﻿84 
  F. 
  W. 
  EDWARDS. 
  

  

  Group 
  I. 
  The 
  bitaeniorhynchus 
  group. 
  Lower 
  mesepimeral 
  bristle 
  absent 
  ; 
  

   proboscis 
  with 
  a 
  distinct 
  and 
  not 
  very 
  broad 
  pale 
  ring 
  in 
  the 
  middle 
  ; 
  tarsi 
  with 
  

   narrow 
  pale 
  rings 
  embracing 
  both 
  ends 
  of 
  the 
  segments. 
  Male 
  aedoeagus 
  generally 
  

   of 
  complicated 
  structure, 
  usualty 
  with 
  one 
  or 
  more 
  pairs 
  of 
  dorsally-directed 
  hooks. 
  

  

  This 
  is 
  evidently 
  a 
  natural 
  group, 
  and 
  includes 
  all 
  the 
  ringed-legged 
  species 
  

   except 
  C. 
  duttoni 
  and 
  C. 
  ventrilloni. 
  It 
  divides 
  into 
  two 
  series, 
  as 
  follows 
  : 
  — 
  

  

  1. 
  The 
  bitaeniorhynchus 
  series 
  (C. 
  quasigelidus, 
  C. 
  consimilis, 
  C. 
  annulioris, 
  

   C. 
  giganteus, 
  and 
  C. 
  bitaeniorhynchus, 
  with 
  its 
  variety 
  aurantapex). 
  Pale 
  scales 
  of 
  

   abdominal 
  tergites 
  to 
  a 
  large 
  extent 
  apical 
  in 
  position 
  ; 
  mesonotum 
  tending 
  to 
  have 
  

   the 
  front 
  two-thirds 
  pale-scaled. 
  Lobe 
  of 
  side-piece 
  of 
  male 
  hypopygium 
  without 
  

   a 
  well-marked 
  leaf. 
  Larva 
  with 
  the 
  scales 
  on 
  the 
  comb 
  of 
  the 
  eighth 
  segment 
  few 
  

   and 
  large 
  ; 
  siphon 
  long. 
  Should 
  it 
  be 
  considered 
  desirable 
  to 
  treat 
  this 
  series 
  as 
  

   a 
  separate 
  subgenus, 
  the 
  name 
  Aporoculex 
  is 
  available, 
  having 
  been 
  proposed 
  for 
  

   C. 
  quasigelidus. 
  

  

  2. 
  The 
  sitiens 
  series 
  (C. 
  sitiens, 
  C. 
  thalassius, 
  C. 
  tritaeniorhynchus). 
  Pale 
  scales 
  

   of 
  abdominal 
  tergites 
  mainly 
  basal 
  ; 
  mesonotum 
  with 
  the 
  pale 
  scales 
  fewer 
  and 
  more 
  

   scattered. 
  Lobe 
  of 
  side-piece 
  with 
  a 
  well-marked 
  leaf. 
  Larva 
  with 
  the 
  scales 
  on 
  

   the 
  comb 
  of 
  the 
  eighth 
  segment 
  numerous 
  and 
  small. 
  

  

  Group 
  II. 
  The 
  duttoni 
  group. 
  Three 
  (in 
  some 
  specimens 
  two 
  or 
  four) 
  lower 
  

   mesepimeral 
  bristles 
  present. 
  Aedoeagus 
  of 
  simple 
  structure. 
  Lobe 
  of 
  side-piece 
  

   with 
  a 
  well-marked 
  leaf. 
  Siphon 
  of 
  larva 
  rather 
  short 
  and 
  swollen 
  towards 
  the 
  

   middle. 
  

  

  This 
  includes 
  only 
  three 
  species, 
  C. 
  duttoni, 
  Theo., 
  C. 
  watti, 
  Edw., 
  and 
  C. 
  pruina, 
  

   Theo. 
  Though 
  they 
  are 
  very 
  dissimilar 
  in 
  coloration, 
  the 
  points 
  of 
  similarity 
  in 
  

   the 
  mesepimeral 
  bristles, 
  in 
  the 
  male 
  hypopygium 
  and 
  in 
  the 
  larval 
  siphon 
  clearly 
  

   indicate 
  that 
  they 
  are 
  related. 
  C. 
  duttoni 
  is 
  obviously 
  not 
  closely 
  connected 
  with 
  

   the 
  other 
  ringed-legged 
  species 
  ; 
  apart 
  from 
  the 
  more 
  important 
  differences 
  mentioned 
  

   above, 
  the 
  colouring 
  of 
  the 
  proboscis 
  is 
  quite 
  unlike 
  that 
  of 
  an}- 
  member 
  of 
  the 
  

   bitaen 
  iorhynch 
  us 
  group. 
  

  

  Two 
  quite 
  different 
  larvae 
  have 
  been 
  attributed 
  to 
  C. 
  pruina, 
  but 
  in 
  view 
  of 
  the 
  

   resemblances 
  now 
  discovered 
  between 
  the 
  adults 
  of 
  this 
  species 
  and 
  of 
  C. 
  duttoni, 
  

   it 
  will 
  be 
  safe 
  to 
  assume 
  that 
  Ingram 
  and 
  Macfiewere 
  correct 
  in 
  their 
  determination, 
  

   while 
  Graham 
  was 
  in 
  error. 
  

  

  This 
  group 
  is 
  not 
  very 
  clearly 
  marked 
  off 
  from 
  the 
  next, 
  C. 
  guiarti 
  and 
  C. 
  grahami 
  

   being 
  in 
  some 
  respects 
  intermediate. 
  The 
  last-named 
  species 
  has 
  two 
  lower 
  mes- 
  

   epimeral 
  bristles. 
  The 
  Palaearctic 
  C. 
  laticinctus, 
  Edw., 
  shows 
  some 
  affinity 
  with 
  

   this 
  group, 
  both 
  as 
  regards 
  adult 
  and 
  larva. 
  

  

  Group 
  III. 
  The 
  pipiens 
  group. 
  One 
  lower 
  mesepimeral 
  bristle 
  (two 
  in 
  C. 
  

   grahami). 
  Proboscis 
  and 
  tarsi 
  without 
  pale 
  rings 
  (except 
  in 
  C. 
  ventrilloni). 
  Abdominal 
  

   tergites 
  with 
  basal 
  pale 
  markings 
  (bands 
  or 
  more 
  or 
  less 
  distinct 
  lateral 
  spots). 
  Male 
  

   aedoeagus 
  nearly 
  always 
  of 
  complicated 
  structure 
  (rather 
  simple 
  in 
  C. 
  guiarti 
  and 
  

   C. 
  grahami, 
  but 
  then, 
  as 
  in 
  most 
  of 
  the 
  other 
  species, 
  with 
  a 
  pair 
  of 
  processes 
  from 
  

   the 
  lower 
  bridge), 
  but 
  without 
  dorsally-directed 
  hooks. 
  Lobe 
  of 
  side-piece 
  with 
  

   a 
  distinct 
  leaf 
  . 
  Larval 
  siphon 
  generally 
  elongate 
  and 
  slender 
  ; 
  comb 
  of 
  eighth 
  segment 
  

   with 
  numerous 
  small 
  scales. 
  

  

  This 
  group 
  includes 
  the 
  majority 
  of 
  the 
  Ethiopian 
  species. 
  It 
  may 
  be 
  divided 
  

   into 
  the 
  following 
  two 
  series 
  : 
  — 
  

  

  1. 
  The 
  pipiens 
  series. 
  Male 
  palpi 
  with 
  a 
  white 
  line 
  on 
  the 
  lower 
  surface 
  of 
  the 
  

   last 
  two 
  segments. 
  Abdominal 
  tergites 
  with 
  complete 
  basal 
  pale 
  bands 
  (except 
  

  

  