﻿452 
  MALCOLM 
  E. 
  MACGREGOR 
  AND 
  S. 
  GEBERT. 
  

  

  but 
  on 
  the 
  lateral 
  aspects 
  long 
  single 
  hairs 
  also 
  occur. 
  Frequently 
  chitinous 
  plates 
  

   are 
  present 
  on 
  the 
  6th, 
  7th, 
  and 
  8th 
  abdominal 
  and 
  anal 
  segments. 
  These 
  plates 
  are, 
  

   however, 
  exceedingly 
  variable, 
  and 
  may 
  be 
  absent 
  altogether 
  or 
  separately 
  present 
  

   in 
  all 
  degrees 
  of 
  formation 
  and 
  chitinisation. 
  Fig. 
  1 
  shows 
  incomplete 
  formation 
  

   of 
  the 
  chitinous 
  plate 
  on 
  the 
  8th 
  segment, 
  of 
  which 
  only 
  the 
  lateral 
  parts 
  have 
  been 
  

   formed. 
  When 
  all 
  the 
  plates 
  are 
  present 
  the 
  6th 
  abdominal 
  segment 
  carries 
  a 
  small 
  

   plate 
  incompletely 
  covering 
  the 
  dorsal 
  surface. 
  The 
  plate 
  on 
  the 
  7th 
  segment 
  is 
  

   larger 
  and 
  completely 
  covers 
  the 
  dorsal 
  surface 
  of 
  the 
  segment. 
  On 
  the 
  8th 
  segment 
  

   the 
  plate 
  is 
  the 
  largest 
  of 
  the 
  three, 
  and 
  extends 
  entirely 
  over 
  the 
  dorsal 
  and 
  lateral 
  

   aspects 
  of 
  the 
  segment 
  to 
  the 
  ventral 
  surface. 
  The 
  median 
  ventral 
  surface 
  is 
  un- 
  

   covered 
  and 
  this 
  plate 
  there 
  embraces 
  the 
  segment 
  as 
  an 
  incomplete 
  ring. 
  Anal 
  

   segment 
  heavily 
  chitinised 
  from 
  apex 
  nearly 
  to 
  base. 
  Where 
  the 
  chitinisation 
  

   ceases 
  towards 
  the 
  base, 
  there 
  is 
  a 
  small 
  uncovered 
  area 
  encircled 
  by 
  a 
  narrow 
  

   chitinous 
  ring. 
  This 
  chitinous 
  ring 
  is 
  exceedingly 
  variable 
  ; 
  it 
  may 
  be 
  absent 
  

   or 
  more 
  frequently 
  present 
  as 
  a 
  segment, 
  or 
  as 
  a 
  nearly 
  complete 
  ring.* 
  On 
  the 
  

   lateral 
  aspects 
  of 
  the 
  8th 
  abdominal 
  segment 
  there 
  are 
  large 
  combs 
  composed 
  of 
  

   two 
  rows 
  of 
  outwardly 
  curved 
  teeth. 
  The 
  teeth 
  in 
  the 
  hind 
  row 
  are 
  about 
  the 
  same 
  

   length 
  as 
  those 
  in 
  the 
  front 
  row. 
  Siphon 
  black 
  and 
  glistening, 
  usually 
  about 
  one 
  

   and 
  a 
  half 
  times 
  as 
  long 
  as 
  the 
  width 
  at 
  its 
  middle 
  (widest 
  point), 
  the 
  size 
  and 
  pro- 
  

   portion 
  nevertheless 
  distinctly 
  variable. 
  One 
  pair 
  of 
  siphonal 
  tufts 
  at 
  about 
  one- 
  

   third 
  from 
  the 
  base, 
  ventrally 
  placed. 
  Pecten 
  absent. 
  Anal 
  gills 
  small 
  and 
  ovoid 
  in 
  

   form. 
  Anal 
  brush 
  composed 
  of 
  long, 
  stout, 
  dark 
  black 
  hairs 
  (Plate 
  xxiii, 
  fig. 
  1). 
  

  

  Larva 
  in 
  Third 
  Instar. 
  

  

  Exactly 
  similar 
  to 
  the 
  fourth 
  instar, 
  but 
  always 
  without 
  any 
  sign 
  of 
  the 
  abdominal 
  

   chitinous 
  plates. 
  Anal 
  segments 
  and 
  siphon, 
  however, 
  fairly 
  heavily 
  chitinised. 
  

  

  Larva 
  in 
  Second 
  Instar. 
  

  

  As 
  in 
  the 
  third 
  instar, 
  but 
  anal 
  segment 
  and 
  siphon 
  transparent, 
  and 
  almost 
  

   entirely 
  un 
  chitinised. 
  

  

  Larva 
  in 
  First 
  Instar. 
  

  

  All 
  the 
  hairs 
  on 
  the 
  head, 
  thorax, 
  and 
  abdomen 
  simple, 
  or 
  at 
  most 
  at 
  certain 
  

   situations 
  bifurcated. 
  No 
  plumes 
  of 
  stellate 
  hairs 
  present, 
  and 
  no 
  heavy 
  chitinisation 
  

   on 
  any 
  part 
  of 
  the 
  body. 
  Larva, 
  including 
  the 
  siphon, 
  therefore 
  very 
  transparent. 
  

   Anal 
  brush 
  (fin) 
  absent, 
  as 
  is 
  the 
  case 
  with 
  most 
  first 
  instar 
  larvae. 
  

  

  Pupa. 
  

  

  Of 
  normal 
  form, 
  but 
  strongly 
  keeled 
  along 
  the 
  anterior 
  dorsal 
  median 
  line 
  of 
  the 
  

   cephalo 
  thorax. 
  The 
  1st 
  abdominal 
  segment 
  bears 
  a 
  pair 
  of 
  float-hairs 
  of 
  unusual 
  

   type 
  consisting 
  of 
  a 
  mass 
  of 
  delicate 
  hairs. 
  On 
  the 
  7th 
  and 
  8th 
  abdominal 
  segments 
  

   there 
  are 
  a 
  pair 
  of 
  characteristic 
  hair-tufts 
  situated 
  near 
  the 
  lateral 
  apices 
  of 
  each 
  

   segment. 
  The 
  tufts 
  on 
  the 
  8th 
  abdominal 
  segment 
  are 
  in 
  the 
  form 
  of 
  dense 
  plumes, 
  

   and 
  are 
  considerably 
  larger 
  than 
  the 
  tufts 
  on 
  the 
  7th 
  segment. 
  

  

  With 
  all 
  the 
  characters 
  of 
  the 
  larva 
  taken 
  together 
  this 
  species 
  could 
  not 
  be 
  

   mistaken 
  for 
  any 
  other, 
  but 
  it 
  illustrates 
  remarkably 
  well 
  how 
  much 
  certain 
  larval 
  

   characters 
  may 
  vary. 
  

  

  Adult 
  males 
  and 
  females 
  have 
  been 
  kept 
  together 
  in 
  the 
  same 
  cage 
  for 
  several 
  

   days, 
  but 
  so 
  far 
  as 
  we 
  were 
  able 
  to 
  judge 
  fertilisation 
  of 
  the 
  females 
  did 
  not 
  occur, 
  

   nor 
  were 
  we 
  able 
  to 
  induce 
  any 
  to 
  " 
  bite." 
  

  

  The 
  eggs 
  of 
  this 
  mosquito 
  have 
  not 
  yet 
  been 
  found, 
  but 
  probably 
  they 
  are 
  laid 
  

   singly, 
  or 
  we 
  should 
  certainly 
  have 
  found 
  " 
  rafts 
  " 
  in 
  the 
  tree-holes 
  in 
  which 
  newly 
  

   hatched 
  larvae 
  have 
  been 
  present. 
  Search 
  for 
  the 
  eggs 
  is 
  now 
  being 
  made. 
  

  

  * 
  Note. 
  — 
  These 
  variable 
  characters 
  are 
  not 
  in 
  any 
  way 
  correlated 
  with 
  the 
  age 
  of 
  the 
  fourth 
  instar 
  

   larva. 
  Pupation 
  may 
  take 
  place 
  with 
  the 
  complete 
  absence 
  of 
  any 
  plate 
  formation 
  (except 
  

   basal 
  chitinisation 
  of 
  the 
  combs) 
  or 
  with 
  the 
  plates 
  present 
  at 
  any 
  stage 
  of 
  formation 
  up 
  to 
  the 
  

   stage 
  when 
  all 
  four 
  plates 
  are 
  present 
  and 
  heavily 
  chitinised. 
  

  

  