﻿402 
  Mr. 
  F. 
  Muir 
  07i 
  Aedeagus 
  of 
  Habrocerus 
  capillaricornis. 
  

  

  membranous 
  aedeagiis 
  which, 
  require 
  further 
  investigation, 
  

   but 
  as 
  the 
  opportunity 
  for 
  carrying 
  on 
  the 
  work 
  will 
  not 
  

   occur 
  for 
  an 
  indefinite 
  period 
  we 
  consider 
  it 
  advisable 
  to 
  

   publish 
  the 
  results 
  as 
  they 
  now 
  stand. 
  

  

  That 
  this 
  species 
  presents 
  profound 
  modifications 
  on 
  

   what 
  is 
  generally 
  recognised 
  as 
  the 
  normal 
  Staphylinid 
  

   morphology 
  must 
  be 
  admitted 
  by 
  all 
  students 
  of 
  this 
  group, 
  

   but 
  unfortunately 
  we 
  have 
  very 
  slight 
  knowledge 
  of 
  the 
  

   morphology 
  of 
  this 
  large 
  group, 
  and 
  so 
  we 
  can 
  only 
  blindly 
  

   speculate 
  as 
  to 
  the 
  line 
  of 
  evolution 
  it 
  travelled 
  to 
  reach 
  its 
  

   present 
  condition. 
  

  

  The 
  theory 
  that 
  nine 
  well-developed 
  abdominal 
  segments 
  

   and 
  a 
  well-defined 
  aedeagus 
  is 
  the 
  older 
  type 
  is 
  founded 
  

   upon 
  good 
  morphological 
  reasons, 
  but 
  forms 
  having 
  once 
  

   arrived 
  at 
  a 
  certain 
  stage 
  of 
  specialisation, 
  such 
  as 
  exists 
  in 
  

   all 
  presently 
  known 
  species, 
  are 
  not 
  likely 
  to 
  undergo 
  a 
  pro- 
  

   found 
  modification. 
  It 
  is 
  therefore 
  early 
  in 
  the 
  phylogeny 
  

   of 
  the 
  group 
  that 
  Habrocerus 
  must 
  have 
  started 
  on 
  its 
  line 
  

   of 
  specialisation. 
  It 
  is 
  possible 
  that 
  further 
  research 
  will 
  

   reveal 
  forms 
  that 
  will 
  show 
  us 
  some 
  of 
  the 
  stages 
  of 
  this 
  

   evolution, 
  but 
  until 
  then 
  it 
  will 
  be 
  safest 
  to 
  consider 
  that 
  

   the 
  genus 
  is 
  very 
  distinct 
  from 
  all 
  the 
  other 
  Staphylinidae 
  

   which 
  we 
  know 
  and 
  must 
  have 
  been 
  so 
  from 
  a 
  very 
  remote 
  

   period 
  in 
  the 
  evolution 
  of 
  the 
  family. 
  

  

  Figure 
  12 
  is 
  from 
  a 
  drawing 
  by 
  my 
  wife, 
  who 
  everted 
  

   this 
  sac 
  and 
  mounted 
  it 
  when 
  working 
  with 
  Dr. 
  David 
  

   Sharp. 
  

  

  Explanation 
  of 
  Plate 
  XX. 
  

  

  Fig. 
  1. 
  Ventral 
  view 
  of 
  ninth 
  abdominal 
  segment 
  and 
  aedeagus 
  of 
  

   Tachyporus 
  solntus 
  Ericli. 
  

  

  2. 
  Dorsal 
  view 
  of 
  the 
  same. 
  

  

  3. 
  Lateral 
  view 
  of 
  riglit 
  side 
  of 
  the 
  same. 
  

  

  4. 
  Dorsal 
  view 
  of 
  the 
  ninth 
  abdominal 
  segment 
  of 
  Leisto- 
  

  

  trophus 
  sp. 
  

  

  5. 
  Ventral 
  view 
  of 
  the 
  same. 
  

  

  6. 
  Ventral 
  view 
  of 
  eighth 
  and 
  ninth 
  abdominal 
  segments 
  of 
  

  

  Habrocerus 
  capillaricornis 
  Grav. 
  

  

  7. 
  Dorsal 
  view 
  of 
  the 
  same. 
  

  

  8. 
  Articulation 
  of 
  eighth 
  tergite 
  and 
  eighth 
  sternite 
  and 
  the 
  

  

  pleural 
  plate. 
  

  

  