﻿4 
  ACT1N0PTERYGII. 
  

  

  Genus. 
  DICTYOPYGE, 
  Egerton. 
  

  

  [Quart. 
  Journ. 
  Geol. 
  Soc. 
  vol. 
  iii. 
  1847, 
  p. 
  276.] 
  

  

  A 
  group 
  of 
  species 
  differing 
  only 
  from 
  Catopterus 
  in 
  the 
  more 
  

   forward 
  position 
  of 
  the 
  dorsal 
  fin, 
  which 
  never 
  arises 
  behind 
  the 
  

   origin 
  of 
  the 
  anal 
  fin. 
  

  

  Dictyopyge 
  macrura 
  (Eedfield). 
  

  

  1841. 
  Catopterus 
  macrurus, 
  W. 
  C. 
  Redfield, 
  Amer. 
  Journ. 
  Sci. 
  vol. 
  xli. 
  

  

  p. 
  27. 
  

   1847. 
  Dictyopyge 
  macrura, 
  Sir 
  P. 
  Egerton, 
  Quart. 
  Journ. 
  Geol. 
  Soc. 
  

  

  vol. 
  iii. 
  p. 
  276, 
  pi. 
  viii., 
  pi. 
  ix. 
  fig. 
  1. 
  

   1857. 
  Catopterus 
  macrurus, 
  W. 
  C. 
  Redfield, 
  Proc. 
  Amer. 
  Assoc. 
  Adv. 
  

  

  Sci. 
  1856, 
  pt. 
  ii. 
  p. 
  186. 
  

   1888. 
  Dictyopyye 
  macrura, 
  J. 
  S. 
  Newberry, 
  Foss. 
  Fishes 
  Trias. 
  N. 
  

  

  Jersey 
  and 
  Connecticut 
  (Mon. 
  U.S. 
  Geol. 
  Surv. 
  no. 
  xiv.), 
  p. 
  64, 
  

  

  pi. 
  xviii. 
  figs. 
  1, 
  2. 
  

  

  Type. 
  Nearly 
  complete 
  fish. 
  

  

  The 
  type 
  species, 
  attaining 
  a 
  length 
  of 
  about 
  # 
  15. 
  Length 
  of 
  

   head 
  with 
  opercular 
  apparatus 
  somewhat 
  less 
  than 
  the 
  maximum 
  

   depth 
  of 
  the 
  trunk, 
  and 
  equalling 
  less 
  than 
  one-fifth 
  of 
  the 
  total 
  

   length 
  of 
  the 
  fish 
  ; 
  depth 
  of 
  caudal 
  pedicle 
  less 
  than 
  half 
  that 
  of 
  

   the 
  abdominal 
  region. 
  Cranial 
  bones 
  externally 
  ornamented 
  with 
  

   fine 
  granulations. 
  Pelvic 
  fins 
  arising 
  midway 
  between 
  the 
  pectoral 
  

   arch 
  and 
  the 
  anal 
  fin 
  ; 
  dorsal 
  fin 
  at 
  least 
  as 
  deep 
  as 
  long, 
  arising 
  

   slightly 
  in 
  advance 
  of 
  the 
  anal 
  and 
  scarcely 
  smaller 
  than 
  the 
  latter, 
  

   which 
  comprises 
  about 
  30 
  rays 
  and 
  extends 
  almost 
  to 
  the 
  base 
  of 
  

   the 
  caudal 
  fin. 
  Scales 
  smooth, 
  not 
  serrated. 
  

  

  Form. 
  Sf 
  Loc. 
  Triassic 
  : 
  Richmond 
  Coalfield, 
  Virginia, 
  U.S.A. 
  

  

  Not 
  represented 
  in 
  the 
  Collection. 
  

  

  Dictyopyge 
  socialis 
  (Berger). 
  

  

  1843. 
  Semionotus 
  socialis, 
  H. 
  A. 
  0. 
  Berger, 
  Neues 
  Jahrb. 
  p. 
  86. 
  

   1864. 
  Dictyopyge 
  socialis, 
  J. 
  Striiver, 
  Zeitschr. 
  deutsch. 
  geol. 
  Ges. 
  

   vol. 
  xvi. 
  p. 
  322, 
  pi. 
  xiii. 
  fig. 
  2. 
  

  

  Type. 
  Nearly 
  complete 
  fish 
  ; 
  University 
  Geological 
  Museum, 
  

   Gottingen. 
  

  

  A 
  large 
  species, 
  attaining 
  a 
  length 
  of 
  about 
  0*2. 
  Length 
  of 
  head 
  

   with 
  opercular 
  apparatus 
  about 
  equal 
  to 
  the 
  maximum 
  depth 
  of 
  the 
  

   trunk 
  and 
  contained 
  five 
  times 
  in 
  the 
  total 
  length 
  of 
  the 
  fish 
  ; 
  

   depth 
  of 
  caudal 
  pedicle 
  slightly 
  less 
  than 
  half 
  that 
  of 
  the 
  abdominal 
  

   region. 
  Cranial 
  bones 
  with 
  an 
  external 
  rugose 
  ornament. 
  Pelvic 
  

   fins 
  arising 
  about 
  midway 
  between 
  the 
  pectoral 
  arch 
  and 
  the 
  anal 
  

  

  