﻿H. 
  G. 
  SEELEY 
  ON 
  MUR^NOSACRUS 
  LEEDSH. 
  197 
  

  

  21. 
  On 
  Mur^n'osattrits 
  Leedsii, 
  a 
  Plesiosattrian 
  from 
  the 
  Oxford 
  

   Clay. 
  Part 
  I. 
  By 
  Harry 
  G. 
  Seeley, 
  Esq., 
  F.L.S., 
  F.G.S. 
  (Read 
  

   May 
  13, 
  1874.) 
  

  

  [Plate 
  XXI.] 
  

  

  While 
  on 
  a 
  visit 
  to 
  Charles 
  E. 
  Leeds, 
  Esq., 
  M.A., 
  of 
  Exeter 
  Col- 
  

   lege, 
  Oxford, 
  a 
  gentleman 
  whose 
  specimens 
  have 
  more 
  than 
  once 
  

   enriched 
  the 
  writings 
  of 
  Professor 
  Phillips, 
  I 
  was 
  shown 
  a 
  Saurian 
  

   in 
  such 
  perfect 
  preservation 
  as 
  previously, 
  so 
  far 
  as 
  I 
  am 
  aware, 
  

   had 
  rarely 
  been 
  seen 
  except 
  from 
  the 
  Lias. 
  It 
  was 
  gathered 
  from 
  

   the 
  Lower 
  Oxford 
  Clay 
  (a 
  stratum 
  abounding 
  in 
  Plesiosaurians 
  in 
  

   the 
  middle 
  of 
  England) 
  in 
  Huntingdonshire, 
  in 
  fragments 
  almost 
  

   innumerable, 
  which 
  have 
  been 
  adjusted 
  and 
  reunited 
  with 
  remark- 
  

   able 
  skill 
  and 
  zeal 
  by 
  the 
  labours 
  of 
  Mr. 
  Charles 
  Leeds 
  and 
  his 
  

   brother 
  Mr. 
  Alfred 
  Leeds, 
  so 
  that 
  now 
  the 
  animal 
  displays 
  : 
  — 
  the 
  

   front 
  and 
  hinder 
  parts 
  of 
  the 
  skull 
  ; 
  the 
  lower 
  jaw, 
  somewhat 
  over 
  

   a 
  foot 
  long 
  ; 
  a 
  vertebral 
  column 
  of 
  79 
  vertebrae, 
  from 
  which, 
  how- 
  

   ever, 
  nearly 
  all 
  the 
  tail 
  is 
  missing 
  — 
  the 
  vertebrae 
  preserved 
  being 
  

   44 
  cervical, 
  3 
  pectoral, 
  20 
  dorsal, 
  4 
  pelvic, 
  and 
  8 
  caudal 
  ; 
  numerous 
  

   ribs 
  ; 
  the 
  coracoids 
  and 
  scapulae 
  ; 
  the 
  pubes, 
  ischia, 
  and 
  iliac 
  bones, 
  

   together 
  with 
  both 
  fore 
  and 
  hind 
  limbs. 
  Whether 
  the 
  tail 
  has 
  be- 
  

   come 
  a 
  prey 
  to 
  the 
  casual 
  collector's 
  unscientific 
  mania 
  for 
  bones 
  I 
  

   know 
  not 
  ; 
  but 
  these 
  remains, 
  being 
  the 
  fruit 
  of 
  long 
  zealous 
  collecting 
  

   and 
  care, 
  could 
  obviously 
  only 
  have 
  been 
  gathered 
  in 
  a 
  district 
  where 
  

   competition 
  was 
  kept 
  subordinate 
  to 
  scientific 
  spirit. 
  Finding 
  that 
  

   this 
  noble 
  specimen 
  (from 
  which 
  hardly 
  any 
  important 
  part 
  except 
  

   the 
  tail 
  is 
  lost) 
  indicated 
  in 
  my 
  opinion 
  a 
  new 
  genus 
  as 
  well 
  as 
  a 
  

   new 
  species, 
  Mr. 
  Charles 
  Leeds 
  volunteered 
  to 
  write 
  from 
  my 
  dic- 
  

   tation 
  the 
  account 
  of 
  the 
  animal 
  which 
  I 
  am 
  thus 
  by 
  his 
  kindness 
  

   able 
  to 
  submit 
  to 
  the 
  Geological 
  Society. 
  The 
  short 
  time 
  at 
  my 
  

   disposal 
  compelled 
  me 
  to 
  leave 
  the 
  hind 
  limbs 
  undescribed, 
  to 
  form 
  

   hereafter 
  the 
  subject 
  of 
  another 
  communication, 
  when 
  I 
  hope 
  to 
  

   offer 
  to 
  the 
  Society 
  some 
  account 
  also 
  of 
  the 
  other 
  undescribed 
  or 
  

   imperfectly 
  indicated 
  Plesiosauria 
  from 
  the 
  Oxford 
  Clay, 
  with 
  which 
  

   this 
  species 
  may 
  be 
  properly 
  compared. 
  

  

  The 
  Skulk. 
  

  

  The 
  skull 
  is 
  represented 
  by 
  the 
  premaxillaries, 
  portions 
  of 
  the 
  max- 
  

   illary 
  bones, 
  the 
  frontal 
  bones, 
  supraorbital, 
  postfrontal, 
  parietal, 
  basi- 
  

   sphenoid, 
  exoccipital 
  and 
  basioccipital 
  bones, 
  and 
  the 
  lower 
  jaw. 
  

  

  The 
  premaxillaries 
  carry 
  five 
  teeth 
  on 
  each 
  of 
  the 
  bones, 
  which 
  are 
  

   connected 
  by 
  a 
  nearly 
  straight 
  median 
  suture. 
  They 
  have 
  the 
  surface 
  

   rough 
  and 
  irregular 
  on 
  the 
  superior 
  and 
  lateral 
  parts 
  as 
  well 
  as 
  on 
  the 
  

   palate, 
  the 
  roughnesses 
  being 
  due 
  to 
  a 
  conical 
  bulging 
  of 
  the 
  bone 
  

   around 
  the 
  entrance 
  to 
  nutritive 
  bloood- 
  vessels. 
  Each 
  premaxillary 
  

   bone 
  is 
  triangular 
  in 
  front; 
  but 
  no 
  sutures 
  can 
  be 
  seen 
  separating 
  the 
  

   bones 
  from 
  the 
  nasal 
  bones 
  behind, 
  perhaps 
  because 
  the 
  premaxillary 
  

  

  Q. 
  J. 
  G. 
  S. 
  No. 
  119. 
  q 
  

  

  