  with 
  only 
  small 
  portions 
  of 
  the 
  

   crowns, 
  now 
  remain. 
  At 
  their 
  inner 
  side, 
  between 
  the 
  second 
  and 
  

   third 
  and 
  the 
  fourth 
  and 
  fifth 
  teeth, 
  two 
  immature 
  crowns 
  are 
  just 
  

   visible. 
  A 
  large 
  triangular 
  palatal 
  process, 
  mesially 
  united 
  to 
  its 
  

   fellow, 
  completely 
  roofs 
  this 
  part 
  of 
  the 
  mouth. 
  From 
  the 
  anterior 
  

   palatine 
  foramen 
  to 
  the 
  posterior 
  extremity 
  of 
  the 
  interpraemaxillary 
  

   suture 
  measures 
  # 
  7 
  inch. 
  This 
  sutural 
  margin 
  is 
  longer 
  than 
  the 
  

   free 
  posterior 
  border, 
  and 
  it 
  forms 
  a 
  projecting 
  angle 
  to 
  which, 
  on 
  

   the 
  right 
  side, 
  the 
  front 
  of 
  a 
  vomer 
  is 
  ( 
  V.) 
  attached. 
  

  

  The 
  teeth 
  all 
  lie 
  behind 
  the 
  anterior 
  palatine 
  foramen 
  ; 
  the 
  small 
  

   portion 
  of 
  the 
  edge 
  of 
  the 
  right 
  jaw 
  in 
  front 
  of 
  this 
  is 
  smooth 
  and 
  

   toothless. 
  

  

  The 
  maxill8e(ilfe. 
  Mx'.) 
  are 
  large 
  subtriangular 
  bones. 
  The 
  left 
  is 
  

   very 
  perfect. 
  Its 
  straight 
  dentigerous 
  border, 
  1*6 
  inch 
  long, 
  contains 
  

   an 
  unbroken 
  series 
  of 
  eleven* 
  compressed 
  sculptured 
  teeth, 
  of 
  which 
  

   the 
  front 
  four 
  are 
  smaller 
  than 
  the 
  others. 
  The 
  hinder 
  margin 
  of 
  

   the 
  crown 
  of 
  each 
  tooth 
  slightly 
  overlaps 
  the 
  front 
  margin 
  of 
  that 
  

   next 
  behind 
  it. 
  The 
  crowns 
  are 
  obliquely 
  worn, 
  the 
  thickly 
  enamelled 
  

   outer 
  contour 
  being 
  the 
  longer. 
  The 
  number 
  of 
  praemaxillary 
  teeth 
  

   agrees 
  with 
  that 
  of 
  Mr. 
  Fox's 
  skull 
  ; 
  the 
  maxillary 
  teeth 
  are 
  one 
  

   more 
  in 
  my 
  skull. 
  The 
  teeth 
  themselves 
  agree 
  so 
  closely 
  with 
  those 
  

   described 
  in 
  my 
  last 
  note 
  as 
  to 
  make 
  any 
  further 
  account 
  of 
  them 
  

   unnecessary. 
  In 
  front 
  of 
  its 
  dentigerous 
  part 
  the 
  lower 
  border 
  of 
  

   the 
  maxilla 
  and 
  its 
  upper 
  border 
  converge 
  and 
  send 
  forward 
  upon 
  

   the 
  deep 
  surface 
  of 
  the 
  praemaxilla 
  the 
  thin 
  grooved 
  plate 
  mentioned 
  

   as 
  receiving 
  the 
  posterior 
  ascending 
  process 
  of 
  the 
  latter. 
  

  

  Above 
  this 
  plate 
  the 
  anterior 
  border 
  of 
  the 
  maxilla 
  rises 
  in 
  a 
  

   sinuous 
  curve 
  to 
  a 
  height 
  of 
  1*1 
  inch 
  above 
  the 
  second 
  tooth, 
  making 
  

   here 
  a 
  blunt 
  angle 
  with 
  its 
  upper 
  border, 
  which 
  behind 
  this 
  declines 
  

   in 
  a 
  gentle 
  hollow 
  curve 
  to 
  a 
  height 
  of 
  *45 
  inch 
  above 
  the 
  last 
  tooth. 
  

   Above 
  this 
  tooth, 
  at 
  the 
  height 
  of 
  *35 
  inch, 
  the 
  surface 
  of 
  the 
  maxilla 
  

   is 
  angulated, 
  and 
  a 
  strong 
  triangular 
  process, 
  at 
  least 
  *6 
  inch 
  long, 
  

   passes 
  backwards. 
  The 
  uncertainty 
  whether 
  a 
  narrow 
  line 
  obliquely 
  

   crossing 
  the 
  junction 
  of 
  this 
  process 
  and 
  the 
  body 
  of 
  the 
  maxilla 
  is 
  

   an 
  accidental 
  crack 
  or 
  a 
  suture 
  leaves 
  it 
  doubtful 
  whether 
  this 
  process 
  

   is 
  part 
  of 
  the 
  maxilla 
  or 
  a 
  separate 
  bone. 
  

  

  * 
  Perhaps 
  one 
  tooth 
  is 
  missing 
  between 
  the 
  second 
  and 
  the 
  third. 
  

  

  c2 
  

  

  