﻿PTCN0D0NT1DJE. 
  

  

  237 
  

  

  squamosal 
  (sq.) 
  are 
  obscurely 
  indicated. 
  The 
  position 
  of 
  

   the 
  jaws 
  is 
  shown 
  by 
  remains 
  of 
  the 
  bones 
  and 
  traces 
  

   both 
  of 
  the 
  prehensile 
  and 
  tritoral 
  teeth. 
  The 
  so-called 
  

   ossified 
  sclerotic 
  (scl.) 
  of 
  the 
  very 
  large 
  eye 
  is 
  also 
  pre- 
  

   served, 
  and 
  seems 
  to 
  exhibit 
  a 
  few 
  minute 
  granulations, 
  

   A 
  few 
  of 
  the 
  small 
  polygonal 
  tesserae 
  (t.) 
  covering 
  the 
  

   cheek 
  can 
  be 
  seen 
  immediately 
  below 
  a 
  fragment 
  of 
  the 
  

   parasphenoid 
  ; 
  and 
  the 
  whole 
  of 
  the 
  gular 
  region 
  as 
  far 
  

   back 
  as 
  the 
  clavicle 
  is 
  invested 
  with 
  similar 
  tesserae 
  (t.) 
  

   bearing 
  sparse 
  tuber 
  culations. 
  A 
  few 
  traces 
  of 
  the 
  cal- 
  

   cified 
  gill-filaments 
  (g.f.) 
  remain 
  at 
  the 
  back 
  of 
  the 
  cheek 
  ; 
  

   while 
  the 
  right 
  operculum 
  and 
  preoperculum 
  are 
  exposed 
  

   from 
  the 
  inner 
  aspect. 
  The 
  operculum 
  (op.) 
  is 
  indented 
  

   on 
  the 
  front 
  margin 
  at 
  its 
  point 
  of 
  suspension 
  from 
  the 
  

   hyomandibular 
  ; 
  the 
  preoperculum 
  (jp.op.) 
  is 
  thickened 
  at 
  

   the 
  upper 
  end 
  and 
  exhibits 
  delicate 
  structural 
  fibres 
  

   radiating 
  from 
  a 
  point 
  at 
  about 
  the 
  middle 
  of 
  its 
  anterior 
  

   margin. 
  Immediately 
  below 
  the 
  preoperculum 
  are 
  two 
  

   branchiostegal 
  rays 
  (br.), 
  and 
  in 
  front 
  of 
  these 
  appear 
  

   fragments 
  of 
  bone 
  perhaps 
  of 
  the 
  hyoid 
  arch. 
  The 
  axial 
  

   skeleton 
  of 
  the 
  trunk 
  is 
  well 
  shown 
  and 
  is 
  noteworthy 
  

   for 
  the 
  form 
  of 
  the 
  expansions 
  on 
  the 
  neural 
  (n.) 
  and 
  

   haemal 
  (h.) 
  spines 
  of 
  the 
  caudal 
  region. 
  Each 
  expansion 
  

   is 
  triangular, 
  contracting 
  at 
  the 
  base, 
  widening 
  distally, 
  

   and 
  almost 
  — 
  though 
  not 
  quite 
  — 
  confined 
  to 
  the 
  anterior 
  

   margin 
  of 
  the 
  spine. 
  Similar 
  expansions 
  appear 
  to 
  occur 
  

   at 
  least 
  on 
  the 
  hindermost 
  neural 
  spines 
  of 
  the 
  abdominal 
  

   region. 
  The 
  lobe 
  of 
  the 
  pectoral 
  fin 
  {p.) 
  is 
  distinctly 
  

   covered 
  with 
  small 
  thin 
  scales, 
  each 
  ornamented 
  with 
  a 
  

   tubercle; 
  and 
  a 
  cluster 
  of 
  elongated 
  basal 
  cartilages 
  is 
  

   preserved. 
  The 
  lower 
  expansion 
  of 
  the 
  clavicle 
  (cl.) 
  

   terminates 
  in 
  a 
  point 
  at 
  the 
  ventral 
  border 
  of 
  the 
  fish. 
  

   The 
  slender 
  pelvic 
  bones 
  (plv.) 
  are 
  imperfectly 
  shown 
  at 
  

   the 
  base 
  of 
  the 
  fragmentary 
  pelvic 
  fins. 
  The 
  median 
  fins 
  

   exhibit 
  no 
  features 
  worthy 
  of 
  special 
  remark 
  ; 
  but 
  just 
  

   in 
  advance 
  of 
  the 
  origin 
  of 
  the 
  anal 
  the 
  problematical 
  

   bone 
  (x) 
  marking 
  the 
  posterior 
  limit 
  of 
  the 
  abdominal 
  

   cavity 
  is 
  well 
  displayed. 
  .Fine 
  serrations, 
  or 
  acuminate 
  

   tubercles, 
  are 
  observed 
  on 
  the 
  dorsal 
  and 
  ventral 
  ridge- 
  

   scales 
  ; 
  and 
  the 
  courses 
  of 
  both 
  " 
  lateral 
  lines 
  " 
  are 
  con- 
  

   spicuous. 
  Egerton 
  Coll. 
  

  

  P. 
  1619, 
  P. 
  3768. 
  More 
  imperfect 
  smaller 
  specimen, 
  in 
  counter- 
  

   part, 
  displaying 
  the 
  scaly 
  lobe 
  of 
  the 
  pectoral 
  fin 
  and 
  six 
  

  

  