﻿336 
  

  

  BRITISH 
  LEPIDOPTERA. 
  

  

  are 
  usually 
  said 
  to 
  be 
  two 
  well-recognised 
  forms 
  : 
  (1) 
  A 
  larger 
  southern 
  

   or 
  lowland 
  form, 
  generally 
  less 
  distinctly 
  marked 
  with 
  black 
  spots 
  and 
  

   streaks. 
  (2) 
  A 
  smaller 
  northern 
  mountain 
  and 
  moorland 
  form, 
  much 
  

   more 
  intensely 
  marked. 
  To 
  a 
  certain 
  extent 
  this 
  distinction 
  holds, 
  

   and 
  the 
  races 
  are 
  more 
  or 
  less 
  to 
  be 
  recognised, 
  but 
  each 
  of 
  these 
  

   forms 
  varies, 
  inter 
  se, 
  and 
  considerable 
  overlapping 
  appears 
  to 
  occur. 
  

   The 
  former, 
  or 
  more 
  typical 
  form, 
  occurs 
  freely, 
  in 
  very 
  varied 
  localities, 
  

   on 
  the 
  chalk-hills, 
  woods, 
  fens, 
  etc., 
  and 
  varies 
  from 
  specimens 
  of 
  an 
  

   unicolorous 
  drab 
  or 
  ashy 
  tint, 
  almost 
  without 
  any 
  indication 
  of 
  mark- 
  

   ings, 
  to 
  others 
  distinctly 
  tinged 
  with 
  brown, 
  but 
  still 
  with 
  indefinite 
  

   markings, 
  and 
  yet 
  on 
  to 
  both 
  greyish 
  and 
  brownish 
  forms 
  with 
  the 
  

   dots 
  at 
  the 
  end 
  of 
  the 
  fissure 
  of 
  the 
  f 
  orewing, 
  and 
  other 
  black 
  dots, 
  fairly 
  

   well 
  marked. 
  Still 
  these 
  southern 
  forms 
  have 
  rarely 
  any 
  of 
  the 
  con- 
  

   spicuous 
  brightness 
  frequent 
  in 
  the 
  form 
  from 
  the 
  Cumbrian 
  moun- 
  

   tains 
  and 
  other 
  similar 
  localities, 
  the 
  specimens 
  of 
  which 
  were 
  referred 
  

   by 
  Stainton 
  to 
  his 
  plagiodactylus, 
  and 
  were 
  called 
  by 
  Gregson, 
  scabio- 
  

   dactylus, 
  or 
  the 
  small 
  size 
  and 
  uniform 
  yellowish-grey 
  tint 
  of 
  Zeller's 
  

   aridus. 
  Barrett 
  (Ent. 
  Mo. 
  Ma;/., 
  xviii., 
  pp. 
  178-179 
  ; 
  hep. 
  Brit. 
  Ides, 
  ix., 
  

   p. 
  173) 
  confused 
  the 
  larger, 
  more 
  typical, 
  form 
  from 
  the 
  southern 
  

   chalk-hills 
  with 
  the 
  barely 
  smaller 
  mountain 
  and 
  moorland 
  form, 
  united 
  

   them 
  under 
  the 
  name 
  of 
  'plagiodactylus 
  (scabiodactylus) 
  , 
  and 
  attempted 
  to 
  

   connect 
  them 
  with 
  Scabiosa 
  columbaria, 
  whilst 
  he 
  refers 
  to 
  two 
  other 
  

   forms 
  — 
  a 
  small 
  one 
  found 
  among 
  S. 
  succisa 
  in 
  moist 
  open 
  pastures, 
  and 
  

   a 
  large 
  umbreous 
  form 
  found 
  in 
  the 
  fens. 
  South's 
  remarks 
  (Ent., 
  

   xxii., 
  p. 
  34) 
  on 
  the 
  variation 
  of 
  this 
  species 
  are 
  largely 
  discounted 
  by 
  

   the 
  remarkable 
  statement 
  that 
  he 
  cannot 
  discriminate 
  the 
  various 
  forms 
  

   of 
  A. 
  bip 
  undid 
  actyla 
  from 
  A. 
  pelidnodactyla 
  and 
  Stenoptilia 
  coprodactyla 
  , 
  

   two 
  very 
  distinct 
  and 
  separate 
  continental 
  species. 
  We 
  have 
  often 
  taken 
  

   the 
  species 
  abroad, 
  and, 
  in 
  some 
  localities, 
  very 
  interesting 
  examp]es 
  

   occur 
  ; 
  at 
  La 
  Grave, 
  in 
  early 
  August, 
  1896, 
  we 
  took 
  several, 
  one 
  form 
  

   having 
  a 
  very 
  dark 
  costa 
  ; 
  another 
  form 
  was 
  of 
  a 
  delicate 
  pale 
  dove 
  -grey, 
  

   others 
  again 
  being 
  very 
  like 
  our 
  southern 
  British 
  examples. 
  Even 
  in 
  

   the 
  same 
  locality 
  there 
  is 
  considerable 
  difference 
  in 
  the 
  specimens 
  of 
  the 
  

   different 
  broods 
  in 
  the 
  same 
  year 
  ; 
  and 
  Hofmann 
  notes 
  that 
  " 
  the 
  moths 
  

   that 
  emerge 
  in 
  June 
  are 
  much 
  more 
  brightly 
  coloured 
  than 
  those 
  which 
  

   fly 
  in 
  August 
  ; 
  they 
  are 
  richer 
  in 
  the 
  white 
  scales 
  on 
  the 
  disc 
  of 
  the 
  

   wing, 
  and 
  have 
  the 
  white 
  transverse 
  line 
  through 
  the 
  black 
  longitudinal 
  

   dash 
  in 
  the 
  upper 
  lobe 
  much 
  more 
  distinct, 
  and 
  runuing 
  into 
  the 
  costal 
  

   fringe; 
  they 
  much 
  resemble 
  the 
  moths 
  of 
  the 
  var. 
  plagiodactylus, 
  Zell." 
  

   He 
  further 
  notes 
  : 
  " 
  Of 
  the 
  typical 
  markings, 
  the 
  dot 
  on 
  the 
  inner 
  

   margin 
  is 
  wanting, 
  or 
  is 
  very 
  indistinct, 
  the 
  discoidal 
  spot 
  is 
  usually 
  

   distinct, 
  although 
  rather 
  less 
  so 
  than 
  in 
  A. 
  pelidnodactyla. 
  He 
  considers 
  

   plagiodactylus 
  a 
  variety 
  of 
  this 
  species, 
  being 
  unable 
  to 
  find 
  any 
  constant 
  

   character 
  between 
  undoubted 
  bipunctidactylaand 
  examples 
  of 
  plagiodac- 
  

   tylus. 
  [Among 
  others 
  examined, 
  are 
  four 
  from 
  Herrich-Schaffer's 
  col- 
  

   lection, 
  from 
  Neustrelitz, 
  and 
  the 
  Schneeberg,* 
  in 
  the 
  Vienna 
  district 
  

   (which 
  are 
  evidently 
  those 
  referred 
  to 
  by 
  Herrich-Schaffer, 
  Sys. 
  Bearb.,\., 
  

   p. 
  377, 
  and 
  from 
  which 
  the 
  description 
  was 
  drawn 
  up, 
  and 
  which 
  exactly 
  

   agree 
  with 
  his 
  Suppl. 
  fig. 
  22) 
  , 
  and 
  two 
  of 
  Zeller's 
  original 
  specimens 
  from 
  

   Bergiin] 
  . 
  I 
  have 
  carefully 
  compared 
  these 
  latter 
  with 
  44 
  examples 
  of 
  

   bipunctidactyla, 
  and 
  found 
  the 
  characters 
  usually 
  relied 
  on 
  excessively 
  

  

  * 
  These 
  are 
  evidently 
  some 
  of 
  Mann's 
  original 
  specimens, 
  see 
  postea. 
  

  

  