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  ACTINOPTEEYGII. 
  

  

  times 
  in 
  the 
  total 
  length 
  from 
  the 
  pectoral 
  arch 
  to 
  the 
  extremity 
  of 
  

   the 
  caudal 
  fin. 
  Superficial 
  granulations 
  of 
  external 
  bones 
  sparse, 
  

   rounded, 
  and 
  those 
  of 
  the 
  pectoral 
  fin 
  similar. 
  Suboperculum 
  

   about 
  as 
  deep 
  as 
  broad, 
  with 
  produced 
  antero-superior 
  angle 
  ; 
  

   operculum 
  much 
  narrower 
  and 
  smaller, 
  with 
  somewhat 
  excavated 
  

   anterior 
  border 
  ; 
  at 
  least 
  nine 
  or 
  ten 
  branchiostegal 
  rays 
  on 
  each 
  

   side. 
  Pelvic 
  fins 
  more 
  than 
  two-thirds 
  as 
  large 
  as 
  the 
  pectorals, 
  

   the 
  distance 
  between 
  these 
  two 
  pairs 
  more 
  than 
  twice 
  as 
  great 
  as 
  

   that 
  between 
  the 
  former 
  and 
  the 
  anal. 
  Anal 
  fin 
  about 
  equal 
  to 
  

   the 
  pelvic 
  fins 
  in 
  size 
  ; 
  dorsal 
  relatively 
  large, 
  as 
  long 
  as 
  deep 
  ; 
  

   caudal 
  fin 
  large. 
  Caudal 
  fulcral 
  scales 
  narrow 
  and 
  sharply 
  pointed. 
  

  

  Form, 
  fy 
  Log, 
  Lower 
  Lias 
  : 
  Dorsetshire 
  and 
  Leicestershire. 
  

  

  All 
  the 
  following 
  specimens 
  were 
  obtained 
  from 
  the 
  neighbour- 
  

   hood 
  of 
  Lyme 
  Eegis, 
  Dorsetshire 
  : 
  — 
  

  

  P. 
  3361. 
  Imperfect 
  trunk, 
  wanting 
  the 
  hinder 
  half 
  of 
  the 
  caudal 
  

   region, 
  but 
  with 
  remains 
  of 
  the 
  head 
  and 
  opercular 
  

   apparatus, 
  described 
  and 
  figured 
  by 
  Egerton, 
  loc. 
  cit. 
  

   p. 
  872, 
  pi. 
  lxvii. 
  This 
  being 
  the 
  first 
  specimen 
  described, 
  

   must 
  be 
  regarded 
  as 
  the 
  type 
  of 
  the 
  species. 
  

  

  EnnishiTlen 
  Coll. 
  

  

  P. 
  3366. 
  Well-preserved 
  fish 
  about 
  one 
  metre 
  in 
  total 
  length, 
  shown 
  

   of 
  one-quarter 
  the 
  natural 
  size 
  in 
  PI. 
  I. 
  fig. 
  1, 
  and 
  

   forming 
  the 
  basis 
  of 
  the 
  restoration 
  in 
  fig. 
  2, 
  p. 
  24. 
  The 
  

   head 
  is 
  obliquely 
  crushed 
  and 
  very 
  imperfect, 
  but 
  several 
  

   elements 
  are 
  distinct. 
  The 
  exposed 
  surface 
  of 
  the 
  bones 
  

   of 
  the 
  cranial 
  roof 
  is 
  finely 
  rugose, 
  exhibiting 
  a 
  few 
  

   tuberculations. 
  Below 
  it 
  is 
  the 
  partially-covered 
  robust 
  

   hyomandibular 
  (Jim.) 
  ; 
  and 
  in 
  the 
  region 
  of 
  the 
  jaws 
  there 
  

   only 
  remain 
  the 
  imperfect 
  pterygoid 
  (pt.) 
  and 
  jugal 
  (ju.) 
  

   of 
  the 
  right 
  side. 
  The 
  small 
  narrow 
  operculum 
  (op.) 
  and 
  

   the 
  relatively 
  large 
  suboperculum 
  (s.op.) 
  are 
  well 
  preserved. 
  

   Both 
  post-temporals 
  are 
  shown, 
  that 
  of 
  the 
  left 
  side 
  from 
  

   the 
  inner, 
  that 
  of 
  the 
  right 
  side 
  from 
  the 
  outer 
  aspect 
  ; 
  

   and 
  the 
  long, 
  narrow 
  supraclavicle 
  (s.cl.) 
  is 
  seen 
  above 
  

   the 
  comparatively 
  large 
  clavicle 
  (cl.). 
  The 
  axial 
  skeleton 
  

   of 
  the 
  trunk 
  is 
  only 
  very 
  imperfectly 
  exhibited 
  ; 
  but 
  a 
  

   few 
  of 
  the 
  slender 
  neural 
  spines 
  with 
  their 
  stouter 
  arches 
  

   occur 
  scattered 
  in 
  the 
  abdominal 
  region. 
  The 
  specially 
  

   robust 
  haemal 
  arches 
  at 
  the 
  base 
  of 
  the 
  lower 
  caudal 
  lobe 
  

   are 
  also 
  seen. 
  All 
  the 
  fins 
  are 
  preserved, 
  only 
  the 
  upper 
  

   extremity 
  of 
  the 
  caudal 
  being 
  wanting. 
  The 
  anterior 
  

   rays 
  in 
  each 
  fin 
  gradually 
  increase 
  in 
  length 
  to 
  its 
  apex, 
  

  

  