﻿396 
  Mr. 
  Martin 
  E. 
  Mosely 
  on 
  

  

  Hydroptila 
  femoralis 
  Eaton 
  (PI. 
  XIX, 
  figs. 
  9 
  and 
  10). 
  

  

  The 
  scent-organ 
  consists 
  of 
  two 
  eversible, 
  tubular 
  

   filaments 
  clothed 
  with 
  black 
  hairs 
  ; 
  there 
  are 
  battledore 
  

   scales 
  very 
  plentifully 
  lining 
  the 
  cup-shaped 
  lobes 
  (PL 
  XIX, 
  

   fig. 
  10). 
  When 
  the 
  filaments 
  are 
  retracted 
  the 
  hairs 
  are 
  

   collected 
  together 
  in 
  a 
  dense 
  brush 
  with 
  their 
  extremities 
  

   resting 
  against 
  the 
  scales 
  of 
  the 
  lobes. 
  The 
  ends 
  of 
  the 
  

   hairs 
  are 
  slightly 
  broadened, 
  and 
  probably, 
  as 
  mentioned 
  

   above, 
  collect 
  the 
  scent 
  matter 
  and 
  distribute 
  it 
  to 
  the 
  

   surrounding 
  atmosphere 
  when 
  the 
  filament 
  is 
  exserted. 
  

  

  H. 
  pulchricornis 
  Pict. 
  

  

  I 
  have 
  seen 
  only 
  two 
  examples 
  of 
  this 
  species, 
  and 
  they 
  

   are 
  both 
  mounted 
  in 
  positions 
  which 
  do 
  not 
  permit 
  of 
  a 
  

   high-power 
  examination 
  of 
  the 
  scent-organs. 
  There 
  are 
  

   two 
  eversible, 
  tubular 
  filaments 
  clothed 
  with 
  black 
  hairs 
  as 
  

   in 
  H. 
  femoralis, 
  but 
  I 
  have 
  been 
  unable 
  to 
  ascertain 
  whether 
  

   there 
  are 
  any 
  scent-scales 
  present. 
  

  

  Hydroptila 
  occulta 
  Eaton 
  (PI. 
  XIX, 
  figs.- 
  11 
  and 
  12). 
  

  

  In 
  Hydroptila 
  occulta 
  the 
  scent-organ 
  is 
  rather 
  complex. 
  

   There 
  are 
  two 
  eversible, 
  tubular 
  filaments 
  clothed 
  with 
  

   golden-yellow 
  hairs. 
  The 
  lobes, 
  which 
  are 
  rather 
  narrow 
  

   and 
  blunt, 
  are 
  each 
  lined 
  with 
  a 
  membrane, 
  and, 
  towards 
  

   the 
  apex, 
  this 
  membrane 
  can 
  be 
  slightly 
  everted 
  to 
  form 
  

   a 
  secondary 
  tubular 
  filament. 
  Towards 
  its 
  extremity 
  

   this 
  filament 
  is 
  clothed 
  with 
  elongated 
  striated 
  scales, 
  

   but 
  hairs, 
  similar 
  to 
  those 
  on 
  the 
  main 
  filaments, 
  are 
  

   absent. 
  

  

  Another 
  cluster 
  of 
  these 
  scales 
  is 
  found 
  towards 
  the 
  

   base 
  of 
  the 
  lobe, 
  and 
  a 
  row 
  of 
  them 
  occurs 
  along 
  the 
  mem- 
  

   brane 
  which 
  extends 
  across 
  the 
  back 
  of 
  the 
  head. 
  At 
  the 
  

   apex 
  of 
  each 
  lobe 
  there 
  is, 
  in 
  addition, 
  a 
  small 
  group 
  of 
  

   striated 
  battledore 
  scales 
  similar 
  in 
  shape 
  to 
  those 
  of 
  

   H.feynoralis 
  (PI. 
  XIX, 
  fig. 
  12). 
  

  

  There 
  are, 
  in 
  addition, 
  two 
  described 
  British 
  species 
  of 
  

   Hydroptila 
  — 
  tigurina 
  Ris., 
  and 
  sylvestris 
  Morton 
  — 
  which 
  I 
  

   have 
  never 
  seen. 
  There 
  are 
  also 
  two 
  undescribed 
  British 
  

   forms 
  in 
  my 
  own 
  collection 
  which 
  unfortunately 
  do 
  not 
  

   display 
  scent-organs 
  sufficiently 
  clearly 
  for 
  description 
  

   here. 
  One 
  species 
  certainly 
  possesses 
  a 
  brush 
  form 
  of 
  

   tubular 
  filament, 
  but 
  a 
  full 
  description 
  must 
  be 
  deferred 
  

   until 
  more 
  material 
  comes 
  to 
  hand. 
  

  

  