﻿4 
  AOTUS 
  

  

  in 
  the 
  East, 
  to 
  the 
  Upper 
  Amazon 
  on 
  the 
  banks 
  of 
  the 
  Cassiquiare 
  River 
  

   near 
  the 
  headwaters 
  of 
  the 
  Rio 
  Negro, 
  Brazil, 
  and 
  westward 
  to 
  £ga, 
  

   in 
  Peru. 
  A. 
  roberti 
  has 
  only 
  been 
  obtained 
  in 
  the 
  Sierra 
  de 
  Chapada, 
  

   Matto 
  Grosso, 
  Brazil; 
  and 
  A. 
  infulatus 
  at 
  Para. 
  The 
  only 
  other 
  

   locality 
  in 
  the 
  eastern 
  part 
  of 
  the 
  continent 
  inhabited 
  by 
  a 
  member 
  of 
  

   this 
  genus, 
  is 
  the 
  right 
  bank 
  of 
  the 
  River 
  Paraguay, 
  northeastern 
  part 
  

   of 
  Argentina, 
  where 
  A. 
  miriquouina 
  is 
  found. 
  A. 
  vociferans 
  has 
  

   been 
  procured 
  on 
  the 
  Ucayali 
  and 
  Huallaga 
  rivers, 
  and 
  at 
  Tabatinga, 
  

   Upper 
  Marafion, 
  on 
  the 
  eastern 
  border 
  of 
  Peru, 
  and 
  also 
  in 
  the 
  

   Tolima 
  Mountains, 
  south 
  western 
  Colombia. 
  In 
  the 
  mountains 
  just 
  

   named 
  A. 
  lanius 
  was 
  obtained. 
  A. 
  griseimembra 
  has 
  been 
  found 
  in 
  

   Santa 
  Marta, 
  and 
  on 
  the 
  Rio 
  Sinu 
  Cerete, 
  Bolivar, 
  northern 
  Colombia. 
  

   Two 
  species 
  inhabit 
  Ecuador, 
  A. 
  gularis 
  at 
  the 
  mouth 
  of 
  the 
  

   Rio 
  Coca, 
  Upper 
  Rio 
  Napo, 
  and 
  A. 
  microdon 
  at 
  Micas. 
  Peru, 
  besides 
  

   A. 
  trivirgata, 
  has 
  two 
  other 
  representatives 
  of 
  the 
  genus, 
  A. 
  nigri- 
  

   cefs 
  from 
  Chanchamayo, 
  and 
  A. 
  senex 
  from 
  Pozuzo, 
  but 
  the 
  extent 
  of 
  

   their 
  range 
  is 
  not 
  yet 
  known, 
  and 
  this 
  may 
  be 
  also 
  said 
  of 
  most 
  of 
  the 
  

   other 
  species. 
  From 
  the 
  Province 
  of 
  Sara, 
  Central 
  Bolivia, 
  A. 
  bolivi- 
  

   ensis 
  comes. 
  Three 
  species 
  remain 
  whose 
  habitats 
  are 
  doubtful 
  or 
  

   unknown. 
  First 
  of 
  these 
  is 
  A. 
  rufipes 
  mentioned 
  above, 
  received 
  in 
  

   London 
  alive 
  from 
  San 
  Juan 
  del 
  Norta, 
  Nicaragua. 
  The 
  type 
  is 
  

   unique 
  and 
  its 
  habitat 
  uncertain, 
  as 
  it 
  may 
  have 
  been 
  brought 
  to 
  San 
  

   Juan 
  from 
  South 
  America. 
  The 
  others 
  are 
  A. 
  oseryi 
  in 
  the 
  Paris 
  

   Museum, 
  whose 
  only 
  habitat 
  is 
  given 
  as 
  "Haute 
  Amazone, 
  Perou," 
  (I. 
  

   Geoff.) 
  ; 
  and 
  A. 
  spixi 
  in 
  the 
  Collection 
  of 
  the 
  same 
  Institution, 
  and 
  

   said 
  to 
  have 
  come 
  from 
  "Amerique 
  Meridionale." 
  

  

  KEY 
  TO 
  THE 
  SPECIES. 
  

  

  A. 
  Black 
  lines 
  on 
  sides 
  of 
  head 
  not 
  going 
  to 
  the 
  throat. 
  

   a. 
  Black 
  lines 
  on 
  head 
  not 
  going 
  to 
  the 
  occiput. 
  

  

  a.' 
  Black 
  lines 
  from 
  eyes 
  encircling 
  the 
  white 
  and 
  

   meeting 
  on 
  crown. 
  

   a." 
  Apical 
  half 
  of 
  hairs 
  on 
  tail 
  black 
  to 
  the 
  

   roots. 
  

   a!" 
  Black 
  lines 
  on 
  head 
  broad. 
  

  

  a. 
  4 
  Hairs 
  on 
  back 
  red 
  and 
  black 
  

  

  towards 
  root 
  A. 
  infulatus. 
  

  

  bA 
  Hairs 
  on 
  back 
  slaty 
  black 
  

  

  towards 
  root 
  A. 
  nigriceps. 
  

  

  b."' 
  Black 
  lines 
  on 
  head 
  narrow 
  A. 
  senex. 
  

  

  