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  BRITISH 
  LEPIDOPTERA. 
  

  

  wings 
  slender, 
  the 
  third 
  segment 
  with 
  the 
  anal 
  angle 
  sufficiently 
  distinct, 
  nearer 
  the 
  

   apex, 
  furnished 
  with 
  a 
  tuft 
  of 
  scales 
  ; 
  the 
  anterior 
  wings 
  flat, 
  covering 
  the 
  posterior 
  

   when 
  at 
  rest. 
  

  

  The 
  genus 
  is 
  exceedingly 
  restricted. 
  There 
  are 
  four 
  described 
  

   Palsearctic 
  species 
  — 
  punctidactyla, 
  Haw., 
  seeboldi, 
  Hofm., 
  moerens, 
  

   Snell., 
  and 
  cosmodactyla, 
  Hb., 
  of 
  which 
  the 
  first 
  and 
  last 
  are 
  

   British. 
  In 
  the 
  Nearctic 
  region, 
  also, 
  there 
  appear, 
  according 
  to 
  

   Fernald 
  and 
  Dyar 
  (List 
  Nth. 
  Amer. 
  Lep., 
  p. 
  442) 
  to 
  be 
  four 
  (or 
  

   five) 
  species 
  — 
  pica, 
  Walsm., 
  cosmodactyla, 
  Hb., 
  marmarodactyla, 
  

   Dyar, 
  punctidactyla, 
  Haw., 
  ? 
  edwardsii, 
  Fish, 
  i.e., 
  two 
  species 
  are 
  

   common 
  to 
  the 
  Palsearctic 
  and 
  Nearctic 
  regions. 
  The 
  closeness 
  of 
  

   these 
  two 
  insects 
  is 
  as 
  great 
  as 
  that 
  between 
  Gillmeria 
  ochrodactyla 
  and 
  

   6r. 
  pallidactyla, 
  and, 
  like 
  these, 
  doubtful 
  specimens 
  can 
  be 
  separated 
  

   by 
  their 
  genitalia, 
  although 
  Hofmann 
  says 
  that 
  he 
  cannot 
  find 
  any 
  

   difference 
  in 
  them. 
  Chapman, 
  however, 
  writes 
  (in 
  litt.) 
  that, 
  although 
  

   he 
  approached 
  the 
  question 
  with 
  the 
  idea 
  that 
  Hofmann's 
  state- 
  

   ment 
  was 
  true, 
  on 
  examining 
  five 
  preparations 
  of 
  the 
  brown 
  species 
  

   (cosmodactyla), 
  and 
  two 
  of 
  the 
  greenish 
  species 
  {punctidactyla), 
  he 
  found 
  a 
  

   constant 
  difference 
  in 
  the 
  clasps. 
  He 
  says 
  that 
  " 
  in 
  the 
  brown 
  form 
  

   the 
  extreme 
  length 
  of 
  the 
  clasp 
  is 
  l-00mm., 
  in 
  the 
  greenish 
  l-08mm., 
  

   and 
  the 
  bird's-head-shaped 
  end 
  is 
  rounder, 
  and 
  with 
  a 
  shorter 
  beak, 
  in 
  

   the 
  brown 
  form, 
  flatter, 
  and 
  with 
  a 
  longer 
  beak, 
  in 
  the 
  green. 
  The 
  

   sedoeagus 
  in 
  these 
  specimens 
  is 
  much 
  larger 
  in 
  the 
  greenish 
  form, 
  though 
  

   obviously 
  variable 
  in 
  both 
  ; 
  its 
  form 
  and 
  structure 
  appear 
  to 
  be 
  

   identical, 
  but 
  the 
  extreme 
  length, 
  over 
  all, 
  varies 
  from 
  0*42mm. 
  to 
  

   0-56mm. 
  in 
  the 
  brown 
  form, 
  and 
  the 
  two 
  of 
  the 
  greenish 
  form 
  are, 
  

   respectively, 
  0*62mm. 
  and 
  0*7 
  lmm." 
  It 
  may 
  be 
  observed 
  that, 
  in 
  these 
  

   species, 
  there 
  exists, 
  as 
  a 
  separate 
  small 
  apophysis, 
  the 
  extra 
  clasp 
  that 
  

   is 
  so 
  well- 
  developed 
  in 
  the 
  Oxyptilids. 
  No 
  trace 
  of 
  this 
  has 
  been 
  

   detected 
  in 
  other 
  genera, 
  even 
  in 
  Marasmarcha, 
  which 
  appears 
  in 
  some 
  

   respects 
  nearest 
  the 
  Oxyptilids." 
  

  

  In 
  their 
  general 
  appearance, 
  the 
  two 
  British 
  species 
  belonging 
  to 
  

   this 
  genus, 
  are 
  similar 
  to 
  each 
  other, 
  but, 
  even 
  on 
  superficial 
  

   characters, 
  are 
  readily 
  distinguishable, 
  e.g., 
  A. 
  punctidactyla 
  is 
  greenish 
  

   in 
  tint 
  ; 
  A. 
  cosmodactyla 
  is 
  red-brown. 
  In 
  their 
  larval 
  characters, 
  

   they 
  are 
  very 
  close, 
  and 
  apparently 
  occur 
  together 
  on 
  the 
  same 
  food- 
  

   plants, 
  yet 
  there 
  is 
  (teste 
  Hofmann) 
  a 
  distinct 
  difference 
  in 
  the 
  structure 
  of 
  

   the 
  larval 
  warts, 
  and 
  Porritt 
  connects 
  (Ent.Mo. 
  Mag. 
  ,xxiii.,p. 
  133) 
  certain 
  

  

  ® 
  It 
  may 
  appear 
  desirable 
  that 
  I 
  should 
  express 
  my 
  opinion 
  as 
  to 
  the 
  value 
  of 
  

   this 
  difference 
  in 
  the 
  appendages 
  of 
  the 
  two 
  forms. 
  I 
  do 
  not 
  think 
  it 
  is 
  in 
  any 
  way 
  con- 
  

   clusive. 
  Were 
  the 
  two 
  forms 
  only 
  found 
  at 
  widely 
  distant 
  localities, 
  I 
  should 
  have 
  no 
  

   hesitation 
  in 
  saying 
  the 
  differences 
  were 
  merely 
  expressions 
  of 
  varietal 
  divergence, 
  

   a 
  long 
  way 
  from 
  necessarily 
  implying 
  specific 
  distinction 
  ; 
  but, 
  as 
  the 
  forms 
  occur 
  

   together 
  in 
  the 
  same 
  localities, 
  the 
  value 
  of 
  these 
  differences 
  is 
  considerably 
  greater, 
  

   and 
  adds 
  an 
  additional 
  weight 
  to 
  the 
  considerations, 
  whatever 
  value 
  they 
  may 
  

   possess, 
  that 
  already 
  are 
  accepted 
  as 
  proof 
  of 
  true 
  separation. 
  I 
  would, 
  however, 
  

   say 
  that 
  my 
  number 
  of 
  preparations 
  is 
  by 
  no 
  means 
  sufficiently 
  great 
  to 
  deserve 
  

   absolute 
  dependence 
  on 
  their 
  indications, 
  clear 
  as 
  they 
  may 
  be, 
  especially 
  in 
  view 
  of 
  

   the 
  considerable 
  variation 
  they 
  show 
  to 
  exist 
  in 
  each 
  form, 
  in 
  the 
  dimensions 
  of 
  the 
  

   sedoeagas. 
  A 
  much 
  greater 
  difference 
  in 
  size 
  in 
  the 
  appendages 
  exists 
  between 
  

   those 
  of 
  Erebia 
  aethiops 
  from 
  Scotland, 
  and 
  from 
  the 
  Engadine, 
  but 
  one 
  does 
  not 
  

   dream 
  (perhaps, 
  however, 
  wrongly) 
  of 
  suggesting 
  more 
  than 
  geographical 
  variety, 
  

   abundantly 
  within 
  the 
  limits 
  of 
  specific 
  identity 
  in 
  that 
  species. 
  Did 
  these 
  two 
  

   forms 
  occur 
  on 
  the 
  same 
  ground, 
  without 
  intermediates, 
  one 
  would 
  attach 
  great 
  

   importance 
  to 
  them. 
  A 
  deeper 
  research 
  may 
  show 
  that 
  there 
  are 
  intermediates 
  in 
  

   the 
  case 
  of 
  Amblyptilia 
  ; 
  so 
  far, 
  I 
  have 
  not 
  found 
  them 
  (Chapman). 
  

  

  