﻿J. 
  W. 
  HT/LKE 
  ON 
  THE 
  ANATOMY 
  OP 
  HYPSLLOPHODON 
  FOXII. 
  23 
  

  

  EXPLANATION 
  OF 
  PLATE 
  III. 
  

  

  Remains 
  of 
  Hypsilophodon 
  Foxii. 
  

  

  Fig. 
  1. 
  Skull 
  : 
  Pa. 
  parietal 
  bone 
  ; 
  Pa', 
  its 
  supraoccipital 
  spinous 
  process 
  ; 
  

   Fr. 
  frontal 
  bone 
  ; 
  Po. 
  postorbital 
  process 
  ; 
  Pro. 
  prseorbital 
  process 
  ; 
  

   Sp. 
  suspensorial 
  process 
  ; 
  S. 
  bony 
  plates 
  of 
  sclerotic 
  coat 
  of 
  eyeball 
  

   lying 
  beneath 
  orbital 
  arch 
  ; 
  Mx. 
  right 
  maxilla 
  ; 
  Mx'. 
  left 
  maxilla 
  ; 
  

   Prmx. 
  pragmaxillce 
  ; 
  V. 
  vomer 
  ; 
  PL 
  right 
  palatal 
  bone 
  ; 
  PI', 
  left 
  palatal 
  

   bone 
  ; 
  Pt. 
  right 
  pterygoid 
  ; 
  PC. 
  left 
  pterygoid 
  ; 
  Sc. 
  scutes. 
  

   2. 
  L. 
  last 
  lumbar 
  vertebra 
  ; 
  Is, 
  2s, 
  3s, 
  first, 
  second, 
  third 
  sacral 
  vertebras 
  ; 
  

   Prz. 
  praszygapophysis 
  ; 
  Psz. 
  postzygapophysis 
  ; 
  II. 
  ileum 
  ; 
  Fe. 
  femur. 
  

  

  Discussion. 
  

  

  Mr. 
  Boyd 
  Dawkins 
  thought 
  there 
  was 
  as 
  much 
  distinction 
  between 
  

   Hypsilophodon 
  and 
  Iguanodon 
  as 
  between 
  Hipparion 
  and 
  Equus, 
  and 
  

   that 
  this 
  was 
  quite 
  sufficient 
  to 
  be 
  regarded 
  as 
  generic 
  rather 
  than 
  

   specific. 
  He 
  was 
  not 
  satisfied 
  as 
  to 
  the 
  additional 
  bone 
  in 
  the 
  foot 
  

   in 
  Mr. 
  Beccles's 
  specimen, 
  but 
  thought 
  it 
  might 
  belong 
  to 
  some 
  other 
  

   part 
  of 
  the 
  animal. 
  He 
  considered 
  that 
  all 
  the 
  teeth 
  of 
  Iguanodon 
  

   were 
  always 
  ground 
  flat 
  by 
  wear. 
  

  

  Mr. 
  Seeley 
  considered 
  that 
  the 
  author 
  was 
  likely 
  to 
  substantiate 
  

   his 
  opinions. 
  He 
  pointed 
  out 
  certain 
  differences 
  in 
  the 
  structure 
  and 
  

   form 
  of 
  the 
  maxillary 
  and 
  other 
  bones 
  of 
  the 
  skull 
  in 
  Hypsilophodon 
  

   and 
  Iguanodon, 
  and 
  especially 
  in 
  the 
  maxillary. 
  He 
  attached 
  great 
  

   importance 
  to 
  the 
  thickening 
  of 
  the 
  enamel 
  at 
  the 
  base 
  of 
  the 
  teeth 
  

   of 
  Hypsilophodon, 
  which 
  approximated 
  to 
  that 
  which 
  was 
  found 
  in 
  

   some 
  mammals. 
  The 
  teeth 
  commonly 
  reputed 
  to 
  be 
  those 
  of 
  Igua- 
  

   nodon 
  might, 
  he 
  thought, 
  belong 
  to 
  different 
  species, 
  if 
  not 
  genera, 
  

   and 
  showed 
  some 
  divergence 
  in 
  character. 
  The 
  observations 
  on 
  the 
  

   palatal 
  bones 
  of 
  Hypsilophodon 
  were, 
  he 
  thought, 
  calculated 
  to 
  throw 
  

   great 
  light 
  on 
  the 
  anatomy 
  of 
  Dinosaurs. 
  

  

  