﻿104 
  REPORT 
  UNITED 
  STATES 
  ENTOMOLOGICAL 
  COMMISSION. 
  

  

  Tvitli 
  a 
  stiff 
  caniers-liair 
  brush 
  will 
  soon 
  denude 
  tlie 
  tip 
  of 
  the 
  abdomen 
  

   without 
  injuring 
  the 
  horny 
  parts, 
  when 
  we 
  shall 
  notice 
  two 
  rounded^ 
  

   brown, 
  horny 
  lobes 
  or 
  clasps 
  extending 
  somewhat 
  beyond 
  the 
  ultimate 
  

   joint 
  (Plate 
  1, 
  Fig. 
  2, 
  A), 
  the 
  lobes 
  some 
  distance 
  apart 
  below, 
  but 
  con- 
  

   verging 
  until 
  they 
  touch 
  above. 
  A 
  careful 
  removal 
  of 
  the 
  chitinous 
  ex- 
  

   terior 
  of 
  the 
  two 
  terminal 
  joints 
  will 
  further 
  reveal 
  to 
  us 
  that 
  these 
  

   lobes 
  are 
  but 
  parts 
  of 
  a 
  somewhat 
  complicated 
  arrangement, 
  admirably 
  

   adapted 
  for 
  seizing 
  the 
  female, 
  and 
  consisting 
  chiefly 
  of 
  the 
  two 
  lobes 
  

   referred 
  to, 
  of 
  two 
  smaller, 
  inferior 
  lobes, 
  and 
  of 
  two 
  intermediate 
  organs 
  

   starting 
  from 
  a 
  knotty 
  base, 
  the 
  upper 
  one 
  curved 
  and 
  ending 
  in 
  a 
  sort 
  

   of 
  beak, 
  the 
  lower 
  one 
  more 
  straight 
  and 
  ending 
  in 
  a 
  small 
  cushion 
  of 
  

   contracted 
  membrane 
  above. 
  

  

  "A 
  still 
  more 
  careful 
  examination 
  will 
  show 
  that 
  the 
  uj^per 
  valves 
  

   (Fig. 
  2, 
  c) 
  have 
  a 
  rather 
  long 
  and 
  gradually 
  narrowing 
  stem, 
  and 
  that 
  

   they 
  broaden 
  irregularly, 
  the 
  hind 
  border 
  obliquing 
  beneath 
  and 
  the 
  

   lower 
  border 
  more 
  strongly 
  curved 
  than 
  the 
  upper; 
  all 
  the 
  borders 
  

   are 
  thickened, 
  the 
  outer 
  surface 
  is 
  polished 
  and 
  dark 
  brown, 
  and 
  the 
  

   iAer 
  surface 
  is 
  clothed 
  with 
  stiff, 
  pale, 
  decumbent 
  hairs, 
  repla-ced 
  to- 
  

   ward 
  the 
  posterior 
  portion 
  with 
  brown, 
  retrorse 
  spines 
  (Fig. 
  2, 
  h). 
  The 
  

   lower 
  valves 
  (Fig. 
  2, 
  d) 
  have 
  a 
  shorter 
  stem 
  and 
  are 
  more 
  regularly 
  

   rounded 
  : 
  each 
  is 
  composed 
  of 
  two 
  corneous 
  layers, 
  soldered 
  and 
  some- 
  

   what 
  thickened 
  at 
  the 
  borders; 
  the 
  outer 
  piece 
  easily 
  fractured 
  and 
  

   detached, 
  pale, 
  and 
  covered 
  sparsely 
  with 
  very 
  minute 
  spines; 
  the 
  in- 
  

   ner 
  one 
  more 
  solid, 
  darker, 
  and 
  covered 
  with 
  a 
  dense 
  brush 
  of 
  long, 
  

   pale 
  hairs. 
  The 
  ux)per 
  intermediate 
  curved 
  organ 
  reminds 
  one, 
  from 
  

   the 
  side, 
  of 
  a 
  swan's 
  neck 
  and 
  head 
  (Fig. 
  2, 
  e) 
  ; 
  it 
  is 
  yellowish 
  and 
  cylin- 
  

   drical, 
  dilated 
  and 
  enlarged 
  toward 
  the 
  end, 
  and 
  terminates 
  in 
  a 
  nar- 
  

   rower, 
  darker 
  beak 
  ; 
  the 
  sides 
  of 
  the 
  dilatation 
  behind 
  are 
  curled 
  up 
  ( 
  Fig. 
  

   2, 
  g) 
  and 
  furnished 
  with 
  long, 
  yellowish 
  hairs 
  behind, 
  and 
  the 
  beak 
  with 
  

   a 
  brush 
  of 
  shorter 
  hairs. 
  The 
  lower 
  organ, 
  or 
  penis 
  (Fig. 
  2,/), 
  is 
  broader, 
  

   composed 
  of 
  membrane 
  supported 
  by 
  two 
  principal 
  ribs 
  — 
  the 
  upper 
  one 
  

   curved, 
  the 
  lower 
  nearly 
  straight 
  — 
  and 
  ends 
  in 
  a 
  sponge-like, 
  superior 
  

   swelling, 
  which 
  in 
  life 
  may 
  be 
  considerably 
  extended 
  in 
  the 
  form 
  of 
  a 
  

   tube. 
  Both 
  those 
  intermediate 
  organs 
  play 
  on 
  a 
  strong 
  horny 
  arcb, 
  

   which 
  is 
  generally 
  retracted, 
  but 
  which 
  can 
  be 
  raised 
  and 
  exserted 
  and 
  

   considerably 
  dilated 
  as 
  in 
  Fig. 
  2, 
  B.^^ 
  

  

  "If 
  wa 
  now 
  take 
  a 
  female, 
  and 
  denude 
  the 
  tip 
  of 
  her 
  abdomen 
  in 
  the 
  

   same 
  way, 
  we 
  shall 
  immediately 
  find 
  a 
  quite 
  different 
  and 
  far 
  more 
  

   simple 
  structure, 
  namely, 
  a 
  thin, 
  vertical, 
  blade-like 
  valve, 
  more 
  or 
  less 
  

   produced 
  or 
  elongated 
  on 
  the 
  upper 
  portion, 
  of 
  a 
  brown 
  color, 
  but 
  with 
  

   a 
  broad, 
  slightly 
  thickened, 
  paler 
  border. 
  This 
  valve 
  plays 
  into 
  two 
  

   retractile 
  subjoints 
  of 
  the 
  bod;y, 
  and 
  maybe 
  hidden 
  within 
  the 
  terminal 
  

   joint 
  proper, 
  so 
  as 
  to 
  show 
  only 
  the 
  ui)per 
  tip, 
  or 
  extended 
  as 
  in 
  the 
  

  

  32 
  A 
  careful 
  examination 
  of 
  the 
  genital 
  organs 
  of 
  thirteen 
  cTs 
  of 
  this 
  species 
  shows 
  very 
  considerable 
  

   Tai-iation 
  in 
  the 
  contour 
  and 
  relative 
  size 
  of 
  all 
  these 
  different 
  parts— 
  so 
  much 
  so 
  as 
  to 
  convince 
  me, 
  

   TThfcu 
  addtd 
  to 
  my 
  limited 
  examinations 
  of 
  the 
  same 
  parts 
  in 
  other 
  species, 
  that 
  nice 
  differences 
  in 
  

   these 
  parts 
  alone 
  are 
  of 
  no 
  specific 
  value. 
  

  

  