﻿Mechanism 
  of 
  the 
  Male 
  Genital 
  Tube 
  in 
  Coleojytera. 
  411 
  

  

  tegmen 
  to 
  the 
  large 
  apical 
  portion 
  of 
  the 
  tegniinal 
  strut 
  

   (tgs). 
  This 
  holds 
  the 
  ring 
  of 
  the 
  legmen 
  into 
  the 
  base 
  of 
  

   the 
  pseudotegmen, 
  where 
  it 
  fits 
  quite 
  tightly, 
  the 
  membrane 
  

   connecting 
  the 
  pseudotegmen 
  and 
  the 
  tegmen 
  forming 
  a 
  

   fold 
  between 
  them. 
  

  

  (c) 
  The 
  retractor 
  of 
  the 
  median 
  lobe 
  connects 
  the 
  base 
  of 
  

   the 
  median 
  lobe 
  and 
  the 
  base 
  of 
  the 
  median 
  struts 
  with 
  the 
  

   inner 
  surface 
  of 
  the 
  apex 
  and 
  the 
  ridge 
  of 
  the 
  tegniinal 
  strut. 
  

  

  (d) 
  The 
  protractor 
  of 
  the 
  median 
  lobe 
  connects 
  the 
  ring 
  

   of 
  the 
  tegmen 
  {tr) 
  with 
  the 
  outer 
  surface 
  of 
  the 
  apex 
  of 
  the 
  

   median 
  struts. 
  

  

  (e) 
  The 
  retractors 
  of 
  the 
  internal 
  sac 
  connect 
  certain 
  

   points 
  {e^, 
  e^, 
  e^, 
  figs. 
  3, 
  4) 
  on 
  the 
  sac 
  with 
  the 
  inner 
  surface 
  

   of 
  the 
  apex 
  of 
  the 
  median 
  struts. 
  At 
  the 
  point 
  on 
  the 
  sac 
  

   where 
  the 
  largest 
  of 
  these 
  muscles 
  (e^) 
  is 
  attached 
  there 
  is 
  

   a 
  large 
  Y-shaped 
  sclerite. 
  A 
  few 
  small 
  muscles 
  connect 
  the 
  

   basal 
  portion 
  of 
  the 
  sac 
  (g) 
  with 
  the 
  median 
  lobe 
  near 
  its 
  

   apex. 
  When 
  it 
  is 
  remembered 
  that 
  the 
  median 
  struts 
  are 
  

   invaginations 
  or 
  prolonged 
  folds 
  of 
  the 
  median 
  lobe 
  it 
  

   will 
  be 
  seen 
  that 
  all 
  the 
  muscles 
  of 
  the 
  internal 
  sac 
  are 
  in 
  

   fact 
  attached 
  to 
  the 
  median 
  lobe. 
  

  

  Figure 
  5 
  represents 
  in 
  a 
  semidiagrammatic 
  manner 
  

   the 
  skeleton 
  of 
  Stranyalia 
  annata 
  with 
  the 
  internal 
  sac 
  

   partly 
  evaginated. 
  In 
  this 
  species 
  of 
  Longicorn 
  the 
  eighth 
  

   tergite 
  is 
  well 
  developed 
  and 
  forms 
  the 
  last 
  visible 
  segment 
  ; 
  

   the 
  eighth 
  sternite 
  (fig. 
  7, 
  viii) 
  is 
  small 
  and 
  membranous 
  

   with 
  two 
  small 
  triangular 
  chitin 
  plates 
  and 
  a 
  short 
  strut 
  or 
  

   spiculum. 
  The 
  ninth 
  tergite 
  (fig. 
  6, 
  9) 
  is 
  distinct 
  and 
  forms 
  

   a 
  small 
  arc, 
  each 
  corner 
  of 
  which 
  is 
  produced 
  into 
  a 
  small 
  

   s]HCulum 
  {Is'p) 
  ; 
  the 
  ninth 
  sternite 
  (ix) 
  is 
  well 
  developed 
  

   and 
  produced 
  into 
  a 
  large 
  spiculum 
  (sp). 
  The 
  membrane 
  

   (m 
  1) 
  connects 
  the 
  ninth 
  segment 
  with 
  the 
  tegmen. 
  The 
  

   tegmen 
  consists 
  of 
  a 
  " 
  ring 
  " 
  with 
  a 
  pair 
  of 
  large, 
  dorsal- 
  

   tegminal 
  lobes 
  (fig. 
  5, 
  tgl), 
  the 
  ventral 
  portion 
  being 
  pro- 
  

   duced 
  into 
  a 
  large 
  strut 
  {Igs), 
  the 
  chitinisation 
  not 
  meeting 
  

   till 
  the 
  apex. 
  The 
  median 
  lobe 
  is 
  tubular 
  with 
  a 
  gusset 
  of 
  

   membrane 
  along 
  each 
  lateral 
  area, 
  the 
  ventral 
  chitinisation 
  

   extending 
  further 
  distad 
  than 
  the 
  dorsal 
  and 
  is 
  pointed 
  and 
  

   hooked 
  at 
  the 
  apex, 
  the 
  base 
  is 
  produced 
  into 
  two 
  wide 
  

   struts 
  (ms). 
  The 
  base 
  of 
  the 
  struts 
  and 
  the 
  base 
  of 
  the 
  

   body 
  of 
  the 
  lobe 
  is 
  indicated 
  by 
  the 
  attachment 
  of 
  the 
  

   membrane 
  {ini 
  2) 
  which 
  connects 
  the 
  tegmen 
  with 
  the 
  

   median 
  lobe. 
  The 
  internal 
  sac 
  is 
  very 
  long, 
  simple, 
  cylin- 
  

   drical, 
  bent 
  about 
  half-way 
  and 
  again 
  near 
  the 
  apex, 
  with 
  

  

  