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  ACTINOPTERTGII. 
  

  

  caudal 
  pedicle, 
  the 
  depth 
  of 
  which 
  equals 
  at 
  least 
  half 
  the 
  maximum 
  

   depth 
  of 
  the 
  trunk. 
  

  

  Form. 
  Sf 
  Loc. 
  Lower 
  Lias 
  : 
  Leicestershire. 
  

  

  The 
  following 
  specimens 
  are 
  preserved 
  in 
  nodules 
  from 
  Earrow- 
  

   on-Soar 
  : 
  — 
  

  

  P. 
  3580. 
  The 
  type 
  specimen, 
  in 
  counterpart. 
  The 
  figure 
  and 
  

   description 
  of 
  the 
  operculum 
  are 
  misleading, 
  this 
  hone 
  

   attaining 
  its 
  maximum 
  width 
  inferiorly 
  and 
  tapering 
  

   above, 
  as 
  proved 
  by 
  the 
  next 
  specimen. 
  EnnisJcillen 
  Coll. 
  

  

  P. 
  2007, 
  P. 
  3580 
  a. 
  Hinder 
  part 
  of 
  head 
  and 
  the 
  abdominal 
  region 
  

   of 
  a 
  large 
  specimen 
  in 
  counterpart. 
  The 
  operculum 
  is 
  

   well 
  shown, 
  and 
  the 
  pectoral 
  fin 
  nearly 
  complete. 
  

  

  Egerton 
  Sf 
  Enniskillen 
  Colls. 
  

  

  P. 
  2007 
  a. 
  Specimen 
  much 
  like 
  the 
  type, 
  but 
  wanting 
  the 
  anterior 
  

   half 
  of 
  the 
  head. 
  The 
  fulcra 
  of 
  the 
  dorsal 
  fin 
  are 
  dis- 
  

   played, 
  and 
  appear 
  to 
  be 
  relatively 
  larger 
  than 
  in 
  H. 
  latus. 
  

  

  Egerton 
  Coll. 
  

  

  P. 
  7565. 
  Trunk 
  wanting 
  head, 
  and 
  the 
  squamation 
  only 
  preserved 
  

   in 
  impression. 
  Fulcra 
  are 
  conspicuous 
  on 
  the 
  anterior 
  

   margin 
  of 
  the 
  dorsal 
  and 
  pelvic 
  fins 
  ; 
  and 
  the 
  greater 
  

   part 
  of 
  the 
  caudal 
  fin 
  is 
  shown. 
  

  

  19488. 
  Posterior 
  abdominal 
  and 
  caudal 
  region 
  of 
  a 
  typical 
  specimen, 
  

   showing 
  the 
  greater 
  part 
  of 
  the 
  dorsal, 
  caudal, 
  and 
  pelvic 
  

   fins. 
  The 
  last-mentioned 
  fins 
  seem 
  to 
  arise 
  just 
  in 
  advance 
  

   of 
  the 
  dorsal, 
  though 
  there 
  may 
  be 
  a 
  displacement. 
  There 
  

   is 
  evidence 
  of 
  robust 
  vertebral 
  elements. 
  

  

  Presented 
  by 
  the 
  Earl 
  of 
  Aylesford, 
  1845. 
  

  

  19488 
  a. 
  Fragment 
  of 
  trunk, 
  showing 
  pleurocentrum 
  and 
  hypo- 
  

   centrum 
  in 
  transverse 
  section. 
  

  

  Presented 
  by 
  the 
  Earl 
  of 
  Aylesford, 
  1845. 
  

  

  Heterolepidotus 
  typieus 
  (Winkler). 
  

  

  1861. 
  Brachyichihys 
  typicus, 
  T. 
  C. 
  Winkler, 
  Descript. 
  Poiss. 
  Foss. 
  

   Solenhofen 
  (Natuurk. 
  Verhandl. 
  Holland. 
  Maatsch. 
  [2] 
  vol. 
  xiv.), 
  

   p. 
  53, 
  fig. 
  9. 
  

  

  Type. 
  Imperfect 
  fish; 
  British 
  Museum. 
  

  

  The 
  type 
  species 
  of 
  the 
  so-called 
  genus 
  Brachyichihys, 
  attaining 
  

   a 
  length 
  of 
  about 
  0*5. 
  Length 
  of 
  head 
  with 
  opercular 
  apparatus 
  

   about 
  equalling 
  the 
  maximum 
  depth 
  of 
  the 
  trunk, 
  and 
  contained 
  

   four 
  times 
  in 
  the 
  total 
  length 
  of 
  the 
  fish. 
  Operculum 
  nearly 
  as 
  

  

  