﻿Scent-organs 
  in 
  the 
  genus 
  Hydroptila. 
  397 
  

  

  I 
  have 
  been 
  fortunate 
  in 
  enlisting 
  the 
  interest 
  of 
  Dr. 
  H. 
  

   Eltringham, 
  M.A., 
  D.Sc, 
  F.Z.S., 
  in 
  these 
  scent-organs. 
  

   His 
  admirable 
  paper 
  on 
  a 
  similar 
  formation 
  in 
  the 
  Danaine 
  

   butterflies, 
  with 
  his 
  splendid 
  drawings, 
  appeared 
  in 
  the 
  

   Transactions 
  of 
  this 
  Society 
  in 
  1913, 
  pp. 
  399-406, 
  and 
  in 
  

   1915, 
  pp. 
  152-176. 
  I 
  should 
  hke 
  to 
  express 
  my 
  thanks 
  to 
  

   him 
  for 
  the 
  enthusiastic 
  manner 
  in 
  which 
  he 
  has 
  given 
  

   his 
  valuable 
  time 
  to 
  the 
  study 
  of 
  my 
  preparations, 
  and 
  he 
  

   has 
  conferred 
  a 
  further 
  obligation 
  on 
  me 
  by 
  promising 
  a 
  

   supplementary 
  paper 
  on 
  the 
  subject, 
  elucidating 
  the 
  

   histological 
  details 
  of 
  the 
  structures. 
  I 
  have 
  seen 
  the 
  

   rough 
  outline 
  of 
  his 
  notes, 
  together 
  with 
  some 
  beautiful 
  

   drawings, 
  and 
  am 
  grateful 
  to 
  him 
  for 
  thus 
  filling 
  in 
  the 
  

   gaps 
  and 
  omissions 
  which, 
  I 
  fear, 
  are 
  all 
  too 
  plentiful 
  in 
  

   the 
  above 
  descriptions. 
  

  

  Explanation 
  of 
  Plate 
  XVIII. 
  

  

  Scent-organs 
  of 
  Hydroptila 
  spp. 
  

  

  Fig. 
  1. 
  Hydroptila 
  sparsa. 
  Tubular 
  filaments 
  fully 
  everted 
  x 
  30. 
  

  

  2. 
  „ 
  „ 
  „ 
  „ 
  partly 
  withdrawn 
  

  

  x36. 
  

  

  3. 
  „ 
  ,, 
  „ 
  „ 
  fully 
  withdrawn 
  X 
  25. 
  

  

  4. 
  „ 
  madachlani. 
  From 
  a 
  dissection 
  x 
  65. 
  

  

  5. 
  ,, 
  simidans. 
  Filaments 
  partly 
  everted 
  x 
  30. 
  

  

  6. 
  „ 
  ,, 
  ,, 
  fully 
  everted 
  x 
  25. 
  

  

  Explanation 
  of 
  Plate 
  XIX 
  

  

  Scent-organs 
  of 
  Hydroptila 
  spp. 
  

  

  Fig. 
  7. 
  Hydroptila 
  forcipata 
  x 
  25. 
  

  

  8. 
  ,, 
  „ 
  From 
  a 
  dissection 
  x 
  105. 
  

  

  9. 
  „ 
  femoralis 
  x 
  22. 
  

  

  10. 
  „ 
  ,, 
  From 
  a 
  dissection 
  (one 
  filament 
  re- 
  

  

  moved 
  to 
  show 
  scales) 
  x 
  60. 
  

  

  11. 
  „ 
  occulta. 
  Filaments 
  slightly 
  retracted 
  x 
  25. 
  

  

  12. 
  ,, 
  „ 
  Lobe, 
  showing 
  the 
  secondary 
  filament 
  

  

  everted 
  and 
  the 
  arrangement 
  of 
  the 
  

   scent-scales 
  x 
  116, 
  

  

  