﻿H. 
  G, 
  SEELEY 
  ON 
  A 
  DINOSAURIAN 
  CORACOID. 
  371 
  

  

  distinguished 
  from 
  the 
  coracoid 
  of 
  Iguanodon 
  by 
  wanting 
  the 
  notch 
  

   between 
  the 
  humeral 
  and 
  scapular 
  surfaces, 
  which 
  in 
  that 
  genus 
  

   represents 
  the 
  foramen 
  in 
  this. 
  

  

  In 
  many 
  characters 
  our 
  Wealden 
  coracoid 
  approaches 
  nearer 
  to 
  

   American 
  types, 
  such 
  as 
  Morosaurus, 
  and 
  especially 
  Camptonotus, 
  

   than 
  to 
  any 
  English 
  form. 
  The 
  resemblance 
  is 
  seen 
  in 
  form, 
  of 
  the 
  

   bone, 
  angle 
  of 
  the 
  scapular 
  margin, 
  and 
  especially 
  in 
  a 
  ridge 
  which 
  

   diverges 
  from 
  the 
  humeral 
  articulation 
  downward 
  over 
  the 
  outer 
  

   surface 
  of 
  the 
  bone. 
  This 
  ridge 
  is 
  well 
  seen 
  in 
  Stegosaurus, 
  and 
  is 
  

   less 
  developed 
  and 
  nearer 
  the 
  margin 
  in 
  Camptonotus. 
  But 
  in 
  no 
  

   American 
  genus 
  are 
  the 
  characters 
  identical 
  with 
  those 
  here 
  seen 
  ; 
  

   for 
  in 
  this 
  coracoid 
  the 
  lateral 
  ridge 
  rises 
  opposite 
  the 
  middle 
  of 
  the 
  

   humeral 
  articular 
  surface. 
  

  

  The 
  large 
  size 
  of 
  the 
  bone 
  makes 
  it 
  probable 
  that 
  the 
  bone, 
  if 
  per- 
  

   taining 
  to 
  a 
  described 
  genus, 
  must 
  be 
  referred 
  to 
  either 
  Pelorosaurus 
  

   or 
  Ornithopsis. 
  The 
  resemblances 
  of 
  the 
  bone 
  to 
  coracoids 
  of 
  Ameri- 
  

   can 
  Stegosauria 
  may 
  make 
  the 
  affinity 
  of 
  the 
  bone 
  with 
  Ornithopsis 
  

   sufficiently 
  probable 
  to 
  be 
  adopted. 
  Pelorosaurus 
  has 
  never 
  been 
  

   critically 
  described 
  ; 
  but 
  many 
  of 
  the 
  bones 
  referred 
  to 
  it 
  seem 
  to 
  

   me 
  unquestionably 
  Iguanodont, 
  probably 
  belonging 
  to 
  a 
  large 
  species 
  

   of 
  Iguanodon 
  ; 
  while 
  other 
  bones 
  like 
  the 
  great 
  humerus 
  (Owen, 
  

   Palaeont. 
  Soc. 
  1859, 
  Suppl. 
  2, 
  p. 
  39, 
  pi. 
  xii.) 
  seem 
  to 
  me 
  to 
  belong 
  

   to 
  Ornithopsis. 
  

  

  So 
  few 
  types 
  of 
  Dinosaurian 
  coracoid 
  have 
  been 
  figured, 
  that 
  I 
  

   believe 
  this 
  form 
  will 
  possess 
  a 
  certain 
  interest 
  in 
  demonstrating 
  

   that 
  generic 
  characters 
  may 
  be 
  found 
  in 
  the 
  shoulder-girdle 
  ; 
  and 
  it 
  

   may 
  furnish 
  new 
  evidence 
  in 
  support 
  of 
  the 
  genus 
  Ornithopsis. 
  

  

  I 
  would 
  express 
  my 
  thanks 
  to 
  Professor 
  Hughes 
  for 
  his 
  kindness 
  

   in 
  allowing 
  me 
  to 
  study 
  this 
  specimen. 
  

  

  Discussion. 
  

  

  The 
  President 
  considered 
  the 
  specimen 
  the 
  most 
  magnificent 
  

   Dinosaurian 
  coracoid 
  he 
  had 
  ever 
  seen. 
  There 
  was 
  one 
  thing 
  to 
  be 
  

   said 
  against 
  regarding 
  this 
  bone 
  as 
  belonging 
  to 
  Ornithopsis, 
  namely 
  

   that 
  it 
  had 
  been 
  found 
  in 
  beds 
  lower 
  than 
  those 
  in 
  which 
  Orni- 
  

   thopsis 
  had 
  hitherto 
  been 
  obtained. 
  He 
  doubted 
  whether 
  there 
  

   had 
  been 
  any 
  mesial 
  sutural 
  union 
  of 
  the 
  coracoids, 
  a 
  feature 
  as 
  

   yet 
  unobserved 
  in 
  Dinosaurs. 
  Iguanodon 
  Seelyi 
  was 
  found 
  at 
  the 
  

   same 
  horizon 
  as 
  this 
  bone. 
  

  

  Prof. 
  Seelet 
  did 
  not 
  see 
  any 
  difficulty 
  in 
  Ornithopsis 
  occurring 
  

   lower 
  in 
  the 
  beds 
  at 
  Brook, 
  since 
  it 
  ranged 
  to 
  Tilgate. 
  He 
  was 
  at 
  

   first 
  disposed 
  to 
  examine 
  whether 
  this 
  coracoid 
  might 
  not 
  belong 
  to 
  

   Pelorosaurus. 
  But 
  most 
  of 
  the 
  bones 
  of 
  that 
  genus 
  so 
  resembled 
  

   Iguanodon 
  that 
  there 
  are 
  no 
  characters 
  in 
  the 
  coracoid 
  or 
  other 
  parts 
  

   of 
  the 
  skeleton 
  which 
  differentiate 
  it 
  clearly. 
  If 
  the 
  bone 
  is 
  attri- 
  

   buted 
  to 
  Iguanodon 
  Seelyi, 
  it 
  proves 
  that 
  that 
  species 
  must 
  be 
  re- 
  

   ferred 
  to 
  some 
  other 
  genus 
  ; 
  for 
  the 
  characters 
  of 
  this 
  coracoid 
  are 
  

   distinct 
  from 
  those 
  of 
  Iguanodon. 
  The 
  reference 
  of 
  an 
  isolated 
  bone 
  

   to 
  its 
  species 
  when 
  the 
  region 
  to 
  which 
  it 
  belongs 
  is 
  previously 
  un- 
  

   known 
  is 
  necessarily 
  a 
  matter 
  of 
  probabilities. 
  

  

  