﻿112 
  Cameron, 
  Hymcnoptera 
  Orientalia. 
  

  

  all 
  of 
  them 
  by 
  the 
  median 
  segment 
  having 
  only 
  one 
  

   transverse 
  keel, 
  and 
  consequently 
  no 
  areaae 
  ; 
  by 
  the 
  meta- 
  

   tarsus 
  being 
  longer 
  than 
  all 
  the 
  other 
  joints 
  united; 
  and 
  by 
  

   the 
  more 
  slender 
  petiole. 
  As, 
  owing 
  to 
  the 
  similarity 
  of 
  

   the 
  alar 
  neuration, 
  these 
  little-known 
  genera 
  are 
  apt 
  to 
  be 
  

   confounded, 
  it 
  may 
  be 
  advisable 
  to 
  give 
  a 
  synoptical 
  table 
  

   of 
  their 
  differences. 
  

  

  A. 
  Middle 
  lobe 
  of 
  the 
  mesonotum 
  triangular, 
  transverse 
  

  

  at 
  the 
  base 
  ; 
  the 
  legs 
  short, 
  stout, 
  the 
  fore 
  claws 
  

   bifid. 
  

  

  Colour 
  black 
  ; 
  the 
  median 
  segment 
  areolated 
  all 
  over, 
  

   the 
  spiracles 
  placed 
  behind 
  the 
  middle 
  of 
  the 
  

   petiole. 
  Macrogaster. 
  

  

  Colour 
  luteous, 
  the 
  median 
  segment 
  not 
  areolated 
  all 
  

   over 
  : 
  the 
  spiracles 
  placed 
  in 
  the 
  middle 
  of 
  the 
  

   petiole. 
  Chreusa. 
  

  

  B. 
  Middle 
  lobe 
  of 
  the 
  mesonotum 
  not 
  triangular, 
  rounded 
  

  

  at 
  the 
  base 
  ; 
  the 
  legs 
  long 
  and 
  slender; 
  the 
  fore 
  

   claws 
  simple. 
  

   Median 
  segment 
  areolated, 
  the 
  post-petiole 
  distinctly 
  

   dilated 
  ; 
  the 
  metatarsus 
  not 
  longer 
  than 
  the 
  other 
  

   joints 
  united. 
  Hemigaster. 
  

  

  Median 
  segment 
  not 
  areolated, 
  the 
  post-petiole 
  not 
  

   dilated 
  ; 
  the 
  metatarsus 
  longer 
  than 
  all 
  the 
  other 
  

   joints 
  united. 
  Arthula. 
  

  

  Arthula 
  brunneocornis, 
  sp. 
  nov. 
  

  

  Nigra; 
  capite 
  tJioracequeflavo-maculatis,pedibus 
  nigris, 
  

   flavo-viaculatis 
  ; 
  abdomine 
  ferrugineo 
  ; 
  alis 
  Jiyalinis, 
  stig- 
  

   matc 
  fasco. 
  $ 
  . 
  

  

  Long. 
  II 
  — 
  12 
  mm. 
  

  

  Antennas 
  as 
  long 
  as 
  the 
  abdomen, 
  stout, 
  scarcely 
  

   tapering 
  towards 
  the 
  apex, 
  dark 
  brownish, 
  darker 
  above 
  ; 
  

   the 
  scape 
  bright 
  lemon-yellow. 
  Head 
  black 
  ; 
  the 
  face, 
  

   clypeus, 
  labrum, 
  and 
  the 
  orbits 
  all 
  round, 
  lemon-yellow 
  ; 
  

   the 
  base 
  of 
  the 
  clypeus, 
  an 
  oblique 
  mark 
  on 
  either 
  side 
  of 
  

  

  