﻿210 
  ' 
  ACTINOPTERYGIT. 
  

  

  P. 
  7437. 
  Left 
  splenial 
  either 
  of 
  this 
  or 
  the 
  preceding 
  species 
  ; 
  

   Portlandian 
  (zone 
  of 
  Ammonites 
  gigas), 
  Duingen, 
  Harz. 
  

  

  Purchased, 
  1895. 
  

  

  Mesodon 
  damoni, 
  A. 
  S. 
  Woodward. 
  

  

  1860. 
  Pycnodus 
  bucklandi, 
  B. 
  Damon 
  (errore), 
  Geol. 
  Weymouth, 
  Suppl. 
  

  

  pi. 
  viii. 
  fig. 
  9. 
  

   1890. 
  Mesodon, 
  sp., 
  Woodward 
  & 
  Sherborn, 
  Catal. 
  Brit. 
  Foss. 
  Verte- 
  

  

  brata, 
  p. 
  121. 
  

   1890. 
  Mesodon 
  damoni, 
  A. 
  S. 
  W 
  T 
  oodward, 
  Geol. 
  Mag. 
  [3] 
  vol. 
  vii. 
  p. 
  158. 
  

   1893. 
  Mesodon 
  damoni, 
  A. 
  S. 
  Woodward, 
  ibid. 
  vol. 
  x. 
  pi. 
  xvi. 
  fig. 
  6. 
  

  

  Type. 
  Left 
  splenial 
  dentition 
  ; 
  British 
  Museum. 
  

  

  A 
  large 
  species, 
  known 
  only 
  by 
  the 
  dentition 
  of 
  the 
  lower 
  jaw. 
  

   Teeth 
  rounded 
  or 
  closely 
  arranged, 
  smooth 
  or 
  very 
  feebly 
  rugose, 
  

   without 
  an 
  apical 
  pit. 
  Teeth 
  of 
  principal 
  series 
  on 
  splenial 
  bone 
  

   almost 
  or 
  quite 
  twice 
  as 
  broad 
  as 
  long 
  ; 
  teeth 
  of 
  the 
  inner 
  series 
  

   considerably 
  larger 
  than 
  any 
  of 
  the 
  outer 
  series, 
  flanked 
  within 
  also 
  

   by 
  an 
  irregular, 
  incomplete 
  row 
  of 
  small 
  teeth 
  ; 
  those 
  of 
  the 
  outer 
  

   series 
  arranged 
  in 
  four 
  irregular 
  rows, 
  variable 
  in 
  size, 
  but 
  the 
  

   innermost 
  and 
  outermost 
  usually 
  the 
  largest. 
  

  

  Form. 
  Sf 
  Loc. 
  Portlandian 
  : 
  Dorsetshire. 
  

  

  P. 
  6165. 
  Left 
  splenial 
  bone, 
  the 
  type 
  specimen 
  ; 
  Portland. 
  

  

  Damon 
  Coll. 
  

  

  P. 
  6180. 
  Bight 
  and 
  left 
  splenial 
  dentition, 
  partly 
  fractured, 
  in 
  

   slab 
  of 
  limestone 
  ; 
  Ilpway, 
  near 
  Weymouth. 
  Damon 
  Coll. 
  

  

  P. 
  1642-3. 
  Imperfect 
  right 
  and 
  left 
  splenials 
  ; 
  near 
  Weymouth. 
  

  

  Egerton 
  Coll. 
  

  

  P. 
  3738. 
  Bight 
  splenial 
  ; 
  near 
  Weymouth. 
  Ennishillen 
  Coll. 
  

  

  P. 
  4678. 
  Fragmentary 
  left 
  splenial 
  ; 
  Bidgway 
  near 
  Weymouth. 
  

  

  Presented 
  by 
  C. 
  Westendarp, 
  Esq., 
  1884. 
  

  

  Mesodon 
  gigas 
  (Agassiz). 
  

  

  1742. 
  Dent 
  de 
  Dentato, 
  L. 
  Bourguet, 
  Traite" 
  des 
  Petrifications, 
  p. 
  78, 
  

  

  pi. 
  lvii. 
  fig. 
  396. 
  

   1833-44. 
  Pycnodus 
  gigas, 
  L. 
  Agassiz, 
  Poiss. 
  Foss. 
  vol. 
  ii. 
  pt. 
  i. 
  p. 
  17, 
  

  

  pt. 
  ii. 
  p. 
  191, 
  pi. 
  lxxi. 
  fig. 
  13, 
  pi. 
  Ixxii. 
  a. 
  figs. 
  56-58. 
  

   1839. 
  Pycnodus 
  gigas, 
  F. 
  A. 
  Boemer, 
  Verstein. 
  Norddeutsch. 
  Ooli- 
  

  

  thengeb., 
  Nachtr. 
  p. 
  54. 
  

   1860. 
  Pycnodus 
  gigas, 
  F. 
  J. 
  Pictet, 
  Bept. 
  & 
  Poiss. 
  Foss. 
  Jura 
  Neu- 
  

  

  chatelois, 
  p. 
  46, 
  pis. 
  x., 
  xi. 
  ; 
  pi. 
  xviii. 
  fig. 
  2. 
  

  

  