﻿4 
  PROCEEDINGS 
  OF 
  THE 
  GEOLOGICAL 
  SOCIETY. 
  [Nov. 
  4, 
  

  

  is 
  more 
  advanced 
  than 
  in 
  any 
  species 
  of 
  Palceoniscus 
  with 
  which 
  I 
  am 
  

   acquainted. 
  It 
  is 
  placed 
  at 
  nearly 
  the 
  centre 
  of 
  the 
  back, 
  as 
  in 
  the 
  

   genus 
  Pholidophorus, 
  instead 
  of 
  more 
  or 
  less 
  behind 
  this 
  point, 
  as 
  in 
  

   the 
  Palceonisci. 
  The 
  tail 
  (if 
  the 
  detached 
  fragment 
  belongs, 
  as 
  is 
  

   stated, 
  to 
  the 
  specimen) 
  is 
  a 
  true 
  heterocercal 
  form 
  undistinguishable 
  

   from 
  that 
  of 
  Palceoniscus. 
  The 
  position 
  of 
  the 
  dorsal 
  tin, 
  although 
  

   not 
  a 
  feature 
  of 
  generic 
  importance 
  unassociated 
  with 
  other 
  discre- 
  

   pancies, 
  gives 
  nevertheless 
  a 
  specific 
  character 
  to 
  this 
  fish, 
  and 
  I 
  pro- 
  

   pose 
  to 
  name 
  it 
  Palceoniscus 
  antipodeus. 
  

  

  The 
  result, 
  then, 
  of 
  the 
  examination 
  of 
  these 
  specimens 
  (in 
  so 
  

   far 
  as 
  materials 
  so 
  imperfect 
  and 
  scanty 
  can 
  be 
  said 
  to 
  lead 
  to 
  

   any 
  result) 
  is 
  the 
  supposition 
  that 
  they 
  give 
  indications 
  of 
  four 
  

   genera 
  of 
  fossil 
  Fishes 
  — 
  one 
  allied 
  to 
  Pygopterus 
  ( 
  Urosthenes, 
  Dana), 
  

   one 
  allied 
  to 
  Acrolepis 
  (Myriolepis, 
  Eg.), 
  one 
  allied 
  to 
  Platysomus 
  

   (Cleithrolepis, 
  Eg.), 
  one 
  undistinguishable 
  from 
  Palceoniscus, 
  Agassiz. 
  

   If, 
  therefore 
  (as 
  I 
  believe), 
  the 
  object 
  Mr. 
  Clarke 
  has 
  in 
  view 
  in 
  

   asking 
  an 
  opinion 
  on 
  the 
  characters 
  of 
  these 
  specimens 
  has 
  reference 
  

   to 
  the 
  probable 
  age 
  of 
  the 
  Australian 
  coal-bearing 
  strata, 
  I 
  fear 
  he 
  

   will 
  be 
  disappointed 
  with 
  the 
  result, 
  since 
  no 
  positive 
  conclusions 
  as 
  

   to 
  generic 
  or 
  specific 
  identity 
  can 
  be 
  deduced 
  from 
  the 
  materials 
  

   sent 
  for 
  examination 
  : 
  but 
  with 
  regard 
  to 
  the 
  larger 
  question 
  of 
  

   geological 
  period, 
  there 
  appears 
  to 
  be 
  sufficient 
  evidence 
  to 
  stamp 
  these 
  

   remains 
  as 
  belonging 
  to 
  the 
  Palaeozoic 
  age. 
  Although 
  the 
  geogra- 
  

   phical 
  range 
  of 
  genera 
  and 
  species 
  at 
  some 
  periods 
  in 
  the 
  sequence 
  

   of 
  the 
  sedimentary 
  deposits 
  of 
  our 
  globe 
  has 
  been 
  shown 
  to 
  be 
  

   immeasurably 
  greater 
  than 
  at 
  the 
  present 
  day, 
  it 
  would 
  nevertheless 
  

   be 
  rather 
  unreasonable 
  to 
  expect 
  to 
  find 
  a 
  coincidence 
  in 
  this 
  respect 
  

   between 
  the 
  organisms 
  of 
  our 
  British 
  strata 
  and 
  those 
  of 
  our 
  antipodes. 
  

   If, 
  however, 
  it 
  is 
  allowable 
  to 
  apply 
  to 
  bygone 
  periods 
  the 
  know- 
  

   ledge 
  we 
  acquire 
  from 
  the 
  study 
  of 
  actual 
  nature, 
  we 
  may 
  argue 
  

   that, 
  as 
  in 
  the 
  existing 
  Fauna 
  and 
  Flora 
  we 
  find 
  beyond 
  the 
  range 
  

   of 
  generic 
  extension 
  certain 
  representative 
  forms 
  (as, 
  for 
  instance, 
  the 
  

   Gorillas 
  and 
  Chimpanzees 
  of 
  Africa, 
  represented 
  by 
  the 
  Orangs 
  of 
  

   Borneo, 
  the 
  Manatees 
  of 
  the 
  Atlantic, 
  by 
  the 
  Dugong 
  of 
  the 
  Indian 
  

   seas, 
  the 
  Crocodiles 
  and 
  Pythons 
  of 
  India, 
  by 
  the 
  Caymans 
  and 
  Boas 
  of 
  

   America, 
  and 
  the 
  Yandas 
  and 
  brides 
  of 
  the 
  East, 
  by 
  the 
  Angraeca 
  of 
  

   Africa 
  and 
  Madagascar), 
  so 
  it 
  may 
  have 
  been 
  in 
  the 
  primaeval 
  world. 
  

   If 
  then 
  we 
  consider 
  the 
  Australian 
  genera 
  as 
  the 
  representatives 
  of 
  

   those 
  Northern 
  forms 
  to 
  which 
  they 
  are 
  most 
  nearly 
  allied, 
  we 
  may 
  

   briefly 
  allude 
  to 
  the 
  circumstances 
  under 
  which 
  the 
  latter 
  occur 
  in 
  the 
  

   European 
  and 
  North- 
  American 
  scale 
  of 
  deposits. 
  The 
  genus 
  Palceo- 
  

   niscus 
  extends 
  from 
  the 
  Keuper 
  to 
  the 
  Coal-measures, 
  both 
  inclusive. 
  

   It 
  contains 
  nearly 
  fifty 
  described 
  species 
  — 
  a 
  greater 
  number 
  than 
  can 
  

   be 
  claimed 
  by 
  any 
  other 
  genus 
  of 
  Ganoid 
  fishes. 
  The 
  individuals 
  

   appear 
  to 
  have 
  swarmed 
  in 
  some 
  seas, 
  and 
  especially 
  in 
  those 
  of 
  the 
  

   Permian 
  and 
  Carboniferous 
  periods. 
  Pygopterus 
  ranges 
  from 
  the 
  

   Magnesian 
  Limestone 
  to 
  the 
  Coal-measures, 
  comprising 
  four 
  species 
  

   from 
  the 
  former 
  and 
  eight 
  from 
  the 
  latter 
  formation. 
  Acrolepis 
  has 
  

   a 
  similar 
  range, 
  and 
  numbers 
  nine 
  species 
  from 
  the 
  Permian 
  and 
  one 
  

   from 
  the 
  Coal-measures. 
  Platysolnus 
  contains 
  two 
  species 
  from 
  the 
  

  

  