﻿210 
  PROCEEDINGS 
  OF 
  THE 
  FOUETH 
  ENTO]\[OLOGICAL 
  MEETING 
  

  

  forms. 
  Iti 
  the 
  Trans-Indus 
  and 
  in 
  the 
  Himalayan 
  area 
  new 
  faunas 
  are 
  

   encountered. 
  The 
  Himalayan 
  area 
  appears 
  to 
  be 
  responsible 
  for 
  quite 
  

   a 
  number 
  of 
  the 
  species 
  restricted 
  to 
  India 
  itself, 
  notably 
  species 
  of 
  

   Ochlerotatus. 
  In 
  this 
  area 
  it 
  is 
  curious 
  to 
  find 
  in 
  the 
  North-Western 
  

   Himalayas 
  at 
  a 
  height 
  of 
  6,000 
  feet 
  or 
  more 
  and 
  among 
  oaks 
  and 
  pines 
  

   such 
  forms 
  as 
  Toxorhynchites 
  leicesteri 
  and 
  Ortho'podomi/ia 
  cmopheloides 
  , 
  

   which 
  one 
  associates 
  with 
  tropical 
  conditions 
  and 
  which 
  are 
  Malayan 
  

   species. 
  

  

  The 
  close 
  similarity 
  of 
  areas 
  based 
  on 
  the 
  distribution 
  of 
  mammals 
  

   to 
  those 
  now 
  brought 
  forward 
  in 
  respect 
  to 
  the 
  distribution 
  of 
  mos- 
  

   quitos 
  is 
  very 
  striking. 
  That 
  there 
  should 
  be 
  such 
  coincidence 
  in 
  the 
  

   case 
  of 
  forms 
  so 
  totally 
  unrelated 
  to 
  one 
  another 
  in 
  zoological 
  position 
  

   and 
  methods 
  of 
  life 
  appears 
  to 
  show 
  that 
  the 
  distribution 
  of 
  forms 
  of 
  

   life 
  in 
  this 
  case 
  has 
  been 
  less 
  the 
  effect 
  of 
  diffusion 
  of 
  individual 
  species, 
  

   working 
  so 
  to 
  speak 
  independently, 
  than 
  of 
  circumstances 
  acting 
  upon 
  

   the 
  great 
  biological 
  systems 
  that 
  are 
  understood 
  when 
  one 
  speaks 
  of 
  a 
  

   fauna. 
  As 
  regards 
  the 
  causes 
  of 
  distribution 
  of 
  the 
  different 
  species 
  of 
  

   Indian 
  mosquitos, 
  even 
  of 
  the 
  Anophelines, 
  it 
  is 
  evident 
  that 
  we 
  must 
  

   primarily 
  consider 
  most 
  of 
  these 
  species 
  as 
  belonging 
  to 
  a 
  great 
  Malayan 
  

   faunal 
  complex 
  in 
  whose 
  history 
  and 
  fate 
  that 
  of 
  the 
  species 
  has 
  been 
  

   involved. 
  Similarly 
  one 
  must 
  expect 
  to 
  find 
  indications 
  of 
  an 
  African 
  

   faunal 
  complex 
  since 
  it 
  is 
  known 
  that 
  at 
  one 
  time 
  the 
  so-called 
  Siwalik 
  

   fauna 
  of 
  African 
  type 
  existed 
  in 
  India 
  and 
  extended 
  far 
  into 
  Central 
  

   Asia. 
  Of 
  this 
  we 
  have 
  not 
  seen 
  such 
  striking 
  evidence 
  as 
  might 
  have 
  

   been 
  expected 
  seeing 
  that 
  the 
  Siwalik 
  fauna 
  succeeded 
  the 
  Malayan 
  in 
  

   North 
  India 
  and 
  is 
  usually 
  considered 
  Pliocene 
  as 
  against 
  Miocene 
  in 
  

   point 
  of 
  time. 
  In 
  the 
  case 
  of 
  the 
  mosquito 
  fauna 
  of 
  India 
  one 
  can 
  

   almost 
  see 
  the 
  eastward 
  recession, 
  due 
  to 
  drier 
  climatic 
  conditions, 
  of 
  

   a 
  faunal 
  area 
  which 
  once 
  extended 
  from 
  Europe 
  to 
  the 
  East. 
  Yet 
  apart 
  

   from 
  the 
  history 
  of 
  the 
  faunal 
  complexes 
  there 
  is 
  evidently 
  much 
  in 
  the 
  

   distribution 
  of 
  mosquitos 
  due 
  to 
  special 
  circumstances 
  affecting 
  indivi- 
  

   dual 
  species. 
  Some 
  of 
  the 
  Anopheline 
  species, 
  as 
  I 
  have 
  shown, 
  have 
  

   very 
  peculiar 
  areas 
  of 
  distribution 
  of 
  which 
  the 
  explanation 
  is 
  not 
  clear" 
  

   yet 
  these 
  must 
  have 
  a 
  definite 
  significance. 
  Why 
  for 
  example, 
  do 
  species 
  

   stop 
  at 
  the 
  Indus 
  ? 
  I 
  have 
  made 
  somewhat 
  of 
  a 
  study 
  of 
  the 
  land 
  changes 
  

   in 
  this 
  area 
  but 
  without 
  convincing 
  myself 
  that 
  I 
  have 
  discovered 
  any 
  

   adequate 
  reason 
  for 
  this. 
  Why 
  does 
  A. 
  stephensii 
  exist 
  up 
  the 
  Tigris 
  

   and 
  Euphrates 
  and 
  A. 
  culicifacies 
  not, 
  and 
  so 
  on. 
  

  

  In 
  conclusion, 
  I 
  may 
  point 
  out 
  how 
  important 
  is 
  our 
  knowledge 
  in 
  

   regard 
  to 
  the 
  Central 
  Asian 
  border 
  of 
  our 
  area 
  and 
  how 
  desirable 
  are 
  

   observations 
  and 
  collections 
  from 
  the 
  Tibutan 
  and 
  Chinese 
  borders. 
  

  

  