﻿472 
  BRITISH 
  LEPIDOPTERA. 
  

  

  towards 
  apex, 
  well-developed 
  on 
  both 
  sides 
  of 
  shaft 
  ; 
  lower 
  margin 
  and 
  

   apex 
  of 
  plumule 
  distinctly 
  snowy- 
  white 
  ; 
  two 
  or 
  three 
  black 
  scales 
  at 
  apex, 
  

   and 
  a 
  few 
  tiny 
  isolated 
  ones 
  between 
  patch 
  and 
  base. 
  

  

  Sexual 
  dimorphism. 
  — 
  The 
  few 
  2 
  s 
  we 
  have 
  in 
  our 
  collection 
  appear 
  

   to 
  be 
  slightly 
  smaller 
  than 
  the 
  J 
  s, 
  and 
  Bankes 
  notices 
  the 
  same 
  

   slight 
  difference 
  in 
  average 
  size 
  among 
  the 
  many 
  bred 
  specimens 
  of 
  

   both 
  sexes 
  in 
  his 
  lengthy 
  series. 
  

  

  Variation. 
  — 
  Barrett, 
  like 
  Haworth, 
  notes 
  the 
  particularly 
  dark 
  

   coloration 
  of 
  this 
  species. 
  The 
  former 
  calls 
  it 
  black-brown, 
  abundantly 
  

   dusted 
  with 
  golden-brown. 
  To 
  the 
  naked 
  eye 
  it 
  certainly 
  looks 
  the 
  

   darkest 
  of 
  our 
  British 
  Oxyptilids, 
  but, 
  under 
  a 
  lens, 
  the 
  normal 
  colora- 
  

   tion 
  in 
  Britain 
  is 
  almost 
  identical 
  with 
  that 
  of 
  0. 
  parvidactyla, 
  a 
  deep 
  

   rich 
  brown, 
  to 
  which 
  the 
  term 
  "chocolate-brown 
  " 
  is 
  better 
  applied 
  

   than 
  to 
  any 
  other 
  British 
  species; 
  nor 
  does 
  the 
  similarity 
  of 
  the 
  

   imagines 
  of 
  these 
  two 
  species 
  end 
  here, 
  for 
  the 
  markings 
  are 
  almost 
  

   identical; 
  the 
  slight 
  curvature 
  of 
  the 
  upper 
  lobal 
  lines, 
  seen 
  in 
  

   parvidactyla, 
  however, 
  is 
  apparently 
  absent, 
  and 
  the 
  outer 
  lobal 
  line 
  

   is 
  much 
  more 
  distinctly 
  marked 
  on 
  the 
  lower 
  lobe 
  in 
  lieterodactyla, 
  

   whilst, 
  in 
  the 
  latter, 
  also, 
  the 
  scale-tuft 
  of 
  the 
  3rd 
  plumule 
  of 
  the 
  

   hindwing 
  is 
  more 
  marked 
  on 
  the 
  upperside 
  of 
  the 
  shaft 
  than 
  in 
  

   parvidactyla 
  ; 
  yet 
  the 
  remarkable 
  fact 
  remains 
  that 
  the 
  two 
  British 
  

   Oxyptilids 
  that 
  are 
  most 
  unlike 
  in 
  their 
  larval 
  and 
  pupal 
  stages, 
  are 
  

   most 
  like 
  superficially 
  in 
  the 
  imaginal, 
  except, 
  of 
  course, 
  in 
  size, 
  and 
  

   here 
  again 
  they 
  are 
  at 
  the 
  two 
  extremes, 
  as 
  the 
  largest 
  and 
  smallest 
  

   of 
  the 
  Oxyptili, 
  excluding 
  the 
  Buckleriids. 
  There 
  is 
  no 
  doubt 
  that 
  

   the 
  two 
  " 
  Coverdale 
  " 
  hieracii 
  (see 
  Brit. 
  Pter., 
  p. 
  69) 
  belong 
  here. 
  

   They 
  are 
  somewhat 
  narrower 
  in 
  the 
  forewings 
  than 
  usual, 
  due 
  probably 
  

   to 
  lessened 
  fringe-scaling, 
  and, 
  perhaps, 
  a 
  trifle 
  worn, 
  and 
  the 
  ground 
  

   colour 
  is 
  a 
  trifle 
  paler. 
  In 
  a 
  series 
  of 
  some 
  26 
  examples, 
  from 
  

   Clevedon, 
  King's 
  Lynn, 
  Canterbury, 
  and 
  Purbeck, 
  little 
  variation 
  is 
  

   exhibited. 
  There 
  is 
  a 
  slight 
  difference 
  in 
  the 
  intensity 
  and 
  brightness 
  

   of 
  the 
  ground 
  colour 
  (some 
  are 
  particularly 
  shiny 
  in 
  appearance), 
  and 
  

   the 
  Canterbury, 
  and 
  some 
  of 
  the 
  Purbeck, 
  examples 
  are, 
  perhaps, 
  a 
  

   shade 
  paler 
  (? 
  greyer) 
  than 
  the 
  others 
  ; 
  a 
  few 
  examples 
  (two 
  from 
  

   Clevedon, 
  two 
  from 
  Purbeck, 
  one 
  from 
  Canterbury) 
  without 
  white 
  

   scaling 
  in 
  the 
  discal 
  area 
  (the 
  pale 
  space, 
  however, 
  is 
  marked), 
  the 
  

   tendency 
  to 
  obsolescence 
  of 
  the 
  inner 
  lobal 
  line 
  in 
  the 
  Clevedon 
  and 
  

   King's 
  Lynn 
  examples 
  (one 
  of 
  the 
  Clevedon, 
  and 
  three 
  of 
  the 
  Purbeck 
  

   examples 
  have 
  this 
  specially 
  strongly 
  marked), 
  and 
  the 
  occasional 
  

   obsolescence 
  of 
  the 
  lower 
  lobal 
  half 
  of 
  the 
  outer 
  line 
  (very 
  noticeable 
  in 
  

   one 
  Clevedon 
  and 
  one 
  Purbeck 
  example), 
  about 
  cover 
  the 
  range 
  of 
  

   variation. 
  The 
  most 
  variegated 
  specimen, 
  with 
  all 
  the 
  white 
  markings 
  

   specially 
  strongly 
  developed, 
  comes 
  from 
  Clevedon. 
  The 
  most 
  

   obsoletely-marked 
  and 
  uniformly-tinted 
  specimens, 
  with 
  only 
  the 
  upper 
  

   halves 
  of 
  the 
  lobal 
  lines, 
  of 
  all 
  the 
  white 
  markings, 
  at 
  all 
  distinctly 
  

   outlined, 
  is 
  from 
  Purbeck. 
  Two 
  forms 
  have 
  been 
  described 
  as 
  distinct 
  

   species 
  from 
  German 
  examples, 
  but 
  Hofmann 
  says 
  that 
  their 
  genitalia 
  

   are 
  identical 
  with 
  those 
  of 
  lieterodactyla. 
  These 
  are 
  : 
  — 
  

  

  a. 
  var. 
  loranus, 
  Fuchs, 
  " 
  Stett. 
  Ent. 
  Zeitg.," 
  p. 
  48 
  (1895); 
  Hofm., 
  "Pter. 
  

   Deutscli.," 
  p. 
  117 
  (1895) 
  ; 
  Fuchs, 
  " 
  Stett. 
  Ent. 
  Zeitg.," 
  p. 
  338 
  (1897) 
  ; 
  Staud. 
  and 
  

   Reb., 
  " 
  Cat.," 
  3rd 
  ed., 
  p. 
  71 
  (1901). 
  Obscurus, 
  Rossi., 
  "Cat.," 
  p. 
  163, 
  no. 
  867 
  in 
  

   part 
  (1881). 
  Parvidactylus, 
  Rossi., 
  " 
  Cat.," 
  p. 
  222, 
  no. 
  1123 
  in 
  part 
  (1881).— 
  

   Under 
  obscurus, 
  Zell., 
  Rossler 
  writes 
  (Cat., 
  p. 
  163) 
  : 
  " 
  The 
  specimens 
  from 
  Lorch 
  

   and 
  the 
  Dennelbach 
  Valley, 
  near 
  Wiesbaden, 
  belong 
  possibly 
  to 
  a 
  distinct 
  species. 
  

  

  