﻿PYCNODONTIDJE. 
  261 
  

  

  1845. 
  Pycnodus 
  subdeltoideus, 
  A. 
  E. 
  Reuss, 
  ibid. 
  pt. 
  i. 
  p. 
  10, 
  pl 
  r 
  iv. 
  

  

  figs. 
  38-42. 
  [Detached 
  teeth.] 
  

   1850. 
  Gyrodus 
  angustus, 
  F. 
  Dixon, 
  Geol. 
  Sussex, 
  p. 
  370, 
  pi. 
  xxx. 
  fig. 
  14, 
  

  

  pi. 
  xxxiii. 
  fig. 
  1. 
  

  

  1855. 
  Pycnodus 
  cretaceus, 
  E. 
  Hubert, 
  Mem. 
  Soc. 
  G6ol. 
  France, 
  [2] 
  vol. 
  v. 
  

   p. 
  353, 
  pi. 
  xxvii. 
  fig. 
  7. 
  

  

  1856. 
  Pycnodus 
  rhomboidalis, 
  C. 
  E. 
  Fischer, 
  Allg. 
  deutsche 
  Nat. 
  Zeit., 
  

   n. 
  s., 
  vol. 
  ii. 
  p. 
  137, 
  figs. 
  2, 
  3. 
  

  

  1875. 
  Pycnodus 
  cretaceus, 
  H. 
  B. 
  Geinitz, 
  Palasontogr. 
  vol. 
  xx. 
  pt. 
  i. 
  

  

  p. 
  300, 
  pi. 
  lxv. 
  tigs. 
  12-14, 
  and 
  pt. 
  ii. 
  p. 
  217, 
  pi. 
  xl. 
  figs. 
  30-32. 
  

   1878. 
  Pycnodus 
  cretaceus, 
  A. 
  Fritsch, 
  Rept. 
  u. 
  Fische 
  bohm. 
  Kreide- 
  

  

  form. 
  p. 
  22, 
  pi. 
  ii. 
  figs. 
  1-4, 
  woodc. 
  48. 
  

   1878. 
  Gyrodus 
  angustus, 
  A. 
  Fritsch, 
  ibid. 
  p. 
  25, 
  woodc. 
  53. 
  

  

  1887. 
  Ccelodus 
  angustus, 
  K. 
  A. 
  von 
  Zittel, 
  Handb. 
  Palaeont. 
  vol. 
  iii. 
  

   p. 
  249. 
  

  

  (?) 
  1887. 
  Coelodus 
  cretaceus, 
  K. 
  A. 
  von 
  Zittel, 
  ibid. 
  p. 
  249. 
  

  

  1888. 
  Coelodus 
  angustus, 
  A. 
  S. 
  Woodward, 
  Proc. 
  Geol. 
  Assoc, 
  vol. 
  x. 
  

   p. 
  307. 
  

  

  (?) 
  1888. 
  Ccelodus 
  cretaceus, 
  A. 
  S. 
  Woodward, 
  ibid. 
  p. 
  308. 
  

  

  Type, 
  Series 
  of 
  teeth 
  ; 
  British 
  Museum 
  (in 
  part). 
  

  

  A 
  small 
  species, 
  known 
  by 
  the 
  dentition 
  and 
  part 
  of 
  the 
  head 
  and 
  

   trunk. 
  Teeth 
  of 
  the 
  principal 
  series 
  on 
  the 
  splenial 
  bone 
  very 
  

   obliquely 
  set, 
  truncated 
  at 
  their 
  outer 
  extremity, 
  rapidly 
  tapering 
  to 
  

   a 
  blunt 
  point 
  at 
  the 
  inner 
  extremity, 
  and 
  when 
  young 
  and 
  unworn 
  

   marked 
  with 
  a 
  slight 
  transverse 
  coronal 
  furrow 
  ; 
  inner 
  teeth 
  in 
  two 
  

   irregular 
  series, 
  those 
  of 
  the 
  first 
  elongated, 
  those 
  of 
  the 
  innermost 
  

   much 
  smaller 
  and 
  round, 
  both 
  deeply 
  pitted 
  ; 
  teeth 
  of 
  the 
  flanking 
  

   series 
  in 
  about 
  three 
  or 
  four 
  very 
  irregular 
  rows, 
  all 
  deeply 
  pitted, 
  the 
  

   innermost 
  transversely 
  elongated 
  and 
  much 
  larger 
  than 
  any 
  of 
  the 
  

   others, 
  which 
  are 
  rounded. 
  Scales 
  marked 
  with 
  coarse 
  reticulations, 
  

   and 
  serrations 
  of 
  the 
  ventral 
  ridge-scales 
  conspicuous, 
  long, 
  and 
  

   slender. 
  

  

  The 
  fragment 
  of 
  dentition 
  named 
  Pycnodus 
  cretaceus 
  seems 
  to 
  

   differ 
  only 
  from 
  the 
  typical 
  corresponding 
  teeth 
  of 
  this 
  species 
  in 
  

   its 
  relatively 
  large 
  size. 
  There 
  are 
  intermediate 
  specimens 
  in 
  the 
  

   Collection. 
  

  

  Form. 
  Sf 
  Loc. 
  Senonian 
  : 
  S.E. 
  England, 
  and 
  Meudon, 
  France. 
  

   Cenomanian 
  : 
  Saxony 
  and 
  Bohemia 
  K 
  

  

  25731, 
  25780. 
  Portion 
  of 
  axial 
  skeleton 
  of 
  trunk, 
  with 
  another 
  

   portion 
  of 
  fish 
  displaying 
  scales 
  and 
  the 
  two 
  splenial 
  

  

  1 
  Specimens 
  are 
  also 
  recorded 
  from 
  Switzerland 
  by 
  W. 
  A. 
  Ooster, 
  Protozoe 
  

   Helvetica, 
  1870, 
  vol. 
  ii. 
  p. 
  45. 
  A 
  right 
  splenial 
  from 
  the 
  Danian 
  of 
  Maastricht, 
  

   apparently 
  not 
  of 
  this 
  species, 
  is 
  named 
  Anomosodus 
  cretaceus 
  (Ag.) 
  by 
  H. 
  

   Forir, 
  Ann. 
  Soc. 
  Geol. 
  Belgique, 
  vol. 
  xvi. 
  (1889), 
  Mem. 
  p. 
  450, 
  pi. 
  xiv. 
  fig. 
  2. 
  

  

  