﻿306 
  ACTINOPTERYGII. 
  

  

  P. 
  2020. 
  Posterior 
  abdominal 
  and 
  caudal 
  region 
  of 
  an 
  equally 
  large 
  

   individual, 
  the 
  scales 
  somewhat 
  scattered 
  dorsally 
  and 
  

   ventrally, 
  and 
  the 
  fins 
  imperfect. 
  Egerton 
  Coll. 
  

  

  P. 
  7564. 
  Crushed 
  specimen 
  as 
  large 
  as 
  the 
  type, 
  with 
  scattered 
  head- 
  

   bones. 
  Several 
  of 
  the 
  elements 
  are 
  displayed, 
  notably 
  the 
  

   hyomandibular 
  and 
  symplectic 
  of 
  both 
  sides. 
  The 
  hyo- 
  

   mandibular 
  is 
  relatively 
  broad, 
  expanded 
  below, 
  and 
  not 
  

   much 
  constricted 
  mesially; 
  the 
  symplectic 
  is 
  elongated, 
  

   triangular 
  in 
  form, 
  the 
  apex 
  being 
  inferior 
  and 
  much 
  

   thickened. 
  History 
  unknown. 
  

  

  P. 
  3579. 
  A 
  slightly 
  smaller 
  specimen, 
  also 
  with 
  displaced 
  head- 
  

   bones 
  and 
  exhibiting 
  some 
  of 
  the 
  incomplete 
  anterior 
  

   vertebral 
  rings. 
  The 
  base 
  of 
  the 
  skull 
  is 
  imperfectly 
  

   shown, 
  and 
  the 
  left 
  quadrato-pterygopalatine 
  arch 
  is 
  

   exposed 
  from 
  the 
  inner 
  side. 
  On 
  the 
  parasphenoid 
  and 
  

   the 
  oral 
  face 
  of 
  the 
  pterygoids, 
  as 
  also 
  on 
  the 
  hinder 
  part 
  

   of 
  the 
  splenial, 
  the 
  dentition 
  is 
  reduced 
  to 
  a 
  fine 
  granu- 
  

   lation 
  ; 
  but 
  at 
  the 
  anteroinferior 
  border 
  of 
  the 
  ectoptery- 
  

   goid, 
  either 
  on 
  that 
  bone 
  itself 
  or 
  on 
  the 
  palatine, 
  the 
  teeth 
  

   are 
  of 
  moderate 
  size 
  and 
  arranged 
  in 
  a 
  dense 
  cluster. 
  

  

  Ennishillen 
  Coll. 
  

  

  P. 
  6395. 
  Hinder 
  portion 
  of 
  head 
  and 
  greater 
  part 
  of 
  the 
  squamation 
  

   of 
  a 
  fish 
  as 
  large 
  as 
  the 
  type, 
  in 
  indurated 
  Lias. 
  The 
  

   postorbital 
  and 
  opercular 
  bones 
  are 
  shown, 
  and 
  the 
  

   ornament 
  of 
  the 
  anterior 
  scales 
  is 
  conspicuous. 
  

  

  Beclcles 
  Coll. 
  

  

  P. 
  3579 
  a. 
  Remains 
  of 
  the 
  trunk 
  of 
  a 
  similar 
  fish, 
  showing 
  the 
  

   axial 
  skeleton. 
  The 
  hypocentra 
  in 
  the 
  abdominal 
  region 
  

   are 
  broad 
  and 
  robust, 
  flattened 
  below, 
  each 
  with 
  a 
  pair 
  of 
  

   lateral 
  processes 
  bearing 
  nearly 
  straight 
  slender 
  ribs. 
  

   The 
  neural 
  and 
  haemal 
  arches 
  in 
  the 
  caudal 
  region 
  are 
  

   robust, 
  and 
  appear 
  to 
  be 
  anchylosed 
  with 
  their 
  respective 
  

   pleurocentra 
  and 
  hypocentra. 
  Enniskillen 
  Coll. 
  

  

  P. 
  2009. 
  Well-preserved 
  smaller 
  fish, 
  wanting 
  the 
  region 
  behind 
  the 
  

   dorsal 
  fin. 
  The 
  supratemporal 
  and 
  post-temporal 
  plates 
  

   are 
  shown 
  behind 
  the 
  cranium 
  and 
  above 
  the 
  operculum, 
  

   ornamented 
  with 
  tuberculations 
  ; 
  the 
  robust 
  maxilla 
  is 
  

   smooth. 
  The 
  perforations 
  of 
  the 
  scales 
  in 
  the 
  lateral 
  line 
  

   are 
  distinguishable, 
  though 
  inconspicuous 
  vertical 
  slits; 
  

  

  