﻿29 
  

  

  The 
  Variation 
  of 
  Epinephele 
  tithonus, 
  L. 
  

  

  By 
  Rev. 
  G. 
  Wheeler, 
  M.A., 
  F.Z.S., 
  F.E.S. 
  Read 
  October 
  Mth, 
  1918. 
  

  

  The 
  directions 
  of 
  variation 
  in 
  Eiiinephele 
  tithonus 
  are 
  few 
  in 
  

   comparison 
  with 
  those 
  of 
  many 
  other 
  species, 
  but 
  in 
  one 
  of 
  these 
  

   directions, 
  viz., 
  the 
  number, 
  size 
  and 
  position 
  of 
  the 
  spots, 
  both 
  on 
  

   the 
  upper 
  and 
  underside, 
  the 
  extent 
  of 
  variation 
  is 
  somewhat 
  

   unusual. 
  It 
  is 
  moreover 
  so 
  much 
  more 
  variable 
  in 
  this 
  matter 
  in 
  

   England 
  than 
  elsewhere, 
  that 
  this 
  gives 
  an 
  added 
  interest 
  to 
  the 
  

   subject 
  for 
  an 
  English 
  Society. 
  The 
  variation 
  in 
  size 
  is 
  much 
  less 
  

   than 
  in 
  many 
  other 
  species 
  and 
  it 
  is 
  distinctly 
  rare 
  to 
  find 
  a 
  

   specimen 
  either 
  abnormally 
  large 
  or 
  abnormally 
  small. 
  Nor 
  does 
  

   its 
  size 
  vary 
  greatly 
  in 
  other 
  parts 
  of 
  its 
  range, 
  though 
  the 
  average 
  

   size 
  in 
  N. 
  Italy 
  and 
  in 
  its 
  one 
  locality 
  in 
  the 
  Rhone 
  Valley 
  is 
  

   perhaps 
  a 
  trifle 
  larger 
  than 
  that 
  of 
  English 
  specimens 
  ; 
  Central 
  

   Italian 
  and 
  Spanish 
  specimens 
  are, 
  on 
  the 
  other 
  hand, 
  rather 
  small. 
  

   The 
  variation 
  in 
  colour 
  is, 
  however, 
  within 
  somewhat 
  narrow 
  limits, 
  

   considerable. 
  The 
  extreme 
  form, 
  ab. 
  )nincki, 
  Seebold, 
  has 
  the 
  usual 
  

   orange 
  brown 
  replaced 
  by 
  pale 
  yellow, 
  a 
  form 
  which 
  was 
  originally 
  

   described 
  from 
  the 
  coast 
  of 
  Spain 
  and 
  Portugal, 
  but 
  which, 
  so 
  far 
  as 
  

   I 
  have 
  been 
  able 
  to 
  trace, 
  is 
  somewhat 
  less 
  scarce 
  in 
  England 
  than 
  

   elsewhere. 
  A 
  further 
  development 
  of 
  this 
  aberration, 
  in 
  which 
  

   the 
  ground 
  colour 
  is 
  silvery 
  white 
  has 
  also 
  been 
  found 
  in 
  this 
  

   country. 
  Short 
  of 
  this 
  extreme 
  coloration, 
  which 
  is 
  sometimes 
  

   found 
  in 
  only 
  part 
  of 
  the 
  area 
  covered 
  by 
  the 
  ground 
  colour, 
  there 
  

   is 
  a 
  decided 
  variation 
  in 
  shade 
  even 
  amongst 
  English 
  specimens, 
  

   while 
  the 
  ground 
  colour 
  tends 
  to 
  become 
  lighter 
  as 
  we 
  advance 
  

   south, 
  at 
  any 
  rate 
  in 
  Central 
  Europe, 
  the 
  Swiss 
  specimens 
  being 
  

   lighter 
  than 
  the 
  English, 
  and 
  the 
  central 
  Italian 
  again 
  markedly 
  

   lighter 
  than 
  the 
  Swiss. 
  Specimens 
  however 
  in 
  the 
  S. 
  Kensington 
  

   Collection 
  from 
  Sardinia 
  and 
  Corsica 
  are 
  not 
  lighter 
  than 
  those 
  

   from 
  the 
  Rhone 
  Valley. 
  The 
  dark 
  portion 
  of 
  the 
  colouring, 
  

   especially 
  of 
  the 
  border 
  of 
  the 
  hindwing 
  is 
  sometimes 
  replaced 
  by 
  a 
  

   sort 
  of 
  mouse-grey 
  ; 
  specimens 
  may 
  be 
  seen 
  in 
  my 
  own 
  series 
  and 
  

   in 
  Mr. 
  Stiff's, 
  doubtless 
  also 
  in 
  many 
  others. 
  The 
  extent 
  of 
  the 
  

   basal 
  suffusion 
  on 
  the 
  upperside 
  also 
  varies 
  considerably 
  ; 
  on 
  the 
  

   forewing 
  it 
  occasionally 
  invades 
  almost 
  the 
  whole 
  inner 
  portion 
  of 
  

   the 
  wing, 
  giving 
  the 
  insect 
  a 
  distinctly 
  Erehia-hke 
  appearance. 
  

   This 
  aberration 
  is 
  said 
  by 
  Tutt 
  (" 
  Brit. 
  Butt.," 
  p. 
  408) 
  to 
  be 
  very 
  

   scarce 
  ; 
  the 
  specimens 
  in 
  Mr. 
  Stiff's 
  series 
  from 
  Tavistock 
  exhibited 
  

   this 
  evening 
  are 
  the 
  only 
  ones 
  with 
  which 
  I 
  am 
  acquainted. 
  ■■• 
  On 
  

  

  * 
  Others 
  were 
  exhibited 
  the 
  same 
  evening. 
  

  

  