﻿390 
  BRITISH 
  LEPIDOPTERA. 
  

  

  contrast 
  with 
  the 
  genera 
  hitherto 
  noticed, 
  where 
  this 
  structure 
  is 
  

   absent, 
  a 
  second 
  small 
  chitincus 
  plate, 
  domed 
  above, 
  and 
  terminating 
  

   on 
  the 
  hind-margin 
  in 
  two 
  short 
  thick 
  pointed 
  processes 
  ; 
  under 
  this 
  

   lies 
  the 
  short, 
  stout, 
  straight 
  penis. 
  The 
  prensors 
  are 
  hollowed 
  like 
  a 
  

   spoon, 
  furnished 
  thickly 
  with 
  stiff 
  bristles 
  in 
  the 
  interior, 
  and 
  

   exhibit 
  at 
  the 
  base 
  a 
  round 
  recess, 
  in 
  which 
  is 
  hidden 
  a 
  double 
  

   chitinous 
  structure 
  rolled 
  round 
  as 
  a 
  watch 
  spring, 
  posteriorly 
  ending 
  

   in 
  two 
  points. 
  The 
  9th 
  ventral 
  plate 
  is 
  very 
  small 
  and 
  narrow 
  (Hof- 
  

   mann). 
  

  

  Variation. 
  — 
  Besides 
  the 
  sexual 
  difference 
  in 
  colour 
  noted 
  above, 
  

   there 
  is 
  considerable 
  variation 
  in 
  the 
  amount 
  and 
  brightness 
  of 
  the 
  

   ochreous 
  mottling 
  and 
  markings 
  present. 
  Eeutti 
  notes 
  that 
  at 
  Carls- 
  

   ruhe, 
  in 
  Baden, 
  a 
  pale 
  specimen 
  with 
  more 
  extended 
  yellow 
  markings 
  

   was 
  captured, 
  that 
  might 
  almost 
  be 
  taken 
  for 
  ehrenberyianus, 
  Zell. 
  

   Bankes 
  observes 
  that 
  each 
  sex 
  shows 
  an 
  appreciable 
  amount 
  of 
  

   variation 
  in 
  the 
  depth 
  of 
  the 
  ground-colour, 
  and 
  that, 
  although 
  the 
  

   females 
  average 
  decidedly 
  paler 
  than 
  the 
  opposite 
  sex, 
  his 
  lengthy 
  

   series 
  of 
  bred 
  Purbeck 
  specimens 
  includes 
  females 
  quite 
  as 
  dark 
  as 
  

   the 
  average 
  male, 
  though 
  a 
  trifle 
  lighter 
  than 
  the 
  very 
  darkest 
  males. 
  

  

  Egglaying. 
  — 
  The 
  eggs 
  are 
  laid 
  chiefly 
  on 
  the 
  underside 
  of 
  a 
  leaf 
  of 
  

   the 
  foodplant, 
  usually 
  singly, 
  but 
  sometimes 
  two 
  or 
  three 
  not 
  far 
  

   removed 
  from 
  one 
  another. 
  Bankes 
  notes, 
  of 
  eggs 
  laid 
  in 
  confinement, 
  

   that 
  a 
  $ 
  , 
  caged 
  with 
  a 
  shoot 
  of 
  Ononis 
  arvensis, 
  laid 
  a 
  number 
  of 
  ova 
  

   on 
  the 
  undersides 
  of 
  the 
  leaves 
  during 
  the 
  night 
  of 
  July 
  11th, 
  1904. 
  

   Bacot 
  observes 
  that 
  the 
  eggs 
  thus 
  laid 
  were 
  very 
  numerous, 
  placed 
  in 
  

   all 
  conceivable 
  positions, 
  one 
  little 
  lot 
  being 
  placed 
  in 
  a 
  mass, 
  a 
  feature 
  

   which 
  appears 
  not 
  to 
  take 
  place 
  in 
  nature, 
  when 
  the 
  eggs 
  are 
  much 
  

   more 
  scattered. 
  We 
  received, 
  on 
  July 
  10th, 
  1899, 
  a 
  considerable 
  

   number 
  of 
  eggs 
  that 
  had 
  been 
  laid 
  in 
  a 
  chip 
  box 
  ; 
  although 
  of 
  the 
  flat 
  

   type, 
  many 
  were 
  laid 
  on 
  one 
  end, 
  with 
  the 
  micropyle 
  at 
  apex, 
  some, 
  

   however, 
  quite 
  normally 
  with 
  the 
  long 
  axis 
  horizontal, 
  whilst 
  others 
  

   were 
  inclined 
  at 
  angles 
  varying 
  from 
  about 
  30° 
  to 
  90°. 
  The 
  eggs 
  hatched 
  

   on 
  July 
  11th 
  and 
  12th, 
  1899. 
  Chapman 
  observes 
  that 
  the 
  eggs 
  are 
  laid 
  

   singly 
  on 
  stems, 
  leaves, 
  and 
  leaf-stalks 
  of 
  Ononis. 
  Nolcken 
  observes 
  

   that, 
  on 
  July 
  3rd, 
  he 
  enclosed 
  a 
  number 
  of 
  moths 
  in 
  a 
  cage 
  with 
  a 
  

   branch 
  of 
  Ononis 
  in 
  bloom 
  ; 
  he 
  observed 
  moths 
  in 
  copula 
  the 
  next 
  

   morning, 
  and, 
  on 
  the 
  5th, 
  a 
  number 
  of 
  eggs 
  were 
  observed 
  mostly 
  laid 
  

   singly 
  on 
  the 
  underside 
  of 
  the 
  leaves, 
  but 
  occasionally 
  two 
  near 
  

   together 
  ; 
  several 
  also 
  were 
  laid 
  on 
  the 
  stem, 
  and, 
  when 
  this 
  was 
  so, 
  

   they 
  were 
  usually 
  placed 
  in 
  small 
  groups 
  ; 
  some 
  were 
  also 
  laid 
  on 
  the 
  

   walls 
  of 
  the 
  cage 
  ; 
  the 
  earliest 
  larvae 
  appeared 
  on 
  July 
  17th, 
  i.e., 
  the 
  

   egg-stage 
  lasted 
  twelve 
  days. 
  

  

  Ovum. 
  — 
  When 
  first 
  laid, 
  pale 
  greenish 
  -yellow 
  in 
  colour 
  (Bankes, 
  

   July 
  12th, 
  1904). 
  In 
  shape 
  oval 
  or 
  ovoid, 
  the 
  sides 
  flattened, 
  but 
  not 
  

   depressed, 
  colour 
  bright 
  yellow-green, 
  with 
  a 
  semitransparent, 
  highly- 
  

   varnished 
  appearance 
  ; 
  the 
  surface 
  roughly 
  and 
  irregularly 
  sculptured, 
  

   or 
  faceted, 
  but 
  the 
  facets 
  crude 
  and 
  vague, 
  not 
  at 
  all 
  clear-cut 
  or 
  sharp, 
  

   yet 
  much 
  plainer 
  than 
  in 
  other 
  plume 
  ova 
  examined 
  up 
  to 
  date 
  

   of 
  observation. 
  Length 
  -550mm. 
  --575mm., 
  width 
  -35mm. 
  --4mm 
  , 
  

   thickne#s 
  slightly 
  over 
  -2mm. 
  (Bacot, 
  July 
  18th, 
  1904, 
  ova 
  received 
  

   from 
  Bankes 
  on 
  July 
  13th). 
  Egg 
  of 
  flat 
  type, 
  oval 
  in 
  outline, 
  notice- 
  

   ably 
  depressed 
  on 
  upper 
  surface 
  ; 
  shell 
  much 
  wrinkled, 
  evidently 
  very 
  

   delicate, 
  but 
  no 
  trace 
  (under 
  low 
  power) 
  of 
  any 
  regular 
  sculpturing. 
  

  

  