﻿PYCNODONTID^!. 
  243 
  

  

  strongly 
  ornamented, 
  while 
  the 
  outer 
  end 
  of 
  the 
  larger 
  teeth 
  is 
  

   raised 
  into 
  a 
  pointed 
  eminence. 
  

  

  Form. 
  Sf 
  Log. 
  Neocomian 
  (Speeton 
  Clay) 
  : 
  Yorkshire. 
  

  

  P. 
  1624. 
  Imperfect 
  left 
  splenial; 
  Speeton. 
  Egerton 
  Coll. 
  

  

  Gyrodus 
  coccoderma, 
  Egerton. 
  

  

  (?) 
  1867. 
  Pycnodus 
  subcontiguidens, 
  H. 
  E. 
  Sauvage, 
  Catal. 
  Poiss. 
  Form. 
  

  

  Second. 
  Boulonnais 
  (Mem. 
  Soc. 
  Acad. 
  Boulogne-sur-Mer, 
  vol. 
  ii.), 
  

  

  p. 
  36, 
  pi. 
  ii. 
  figs. 
  10, 
  11. 
  

   1869. 
  Gyrodus 
  coccoderma, 
  Sir 
  P. 
  Egerton, 
  Quart. 
  Journ. 
  Geol. 
  Soc. 
  

  

  vol. 
  xxv. 
  p. 
  383, 
  figs. 
  3, 
  4. 
  

   1880. 
  Gyrodus 
  coccoderma, 
  R. 
  Damon, 
  Geol. 
  Weymouth, 
  ed. 
  2, 
  Suppl. 
  

  

  pi. 
  xi. 
  fig. 
  5. 
  

   (?) 
  1880. 
  Mesodon 
  subcontiguidens, 
  H. 
  E. 
  Sauvage, 
  Bull. 
  Soc. 
  Geol 
  

  

  France, 
  [3] 
  vol. 
  viii. 
  p. 
  528. 
  

  

  Type. 
  Vomer 
  ; 
  Museum 
  of 
  Practical 
  Geology, 
  London. 
  

  

  A 
  species 
  of 
  large 
  or 
  moderate 
  size, 
  known 
  only 
  by 
  the 
  dentition. 
  

   Teeth 
  closely 
  arranged 
  and 
  all 
  with 
  a 
  feeble 
  ornamentation, 
  rapidly 
  

   obliterated 
  by 
  wearing. 
  Vomer 
  with 
  a 
  prominent 
  median 
  series 
  of 
  

   teeth, 
  at 
  least 
  equalling 
  the 
  two 
  flanking 
  series 
  in 
  width 
  ; 
  the 
  outer 
  

   of 
  the 
  latter 
  obtusely 
  conical, 
  not 
  much 
  elevated 
  and 
  exceeding 
  in 
  

   size 
  the 
  inner 
  series 
  of 
  flanking 
  teeth, 
  which 
  are 
  round 
  or 
  antero- 
  

   posteriorly 
  elongated. 
  Splenial 
  differing 
  from 
  that 
  of 
  G. 
  circularis 
  

   and 
  G. 
  cuvieri 
  merely 
  in 
  the 
  comparative 
  smoothness 
  of 
  the 
  teeth. 
  

  

  Though 
  the 
  name 
  G. 
  coccoderma 
  was 
  originally 
  proposed 
  for 
  some 
  

   specifically 
  indeterminable 
  scales, 
  it 
  has 
  gradually 
  become 
  applied 
  

   to 
  the 
  dentition 
  above 
  described, 
  and 
  the 
  vomer 
  provisionally 
  

   assigned 
  to 
  this 
  species 
  by 
  Egerton 
  may 
  thus 
  be 
  regarded 
  as 
  the 
  

   type 
  specimen. 
  

  

  Form, 
  fy 
  Loc. 
  Kimmeridgian 
  : 
  Dorsetshire 
  and 
  Cambridgeshire 
  ; 
  

   N. 
  France. 
  

  

  P. 
  6747. 
  Fine 
  large 
  vomer 
  k 
  028 
  in 
  maximum 
  width, 
  with 
  little- 
  

   worn 
  dentition 
  ; 
  Kimmeridge 
  Clay, 
  Weymouth. 
  

  

  Purchased, 
  1892. 
  

  

  P. 
  6167. 
  Two 
  somewhat 
  smaller 
  specimens, 
  one 
  figured 
  by 
  Damon, 
  

   op. 
  cit. 
  pi. 
  xi. 
  fig. 
  5 
  ; 
  Weymouth. 
  Damon 
  Coll. 
  

  

  43560, 
  43562. 
  Portion 
  of 
  similar 
  vomer, 
  and 
  a 
  smaller 
  specimen 
  ; 
  

   Weymouth. 
  Purchased, 
  1872. 
  

  

  40637, 
  41175, 
  P. 
  3785 
  a. 
  Three 
  fine 
  much-worn 
  vomers 
  ; 
  Wey- 
  

   mouth. 
  Purchased, 
  1867-68 
  and 
  Enniskillen 
  CoV. 
  

  

  r2 
  

  

  