﻿494 
  

  

  BRITISH 
  LEPIDOPTERA. 
  

  

  Barr., 
  "Lep. 
  Brit. 
  Isles," 
  ix., 
  p. 
  396, 
  pi. 
  417, 
  fig. 
  4 
  (1904) 
  ; 
  Chaprnn., 
  " 
  Trans. 
  

   Enfc. 
  Soc. 
  London," 
  p. 
  133 
  (1906). 
  

  

  Original 
  description. 
  — 
  Alis 
  anterioribus 
  rufo-griseis, 
  laciniis 
  niveo- 
  

   'bistrigatis, 
  digito 
  tertio 
  setaceo 
  non 
  atro-sqaamato. 
  (Forewings 
  reddish- 
  

   grey, 
  with 
  two 
  snow-white 
  transverse 
  lines 
  across 
  the 
  lobes, 
  the 
  3rd 
  

   plumule 
  bristle-like, 
  without 
  black 
  scales) 
  (one 
  male 
  and 
  three 
  females) 
  

   Isis, 
  1839, 
  p. 
  277." 
  The 
  smallest 
  plume, 
  even 
  less 
  than 
  P. 
  microdactylia. 
  

   In 
  colour 
  and 
  markings 
  it 
  appears 
  similar 
  to 
  the 
  species 
  related 
  to 
  

   P. 
  hieracii 
  (section 
  b 
  of 
  the 
  genus), 
  but 
  differs 
  essentially 
  in 
  that 
  the 
  fore- 
  

   wings 
  are 
  fissured 
  more 
  than 
  to 
  the 
  middle, 
  that 
  the 
  lower 
  lobe, 
  like 
  the 
  

   upper 
  lobe, 
  is 
  quite 
  bristle-like, 
  and 
  that 
  the 
  3rd 
  plumule 
  is 
  quite 
  without 
  

   the 
  black 
  scale-tufts 
  in 
  the 
  fringes. 
  It 
  belongs, 
  therefore, 
  to 
  the 
  same 
  

   section 
  as 
  P. 
  pentadactylus, 
  from 
  which 
  it 
  is 
  distinguished 
  by 
  its 
  short, 
  but 
  

   very 
  long-spurred, 
  legs. 
  Body 
  brownish-grey. 
  Upper 
  margin 
  of 
  the 
  

   eyes 
  white. 
  Antennae 
  brownish, 
  with 
  a 
  white 
  longitudinal 
  line, 
  and 
  

   with 
  short 
  bristle-like, 
  somewhat 
  erect, 
  threads 
  on 
  the 
  joints 
  in 
  both 
  

   sexes. 
  Palpi 
  much 
  longer 
  than 
  the 
  head, 
  curved 
  upwards, 
  slender, 
  

   whitish, 
  with 
  a 
  brown 
  longitudinal 
  line 
  on 
  the 
  side 
  ; 
  the 
  apical 
  joint 
  

   slender, 
  rather 
  long, 
  projecting 
  horizontally, 
  brown 
  beneath. 
  Legs 
  

   shorter 
  than 
  usual. 
  Coxae 
  brownish 
  dust-colour; 
  the 
  four 
  hinder 
  ones 
  

   whitish. 
  Femora 
  on 
  one 
  side 
  silvery-whitish, 
  on 
  the 
  other 
  brownish, 
  

   with 
  white 
  lines;! 
  tibiae 
  white, 
  with 
  a 
  brownish 
  longitudinal 
  line, 
  

   thickened 
  at 
  the 
  ends 
  with 
  brownish 
  scales; 
  those 
  on 
  the 
  hind 
  tibiae 
  

   are 
  conspicuous 
  by 
  their 
  white 
  terminations. 
  Tarsal 
  joints 
  silvery- 
  

   white, 
  brownish 
  at 
  their 
  ends. 
  Abdomen, 
  upper- 
  and 
  undersides, 
  with 
  

   interrupted, 
  and 
  partially 
  extinguished, 
  silvery 
  lines. 
  f 
  The 
  narrow 
  

   forewings 
  fissured 
  to 
  more 
  than 
  the 
  middle, 
  brownish-grey, 
  on 
  the 
  inner 
  

   margin 
  just 
  before, 
  and 
  at, 
  the 
  fissure, 
  with 
  crowded 
  whitish 
  scaling. 
  

   The 
  two 
  lobes 
  have, 
  at 
  the 
  commencement 
  of 
  the 
  second 
  and 
  third 
  

   thirds, 
  a 
  broad, 
  somewhat 
  faint, 
  silvery- 
  white 
  transverse 
  line, 
  wmich 
  

   runs 
  on 
  the 
  costa 
  into 
  the 
  fringes. 
  Fringes 
  blackish, 
  here 
  and 
  there 
  

   with 
  whitish 
  spots, 
  with 
  which 
  that 
  before 
  the 
  apex 
  of 
  the 
  inner 
  

   margin 
  of 
  the 
  3rd 
  plumule 
  contrasts 
  well. 
  Hindwmgs 
  pale 
  brown, 
  

   with 
  rather 
  long 
  grey 
  fringes 
  ; 
  the 
  fringes 
  at 
  the 
  apex 
  of 
  the 
  3rd 
  

   plumule 
  whitish. 
  All 
  the 
  plumules 
  very 
  narrow, 
  the 
  two 
  first 
  as 
  long 
  

   as 
  two-thirds 
  of 
  the 
  total 
  length 
  of 
  the 
  hindwmgs. 
  I 
  took 
  eight 
  

   examples 
  of 
  this 
  species 
  (and 
  could 
  have 
  taken 
  more 
  if 
  I 
  had 
  not 
  merely 
  

   considered 
  them 
  remarkable 
  on 
  account 
  of 
  the 
  situation 
  and 
  small 
  size) 
  

   near 
  Frankfort-on-the-Oder, 
  at 
  the 
  end 
  of 
  July, 
  on 
  a 
  peat-moor, 
  where 
  

   I 
  also 
  collected 
  Tijnda 
  fasciata, 
  Chrysops 
  sepulcliralis, 
  and 
  Tabanus 
  

  

  * 
  Yet 
  another 
  species 
  has 
  a 
  resemblance 
  to 
  didactylus, 
  which, 
  however, 
  

   immediately 
  falls 
  away, 
  when 
  one 
  observes 
  the 
  long, 
  narrow, 
  3rd 
  plumule 
  of 
  the 
  

   hindwings 
  entirely 
  destitute 
  of 
  the 
  black 
  scale-tufts, 
  wherefore, 
  also, 
  I 
  did 
  not 
  at 
  

   all 
  take 
  it 
  into 
  consideration 
  above. 
  It 
  is 
  like 
  the 
  very 
  smallest 
  didactyli, 
  and 
  has, 
  in 
  

   common 
  with 
  this 
  species, 
  and 
  with 
  Pterophorus 
  tristis, 
  the 
  long 
  hind 
  tibial 
  spurs, 
  the 
  

   longest 
  in 
  the 
  whole 
  genus 
  ; 
  its 
  palpi, 
  however, 
  are 
  different 
  from 
  those 
  of 
  both 
  

   species. 
  I 
  took 
  eight 
  examples, 
  of 
  which 
  my 
  collection 
  only 
  retains 
  four, 
  on 
  a 
  

   peat-moor 
  near 
  Frankfort, 
  at 
  the 
  end 
  of 
  July. 
  It 
  is 
  named 
  Pterophorus 
  pallidum, 
  

   Zell. 
  (amaurodactylus, 
  in 
  litt.), 
  and 
  should, 
  still 
  less 
  than 
  P. 
  tristis, 
  be 
  considered 
  

   in 
  connection 
  with 
  Degeer's 
  or 
  Linne's 
  didactylus 
  (Zeller, 
  Isis, 
  1839, 
  p. 
  277). 
  

  

  f 
  This 
  description 
  is 
  taken 
  from 
  Zeller's 
  own 
  copy 
  (in 
  Nat. 
  Hist. 
  Museum 
  

   Library); 
  both 
  the 
  paragraphs 
  marked 
  f 
  are 
  "?" 
  in 
  Zeller's 
  handwriting, 
  and 
  

   unterbrochen 
  ( 
  = 
  interrupted) 
  is 
  deleted, 
  verloschen 
  ( 
  = 
  extinguished 
  or 
  faint) 
  

   being 
  substituted. 
  

  

  