﻿J. 
  W. 
  HTTLKE 
  ON 
  SOME 
  IGX7ANODON-EEMAIN8. 
  141 
  

  

  backwards 
  a 
  lip 
  adapted 
  to 
  the 
  intercondylar 
  groove 
  of 
  the 
  phalanx 
  

   next 
  behind 
  ; 
  and 
  the 
  nnder 
  surface 
  is 
  reduced 
  to 
  a 
  minimum 
  by 
  the 
  

   plantar 
  prolongation 
  backwards 
  of 
  the 
  distal 
  articular 
  surface. 
  The 
  

   ungual 
  phalanx 
  of 
  this 
  toe 
  is 
  smaller 
  than 
  that 
  of 
  the 
  other 
  toes. 
  

   Its 
  figure 
  is 
  less 
  symmetrical 
  than 
  that 
  of 
  the 
  middle 
  toe. 
  An 
  out- 
  

   ward 
  inclination 
  serves 
  to 
  distinguish 
  it 
  from 
  the 
  claw-bone 
  of 
  the 
  

   inner 
  toe, 
  than 
  which 
  it 
  is 
  also 
  less 
  blunt. 
  Its 
  present 
  length 
  is 
  

   14 
  centim. 
  (5| 
  in.); 
  but 
  when 
  perfect 
  it 
  was 
  probably 
  not 
  less 
  

   than 
  15-5 
  centim. 
  (6 
  in.) 
  long. 
  The 
  vertical 
  diameter 
  of 
  its 
  proxi- 
  

   imal 
  end 
  is 
  6'1 
  centim. 
  (2| 
  in.), 
  and 
  the 
  horizontal 
  diameter 
  57 
  

   centim. 
  (2J 
  in.). 
  The 
  breadth 
  of 
  the 
  phalanx 
  at 
  the 
  base 
  of 
  the 
  

   claw-groove 
  is 
  8*3 
  centim. 
  (3 
  J 
  in.), 
  and 
  at 
  2 
  centim. 
  (-J 
  in.) 
  from 
  the 
  

   distal 
  end 
  it 
  is 
  4*2 
  centim. 
  (1-| 
  in.). 
  

  

  Vertebras 
  (fig. 
  2). 
  — 
  The 
  three 
  caudal 
  vertebrae 
  were 
  found 
  cemen- 
  

   ted 
  together 
  by 
  rock, 
  which 
  has 
  preserved 
  their 
  natural 
  sequence. 
  A 
  

   slight 
  lateral 
  dislocation 
  has 
  permitted 
  me 
  to 
  lay 
  bare 
  their 
  articular 
  

   surfaces. 
  The 
  centra 
  are 
  short 
  ; 
  measured 
  along 
  the 
  neural 
  surface 
  

   their 
  length 
  is 
  only 
  11*4 
  centim., 
  11 
  centim., 
  and 
  10*6 
  centim. 
  (4-1-, 
  

   4-L, 
  and 
  4-J 
  in.). 
  The 
  vertical 
  dimension, 
  or 
  height, 
  measured 
  from 
  

   the 
  neural 
  surface 
  to 
  the 
  under 
  surface 
  between 
  the 
  chevron-facets, 
  

   is 
  18-6 
  centim., 
  18*4 
  centim., 
  and 
  17 
  centim. 
  (7J, 
  7-J-, 
  and 
  7^ 
  in.). 
  

   The 
  horizontal 
  diameter 
  below 
  the 
  root 
  of 
  the 
  transverse 
  process 
  

   is 
  13-2 
  centim., 
  13*4 
  centim., 
  and 
  12-3 
  centim. 
  (54-, 
  5J, 
  and 
  4-| 
  in.). 
  

  

  Fig. 
  2. 
  — 
  Oblique 
  anterior 
  View 
  of 
  an 
  early 
  Caudal 
  Vertebra 
  of 
  

   Iguanodon 
  Seelyi. 
  (About 
  \ 
  nat. 
  size.) 
  

  

  A 
  gentle 
  expansion 
  of 
  the 
  centrum 
  towards 
  its 
  articular 
  ends 
  

   imparts 
  to 
  the 
  lateral 
  surfaces 
  a 
  slight 
  concavity 
  in 
  the 
  antero- 
  

   posterior 
  direction. 
  These 
  surfaces 
  are 
  nearly 
  plane 
  in 
  the 
  vertical 
  

   direction 
  ; 
  and 
  below 
  they 
  converge 
  slightly. 
  The 
  under 
  surface 
  is 
  

   much 
  reduced 
  by 
  the 
  encroachment 
  of 
  the 
  chevron-facets, 
  of 
  which 
  

   the 
  posterior 
  is 
  much 
  the 
  larger. 
  The 
  great 
  size 
  of 
  these 
  facets 
  

   diminishes 
  the 
  lateral 
  surfaces 
  in 
  the 
  lower 
  third 
  of 
  their 
  extent 
  ; 
  

  

  