﻿396 
  AOTINOPTERYGII. 
  

  

  The 
  blunt 
  anterior 
  end 
  of 
  the 
  rostrum, 
  well 
  shown 
  in 
  

   side-view 
  (fig. 
  1 
  a), 
  exhibits 
  a 
  slight 
  mesial 
  vertical 
  ridge. 
  

   There 
  are 
  some 
  traces 
  of 
  closed 
  sutures 
  in 
  the 
  cranial 
  roof, 
  

   but 
  the 
  fragments 
  are 
  too 
  imperfect 
  for 
  satisfactory 
  deter- 
  

   mination. 
  Leeds 
  Coll. 
  

  

  P. 
  6914. 
  Imperfect 
  rostrum 
  about 
  half 
  as 
  large 
  as 
  the 
  type, 
  asso- 
  

   ciated 
  with 
  the 
  tooth-bearing 
  border 
  of 
  the 
  dentary 
  bone 
  ; 
  . 
  

   near 
  Peterborough. 
  Only 
  the 
  base 
  of 
  the 
  left 
  vomerine 
  

   tooth 
  is 
  preserved 
  ; 
  and 
  instead 
  of 
  two 
  enlarged 
  marginal 
  

   teeth 
  anteriorly, 
  there 
  is 
  but 
  one. 
  A 
  transverse 
  section 
  

   of 
  one 
  of 
  the 
  large 
  teeth 
  of 
  the 
  dentary 
  is 
  prepared 
  for 
  

   microscopical 
  examination, 
  and 
  exhibits 
  the 
  complex 
  

   structure 
  noted 
  in 
  Ann. 
  Mag. 
  Nat. 
  Hist. 
  [6] 
  vol. 
  xiii. 
  

   (1894), 
  p. 
  511. 
  Leeds 
  Coll. 
  

  

  P. 
  6915. 
  Abraded 
  large 
  right 
  splenial 
  with 
  remains 
  of 
  anterior 
  end 
  

  

  of 
  dentary, 
  probably 
  of 
  this 
  species 
  

  

  near 
  Peterborough. 
  

   Leeds 
  Coll. 
  

  

  P. 
  6833. 
  Fragments 
  of 
  skull 
  and 
  pectoral 
  fin 
  probably 
  of 
  this 
  

   species 
  ; 
  near 
  Peterborough. 
  Leeds 
  Coll. 
  

  

  Hypsocormus 
  tenuirostris, 
  A. 
  S. 
  Woodward. 
  

   [Plate 
  XI. 
  figs. 
  2-6.] 
  

  

  1889. 
  Hypsocormus 
  tenuirostris, 
  

   vol. 
  vi. 
  p. 
  451. 
  

  

  A. 
  S. 
  Woodward, 
  Geol. 
  Mag. 
  [3] 
  

  

  Type. 
  Remains 
  of 
  skull 
  ; 
  British 
  Museum. 
  

  

  An 
  imperfectly 
  known 
  species 
  about 
  as 
  large 
  as 
  H. 
  macrodon. 
  

   Snout 
  acutely 
  pointed 
  and 
  produced 
  so 
  that 
  its 
  length 
  in 
  advance 
  of 
  

   the 
  large 
  vomerine 
  teeth 
  somewhat 
  exceeds 
  its 
  breadth 
  at 
  their 
  

   insertion 
  ; 
  external 
  surface 
  finely 
  granulated 
  ; 
  the 
  large 
  vomerine 
  

   teeth 
  directed 
  almost 
  vertically. 
  

  

  Form. 
  Sf 
  Loc. 
  Oxfordian 
  : 
  Huntingdonshire. 
  

  

  P. 
  6916. 
  The 
  type 
  specimen, 
  comprising 
  rostrum, 
  right 
  maxilla 
  and 
  

   premaxilla, 
  portion 
  of 
  left 
  dentary, 
  and 
  other 
  associated 
  

   fragments 
  ; 
  Oxford 
  Clay, 
  near 
  Peterborough. 
  The 
  ros- 
  

   trum 
  (PI. 
  XI. 
  figs. 
  2, 
  2 
  a) 
  is 
  comparatively 
  narrow 
  and 
  

   acutely 
  pointed, 
  and 
  there 
  is 
  a 
  considerable 
  extension 
  in 
  

   advance 
  of 
  the 
  vomerine 
  area 
  (fig. 
  2, 
  v. 
  a.). 
  The 
  whole 
  of 
  

   the 
  external 
  surface 
  is 
  ornamented 
  with 
  fine 
  tubercles. 
  

   The 
  two 
  vomers 
  seem 
  to 
  be 
  fused 
  into 
  one 
  bone, 
  and 
  the 
  

   greater 
  part 
  of 
  the 
  large 
  tooth 
  of 
  the 
  right 
  side 
  is 
  pre- 
  

   served, 
  while 
  the 
  socket 
  only 
  of 
  that 
  on 
  the 
  left 
  is 
  exhibited. 
  

  

  