﻿244 
  ME. 
  E. 
  LTDEKKEE 
  ON 
  EEMAINS 
  OF 
  EOCENE 
  AND 
  MESOZOIC 
  

  

  having 
  led 
  me 
  to 
  recognize 
  that 
  the 
  teeth 
  mentioned 
  below 
  are 
  refer- 
  

   able 
  to 
  the 
  same 
  suborder. 
  

  

  The 
  present 
  specimen 
  is 
  somewhat 
  more 
  worn 
  at 
  the 
  summit 
  and 
  

   at 
  the 
  edges 
  than 
  the 
  preceding 
  example, 
  and 
  also 
  differs 
  slightly 
  in 
  

   contour 
  from 
  the 
  latter. 
  These 
  differences 
  are, 
  however, 
  not 
  greater 
  

   than 
  might 
  reasonably 
  be 
  expected 
  to 
  occur 
  in 
  teeth 
  from 
  different 
  

   parts 
  of 
  the 
  jaw 
  of 
  one 
  and 
  the 
  same 
  species 
  ; 
  but 
  I 
  do 
  not 
  desire 
  to 
  

   press 
  the 
  point 
  of 
  specific 
  characters 
  one 
  way 
  or 
  the 
  other. 
  That 
  

   which, 
  however, 
  has 
  especially 
  interested 
  me 
  in 
  that 
  specimen 
  is 
  its 
  

   general 
  resemblance 
  to 
  teeth 
  from 
  the 
  Portlandian 
  of 
  Boulogne, 
  

   which 
  have 
  been 
  described 
  and 
  figured, 
  firstly 
  under 
  the 
  name 
  of 
  

   Neosodon, 
  and 
  subsequently 
  as 
  Caulodon. 
  The 
  type 
  of 
  the 
  former 
  

   is 
  figured 
  by 
  Count 
  de 
  la 
  Moussaye 
  in 
  a 
  paper 
  published 
  in 
  1885 
  * 
  ; 
  

   and 
  consists 
  of 
  the 
  worn 
  crown 
  of 
  a 
  large 
  tooth, 
  having 
  a 
  transverse 
  

   diameter 
  of 
  one 
  and 
  a 
  half 
  inch. 
  A 
  comparison 
  of 
  this 
  figure 
  with 
  

   the 
  figures 
  of 
  the 
  two 
  English 
  teeth 
  from 
  the 
  Wealden 
  shows 
  at 
  

   once 
  that 
  the 
  three 
  belong 
  to 
  closely 
  allied 
  forms, 
  although 
  the 
  

   English 
  specimens 
  are 
  only 
  one 
  inch 
  in 
  diameter. 
  This 
  general 
  

   identity 
  is 
  manifest 
  by 
  the 
  general 
  spatulate 
  contour 
  of 
  the 
  crown, 
  

   with 
  the 
  concave 
  inner 
  and 
  convex 
  outer 
  surface, 
  and 
  the 
  truncate 
  

   inverted 
  V, 
  formed 
  by 
  the 
  worn 
  summit 
  and 
  margins. 
  Count 
  Mous- 
  

   saye 
  makes 
  no 
  suggestion 
  as 
  to 
  the 
  affinity 
  of 
  his 
  Neosodon, 
  beyond 
  

   saying 
  that 
  the 
  tooth 
  appeared 
  to 
  be 
  somewhat 
  intermediate 
  between 
  

   the 
  teeth 
  of 
  Iguanodon 
  and 
  Megalosaurus. 
  

  

  The 
  next 
  communication 
  on 
  the 
  subject 
  which 
  I 
  have 
  to 
  notice 
  is 
  

   one 
  recently 
  published 
  by 
  Dr. 
  E. 
  Sauvage, 
  who 
  describes 
  and 
  figuresf 
  

   other 
  teeth 
  from 
  the 
  Portlandian 
  of 
  Boulogne 
  which 
  are 
  similar 
  to 
  

   the 
  type 
  of 
  Neosodon. 
  M. 
  Sauvage, 
  however, 
  identifies 
  them 
  with 
  a 
  

   tooth 
  previously 
  described 
  by 
  himself 
  as 
  Iguanodon 
  precursor 
  %, 
  and 
  on 
  

   the 
  verbal 
  evidence 
  of 
  Prof. 
  Cope 
  refers 
  them 
  to 
  the 
  genus 
  Caulodon, 
  

   founded 
  by 
  the 
  latter 
  writer 
  on 
  specimens 
  from 
  the 
  Upper 
  Jurassic 
  

   of 
  North 
  America. 
  As 
  to 
  whether 
  the 
  latter 
  reference 
  is 
  or 
  is 
  not 
  

   correct, 
  I 
  have 
  nothing 
  to 
  say, 
  because, 
  so 
  far 
  as 
  I 
  am 
  aware, 
  the 
  

   teeth 
  of 
  the 
  typical 
  Caulodon 
  are 
  not 
  figured, 
  and 
  I 
  know 
  not 
  

   whether 
  that 
  genus 
  is 
  distinct 
  from 
  all 
  of 
  those 
  described 
  by 
  Prof. 
  

   Marsh. 
  

  

  "When, 
  however, 
  M. 
  Sauvage 
  proceeds 
  to 
  say 
  that 
  these 
  teeth 
  indi- 
  

   cate 
  a 
  member 
  of 
  the 
  Iguanodontidse,' 
  he 
  is 
  clearly 
  mistaken, 
  since 
  

   there 
  can 
  be 
  no 
  question 
  but 
  that 
  they 
  are 
  of 
  the 
  general 
  type 
  of 
  the 
  

   above-mentioned 
  English 
  teeth, 
  which 
  are 
  undoubtedly 
  Sauropo- 
  

   dous. 
  It 
  is 
  quite 
  probable, 
  indeed, 
  that 
  they 
  may 
  be 
  referable 
  to 
  

   Ornithopsis 
  humerocristatus 
  § 
  of 
  the 
  Kimeridgian 
  of 
  Weymouth, 
  or 
  

   to 
  a 
  closely-allied 
  form. 
  And 
  here 
  I 
  take 
  the 
  opportunity 
  of 
  cor- 
  

   recting 
  an 
  error 
  in 
  my 
  previously 
  quoted 
  paper, 
  into 
  which 
  I 
  was 
  

   led 
  by 
  a 
  mistaken 
  interpretation 
  of 
  a 
  figure 
  in 
  one 
  of 
  Prof. 
  Marsh's 
  

   memoirs. 
  I 
  there 
  referred 
  the 
  vertebrae 
  from 
  the 
  Kimeridgian 
  of 
  

  

  * 
  Bull. 
  Soc. 
  Geol. 
  France, 
  ser. 
  3, 
  vol. 
  xiii. 
  p. 
  51, 
  fig. 
  1 
  (1885). 
  

  

  t 
  Ibid. 
  ser. 
  3, 
  vol. 
  xyi. 
  p. 
  626, 
  pi. 
  xii. 
  figs. 
  1-4 
  (1888). 
  

  

  % 
  See 
  also 
  Dollo, 
  Eev. 
  Quest. 
  Sci. 
  vol. 
  xvii. 
  p. 
  627. 
  

  

  § 
  = 
  Cetiosaurus 
  humerocristatus, 
  Hulke 
  ; 
  vide 
  Q. 
  J. 
  G-. 
  S. 
  vol. 
  xliv. 
  p. 
  57. 
  

  

  