﻿50 
  Eev. 
  T. 
  A. 
  Marshall's 
  Monograph 
  of 
  

  

  vi. 
  BiosTERES, 
  Forster. 
  

   Forst., 
  Verb. 
  pr. 
  EheinL, 
  1862, 
  p. 
  259. 
  

  

  Clypeus 
  reaching 
  the 
  mandibles 
  and 
  closing 
  the 
  mouth, 
  except 
  

   in 
  B. 
  placidus, 
  Hal. 
  Second 
  cubital 
  areolet, 
  measured 
  hori- 
  

   zontally, 
  shorter 
  than 
  in 
  Opms, 
  the 
  2d 
  abscissa 
  of 
  the 
  radius 
  not 
  

   exceeding 
  in 
  length 
  the 
  1st 
  intercubital 
  nervure 
  ; 
  stigma 
  naiTow, 
  

   elongate, 
  emitting 
  the 
  radius 
  from 
  the 
  middle, 
  or 
  from 
  a 
  point 
  

   just 
  before 
  the 
  middle. 
  The 
  other 
  characters 
  are 
  those 
  of 
  Ojpius. 
  

   In 
  Diachasma 
  the 
  clypeus 
  does 
  not 
  reach 
  the 
  mandibles, 
  and 
  the 
  

   stigma 
  is 
  shorter 
  and 
  thicker, 
  emitting 
  the 
  radius 
  generally 
  from 
  a 
  

   point 
  beyond 
  the 
  middle. 
  

  

  Ten 
  British 
  species 
  may 
  be 
  assigned 
  to 
  the 
  genus 
  

   Biosteres 
  ,• 
  they 
  include 
  the 
  largest 
  of 
  the 
  present 
  sub- 
  

   family, 
  and 
  have 
  a 
  superficial 
  resemblance 
  to 
  the 
  

   Alysiids, 
  especially 
  of 
  the 
  genus 
  Phanocarpa. 
  They 
  

   have 
  a 
  certain 
  facies 
  which 
  distinguishes 
  them 
  from 
  

   Opius 
  without 
  the 
  aid 
  of 
  artificial 
  characters 
  ; 
  but 
  closer 
  

   examination 
  shows 
  that 
  this 
  difl'erence 
  is 
  mainly 
  de- 
  

   pendent 
  upon 
  size, 
  and 
  that 
  their 
  structure 
  presents 
  

   hardl}^ 
  any 
  modification. 
  

  

  Table 
  of 
  Species. 
  

  

  (18) 
  1. 
  Clypeus 
  reaching 
  the 
  mandible 
  and 
  closing 
  

   the 
  mouth. 
  

   (5) 
  2. 
  Mesopleur* 
  with 
  a 
  smooth 
  impunctale 
  

  

  furrow. 
  

   (4) 
  3. 
  Abdominal 
  segments 
  2 
  — 
  4 
  black, 
  hard, 
  and 
  

  

  shining 
  , 
  . 
  . 
  , 
  . 
  . 
  . 
  . 
  . 
  . 
  1. 
  carbonarius, 
  Nees. 
  

  

  (3) 
  4. 
  Abdominal 
  segments 
  2^-4 
  fusco-testa- 
  

   ceous, 
  with 
  a 
  soft 
  cuticle 
  which 
  shrinks 
  

   after 
  death, 
  leaving 
  transverse 
  impres- 
  

   sions 
  upon 
  the 
  abdomen 
  . 
  . 
  . 
  . 
  2. 
  impressus, 
  Wesm. 
  

  

  (2) 
  5. 
  MesopleuriB 
  with 
  a 
  crenate 
  or 
  rugose 
  fur- 
  

   row. 
  

   Scutellum 
  smooth 
  . 
  . 
  . 
  . 
  . 
  . 
  . 
  . 
  3. 
  btcolor, 
  Wesm. 
  

  

  Scutellum 
  rugulose 
  or 
  punctate, 
  at 
  least 
  

  

  at 
  the 
  apex. 
  

   Abdomen 
  partly 
  rufous. 
  

   Scutellum 
  entirely 
  lugulose 
  .. 
  ..4. 
  lurmoirlioiis, 
  lifvl. 
  

  

  (9) 
  10. 
  Scutellum 
  punctate 
  at 
  the 
  apex 
  5. 
  hla>uius, 
  Hal. 
  

  

  (8) 
  11. 
  Abdomen 
  entirely 
  black. 
  

   (13) 
  12. 
  Scutellum 
  punctate 
  at 
  the 
  apex 
  . 
  . 
  . 
  . 
  6. 
  rusticus, 
  Hal. 
  

   (12) 
  13. 
  Scutellum 
  entirely 
  rugulose. 
  

   (15) 
  14. 
  Verlex 
  rugulose, 
  dull; 
  3 
  longitudinal 
  

   bands 
  of 
  similar 
  rugosity 
  on 
  the 
  meso- 
  

   thorax 
  7. 
  scabricuhts, 
  Wesm. 
  

  

  (7) 
  

  

  6 
  

  

  (6) 
  

  

  7 
  

  

  (11) 
  

  

  8 
  

  

  (10) 
  

  

  9. 
  

  

  