﻿J. 
  W. 
  HTTLKE 
  ON 
  A 
  MODIFIED 
  FORM 
  OF 
  DlNOSAtTRIAN 
  ILIUM. 
  523 
  

  

  Collection 
  and 
  in 
  Prof. 
  Owen's 
  monograph 
  on 
  this 
  Saurian 
  scarcely- 
  

   allowed 
  me 
  to 
  doubt, 
  I 
  could 
  not 
  perceive 
  how 
  such 
  a 
  bone 
  could 
  be 
  

   united 
  to 
  that 
  which 
  Cuvier 
  and 
  Owen 
  had 
  taught 
  me 
  to 
  regard 
  as 
  

   its 
  coracoid. 
  

  

  The 
  first 
  light 
  reached 
  me 
  from 
  Prof. 
  Huxley's 
  valuable 
  paper 
  

   on 
  the 
  " 
  Classification 
  of 
  the 
  Dinosauria," 
  read 
  at 
  a 
  Meeting 
  of 
  

   our 
  Society, 
  10th 
  Nov., 
  1869, 
  in 
  which 
  the 
  previously 
  reputed 
  

   coracoid 
  of 
  Megalosaurus 
  was 
  shown 
  to 
  be 
  its 
  ilium, 
  and 
  the 
  forms 
  

   of 
  the 
  genuine 
  coracoid 
  and 
  scapula 
  were 
  made 
  known 
  (cf. 
  Prof. 
  J. 
  

   Phillips's 
  letter 
  of 
  July 
  1, 
  1869, 
  here 
  given). 
  I 
  now 
  knew 
  certainly 
  

   that 
  the 
  "scapula 
  of 
  an 
  unknown 
  reptile," 
  relegated 
  from 
  Iguanodon 
  

   to 
  Megalosaurus 
  did 
  not 
  enter 
  into 
  the 
  shoulder-girdle 
  of 
  the 
  latter. 
  

   At 
  one 
  time 
  I 
  conjectured 
  it 
  might 
  be 
  an 
  os 
  pubis, 
  in 
  its 
  spatulate 
  

   form 
  having 
  some 
  resemblance 
  to 
  that 
  of 
  the 
  crocodile 
  ; 
  but 
  becoming 
  

   better 
  acquainted 
  with 
  Dinosaurian 
  ilia 
  I 
  began 
  to 
  suspect 
  that 
  it 
  

   might 
  be 
  a 
  modified 
  form 
  of 
  ilium, 
  and 
  on 
  comparing 
  it 
  with 
  the 
  

   ilia 
  of 
  Iguanodon 
  Mantelli 
  and 
  of 
  Hypsilophodon 
  Foxii 
  I 
  was 
  grati- 
  

   fied 
  to 
  find 
  its 
  leading 
  features 
  repeated 
  in 
  these. 
  In 
  my 
  following- 
  

   autumn 
  holiday 
  (1870) 
  I 
  saw 
  in 
  Dr. 
  Wilkins's 
  collection 
  two 
  pre- 
  

   viously 
  unrecognized 
  bones 
  obviously 
  identical 
  with 
  Man 
  tell 
  's 
  type 
  

   " 
  scapula 
  of 
  an 
  unknown 
  reptile." 
  Wholly 
  stripped 
  of 
  their 
  matrix, 
  

   so 
  that 
  they 
  could 
  be 
  viewed 
  from 
  every 
  side, 
  they 
  illustrated 
  some 
  

   points 
  in 
  their 
  structure 
  better 
  than 
  the 
  only 
  two 
  previously 
  known 
  

   specimens, 
  and 
  substantiated, 
  I 
  thought, 
  my 
  surmise 
  that 
  the 
  reputed 
  

   scapula 
  wasan 
  ilium. 
  Dr.Wilkins 
  has 
  lately 
  very 
  courteously 
  afforded 
  

   me 
  an 
  opportunity 
  of 
  studying 
  these 
  bones 
  at 
  my 
  leisure, 
  and 
  he 
  

   kindly 
  permits 
  me 
  to 
  exhibit 
  them 
  this 
  evening. 
  

  

  The 
  smaller 
  bone 
  (PI. 
  XXXII. 
  fig. 
  1) 
  formally 
  repeats 
  Mantell's 
  

   and 
  Holmes's 
  specimens. 
  Its 
  glenoid 
  (or 
  acetabular) 
  end 
  is 
  in 
  some 
  

   of 
  its 
  details 
  much 
  more 
  complete 
  than 
  theirs 
  ; 
  but 
  a 
  considerable 
  part 
  

   of 
  the 
  body 
  is 
  missing 
  ; 
  it 
  has 
  been 
  broken 
  off 
  at 
  the 
  distance 
  of 
  one 
  inch 
  

   above 
  the 
  upper 
  root 
  of 
  the 
  long 
  anterior 
  process, 
  which 
  has 
  been 
  

   likened 
  to 
  a 
  connate 
  clavicle. 
  From 
  the 
  level 
  of 
  this 
  process 
  upwards 
  

   the 
  front 
  and 
  back 
  margins 
  of 
  the 
  body 
  converge 
  gently, 
  with 
  a 
  corre- 
  

   sponding 
  decrease 
  of 
  width 
  of 
  the 
  body, 
  as 
  far 
  as 
  this 
  has 
  been 
  pre- 
  

   served. 
  The 
  anterior 
  border 
  is 
  thin 
  and 
  sharp, 
  the 
  posterior 
  border 
  is 
  

   thicker. 
  The 
  greatest 
  thickness 
  of 
  the 
  body, 
  where 
  broken 
  across, 
  is 
  

   •7 
  inch. 
  Towards 
  the 
  glenoid 
  (or 
  acetabular) 
  end 
  the 
  body 
  widens 
  out 
  

   and 
  it 
  thickens. 
  The 
  terminal 
  aspect 
  of 
  this 
  end 
  is 
  chiefly 
  occupied 
  

   by 
  an 
  arched, 
  hollow, 
  smooth, 
  articular 
  surface 
  (fig. 
  1, 
  a, 
  & 
  fig. 
  2), 
  the 
  

   chord 
  of 
  which 
  forms 
  nearly 
  a 
  right 
  angle 
  with 
  the 
  axis 
  of 
  the 
  ex- 
  

   panded 
  blade 
  or 
  body 
  of 
  the 
  bone, 
  and 
  in 
  its 
  now 
  mutilated 
  condition 
  

   measures 
  about 
  3*5 
  inches. 
  In 
  the 
  direction 
  of 
  its 
  short 
  diameter, 
  or 
  

   transversely, 
  this 
  articular 
  surface 
  measures 
  at 
  its 
  anterior 
  extremity 
  

   1 
  inch, 
  which 
  increases 
  to 
  1'5 
  inch 
  at 
  its 
  posterior 
  end; 
  and 
  in 
  this 
  

   direction 
  the 
  surface 
  is 
  slightly 
  concave. 
  The 
  uninterrupted 
  smooth- 
  

   ness 
  of 
  this 
  arched 
  surface 
  throughout 
  its 
  whole 
  extent 
  unmistakably 
  

   indicates 
  that 
  the 
  whole 
  formed 
  one 
  part 
  of 
  a 
  joint 
  in 
  which 
  another 
  

   bone 
  played 
  freely 
  as 
  a 
  ball 
  in 
  a 
  socket. 
  At 
  each 
  end 
  this 
  arc 
  is 
  termi- 
  

   nated 
  by 
  a 
  process, 
  of 
  which 
  the 
  anterior 
  (p) 
  is 
  small 
  (in 
  the 
  speci- 
  

  

  2o 
  2 
  

  

  