﻿278 
  ACTTNOPTERYGII. 
  

  

  P. 
  4721. 
  Well-preserved 
  left 
  splenial 
  bone, 
  with 
  worn 
  dentition 
  ; 
  

  

  Sheppey. 
  Purchased, 
  1884. 
  

  

  P. 
  3759. 
  Smaller 
  more 
  abraded 
  specimen 
  ; 
  Sheppey. 
  

  

  EnnisJcillen 
  Coll. 
  

  

  The 
  following 
  specimens 
  probably 
  pertain 
  either 
  to 
  this 
  species 
  

   or 
  to 
  Pycnodus 
  bowerbanki 
  : 
  — 
  

  

  P. 
  610. 
  Ethmo-vomerine 
  region 
  of 
  skull 
  with 
  vomerine 
  dentition, 
  

   described 
  and 
  figured 
  as 
  the 
  type 
  specimen 
  of 
  Pycnodus 
  

   pachyrhinus, 
  Egerton, 
  Geol. 
  Mag. 
  [~2] 
  vol. 
  iv. 
  1877, 
  p. 
  54, 
  

   pi. 
  iv. 
  figs. 
  1,2; 
  London 
  Clay, 
  Isle 
  of 
  Sheppey. 
  The 
  

   fragment 
  of 
  bone 
  marked 
  s 
  in 
  Egerton's 
  figure 
  is 
  now 
  

   wanting. 
  Egerton 
  Coll. 
  

  

  P. 
  170. 
  Portion 
  of 
  similar 
  vomerine 
  dentition, 
  much 
  worn 
  ; 
  Sheppey. 
  

  

  Purchased, 
  1880. 
  

  

  Pycnodus 
  koenigi 
  (Agassiz). 
  

  

  1839-44. 
  Periodns 
  koenigii, 
  L. 
  Agassiz, 
  Poiss. 
  Foss. 
  vol. 
  ii. 
  pt. 
  ii. 
  p. 
  201, 
  

  

  pi. 
  lxxii. 
  a. 
  figs. 
  61, 
  62. 
  

   1850. 
  Periodus 
  koenigii, 
  F. 
  Dixon, 
  Geol. 
  Sussex, 
  p. 
  205, 
  pi. 
  x. 
  fig. 
  13. 
  

   1877. 
  Periodus 
  koenigi 
  = 
  Pycnodus 
  toliapicus, 
  Sir 
  P. 
  Egerton, 
  Geol. 
  

  

  Mag. 
  [2] 
  vol. 
  iv. 
  p. 
  53. 
  

   1890. 
  Periodus 
  koenigii 
  = 
  Pycnodus 
  toliapicus, 
  Woodward 
  & 
  Sherborn, 
  

  

  Catal. 
  Brit. 
  Foss. 
  Vertebrata, 
  p. 
  173. 
  

  

  Type. 
  Eight 
  splenial 
  dentition 
  ; 
  British 
  Museum. 
  

  

  The 
  type 
  species 
  of 
  Periodus, 
  known 
  only 
  by 
  the 
  splenial 
  dentition, 
  

   which 
  is 
  now 
  usually 
  assigned 
  to 
  P. 
  toliapicus. 
  From 
  the 
  latter, 
  

   however, 
  it 
  differs 
  in 
  the 
  outer 
  row 
  of 
  splenial 
  teeth 
  being 
  tilted 
  

   considerably 
  at 
  their 
  outer 
  border 
  and 
  in 
  the 
  relatively 
  longer 
  form 
  

   of 
  the 
  teeth 
  of 
  the 
  second 
  series. 
  

  

  Form. 
  Sf 
  Loc. 
  Middle 
  Eocene 
  : 
  Sussex 
  ; 
  Belgium. 
  

  

  25697. 
  Type 
  specimen 
  ; 
  Bracklesham 
  Beds, 
  Bracklesham 
  Bay, 
  

   Sussex. 
  Dixon 
  Coll. 
  

  

  42848. 
  Imperfect 
  left 
  splenial, 
  with 
  worn 
  dentition 
  ; 
  St. 
  Pierre 
  a 
  

   Gand. 
  Van 
  Breda 
  Coll. 
  

  

  P. 
  3752. 
  Imperfect 
  left 
  splenial 
  with 
  dentition, 
  perhaps 
  an 
  abnormal 
  

   example 
  of 
  this 
  species 
  ; 
  Bracklesham 
  Beds, 
  Bracklesham 
  

   Bay. 
  EnnisJcillen 
  Coll. 
  

  

  