﻿CHOKDROSTEID^. 
  29 
  

  

  the 
  short 
  foremost 
  of 
  these 
  being 
  apparently 
  unjointed 
  ; 
  

   all 
  the 
  rays 
  beyond 
  the 
  apex 
  are 
  articulated 
  and 
  finely 
  

   branched 
  distally. 
  The 
  anterior 
  pectoral 
  rays 
  are 
  not 
  

   much 
  enlarged, 
  and 
  there 
  are 
  indications 
  of 
  the 
  super- 
  

   ficial 
  tubercles 
  on 
  this 
  fin. 
  The 
  pelvic 
  fins 
  appear 
  to 
  be 
  

   slightly 
  deeper 
  than 
  long, 
  and 
  each 
  is 
  supported 
  by 
  a 
  

   regular 
  series 
  of 
  short 
  and 
  stout 
  hour-glass-shaped 
  basals. 
  

   The 
  dorsal 
  fin 
  is 
  opposed 
  to 
  the 
  latter 
  and 
  is 
  shown 
  to 
  

   have 
  been 
  supported 
  by 
  short, 
  stout 
  baseosts 
  and 
  slender, 
  

   elongated 
  axonosts, 
  which 
  taper 
  towards 
  the 
  neural 
  

   arches 
  of 
  the 
  axial 
  skeleton. 
  The 
  anal 
  fin 
  is 
  smaller 
  than 
  

   the 
  dorsal, 
  and 
  its 
  endoskeletal 
  supports 
  are 
  only 
  feebly 
  

   indicated. 
  A 
  series 
  of 
  supports, 
  slender 
  anteriorly, 
  

   becoming 
  shorter 
  and 
  robust 
  behind, 
  is 
  displayed 
  beneath 
  

   the 
  fulcral 
  scales 
  of 
  the 
  upper 
  caudal 
  lobe 
  ; 
  seven 
  scales 
  

   resting 
  upon 
  ten 
  or 
  eleven 
  supports. 
  The 
  caudal 
  fin 
  is 
  

   nearly 
  equilobate. 
  The 
  oat-shaped 
  scales 
  are 
  well- 
  

   preserved 
  on 
  the 
  sides 
  of 
  the 
  upper 
  caudal 
  lobe, 
  smooth 
  

   and 
  flattened 
  externally, 
  tumid 
  on 
  their 
  attached 
  face. 
  

   There 
  is 
  no 
  evidence 
  of 
  other 
  dermal 
  armature; 
  but 
  

   fragments 
  apparently 
  of 
  the 
  skin 
  are 
  preserved 
  in 
  the 
  

   upper 
  half 
  of 
  the 
  abdominal 
  region, 
  and 
  these 
  exhibit 
  a 
  

   series 
  of 
  short 
  double 
  ridges 
  evidently 
  indicating 
  the 
  

   course 
  of 
  the 
  lateral 
  line. 
  Some 
  coprolitic 
  matter 
  occurs 
  

   above 
  the 
  pelvic 
  fins. 
  EnnisJcillen 
  Coll. 
  

  

  P. 
  2047. 
  Imperfect 
  small 
  individual, 
  originally 
  about 
  0*42 
  in 
  length. 
  

  

  Egerton 
  Coll. 
  

  

  38545. 
  Imperfect 
  small 
  individual, 
  about 
  0*56 
  in 
  length, 
  showing 
  

   portions 
  of 
  all 
  the 
  fins. 
  Purchased, 
  1864, 
  

  

  P. 
  3367. 
  Slightly 
  larger 
  specimen, 
  with 
  imperfectly 
  preserved 
  tail, 
  

   wanting 
  the 
  anal 
  fin. 
  The 
  maxillary 
  and 
  pterygoid 
  bones 
  

   are 
  described 
  and 
  figured 
  by 
  Traquair, 
  loc. 
  cit. 
  p. 
  254, 
  fig. 
  4, 
  

   and 
  re-drawn 
  of 
  the 
  natural 
  size 
  in 
  PL 
  I. 
  fig. 
  3 
  of 
  the 
  

   present 
  volume. 
  The 
  left 
  operculum 
  and 
  suboperculum 
  

   are 
  also 
  shown, 
  and 
  the 
  pectoral 
  fins 
  are 
  especially 
  well- 
  

   preserved 
  ; 
  most 
  of 
  the 
  rays 
  of 
  these 
  fins 
  exhibit 
  a 
  

   longitudinal 
  series 
  of 
  tubercles 
  fused 
  with 
  their 
  basal 
  half. 
  

  

  Enniskillen 
  Coll. 
  

  

  P. 
  2050. 
  Eemains 
  of 
  head 
  and 
  abdominal 
  region, 
  exhibiting 
  the 
  

   form 
  of 
  the 
  clavicle, 
  and 
  displaying 
  a 
  long 
  series 
  of 
  

   neural 
  arches 
  with 
  their 
  loosely 
  apposed 
  neural 
  spines. 
  A 
  

  

  