﻿Aruba, 
  Curacao, 
  and 
  Bonaire. 
  331 
  

  

  '/"15. 
  CONURUS 
  XANTHOGENIUS^ 
  Bp. 
  

  

  Bonaparte 
  (Consp. 
  i. 
  p. 
  1) 
  described 
  Conurus 
  xanthogenius 
  

   from 
  a 
  single 
  sj)ecimen^ 
  without 
  locality, 
  in 
  the 
  Leyden 
  

   Museum. 
  He 
  gave 
  Brazil 
  as 
  its 
  habitat, 
  but 
  this, 
  of 
  course, 
  

   was 
  wrong. 
  The 
  careful 
  description 
  of 
  the 
  type 
  specimen 
  

   and 
  notes 
  on 
  it 
  in 
  Finsch's 
  work 
  left 
  me 
  little 
  doubt 
  that 
  

   C. 
  xanthogenius 
  was 
  the 
  same 
  as 
  my 
  Conurus 
  from 
  Bonaire. 
  

   To 
  make 
  sure 
  I 
  sent 
  two 
  of 
  my 
  specimens 
  to 
  my 
  friend 
  Biitti- 
  

   kofer, 
  who 
  kindly 
  compared 
  them, 
  and 
  found 
  them 
  identical 
  

   with 
  the 
  type 
  of 
  C. 
  xanthogenius. 
  

  

  C. 
  xanthogenius 
  is 
  similar 
  to 
  C. 
  pertinax, 
  except 
  that 
  in 
  

   adult 
  specimens 
  the 
  entire 
  top 
  of 
  the 
  head 
  is 
  of 
  a 
  beautiful 
  

   golden-yellow 
  colour, 
  somewhat 
  more 
  orange 
  on 
  the 
  forehead, 
  

   while 
  in 
  C. 
  pertinax 
  the 
  forehead 
  only 
  is 
  orange-yellow. 
  One 
  

   specimen 
  only 
  having 
  been 
  known 
  until 
  lately, 
  it 
  was, 
  in 
  my 
  

   opinion, 
  quite 
  reasonable 
  to 
  consider 
  this 
  form 
  merely 
  as 
  an 
  

   individual 
  variety, 
  as 
  has 
  been 
  done 
  by 
  Finsch, 
  Schlegel, 
  

   Salvadori, 
  and 
  others. 
  Since, 
  however, 
  all 
  the 
  adult 
  speci- 
  

   mens 
  from 
  Bonaire 
  have 
  the 
  entire 
  top 
  of 
  the 
  head 
  golden 
  

   yellow, 
  or 
  at 
  least 
  strongly 
  intermixed 
  with 
  golden 
  yellow 
  

   (all 
  the 
  new-coming 
  feathers 
  being 
  of 
  this 
  colour), 
  there 
  can 
  

   be 
  no 
  doubt 
  that 
  C. 
  xanthogenius 
  must 
  stand 
  as 
  a 
  distinct 
  

   insular 
  form. 
  There 
  is 
  among 
  the 
  series 
  of 
  C. 
  pertinax 
  in 
  

   the 
  British 
  and 
  Leyden 
  Museums, 
  and 
  among 
  those 
  collected 
  

   by 
  Herr 
  Peters 
  and 
  myself 
  on 
  Cura9ao, 
  not 
  one 
  specimen 
  

   with 
  the 
  top 
  of 
  the 
  head 
  yellow, 
  although 
  occasionally, 
  but 
  

   very 
  rarely, 
  a 
  yellow 
  feather 
  appears 
  there, 
  chiefly 
  in 
  caged 
  

   birds, 
  as 
  is 
  common 
  in 
  Parrots^ 
  which 
  are 
  so 
  much 
  inclined 
  

   to 
  xanthochroism. 
  

  

  The 
  young 
  of 
  C. 
  xanthogenius 
  are 
  similar 
  to 
  the 
  young 
  of 
  

   C. 
  pertinax, 
  but 
  begin 
  to 
  show 
  yellow 
  feathers 
  on 
  the 
  head 
  

   at 
  an 
  early 
  age. 
  While 
  the 
  young 
  examples 
  of 
  C. 
  pertinax 
  

   from 
  Curacao 
  have 
  the 
  upper 
  mandible 
  always 
  whitish, 
  this 
  

   part 
  is 
  brown 
  (as 
  in 
  adult 
  birds) 
  in 
  three 
  immature 
  speci- 
  

   mens 
  from 
  Bonaire, 
  but 
  in 
  one 
  from 
  the 
  same 
  locality 
  it 
  is 
  

   more 
  whitish. 
  

  

  It 
  seems 
  that 
  the 
  culmen 
  in 
  the 
  Bonaire 
  species 
  is 
  some- 
  

   what 
  longer, 
  as 
  a 
  rule. 
  The 
  measurements 
  of 
  twelve 
  speci- 
  

  

  