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  Pupa 
  — 
  about 
  2mm. 
  ; 
  yellowish 
  ; 
  wing-cases 
  extending 
  nearly 
  

   to 
  apex 
  of 
  3rd 
  abdominal 
  segment, 
  free 
  at 
  the 
  tip; 
  abdom- 
  

   inal 
  segments 
  3-8 
  freely 
  movable, 
  apical 
  edges 
  somewhat 
  pro- 
  

   duced 
  and 
  there 
  are 
  several 
  spines 
  on 
  dorsal 
  apical 
  margins, 
  

   on 
  ventral 
  side 
  are 
  2 
  spines 
  per 
  segment 
  about 
  midway 
  between 
  

   base 
  and 
  apex; 
  from 
  the 
  movability 
  of 
  the 
  segments 
  with 
  the 
  

   assistance 
  of 
  these 
  spines 
  the 
  pupa 
  is 
  capable 
  of 
  progressing 
  

   thru 
  the 
  material 
  in 
  which 
  it 
  lives. 
  Compound 
  eyes 
  distinct; 
  

   two 
  thoracic 
  forward-projecting 
  respiratory 
  tubes. 
  

  

  The 
  length 
  of 
  time 
  for 
  the 
  different 
  stages 
  was 
  not 
  ascer- 
  

   tained, 
  nor 
  other 
  details 
  of 
  life 
  history. 
  When 
  the 
  flies 
  emerge 
  

   from 
  the 
  pupae 
  their 
  wings 
  develop 
  with 
  great 
  rapidity, 
  being 
  

   ready 
  for 
  use 
  in 
  a 
  very 
  few 
  moments. 
  

  

  Of 
  the 
  34 
  species 
  of 
  Psychodidae 
  described 
  for 
  North 
  Amer- 
  

   ica, 
  the 
  life 
  history 
  of 
  but 
  one 
  is 
  known. 
  This 
  is 
  Pericoma 
  

   calif 
  omica 
  Kincaid.* 
  The 
  larvae 
  are 
  elongate 
  oval 
  in 
  form 
  

   and 
  have 
  a 
  row 
  of 
  eight 
  median 
  ventral 
  suckers 
  by 
  which 
  they 
  

   cling 
  to 
  rocks 
  in 
  or 
  on 
  the 
  margin 
  of 
  streams, 
  where 
  they 
  are 
  

   constantly 
  wetted 
  by 
  the 
  dashing 
  water. 
  They 
  breathe 
  by 
  

   means 
  of 
  two 
  spiracles 
  at 
  the 
  posterior 
  end. 
  When 
  ready 
  to 
  

   pupate 
  the 
  larvae 
  crawl 
  a 
  little 
  higher 
  on 
  the 
  stones, 
  where 
  only 
  

   the 
  spray 
  will 
  reach 
  them, 
  and 
  fix 
  themselves 
  to 
  the 
  rock 
  and 
  

   transform 
  to 
  small 
  turtle-back 
  shaped 
  pupae 
  in 
  which 
  they 
  

   remain 
  about 
  two 
  weeks. 
  

  

  Other 
  species 
  have 
  been 
  reared 
  from 
  manure, 
  but 
  the 
  larvae 
  

   not 
  obtained. 
  Dr. 
  Howard 
  reared 
  Psychoda 
  ndnuta 
  from 
  cow 
  

   manure 
  while 
  making 
  studies 
  on 
  the 
  horn-fly. 
  

  

  The 
  life 
  history 
  of 
  one 
  British 
  species 
  is 
  known. 
  (Pencoma 
  

   ccmescens)^ 
  It 
  lives 
  in 
  water, 
  and 
  feeds 
  on 
  green 
  algae. 
  

   Three 
  Brazilian 
  species 
  have 
  similar 
  habits 
  : 
  Maruina 
  Ursula, 
  

   M. 
  spinosa 
  and 
  M. 
  pilosella.^* 
  The 
  larvae 
  have 
  a 
  row 
  of 
  

   8 
  suctorial 
  discs 
  on 
  the 
  ventral 
  side 
  by 
  w^hich 
  they 
  cling 
  to 
  

   "rocky 
  walls 
  covered 
  with 
  a 
  slippery 
  carpet 
  of 
  algae, 
  and 
  kept 
  

   moist 
  by 
  the 
  spray 
  of 
  waterfalls 
  or 
  by 
  drops 
  of 
  water 
  running 
  

   dowm 
  from 
  above." 
  In 
  two 
  species, 
  they 
  have 
  tracheal 
  gills 
  

   situated 
  at 
  the 
  posterior 
  end 
  of 
  body; 
  in 
  one 
  species 
  the 
  

   tracheal 
  gills 
  are 
  situated 
  along 
  sides, 
  and 
  a 
  respiratory 
  tube 
  

   at 
  posterior 
  end. 
  They 
  have 
  two 
  eyes. 
  

  

  *Kellogg, 
  Ent. 
  News, 
  p. 
  46, 
  1901. 
  

  

  tMiall 
  and 
  Walker, 
  Trans. 
  Ent. 
  Soc. 
  London, 
  p. 
  141, 
  1895. 
  

  

  * 
  *Muller, 
  Trans. 
  Ent. 
  Soc. 
  London, 
  p. 
  483, 
  1895. 
  

  

  