﻿J. 
  W. 
  HULKE 
  ON 
  A 
  MODIFIED 
  FORM 
  OF 
  DINOSAURIAN 
  ILIUM. 
  527 
  

  

  ferent. 
  As 
  in 
  other 
  lizards, 
  it 
  and 
  the 
  coracoid 
  processes 
  are 
  com- 
  

   pressed 
  flat 
  blades, 
  the 
  thin 
  edges 
  of 
  which 
  are 
  adapted 
  to 
  the 
  

   attachment 
  of 
  the 
  membrane 
  which 
  fills 
  the 
  nnossified 
  spaces 
  between 
  

   them 
  ; 
  whereas 
  the 
  long, 
  slender 
  anterior 
  process 
  of 
  the 
  unknown 
  

   reptile's 
  scapula 
  is 
  subcylindrical, 
  and, 
  where 
  compressed, 
  this 
  is 
  in 
  

   the 
  opposite 
  direction 
  to 
  that 
  of 
  the 
  scapular 
  processes 
  of 
  living 
  

   lizards. 
  Here, 
  too, 
  I 
  suggest, 
  the 
  comparison 
  fails. 
  

  

  The 
  difficulties 
  of 
  the 
  scapular 
  hypothesis 
  appear 
  to 
  me 
  insur- 
  

   mountable. 
  On 
  the 
  other 
  hand, 
  upon 
  a 
  comparison 
  of 
  these 
  reputed 
  

   scapulse 
  with 
  a 
  typical 
  Dinosaurian 
  ilium, 
  e. 
  g. 
  of 
  Iguanodon 
  Man- 
  

   telli, 
  the 
  essential 
  correspondence 
  of 
  all 
  their 
  several 
  parts 
  is 
  so 
  

   evident 
  as 
  to 
  render 
  irresistible 
  the 
  conviction 
  that 
  they 
  are 
  identical 
  

   members 
  of 
  the 
  skeleton 
  : 
  a 
  is 
  the 
  acetabulum, 
  p 
  its 
  pubic 
  pro- 
  

   cess, 
  * 
  its 
  ischial 
  process 
  ; 
  Sj> 
  the 
  long, 
  upper, 
  anterior, 
  slender 
  

   process, 
  is 
  the 
  suprapubic 
  process 
  so 
  largely 
  developed 
  in 
  Iguanodon 
  

   Mantelli 
  ; 
  and 
  b 
  is 
  the 
  expanded 
  part 
  or 
  body 
  of 
  the 
  ilium 
  ; 
  the 
  

   notch 
  (n) 
  corresponds 
  to 
  that 
  beneath 
  the 
  small 
  anterior 
  process 
  in 
  

   existing 
  lizards, 
  beneath 
  which 
  the 
  nerves 
  and 
  vessels 
  wind 
  which 
  

   are 
  destined 
  for 
  the 
  front 
  and 
  upper 
  surfaces 
  of 
  the 
  hip-joint 
  and 
  

   thigh. 
  The 
  most 
  obvious 
  differences 
  of 
  these 
  ilia 
  from 
  that 
  of 
  Igua- 
  

   nodon 
  are 
  the 
  angle 
  which 
  the 
  axis 
  of 
  their 
  body 
  makes 
  with 
  that 
  

   of 
  the 
  long, 
  slender 
  process, 
  and 
  the 
  aboence 
  of 
  any 
  distinct 
  stamp 
  

   of 
  a 
  sacral 
  attachment. 
  

  

  In 
  the 
  three 
  smaller 
  ilia 
  which 
  have 
  been 
  mentioned 
  in 
  this 
  note, 
  

   viz. 
  Dr. 
  Mantell's, 
  Mr. 
  G. 
  B. 
  Holmes's, 
  and 
  Dr. 
  Wilkins's 
  smaller 
  

   specimen, 
  the 
  long, 
  slender 
  process 
  makes 
  nearly 
  a 
  light 
  angle 
  with 
  

   the 
  axis 
  of 
  the 
  body 
  ; 
  in 
  Dr. 
  Wilkins's 
  larger 
  specimen 
  this 
  angle 
  is 
  

   more 
  obtuse, 
  whereas 
  in 
  Iguanodon 
  the 
  body 
  and 
  the 
  long, 
  slender 
  

   suprapubic 
  process 
  are 
  most 
  extended 
  in 
  nearly 
  the 
  same 
  line. 
  As 
  

   the 
  ilium 
  forms 
  the 
  upper 
  part 
  of 
  the 
  acetabulum, 
  the 
  axis 
  of 
  its 
  

   body, 
  which 
  is 
  nearly 
  vertical 
  to 
  the 
  chord 
  of 
  the 
  acetabular 
  arc, 
  

   is 
  highly 
  inclined 
  or 
  nearly 
  vertical 
  to 
  the 
  vertebral 
  column, 
  and 
  

   the 
  ilium 
  would 
  therefore 
  necessarily 
  be 
  connected 
  with 
  fewer 
  sacral 
  

   vertebrae 
  than 
  in 
  typical 
  Dinosaurs 
  — 
  dispositions 
  resembling 
  those 
  

   which 
  obtain 
  in 
  existing 
  lizards, 
  where, 
  as 
  is 
  well 
  known, 
  the 
  

   number 
  of 
  sacral 
  vertebras 
  is 
  two, 
  and 
  the 
  slant 
  of 
  the 
  ilium 
  is 
  con- 
  

   siderable, 
  notably 
  in 
  Hatteria, 
  in 
  which 
  it 
  includes, 
  with 
  the 
  ver- 
  

   tebral 
  column, 
  an 
  angle 
  of 
  about 
  80° 
  (Dr. 
  Giinther), 
  and 
  in 
  Clia- 
  

   mceleon, 
  in 
  which 
  the 
  ilium 
  depends 
  nearly 
  vertically 
  from 
  the 
  sacrum. 
  

   These, 
  it 
  is 
  worth 
  notice, 
  exhibit 
  some 
  closer 
  skeletal 
  resemblances 
  

   to 
  Dinosauria 
  than 
  do 
  other 
  existing 
  lizards. 
  

  

  As 
  regards 
  the 
  absence 
  of 
  distinct 
  marks 
  of 
  attachment 
  to 
  the 
  

   sacrum 
  from 
  both 
  the 
  lateral 
  surfaces 
  of 
  the 
  body, 
  I 
  would 
  speak 
  

   cautiously. 
  Only 
  one 
  surface 
  of 
  Dr. 
  Mantell's 
  and 
  Mr. 
  Holmes's 
  

   specimens 
  is 
  exposed 
  ; 
  and 
  Mr. 
  Beccles 
  writes 
  me 
  that 
  one 
  surface 
  

   of 
  his 
  specimen 
  of 
  this 
  bone 
  is 
  backed 
  with 
  plaster 
  of 
  Paris. 
  In 
  

   neither 
  of 
  Dr. 
  Wilkins's 
  bones 
  do 
  I 
  find 
  these 
  marks 
  ; 
  but 
  in 
  each 
  

   the 
  upper 
  end 
  of 
  the 
  body 
  is 
  missing, 
  and 
  they 
  may 
  have 
  been 
  pre- 
  

   sent 
  here, 
  where 
  we 
  find 
  them 
  in 
  existing 
  lizards. 
  

  

  The 
  Bev. 
  W. 
  Fox, 
  to 
  whom 
  I 
  turned 
  for 
  some 
  information 
  on 
  this 
  

  

  