﻿268 
  PROF. 
  M. 
  BEZZI. 
  

  

  of 
  the 
  discoidal 
  cell, 
  but 
  near 
  the 
  middle 
  of 
  the 
  lower 
  border 
  of 
  the 
  same 
  cell. 
  

   Cubital 
  fold 
  well 
  developed 
  and 
  forked 
  outwardly, 
  evenly 
  chitinised. 
  Hind 
  cross- 
  

   vein 
  broadly 
  S-shaped, 
  but 
  placed 
  very 
  obliquely 
  so 
  that 
  its 
  upper 
  end 
  is 
  near 
  the 
  

   middle 
  of 
  the 
  wing, 
  while 
  its 
  lower 
  end 
  is 
  very 
  near 
  the 
  end 
  of 
  the 
  fifth 
  longitudinal 
  

   vein 
  ; 
  the 
  lower 
  external 
  angle 
  of 
  the 
  discoidal 
  cell 
  is 
  therefore 
  very 
  acute 
  and 
  much 
  

   produced 
  outwardly. 
  Anal 
  cell 
  broad, 
  with 
  its 
  lower 
  outer 
  angle 
  acute 
  and 
  produced 
  

   longer 
  than 
  the 
  2nd 
  basal 
  cell 
  ; 
  sixth 
  vein 
  prolonged 
  to 
  the 
  hind 
  border 
  of 
  the 
  wing. 
  

   Axillary 
  lobe 
  broad 
  and 
  rounded, 
  with 
  a 
  distinct 
  long 
  axillary 
  vein 
  ; 
  alula 
  well 
  

   developed, 
  rounded. 
  The 
  wing 
  pattern 
  is 
  a 
  very 
  characteristic 
  one, 
  consisting 
  

   of 
  a 
  broad, 
  light 
  brown 
  patch, 
  occupying 
  the 
  middle 
  and 
  extending 
  over 
  the 
  whole 
  

   hind 
  portion 
  of 
  the 
  wing, 
  except 
  the 
  apex 
  ; 
  this 
  patch 
  shows 
  black 
  spots, 
  shining 
  

   " 
  bullae 
  " 
  and 
  subhyaline 
  spots 
  near 
  the 
  hind 
  border 
  ; 
  from 
  this 
  patch 
  depart 
  

   numerous 
  long 
  rays, 
  which 
  extend 
  to 
  the 
  costa 
  along 
  the 
  entire 
  fore 
  border 
  and 
  the 
  

   entire 
  apex. 
  

  

  Type 
  : 
  the 
  following 
  new 
  species. 
  

  

  Perirhithrum 
  marshalli, 
  sp. 
  nov. 
  (PL 
  xviii, 
  fig. 
  10). 
  

  

  A 
  strange 
  and 
  beautiful 
  insect 
  of 
  comparatively 
  large 
  size, 
  strikingly 
  distinguished 
  

   by 
  the 
  very 
  peculiar 
  wings. 
  

  

  (J. 
  Length 
  of 
  body 
  5*5 
  mm. 
  ; 
  of 
  wing 
  5'5 
  mm. 
  ; 
  breadth 
  of 
  wing 
  3 
  mm. 
  

  

  Head 
  yellowish, 
  darkened 
  towards 
  the 
  middle 
  of 
  the 
  occiput. 
  Frons 
  with 
  a 
  dark 
  

   ocellar 
  spot 
  and 
  with 
  a 
  transverse 
  dark 
  band 
  in 
  front 
  before 
  the 
  lunula. 
  Antennae 
  

   reddish 
  yellow, 
  with 
  the 
  third 
  joint 
  blackened 
  along 
  its 
  upper 
  border 
  ; 
  arista 
  

   whitish, 
  cheeks 
  white, 
  with 
  a 
  small 
  deep 
  black, 
  rounded 
  spot 
  above 
  on 
  each 
  side, 
  

   near 
  the 
  roots 
  of 
  the 
  antennae 
  ; 
  jowls 
  yellowish, 
  with 
  a 
  reddish 
  spot 
  on 
  each 
  side 
  

   in 
  front 
  ; 
  face 
  yellowish, 
  darkened 
  towards 
  the 
  middle. 
  Eyes 
  reddish 
  brown 
  and 
  

   apparently 
  unicolorous. 
  Palpi 
  whitish 
  at 
  base, 
  reddish 
  yellow 
  on 
  the 
  apical 
  half, 
  

   and 
  clothed 
  there 
  with 
  short 
  black 
  bristles 
  ; 
  proboscis 
  reddish 
  yellow. 
  The 
  ocp., 
  

   the 
  outer 
  vt. 
  and 
  the 
  pvt. 
  are 
  whitish 
  ; 
  the 
  long 
  inner 
  vt. 
  are 
  black, 
  while 
  the 
  oc. 
  

   are 
  pale 
  yellowish 
  ; 
  the 
  long 
  and 
  strong 
  s. 
  or. 
  are 
  black 
  with 
  a 
  brownish 
  end 
  and 
  

   are 
  inserted 
  over 
  distinct, 
  black, 
  slightly 
  prominent 
  tubercles, 
  like 
  the 
  first 
  (or 
  

   inner) 
  of 
  the 
  i. 
  or., 
  which 
  is 
  likewise 
  black 
  with 
  a 
  brownish 
  tip 
  ; 
  the 
  two 
  apical 
  

   pairs 
  of 
  the 
  i. 
  or. 
  are 
  on 
  the 
  contrary- 
  shorter 
  and 
  whitish. 
  The 
  genal 
  bristle 
  is 
  

   black, 
  while 
  the 
  rather 
  long, 
  bristly 
  hairs 
  near 
  it 
  on 
  the 
  chin, 
  and 
  those 
  on 
  the 
  

   lower 
  part 
  of 
  the 
  occiput, 
  are 
  whitish. 
  Thorax 
  on 
  the 
  back 
  black 
  in 
  ground-colour, 
  

   but 
  covered 
  with 
  dark 
  grey 
  dust 
  ; 
  the 
  suture 
  is 
  broadly 
  interrupted 
  in 
  the 
  middle, 
  

   with 
  whitish 
  dust 
  on 
  the 
  sides 
  and 
  has 
  inwardly 
  a 
  brownish 
  transverse 
  band, 
  which 
  

   is 
  interrupted 
  towards 
  the 
  middle 
  ; 
  the 
  points 
  of 
  insertion 
  of 
  the 
  bristles 
  are 
  darker 
  

   and 
  spot-like, 
  and 
  there 
  are 
  in 
  the 
  centre 
  two 
  dark 
  brownish 
  rounded 
  spots, 
  one 
  

   on 
  each 
  side, 
  interiorly 
  and 
  posteriorly 
  of 
  the 
  anterior 
  dc. 
  ; 
  the 
  back 
  is 
  denuded 
  

   in 
  the 
  type, 
  but 
  in 
  front 
  of 
  the 
  scutellum 
  it 
  shows 
  rather 
  long 
  and 
  scattered 
  whitish 
  

   hairs. 
  The 
  pleurae 
  are 
  yellowish 
  near 
  the 
  sutures 
  and 
  towards 
  the 
  breast, 
  but 
  are 
  

   darkened 
  towards 
  the 
  centre 
  of 
  the 
  sclerites 
  ; 
  they 
  are 
  clothed 
  with 
  a 
  whitish-grey 
  

   dust. 
  All 
  the 
  macrochaetae 
  are 
  pale 
  yellowish, 
  but 
  those 
  of 
  the 
  back 
  are 
  distinctly 
  

   black 
  at 
  base, 
  though 
  less 
  so 
  in 
  the 
  case 
  of 
  the 
  mpl. 
  and 
  st., 
  while 
  the 
  pt. 
  is 
  entirely 
  

   whitish. 
  Scutellum 
  coloured 
  like 
  the 
  back 
  of 
  the 
  mesonotum, 
  but 
  less 
  obviously 
  

  

  