﻿258 
  Mr. 
  A. 
  R. 
  Wallace 
  on 
  the 
  HaUts 
  of 
  the 
  

  

  species 
  of 
  HeUconia, 
  Thyr'idia 
  and 
  Ithomia, 
  which 
  prefer 
  the 
  forest 
  

   shades, 
  are 
  confined 
  to 
  a 
  comparatively 
  limited 
  district. 
  The 
  most 
  

   characteristic 
  of 
  the 
  Amazon 
  valley 
  are 
  those 
  species 
  o? 
  Hellconia 
  

   with 
  white 
  or 
  yellow 
  spots 
  on 
  a 
  shining 
  blue 
  or 
  black 
  ground, 
  such 
  

   as 
  tlie 
  Antiocha, 
  Thamar, 
  and 
  several 
  others 
  ; 
  those 
  with 
  radiating 
  

   red 
  lines 
  on 
  the 
  lower 
  wings, 
  such 
  as 
  Erijthrcea, 
  Egeria, 
  Doris, 
  

   and 
  several 
  undescribed 
  species; 
  and, 
  lastly, 
  the 
  delicate 
  little 
  

   clear 
  wings 
  of 
  the 
  genera 
  Thyrul'ia, 
  Jlhomia 
  and 
  Sais. 
  All 
  these 
  

   groups 
  are 
  exceedingly 
  productive 
  in 
  closely 
  allied 
  species 
  and 
  

   varieties 
  of 
  the 
  most 
  interesting 
  description, 
  and 
  often 
  having 
  a 
  

   very 
  limited 
  range 
  ; 
  and 
  as 
  there 
  is 
  every 
  reason 
  to 
  believe 
  that 
  

   the 
  banks 
  of 
  the 
  lower 
  Amazon 
  are 
  among 
  the 
  most 
  recently 
  

   formed 
  parts 
  of 
  South 
  America, 
  we 
  may 
  fairly 
  regard 
  those 
  in- 
  

   sects, 
  which 
  are 
  peculiar 
  to 
  that 
  district, 
  as 
  among 
  the 
  youngest 
  

   of 
  species, 
  the 
  latest 
  in 
  the 
  long 
  series 
  of 
  modifications 
  which 
  the 
  

   forms 
  of 
  animal 
  life 
  have 
  undergone. 
  

  

  The 
  Heliconidce 
  are 
  the 
  most 
  elegant 
  of 
  butterflies, 
  whether 
  

   upon 
  the 
  wing 
  or 
  in 
  a 
  state 
  of 
  repose. 
  Their 
  bodies, 
  their 
  wings 
  

   and 
  their 
  antennae 
  are 
  all 
  long, 
  slender 
  and 
  well 
  formed, 
  and 
  they 
  

   are 
  universally 
  adorned 
  with 
  the 
  most 
  brilliant 
  and 
  harmonious 
  

   colours. 
  They 
  fly 
  rather 
  slowly, 
  and 
  the 
  little 
  Ithomias 
  hover 
  

   almost 
  invisible 
  among 
  the 
  dark 
  foliage. 
  They 
  all 
  rest 
  with 
  their 
  

   wings 
  erect, 
  upon 
  leaves 
  and 
  flowers, 
  and 
  at 
  night 
  I 
  have 
  observed 
  

   them 
  asleep, 
  hanging 
  at 
  the 
  extreme 
  end 
  of 
  a 
  slender 
  twig, 
  which 
  

   bends 
  with 
  their 
  weight 
  and 
  swings 
  gently 
  with 
  the 
  evening 
  

   breeze. 
  

  

  At 
  the 
  extremity 
  of 
  the 
  abdomen 
  these 
  insects 
  possess 
  a 
  pecu- 
  

   liar 
  gland 
  or 
  appendage, 
  concealed 
  between 
  the 
  valves 
  of 
  the 
  anus, 
  

   but 
  capable 
  of 
  being 
  protruded. 
  It 
  is 
  most 
  developed 
  in 
  Lycorea 
  

   halia, 
  where 
  it 
  takes 
  the 
  form 
  of 
  a 
  radiate 
  tuft 
  of 
  liairs, 
  forming, 
  

   when 
  exserted, 
  two 
  feathery 
  globes 
  at 
  tlie 
  extremity 
  of 
  the 
  abdo- 
  

   men. 
  In 
  an 
  undescribed 
  species 
  allied 
  to 
  Heliconia 
  Erythrcea 
  it 
  

   is 
  also 
  much 
  developed, 
  in 
  the 
  shape 
  of 
  small 
  fleshy 
  balls 
  of 
  an 
  

   orange 
  colour, 
  which 
  are 
  always 
  exserted 
  when 
  the 
  insect 
  is 
  

   captured, 
  and 
  give 
  out 
  a 
  penetrating 
  aromatic 
  odour 
  something 
  

   resembling 
  chamomile. 
  

  

  As 
  a 
  whole, 
  the 
  Helicnnidce 
  are 
  the 
  most 
  abundant 
  butterflies 
  of 
  

   the 
  Amazon, 
  and 
  form 
  by 
  far 
  the 
  most 
  striking 
  feature 
  in 
  the 
  En- 
  

   tomology 
  of 
  the 
  country. 
  

  

  The 
  species 
  of 
  Jcrcca, 
  Eneides 
  and 
  Eres'ia 
  remarkably 
  resemble 
  

   Heliconidce 
  in 
  their 
  mode 
  of 
  flight 
  and 
  habits, 
  as 
  well 
  as 
  in 
  their 
  

   form 
  and 
  markings, 
  and 
  they 
  are 
  almost 
  always 
  found 
  in 
  com- 
  

  

  