﻿PLATYPTILIA 
  ISODACTYLUS. 
  185 
  

  

  colouring 
  of 
  the 
  lobes 
  of 
  the 
  anterior 
  wings, 
  which, 
  instead 
  of 
  being 
  

   partially 
  much 
  darker, 
  are 
  rather 
  paler 
  than 
  the 
  remaining 
  surface 
  of 
  

   the 
  wings 
  and 
  have 
  only 
  an 
  almost 
  imperceptible 
  trace 
  of 
  the 
  whitish 
  

   transverse 
  line. 
  Again, 
  the 
  cilia 
  of 
  the 
  inner 
  margin 
  are 
  dirty 
  

   yellowish-grey, 
  and 
  there 
  is 
  no 
  trace 
  of 
  the 
  two 
  deep 
  black 
  tufts 
  of 
  

   scales 
  on 
  them 
  ; 
  whilst 
  the 
  streak-like 
  collection 
  of 
  scales 
  in 
  the 
  cilia 
  

   of 
  the 
  third 
  feather 
  of 
  the 
  hindwing 
  of 
  gonodactylus 
  is 
  here 
  reduced 
  to 
  

   the 
  half, 
  which, 
  as 
  in 
  that 
  species, 
  lies 
  rather 
  nearer 
  to 
  the 
  tip 
  than 
  to 
  

   the 
  base 
  of 
  the 
  feather. 
  The 
  following 
  marking 
  would 
  also 
  furnish 
  a 
  

   good 
  specific 
  character 
  if 
  it 
  should 
  prove 
  constant 
  — 
  the 
  pale 
  spot 
  or 
  

   dot 
  in 
  the 
  brown 
  line, 
  which 
  in 
  gonodactylus 
  runs 
  along 
  the 
  cilia 
  near 
  

   the 
  hindmargin 
  of 
  the 
  anterior 
  lobe, 
  is 
  entirely 
  wanting 
  in 
  isodactylus. 
  

   Capnodactylus 
  has 
  certainly 
  anterior 
  wings 
  of 
  a 
  similar 
  form, 
  and 
  also 
  

   an 
  interrupted 
  brown 
  line 
  in 
  the 
  cilia 
  of 
  the 
  anterior 
  lobe, 
  but, 
  besides 
  

   other 
  differences, 
  the 
  second 
  feather 
  of 
  the 
  hindwing 
  is 
  much 
  broader 
  

   and 
  blunter, 
  and, 
  in 
  the 
  third 
  feather, 
  the 
  strong 
  black 
  bundle 
  of 
  scales 
  

   lies 
  very 
  far 
  towards 
  the 
  apex. 
  The 
  thorax 
  much 
  damaged. 
  The 
  

   legs 
  less 
  pure 
  white, 
  otherwise 
  marked 
  as 
  in 
  gonodactylus. 
  The 
  fore- 
  

   wings 
  of 
  a 
  brownish- 
  clay 
  colour, 
  very 
  dull, 
  becoming 
  whitish 
  at 
  the 
  

   base 
  along 
  the 
  inner 
  margin 
  ; 
  the 
  costa 
  darker, 
  without 
  white 
  

   markings. 
  The 
  brown 
  costal 
  triangle 
  in 
  the 
  same 
  position 
  as 
  in 
  

   gonodactylus, 
  but 
  paler, 
  less 
  sharply 
  margined, 
  and 
  less 
  extended 
  along 
  

   the 
  costa 
  towards 
  the 
  first 
  lobe 
  ; 
  on 
  the 
  inner 
  edge 
  it 
  fades 
  into 
  the 
  

   ground-colour. 
  At 
  the 
  cleft 
  is 
  a 
  darker 
  spot 
  with 
  a 
  smaller 
  one 
  above 
  

   it. 
  The 
  two 
  lobes 
  with 
  a 
  paler, 
  more 
  yellowish, 
  ground-colour 
  than 
  

   the 
  rest 
  of 
  the 
  wing, 
  darkening 
  slightly 
  only 
  on 
  the 
  terminal 
  third, 
  

   the 
  darkening 
  deeper 
  and 
  wider 
  in 
  the 
  lower 
  portion, 
  whilst 
  in 
  front 
  

   of 
  the 
  darkened 
  area 
  is 
  the 
  slightest 
  trace 
  of 
  a 
  transverse 
  line. 
  The 
  

   hind 
  marginal 
  fringes 
  whitish, 
  traversed 
  nearly 
  at 
  the 
  base 
  by 
  an 
  

   interrupted 
  dark 
  brown 
  line, 
  between 
  which 
  and 
  the 
  hind 
  margin 
  the 
  

   colour 
  is 
  brownish-yellow, 
  as 
  in 
  gonodactylus 
  ; 
  at 
  the 
  anal 
  angle 
  of 
  the 
  

   hinder 
  lobe 
  the 
  fringes 
  are 
  also 
  similarly 
  blackish 
  ; 
  the 
  inner 
  marginal 
  

   fringes 
  are 
  darker 
  without 
  black 
  scale-tufts 
  (as 
  noted 
  above). 
  The 
  

   plumules 
  of 
  the 
  hindwings 
  are" 
  grey-brown 
  ; 
  the 
  fringes 
  much 
  darker, 
  

   particularly 
  those 
  of 
  the 
  third 
  plumule. 
  On 
  the 
  underside, 
  the 
  apex 
  of 
  the 
  

   first 
  lobe 
  of 
  the 
  forewing 
  is 
  noticeably 
  pale 
  yellowish, 
  and 
  the 
  trans- 
  

   verse 
  line 
  is 
  more 
  distinct 
  ; 
  the 
  first 
  plumule 
  of 
  the 
  hindwing 
  on 
  the 
  

   outer 
  two-thirds 
  has 
  many 
  scattered 
  whitish 
  scales, 
  without 
  forming, 
  

   however, 
  a 
  transverse 
  line. 
  This 
  doubtful 
  species 
  has 
  been 
  found 
  in 
  

   several 
  localities 
  in 
  England. 
  I 
  am 
  greatly 
  surprised 
  that 
  it 
  should 
  

   have 
  been 
  already 
  split 
  up 
  into 
  two 
  species" 
  (=similidactylm 
  } 
  Dale, 
  

   Stphs., 
  lllus.y 
  iv., 
  p. 
  375, 
  and 
  monodactyla, 
  Haw., 
  Stphs., 
  lllus., 
  iv., 
  p. 
  

   373) 
  (Zeller, 
  Linnaea 
  Kntomologica, 
  vi., 
  pp. 
  328-9). 
  

  

  * 
  It 
  seems 
  to 
  us 
  the 
  more 
  remarkable 
  that 
  Zellev, 
  having 
  been 
  informed 
  (he 
  

   only 
  had 
  one 
  worn 
  example 
  for 
  description) 
  that 
  this 
  species 
  had 
  apparently 
  been 
  

   already 
  twice 
  described 
  (1) 
  as 
  similidactyla, 
  Dale, 
  and 
  {2) 
  B.S 
  monodactyla, 
  Haw., 
  

   should 
  redescribe 
  it, 
  for, 
  had 
  the 
  name 
  similidactyla, 
  Dale, 
  been 
  really 
  given 
  to 
  this 
  

   species 
  it 
  would 
  of 
  course 
  have 
  stood. 
  As 
  matters 
  of 
  fart 
  (1) 
  Stephens 
  and 
  Wood 
  

   wrongly 
  referred 
  it 
  to 
  similidactyla, 
  Dale, 
  which 
  lithodactyla, 
  Tr. 
  ; 
  (2) 
  Haworth's 
  

   monodactyla 
  seems 
  to 
  have 
  been 
  partly 
  original 
  and 
  partly 
  a 
  Literary 
  description 
  

   quoted 
  from 
  de 
  Villers, 
  and 
  he 
  appears 
  to 
  have 
  erroneously 
  referred 
  a 
  specimen 
  of 
  

   isodactylus 
  in 
  his 
  collection 
  to 
  monodactyla, 
  Linn. 
  Bankes 
  says 
  that 
  a 
  specimen, 
  

   presumably 
  the 
  one 
  described 
  by 
  Haworth, 
  and 
  bearing 
  his 
  label, 
  agrees 
  with 
  the 
  

   latter's 
  short 
  description, 
  and 
  his 
  remark 
  as 
  to 
  " 
  Habitat." 
  to 
  some 
  extent, 
  supports 
  

   the 
  idea 
  of 
  an 
  independent 
  description. 
  

  

  