﻿6 
  Ilev. 
  T. 
  A. 
  Marshall's 
  Monograph 
  of 
  

  

  whicli 
  2 
  — 
  3 
  are 
  connate 
  and 
  much 
  the 
  longest 
  ; 
  the 
  2d 
  suture 
  

   almost 
  always 
  invisible, 
  except 
  in 
  Gnamptodon 
  ; 
  1st 
  segment 
  

   short, 
  seldom 
  more 
  than 
  ^ 
  of 
  the 
  length 
  of 
  the 
  abdomen, 
  some- 
  

   what 
  dilated 
  posteriorly, 
  narrower 
  than 
  the 
  following 
  segments, 
  

   and 
  variously 
  sculptured. 
  Eadial 
  areolet 
  cultrate, 
  ending 
  not 
  far 
  

   from 
  the 
  extremity 
  of 
  the 
  fore 
  wing 
  ; 
  stigma 
  from 
  ovate 
  or 
  lanceo- 
  

   late, 
  becoming 
  more 
  and 
  more 
  linear 
  and 
  elongate 
  until 
  it 
  occupies 
  

   I 
  of 
  the 
  metacarpus, 
  as 
  in 
  the 
  inferior 
  Ahjsiides 
  ; 
  2d 
  cubital 
  areolet 
  

   also 
  elongate 
  and 
  attenuated 
  in 
  various 
  degrees 
  ; 
  usually 
  the 
  sides 
  

   converge 
  slightly 
  towards 
  the 
  extremity 
  of 
  the 
  wing, 
  but 
  some- 
  

   times 
  they 
  are 
  almost 
  parallel 
  ; 
  2d 
  intercubital 
  transverse 
  nerATire 
  

   faintly 
  traced 
  or 
  extinct 
  ; 
  prse- 
  and 
  pobrachial 
  areolets 
  equal, 
  or 
  the 
  

   latter 
  somewhat 
  the 
  longer 
  ; 
  cubitus 
  more 
  or 
  less 
  effaced 
  after 
  

   passing 
  the 
  transverse 
  nervures. 
  The 
  legs 
  offer 
  no 
  peculiarity. 
  

  

  The 
  Opiides 
  form 
  a 
  natural 
  group 
  of 
  considerable 
  

   extent, 
  found 
  in 
  both 
  hemispheres, 
  more 
  abundantly 
  in 
  

   the 
  northern 
  and 
  central 
  countries. 
  They 
  are 
  well 
  

   placed 
  next 
  to 
  the 
  Alysiides, 
  from 
  which 
  some 
  of 
  them 
  

   are 
  not 
  distinguishable 
  at 
  first 
  sight 
  ; 
  but 
  the 
  latter 
  may 
  

   always 
  be 
  known 
  by 
  their 
  everted 
  mandibles. 
  Many 
  

   Opiids 
  also 
  resemble 
  the 
  Bracons 
  ; 
  but 
  they 
  have 
  not 
  

   the 
  oral 
  aperture 
  peculiar 
  to 
  the 
  Cydostomi 
  ; 
  they 
  differ, 
  

   moreover, 
  in 
  the 
  habits 
  of 
  their 
  larvae, 
  and 
  in 
  having 
  for 
  

   the 
  most 
  part 
  a 
  concealed 
  terebra. 
  They 
  do 
  not 
  settle 
  

   upon 
  flowers, 
  but 
  frequent 
  shady 
  places, 
  where 
  they 
  may 
  

   be 
  captured, 
  though 
  never 
  abundantly, 
  upon 
  low 
  plants 
  

   in 
  the 
  neighbourhood 
  of 
  water. 
  Their 
  parasitism 
  has 
  

   seldom 
  been 
  observed, 
  but 
  Goureau 
  reared 
  several 
  from 
  

   dipterous 
  larvee 
  belonging 
  to 
  the 
  genera 
  CJdlosia, 
  Cor- 
  

   dyla, 
  Tephritis, 
  and 
  Phytomyza 
  ; 
  and, 
  according 
  to 
  Eatze- 
  

   burg, 
  they 
  also 
  attack 
  Lepidoptera 
  : 
  not 
  Coleoptera, 
  for 
  

   Opiiis 
  ruhrkejjs, 
  Ratz., 
  parasite 
  of 
  Scolytus, 
  is 
  a 
  Ccno- 
  

   coeliiis. 
  

  

  The 
  genus 
  Ojnus 
  is 
  of 
  Wesmael's 
  creation; 
  he 
  described 
  

   40 
  species, 
  including 
  Haliday's 
  Ademon, 
  which 
  the 
  

   latter 
  writer, 
  following 
  Nees 
  v. 
  Esenbeck, 
  considered 
  as 
  

   a 
  section 
  of 
  Rhogas 
  ; 
  but, 
  from 
  the 
  absence 
  of 
  the 
  oral 
  

   aperture 
  proper 
  to 
  a 
  Cyclostome, 
  it 
  is 
  better 
  placed 
  in 
  

   its 
  present 
  position. 
  The 
  only 
  other 
  writer 
  who 
  has 
  

   much 
  elucidated 
  the 
  groups 
  is 
  Haliday, 
  whose 
  mono- 
  

   graph 
  extends 
  to 
  49 
  British 
  species 
  ; 
  one 
  of 
  these 
  con- 
  

   stitutes 
  his 
  genus 
  Gnamptodon, 
  and, 
  of 
  the 
  rest, 
  22 
  were 
  

   unknown 
  to 
  Wesmael. 
  Ten 
  species 
  were 
  previously 
  

  

  