﻿26.— 
  THE 
  DIBTRIBUTION 
  OF 
  MOSQUITOS 
  IN 
  RELATION 
  TO 
  

   THE 
  ZOOGEOGRAPHICAL 
  AREAS 
  OF 
  THE 
  INDIAN 
  EMPIRE. 
  

  

  (Plate 
  XXXVII). 
  

   By 
  Major 
  S. 
  R. 
  Christophers, 
  C.I.E., 
  I.M.S., 
  Central 
  Malaria 
  Bureau,^ 
  

  

  Kasauli. 
  

  

  In 
  1916 
  I 
  published 
  a 
  " 
  revision 
  " 
  of 
  the 
  Indian 
  Anophelina) 
  in 
  which 
  

   I 
  gave, 
  under 
  the 
  different 
  species, 
  the 
  various 
  areas 
  from 
  which 
  up 
  to 
  

   that 
  date 
  they 
  had 
  been 
  recorded, 
  whether 
  in 
  published 
  works 
  or 
  the 
  

   collection 
  at 
  the 
  Central 
  Malaria 
  Bureau. 
  It 
  seems 
  desirable 
  however 
  

   to 
  supplement 
  this 
  information 
  with 
  such 
  further 
  facts 
  as 
  have 
  been 
  

   gathered 
  and 
  to 
  put 
  it 
  in 
  a 
  form 
  which 
  will 
  make 
  the 
  zoogeographical 
  

   distribution 
  of 
  this 
  group 
  more 
  easily 
  appreciated. 
  

  

  Regarding 
  other 
  mosquitos 
  than 
  Anophelines 
  only 
  very 
  few 
  tentative 
  

   data 
  regarding 
  their 
  distribution 
  can 
  as 
  yet 
  be 
  given, 
  partly 
  because 
  

   they 
  are 
  less 
  thoroughly 
  collected 
  than 
  are 
  Anophelines 
  and 
  partly 
  

   owing 
  to 
  difficulties 
  of 
  synonomy 
  which 
  as 
  regards 
  the 
  Anophelines 
  

   have 
  now 
  largely 
  disappeared. 
  

  

  The 
  Anophelines 
  form 
  a 
  very 
  suitable 
  group 
  for 
  a 
  basis 
  in 
  the 
  study 
  

   of 
  the 
  geographical 
  distribution 
  of 
  the 
  Culicida3 
  both 
  because 
  they 
  have 
  

   been 
  very 
  thoroughly 
  collected 
  and 
  because 
  much 
  work 
  has 
  been 
  done 
  

   in 
  regard 
  to 
  the 
  affinities 
  of 
  the 
  species. 
  Also 
  the 
  areas 
  of 
  distribution 
  

   of 
  these 
  species 
  are 
  of 
  a 
  very 
  suitable 
  size, 
  neither 
  too 
  large 
  nor 
  too 
  small 
  

   to 
  be 
  instructive. 
  Among 
  Anophelines 
  there 
  is 
  at 
  present 
  recognised 
  

   only 
  one 
  genus. 
  In 
  the 
  case 
  of 
  the 
  Culicidse 
  there 
  are 
  many 
  and 
  the 
  

   divergence 
  of 
  forms 
  is 
  obviously 
  much 
  greater. 
  We 
  might 
  think 
  a 
  priori 
  

   therefore 
  that 
  in 
  the 
  Anophelines 
  we 
  have, 
  at 
  least 
  in 
  part, 
  to 
  study 
  a 
  

   relatively 
  more 
  recent 
  diffusion. 
  As 
  we 
  shall 
  see 
  it 
  is 
  necessary 
  to 
  re- 
  

   cognise 
  caution 
  where, 
  as 
  is 
  evidently 
  the 
  case, 
  the 
  distribution 
  of 
  indivi- 
  

   dual 
  species 
  is 
  often 
  but 
  a 
  part 
  of 
  general 
  faunal 
  changes. 
  

  

  As 
  is 
  well 
  known 
  the 
  surface 
  of 
  the 
  earth 
  has, 
  on 
  a 
  zoogeographical 
  

   basis, 
  been 
  divided 
  into 
  certain 
  faunistic 
  provinces 
  and 
  regions. 
  For 
  

   reasons 
  I 
  need 
  not 
  enter 
  upon 
  here 
  these 
  have 
  largely 
  been 
  based 
  upon 
  

   the 
  distribution 
  of 
  mammals, 
  to 
  a 
  less 
  extent 
  on 
  that 
  of 
  birds 
  and 
  rep- 
  

   tiles 
  and 
  much 
  less 
  closely, 
  if 
  in 
  some 
  cases 
  at 
  all, 
  upon 
  lower 
  forms 
  of 
  

   life 
  including 
  the 
  Insecta. 
  

  

  As 
  regards 
  India, 
  Blanford 
  (i), 
  who 
  is 
  the 
  chief 
  authority 
  on 
  the 
  

   Indian 
  faunal 
  areas, 
  in 
  one 
  of 
  his 
  earlier 
  papers 
  divides 
  the 
  Indian 
  

   Empire 
  into 
  four 
  main 
  areas 
  : 
  — 
  

  

  (1) 
  The 
  Punjab, 
  including 
  Siud, 
  the 
  desert 
  country 
  east 
  of 
  the 
  

   Indus, 
  Cutch 
  and 
  Western 
  Rajputana. 
  

   ( 
  205 
  ) 
  

  

  