﻿2 
  PROCEEDINGS 
  OF 
  THE 
  GEOLOGICAL 
  SOCIETY. 
  [Nov. 
  4, 
  

  

  excavating' 
  for 
  the 
  dry 
  dock. 
  The 
  shale 
  is 
  a 
  bed 
  between 
  thick 
  beds 
  

   of 
  the 
  great 
  sandstone 
  or 
  Hawkesbury 
  rocks, 
  below 
  the 
  Wiananiatta 
  

   beds. 
  

  

  2. 
  A 
  fossil 
  Fish 
  from 
  the 
  same 
  locality. 
  

  

  3. 
  A 
  fossil 
  Fish 
  from 
  Parsonage 
  Hill, 
  near 
  Paramatta 
  (Wianamatta 
  

   basin). 
  

  

  In 
  addition 
  to 
  these 
  the 
  box 
  contained 
  a 
  cast 
  of 
  the 
  specimen 
  of 
  

   Urosihenes 
  australis, 
  named 
  and 
  described 
  by 
  Professor 
  Dana, 
  of 
  the 
  

   United 
  States 
  Exploring 
  Expedition. 
  The 
  specimen 
  of 
  which 
  this 
  

   is 
  a 
  cast 
  was 
  found 
  at 
  Newcastle, 
  on 
  the 
  Hunter 
  lliver, 
  in 
  the 
  same 
  

   block 
  from 
  which 
  the 
  Plants 
  described 
  by 
  Professors 
  M'Coy 
  and 
  

   Morris 
  were 
  derived. 
  On 
  comparing 
  this 
  with 
  the 
  description 
  given 
  

   in 
  the 
  'Annals 
  and 
  Magazine 
  of 
  Natural 
  History 
  ' 
  (2nd 
  ser. 
  vol. 
  ii. 
  

   1848, 
  p. 
  149), 
  I 
  am 
  inclined 
  to 
  consider 
  Urosthenes 
  more 
  nearly 
  allied 
  

   to 
  Pygopterus 
  than 
  to 
  Palceoniscus. 
  The 
  powerful 
  heterocercal 
  tail, 
  

   the 
  general 
  form 
  of 
  the 
  body, 
  the 
  large 
  size, 
  and 
  the 
  backward 
  position 
  

   of 
  the 
  dorsal 
  and 
  anal 
  fins, 
  are 
  all 
  characteristic 
  features 
  of 
  Pygo- 
  

   pterus, 
  whereas 
  I 
  am 
  unable 
  to 
  detect 
  any 
  material 
  point 
  of 
  resem- 
  

   blance 
  between 
  Urosthenes 
  and 
  Palceoniscus. 
  The 
  dorsal 
  fin 
  is 
  situated 
  

   immediately 
  over 
  the 
  anal 
  fin 
  *, 
  and 
  both 
  these 
  organs 
  are 
  shorter 
  

   and 
  placed 
  nearer 
  to 
  the 
  tail 
  than 
  they 
  are 
  in 
  the 
  genus 
  Pygopterus. 
  

   These 
  features 
  and 
  the 
  smooth 
  character 
  of 
  the 
  scales 
  of 
  Urosthenes 
  

   sufficiently 
  distinguish 
  it 
  from 
  Pygopterus. 
  

  

  Of 
  the 
  two 
  specimens 
  forwarded 
  by 
  Mr. 
  Clarke 
  the 
  larger 
  one 
  

   consists 
  of 
  a 
  part 
  only 
  of 
  the 
  bod}^ 
  of 
  a 
  Fish 
  of 
  moderate 
  size, 
  a 
  foot 
  

   or 
  rather 
  more 
  in 
  length. 
  The 
  ironstone-nodule 
  in 
  which 
  it 
  is 
  con- 
  

   tained 
  is 
  traversed 
  through 
  the 
  middle 
  by 
  a 
  fault, 
  the 
  effect 
  of 
  which 
  

   has 
  been 
  to 
  disfigure 
  the 
  hinder 
  half 
  of 
  the 
  specimen. 
  It 
  appears 
  

   as 
  if 
  a 
  portion 
  of 
  the 
  integument, 
  together 
  with 
  a 
  group 
  of 
  fin-rays, 
  

   had 
  been 
  thrown 
  down 
  from 
  the 
  opposite 
  flank, 
  thus 
  giving 
  the 
  ap- 
  

   pearance 
  of 
  greater 
  breadth 
  of 
  body 
  than 
  existed 
  in 
  nature. 
  The 
  

   anterior 
  half 
  of 
  the 
  specimen 
  retains 
  its 
  natural 
  outline, 
  and 
  is 
  pretty 
  

   well 
  preserved. 
  It 
  measures 
  3^ 
  inches 
  in 
  depth, 
  and, 
  probably, 
  

   represents 
  a 
  portion 
  of 
  the 
  trunk 
  immediately 
  behind 
  the 
  dorsal 
  fin 
  ; 
  

   but 
  as 
  none 
  of 
  the 
  fins 
  are 
  preserved 
  in 
  situ, 
  this 
  is 
  mere 
  conjecture. 
  

   The 
  scales 
  are 
  small 
  and 
  very 
  numerous 
  ; 
  each 
  one 
  is 
  marked 
  by 
  

   two 
  or 
  three 
  deep 
  longitudinal 
  sulci, 
  and 
  is 
  invested 
  with 
  a 
  thick 
  

   coating 
  of 
  dense 
  ganoine. 
  I 
  am 
  inclined 
  to 
  think 
  that 
  the 
  larger 
  of 
  

   the 
  two 
  specimens 
  found 
  at 
  Cockatoo 
  Island, 
  of 
  which 
  a 
  photograph 
  

   is 
  sent, 
  is 
  referable 
  to 
  the 
  same 
  genus 
  as 
  this 
  specimen 
  from 
  Chapel 
  

   Hill. 
  If 
  this 
  conjecture 
  be 
  correct, 
  we 
  gain 
  additional 
  evidence 
  of 
  

   some 
  value 
  in 
  ascertaining 
  the 
  affinities 
  of 
  the 
  genus. 
  The 
  depth 
  of 
  

   the 
  two 
  fishes 
  is 
  about 
  the 
  same 
  ; 
  so 
  also 
  are 
  the 
  characters 
  of 
  the 
  

   scales, 
  as 
  far 
  as 
  can 
  be 
  determined 
  in 
  the 
  absence 
  of 
  the 
  original 
  

   from 
  which 
  the 
  photograph 
  was 
  taken. 
  The 
  pectoral 
  fins 
  are 
  com- 
  

   paratively 
  small. 
  The 
  ventral 
  fins, 
  of 
  large 
  size, 
  are 
  situated 
  about 
  

  

  * 
  The 
  dorsal 
  fin 
  is 
  described, 
  in 
  the 
  c 
  Annals 
  of 
  Natural 
  History,' 
  as 
  being 
  

   over 
  the 
  anterior 
  part 
  of 
  the 
  caudal 
  fin. 
  This 
  is 
  an 
  impossibility, 
  since 
  any 
  

   interspinous 
  bones 
  of 
  the 
  caudal 
  vertebrae 
  carrying 
  fin-rays 
  must 
  necessarily 
  

   belong 
  to 
  the 
  caudal 
  appendage. 
  

  

  