﻿52 
  

  

  ACTINOPTEETGII. 
  

  

  Type. 
  Imperfect 
  fish 
  ; 
  Newcastle-upon-Tyne 
  Museum. 
  

  

  The 
  type 
  species, 
  attaining 
  a 
  length 
  of 
  about 
  0*09. 
  Head 
  with 
  

   opercular 
  apparatus 
  occupying 
  slightly 
  less 
  than 
  one-quarter 
  of 
  the 
  

   total 
  length 
  : 
  maximum 
  depth 
  of 
  trunk 
  equalling 
  about 
  twice 
  that 
  

   of 
  the 
  caudal 
  pedicle, 
  and 
  comprised 
  four 
  times 
  in 
  the 
  total 
  length. 
  

   Head 
  and 
  opercular 
  bones 
  faintly 
  rugose 
  ; 
  operculum 
  broader 
  than 
  

   deep. 
  Dorsal 
  fin 
  with 
  about 
  10, 
  and 
  anal 
  with 
  8 
  rays. 
  Scales 
  

   unornamented, 
  not 
  serrated. 
  

  

  Form. 
  <$f 
  Log. 
  Upper 
  Permian 
  (Magnesian 
  Limestone) 
  : 
  Durham, 
  

  

  36388-90. 
  Two 
  typical 
  specimens, 
  the 
  first 
  wanting 
  the 
  extremity 
  

   of 
  the 
  snout 
  and 
  the 
  paired 
  fins, 
  the 
  second 
  more 
  imper- 
  

   fect 
  ; 
  also 
  a 
  smaller 
  fish 
  ; 
  Fulwell 
  Hill, 
  near 
  Sunderland. 
  

   Presented 
  by 
  Sir 
  He&worih 
  Williamson, 
  Bart., 
  1862. 
  

  

  P. 
  3481 
  a, 
  b. 
  Two 
  fine 
  specimens 
  about 
  0*09 
  in 
  length, 
  somewhat 
  

   fractured, 
  but 
  showing 
  parts 
  of 
  all 
  the 
  fins 
  ; 
  Fulwell 
  Hill. 
  

   In 
  the 
  second 
  specimen 
  the 
  scales 
  are 
  distinctly 
  shown 
  to 
  

   be 
  smooth. 
  Enniskillen 
  Coll. 
  

  

  P, 
  3481 
  C. 
  Slightly 
  smaller 
  fish 
  displaying 
  portions 
  of 
  the 
  median 
  

   fins 
  ; 
  Fulwell 
  Hill. 
  Bnniskillen 
  Coll. 
  

  

  P. 
  3481, 
  P. 
  3483, 
  P. 
  4342. 
  Four 
  more 
  imperfect 
  specimens, 
  three 
  

   being 
  much 
  smaller 
  than 
  the 
  preceding 
  ; 
  Fulwell 
  Hill. 
  

   One 
  of 
  the 
  two 
  specimens 
  occurring 
  on 
  a 
  single 
  slab 
  

   appears 
  to 
  exhibit 
  traces 
  of 
  styliform 
  teeth 
  in 
  the 
  dentary, 
  

   and 
  enlarged 
  anal 
  scales 
  in 
  advance 
  of 
  the 
  median 
  fin. 
  

  

  Enniskillen 
  Coll. 
  

  

  P. 
  1032. 
  Fish 
  about 
  0-065 
  in 
  length 
  and 
  two 
  smaller 
  more 
  im- 
  

   perfect 
  specimens 
  ; 
  Fulwell 
  Hill. 
  Egerton 
  Coll. 
  

  

  P. 
  1032 
  a. 
  The 
  hinder 
  abdominal 
  and 
  caudal 
  region 
  of 
  two 
  asso- 
  

   ciated 
  individuals 
  ; 
  Fulwell 
  Hill. 
  The 
  dorsal 
  ridge-scales 
  

   are 
  shown 
  to 
  be 
  relatively 
  large, 
  but 
  not 
  acuminate. 
  

  

  Egerton 
  Coll. 
  

  

  44210. 
  Small 
  well-preserved 
  fish, 
  wanting 
  the 
  extremity 
  of 
  the 
  

   head 
  and 
  tail 
  ; 
  Fulwell 
  Hill. 
  Purchased, 
  1873. 
  

  

  Acentrophorus 
  abbsi 
  (Kirkby). 
  

  

  1862. 
  Palceoniscus 
  abbsii, 
  J. 
  W. 
  Kirkby, 
  Ann. 
  Mag. 
  Nat. 
  Hist. 
  [3] 
  

  

  vol. 
  ix. 
  p. 
  268. 
  

   1864. 
  Palceoniscus 
  abbsii, 
  J.W. 
  Kirkby, 
  Quart. 
  Journ. 
  Geol. 
  Soc. 
  vol. 
  xx. 
  

  

  p. 
  355, 
  pi. 
  xviii. 
  fig. 
  3. 
  

   1877 
  Acentrophorus 
  abbsii, 
  R. 
  H. 
  Traquair, 
  Quart. 
  Journ. 
  Geol. 
  Soc. 
  

  

  vol. 
  xxxiii. 
  p. 
  565. 
  

  

  I 
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