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  XII. 
  The 
  Male 
  Abdominal 
  Segments 
  and 
  Aedeagus 
  of 
  Hahro- 
  

   cerus 
  capillaricornis 
  Grav. 
  [Coleoptera, 
  Staphylinidae]. 
  

   By 
  F. 
  Mum. 
  

  

  [Read 
  October 
  15th, 
  1919.] 
  

  

  Plate 
  XX. 
  

  

  In 
  1911 
  Dr. 
  L. 
  Weber,* 
  in 
  an 
  interesting 
  paper, 
  described 
  

   and 
  figured 
  the 
  male 
  genitalia 
  of 
  a 
  number 
  of 
  species 
  

   of 
  Staphylinidae, 
  Habrocerus 
  capillaricornis 
  Grav., 
  being 
  

   among 
  them. 
  The 
  figures 
  and 
  description 
  of 
  this 
  species 
  

   show 
  that 
  it 
  departs 
  so 
  greatly 
  from 
  the 
  normal 
  Staphyhnid 
  

   type 
  that 
  the 
  homologies 
  of 
  the 
  terminal 
  abdominal 
  seg- 
  

   ments 
  and 
  the 
  aedeagus 
  are 
  not 
  easily 
  recognised. 
  While 
  

   Dr. 
  Weber 
  is 
  correct 
  in 
  the 
  main 
  points, 
  there 
  are 
  certain 
  

   others 
  which 
  we 
  consider 
  of 
  importance, 
  such 
  as 
  the 
  recog- 
  

   nition 
  of 
  the 
  membranous 
  condition 
  of 
  the 
  aedeagus, 
  

   which 
  he 
  does 
  not 
  mention, 
  and 
  some 
  of 
  his 
  interpretations 
  

   we 
  do 
  not 
  agree 
  with. 
  For 
  these 
  reasons, 
  and 
  for 
  the 
  

   interest 
  attaching 
  to 
  the 
  departure 
  of 
  a 
  species 
  from 
  the 
  

   normal 
  type 
  of 
  a 
  very 
  large 
  group 
  of 
  which 
  it 
  forms 
  part, 
  

   the 
  following 
  notes 
  are 
  published. 
  

  

  In 
  all 
  the 
  male 
  Staphylinidae 
  which 
  we 
  have 
  examined 
  

   with 
  this 
  one 
  exception 
  there 
  are 
  nine 
  abdominal 
  segments 
  

   and 
  an 
  aedeagus. 
  The 
  first 
  tergite 
  is 
  in 
  intimate 
  relation 
  

   with 
  the 
  metanotum, 
  the 
  lateral 
  portion 
  being 
  longer 
  

   than 
  the 
  middle 
  and 
  including 
  the 
  first 
  abdominal 
  spiracle, 
  

   which 
  is 
  sometimes 
  very 
  large 
  ; 
  the 
  second 
  tergite, 
  which 
  

   is 
  often 
  short, 
  and 
  the 
  following 
  seven 
  are 
  well 
  defined. 
  

   The 
  first 
  two 
  sternites 
  are 
  mostly 
  membranous 
  and 
  modi- 
  

   fied 
  to 
  accommodate 
  the 
  hind 
  coxae 
  (as 
  is 
  the 
  rule 
  in 
  the 
  

   Coleoptera) 
  ; 
  the 
  following 
  seven 
  are 
  well 
  defined. 
  The 
  

   hind 
  margin 
  of 
  the 
  eighth 
  sternite 
  is 
  emarginate 
  in 
  some 
  

   species. 
  Each 
  of 
  the 
  first 
  eight 
  abdominal 
  segments 
  bears 
  

   a 
  spiracle. 
  The 
  eighth 
  segment, 
  in 
  many 
  species, 
  is 
  

   attached 
  to 
  the 
  seventh 
  by 
  a 
  large 
  membrane, 
  which 
  

   allows 
  of 
  the 
  former 
  being 
  drawn 
  within 
  the 
  latter. 
  The 
  

   ninth 
  segment 
  is 
  modified 
  and 
  dift'ers 
  considerably 
  in 
  

   different 
  genera 
  ; 
  it 
  is 
  attached 
  to 
  the 
  eighth 
  by 
  a 
  con- 
  

   siderable 
  membrane, 
  which 
  allows 
  of 
  great 
  mobility. 
  

   * 
  " 
  Fests. 
  Ver. 
  Nat.," 
  Cassel, 
  1911, 
  pji. 
  284-313. 
  

  

  TRANS. 
  ENT. 
  SOC. 
  LOND. 
  1919. 
  — 
  PARTS 
  III, 
  IV. 
  (dEC.) 
  

  

  