﻿PYCXODOXTID-E. 
  277 
  

  

  (including 
  the 
  caudal 
  fin) 
  ; 
  head 
  with 
  opercular 
  apparatus 
  occupying 
  

   somewhat 
  more 
  than 
  one-quarter 
  of 
  the 
  total 
  length. 
  Teeth 
  and 
  

   fins 
  apparently 
  as 
  in 
  the 
  type 
  species. 
  

  

  This 
  form 
  was 
  regarded 
  by 
  Agassiz, 
  in 
  his 
  final 
  description, 
  as 
  

   the 
  young 
  of 
  P. 
  platessus. 
  It 
  is 
  here 
  assigned 
  to 
  a 
  distinct 
  species 
  

   on 
  the 
  authority 
  of 
  Heckel, 
  who 
  refers 
  to 
  three 
  small 
  specimens 
  of 
  

   P. 
  platessus 
  as 
  showing 
  the 
  same 
  proportions 
  of 
  the 
  trunk 
  as 
  the 
  

   typical 
  adult. 
  

  

  Form. 
  <$f 
  Loc. 
  Upper 
  Eocene 
  : 
  N. 
  Italy. 
  

  

  P. 
  7459. 
  Specimen 
  0-135 
  in 
  length, 
  displaying 
  proportions 
  of 
  splenial 
  

   teeth 
  and 
  remains 
  of 
  paired 
  fins 
  ; 
  Monte 
  Bolca, 
  near 
  

   Yerona. 
  Purchased. 
  

  

  P. 
  1633^i. 
  Two 
  smaller 
  specimens, 
  the 
  second 
  imperfect 
  dorsally 
  

   and 
  wanting 
  the 
  hinder 
  half 
  of 
  the 
  caudal 
  region 
  ; 
  Monte 
  

   Bolca. 
  Egerton 
  Coll. 
  

  

  P. 
  4386. 
  More 
  imperfect 
  fish 
  showing 
  the 
  hollowed 
  crown 
  of 
  the 
  

   splenial 
  teeth 
  ; 
  Monte 
  Bolca. 
  Enniskillen 
  Coll. 
  

  

  P. 
  1632, 
  P. 
  3760. 
  Small 
  specimen, 
  0-06 
  in 
  length, 
  in 
  counterpart 
  ; 
  

   Monte 
  Bolca. 
  Egerton 
  and 
  Enniskillen 
  Colls< 
  

  

  Pycnodus 
  toliapicus, 
  Agassiz. 
  

  

  1839-44. 
  Pycnodus 
  toliapicus, 
  L. 
  Agassiz, 
  Poiss. 
  Foss. 
  toI. 
  ii. 
  pt. 
  ii. 
  

  

  p. 
  196, 
  pi. 
  lxxii. 
  a. 
  fig. 
  55. 
  

   1877. 
  Pycnodus 
  toliapicus, 
  Sir 
  P. 
  Egerton, 
  Geol. 
  Mag. 
  [2] 
  vol. 
  iv. 
  p.- 
  53. 
  

  

  Type. 
  Imperfect 
  splenial 
  dentition 
  ; 
  Oxford 
  Museum. 
  

  

  A 
  large 
  species, 
  known 
  only 
  by 
  the 
  splenial 
  dentition. 
  Teeth 
  of 
  

   inner 
  or 
  principal 
  series 
  on 
  the 
  splenial 
  bone 
  attaining 
  a 
  width 
  

   more 
  than 
  twice 
  as 
  great 
  as 
  their 
  length, 
  equalling 
  the 
  two 
  flank^ 
  

   ing 
  series 
  in 
  breadth 
  and 
  the 
  latter 
  almost 
  in 
  the 
  same 
  plane 
  ; 
  teeth 
  

   of 
  second 
  series 
  considerably 
  broader 
  than 
  long, 
  with 
  rugose 
  aud 
  

   slightly 
  indented 
  crown 
  : 
  those 
  of 
  the 
  outer 
  series 
  smaller, 
  nearly 
  

   as 
  long 
  as 
  broad, 
  similarly 
  rugose 
  and 
  indented. 
  

  

  Form. 
  Sf 
  Loc. 
  Lower 
  Eocene 
  : 
  London 
  Basin. 
  

  

  38825-26. 
  Splenial 
  dentition, 
  imperfect 
  and 
  abnormal 
  on 
  the 
  left 
  

   side, 
  the 
  anterior 
  principal 
  teeth 
  being 
  subdivided 
  into 
  

   small 
  teeth 
  ; 
  London 
  Clay, 
  Isle 
  of 
  Sheppey. 
  This 
  specimen 
  

   is 
  described 
  by 
  Egerton, 
  loc. 
  cit. 
  p. 
  53. 
  Bowerbank 
  Coll. 
  

  

  ZZ. 
  12 
  (Cracherode 
  Catalogue). 
  Smaller 
  left 
  splenial 
  dentition 
  : 
  

   Sheppey. 
  Cracherode 
  Bequest. 
  

  

  