﻿112 
  BRITISH 
  LEPIDOPTERA. 
  

  

  paler 
  ground-colour, 
  the 
  black 
  points 
  are 
  less 
  coloured, 
  and 
  the 
  large 
  

   white 
  ones 
  are 
  more 
  numerous, 
  15-18 
  to 
  a 
  segment. 
  Each 
  segment 
  is 
  

   divided 
  into 
  two 
  very 
  distinct 
  subsegments 
  by 
  a 
  depression 
  passing 
  

   across 
  dorsum 
  from 
  just 
  behind 
  spiracle. 
  The 
  posterior 
  of 
  these 
  

   (rather 
  the 
  smaller) 
  is 
  again 
  less 
  markedly 
  divided 
  into 
  a 
  smaller 
  

   posterior, 
  and 
  larger 
  anterior, 
  subsegment. 
  The 
  white 
  points 
  tend 
  to 
  

   run 
  into 
  a 
  transverse 
  line 
  at 
  the 
  anterior 
  border 
  of 
  the 
  segment, 
  but 
  

   neither 
  they, 
  nor 
  the 
  smaller, 
  seem 
  to 
  give 
  any 
  aid 
  in 
  making 
  out 
  

   subsegments, 
  since 
  they 
  are 
  ranged 
  (so 
  far 
  as 
  they 
  are 
  ranged) 
  into 
  25 
  

   or 
  30 
  transverse 
  rows 
  ; 
  though 
  these 
  rows 
  are 
  often 
  for 
  some 
  distance 
  

   separated 
  by 
  sulci, 
  it 
  is 
  impossible 
  to 
  follow 
  any 
  individual 
  row 
  for 
  more 
  

   than 
  a 
  short 
  distance. 
  In 
  calling 
  the 
  processes 
  of 
  the 
  prothorax 
  and 
  

   of 
  9th 
  abdominal 
  horns, 
  an 
  erroneous 
  impression 
  may 
  be 
  given, 
  since 
  

   they 
  are 
  very 
  wide 
  at 
  base 
  and 
  blunt. 
  Those 
  on 
  prothorax 
  might 
  be 
  

   described 
  as 
  being 
  an 
  anterior 
  projection 
  of 
  the 
  margin 
  of 
  prothorax 
  over 
  

   the 
  head, 
  not 
  very 
  dissimilar 
  to 
  that 
  in 
  larva 
  of 
  Lycamids, 
  Anthrocerids, 
  

   or 
  Lymantriids, 
  but 
  with 
  the 
  front 
  margin 
  deeply 
  indented 
  medially. 
  

   The 
  two 
  sides 
  of 
  each 
  horn 
  are 
  at 
  an 
  angle 
  to 
  each 
  other 
  of 
  about 
  60°. 
  

   The 
  tail-horn 
  is 
  more 
  raised, 
  i.e., 
  more 
  vertical, 
  at 
  an 
  angle 
  of 
  about 
  45° 
  

   from 
  the 
  horizontal. 
  The 
  9th 
  abdominal 
  segment 
  is 
  very 
  narrow 
  ventrally, 
  

   but 
  is 
  dorsally, 
  from 
  anterior 
  border 
  to 
  end 
  of 
  horn, 
  about 
  equal 
  in 
  length 
  

   to 
  the 
  8th 
  ; 
  the 
  horn 
  is 
  half 
  this 
  dorsally, 
  ventrally 
  one-third 
  of 
  the 
  8th. 
  

   The 
  sides 
  of 
  the 
  horn 
  are 
  at 
  an 
  angle 
  of 
  about 
  30° 
  to 
  each 
  other, 
  tbe 
  upper 
  

   and 
  lower 
  surfaces 
  being 
  so 
  rounded 
  that 
  any 
  angle 
  may 
  be 
  quoted 
  ; 
  they 
  

   may 
  even 
  be 
  called 
  parallel. 
  One 
  chief 
  point 
  is 
  that 
  their 
  surfaces 
  are 
  

   not 
  in 
  any 
  way 
  differentiated 
  from 
  the 
  rest 
  of 
  the 
  surface, 
  so 
  that 
  they 
  

   are 
  rather 
  warts, 
  humps, 
  or 
  processes, 
  rather 
  than 
  horns, 
  as 
  for 
  example, 
  

   those 
  of 
  Sphingid 
  larva, 
  etc., 
  are. 
  The 
  tubercles 
  on 
  an 
  (say 
  1th) 
  

   abdominal 
  segment 
  are 
  — 
  i. 
  which 
  differs 
  from 
  all 
  the 
  others 
  in 
  having 
  

   as 
  base 
  a 
  finely 
  shagreened 
  circular 
  area, 
  O09mm. 
  across, 
  the 
  tubercle 
  

   in 
  the 
  centre 
  being, 
  much 
  as 
  the 
  others, 
  a 
  raised 
  chitinous 
  ring 
  with 
  a 
  

   short 
  colourless 
  (slightly 
  spiculated) 
  club, 
  about 
  O03mni. 
  in 
  length 
  ; 
  

   this 
  tubercle 
  is 
  near 
  the 
  middle 
  line 
  and 
  on 
  1st 
  (broad) 
  subsegment; 
  

   tubercle 
  ii, 
  on 
  anterior 
  portion 
  of 
  2nd 
  subsegment 
  (or 
  on 
  middle 
  of 
  its 
  front 
  

   half, 
  if 
  these 
  further 
  divisions 
  be 
  recognised) 
  , 
  a 
  little 
  further 
  out 
  than 
  i, 
  with 
  

   no 
  special 
  base, 
  but 
  its 
  chitinous 
  mammilla 
  about 
  twice 
  the 
  diameter 
  of 
  the 
  

   white 
  points, 
  baton 
  as 
  in 
  i 
  ; 
  tubercle 
  iii 
  about 
  in 
  line 
  (transversely) 
  with 
  i, 
  

   just 
  above 
  and 
  slightly 
  forward 
  of 
  spiracle, 
  structure 
  as 
  ii, 
  but 
  base 
  

   slightly 
  smaller. 
  Below 
  the 
  spiracle 
  are 
  two 
  tubercles, 
  iv 
  and 
  v, 
  on 
  a 
  

   slightly 
  raised 
  and 
  rounded 
  eminence 
  (flange, 
  subspiracular 
  portion) 
  

   occupying 
  anterior 
  half 
  of 
  segment 
  ; 
  one 
  of 
  these 
  (the 
  anterior, 
  vj 
  is 
  

   about 
  twice 
  as 
  far 
  below, 
  as 
  iii 
  is 
  above, 
  spiracle, 
  and 
  nearly 
  twice 
  as 
  

   much 
  in 
  advance 
  of 
  it, 
  the 
  other 
  (the 
  posterior, 
  iv) 
  is 
  not 
  so 
  far 
  below 
  the 
  

   spiracle 
  as 
  the 
  anterior, 
  but 
  is 
  further 
  behind 
  it, 
  than 
  the 
  other 
  is 
  in 
  front 
  ; 
  

   vi 
  ? 
  is 
  another 
  quite 
  similar 
  tubercle 
  that 
  lies 
  about 
  the 
  middle 
  of 
  segment 
  

   (from 
  back 
  to 
  front) 
  and 
  about 
  half 
  way 
  from 
  spiracle 
  to 
  prolegs. 
  On 
  

   base 
  of 
  proleg 
  are 
  three 
  tubercular 
  hairs 
  set 
  triangularly, 
  rather 
  larger 
  

   than 
  the 
  others, 
  and 
  decidedly 
  bristles 
  and 
  not 
  batons 
  or 
  clubs; 
  the 
  (1st) 
  

   longest 
  is 
  posterior, 
  the 
  other 
  two 
  are 
  — 
  one 
  well 
  above 
  the 
  others 
  and 
  

   to 
  front 
  of 
  1st, 
  the 
  other 
  a 
  little 
  below 
  the 
  1st, 
  and 
  a 
  little 
  in 
  front 
  of 
  2nd 
  ; 
  

   on 
  the 
  2nd 
  abdominal 
  (and 
  those 
  segments 
  without 
  prolegs) 
  only 
  the 
  1st 
  

   and 
  2nd 
  of 
  these 
  seem 
  to 
  be 
  present 
  ; 
  there 
  is 
  also 
  a 
  minute 
  tubercle 
  inside 
  

   proleg, 
  which 
  is 
  present 
  also 
  on 
  the 
  segments 
  without 
  prolegs. 
  The 
  

  

  