﻿362 
  PROCEEDINGS 
  OF 
  THE 
  NATIONAL 
  MUSEUM 
  vol.98 
  

  

  Mars 
  Orange; 
  shoulder 
  patch 
  obsolete; 
  front 
  side 
  of 
  arm 
  Burnt 
  

   Sienna, 
  lateral 
  and 
  rear 
  surfaces 
  of 
  forearm 
  Chestnut, 
  upper 
  surface 
  

   of 
  hand 
  darker. 
  Lateral 
  surface 
  of 
  thigh 
  Front's 
  Brown 
  grading 
  into 
  

   Burnt 
  Sienna 
  of 
  rear; 
  foreleg 
  Burnt 
  Sienna 
  becoming 
  Chestnut 
  ou 
  

   ankle 
  and 
  top 
  of 
  foot. 
  Upper 
  proximal 
  surface 
  of 
  tail 
  Front's 
  Brown, 
  

   the 
  hairs 
  tipped 
  with 
  Orange-Rufous, 
  underside 
  Mars 
  Orange, 
  the 
  

   whole 
  becoming 
  paler 
  distally 
  for 
  nearly 
  two-thirds 
  of 
  length 
  where 
  

   tail 
  is 
  bobbed. 
  

  

  The 
  above 
  specimen 
  was 
  taken 
  in 
  the 
  Cordillera 
  Central 
  southwest 
  

   of 
  NorosI, 
  altitude 
  about 
  125 
  meters. 
  At 
  the 
  time 
  of 
  collecting 
  in 
  

   this 
  locality 
  (June 
  1943) 
  during 
  a 
  very 
  rainy 
  period, 
  monkeys 
  were 
  

   scarce. 
  However, 
  they 
  were 
  said 
  to 
  be 
  numerous 
  during 
  the 
  dry 
  

   season. 
  At 
  the 
  same 
  time, 
  pleei 
  was 
  abundant 
  in 
  the 
  flooded 
  lowlands 
  

   between 
  Norosi 
  and 
  the 
  Rio 
  Magdalena. 
  

  

  Measurements. 
  — 
  Those 
  of 
  the 
  holotype 
  are 
  followed 
  by 
  those 
  of 
  an 
  

   adult 
  male 
  paratype, 
  and 
  an 
  adult 
  male 
  from 
  Rio 
  San 
  Fedro: 
  Head 
  

   and 
  body, 
  397, 
  392, 
  422; 
  tail, 
  495, 
  478, 
  — 
  ; 
  hind 
  foot, 
  135, 
  134, 
  126; 
  

   ear, 
  38, 
  34, 
  35; 
  greatest 
  length 
  of 
  skull, 
  95.0, 
  91.7, 
  94.1; 
  condylobasal 
  

   length, 
  73.6, 
  71.7, 
  74.8; 
  zygomatic 
  breadth, 
  60.6, 
  60.5, 
  63.5; 
  width 
  of 
  

   brain 
  case, 
  47.7, 
  48.2, 
  49.3; 
  length 
  of 
  brain 
  case, 
  74.3, 
  74.1, 
  76.3; 
  

   orbital 
  breadth, 
  49.4, 
  49.4, 
  54.0; 
  greatest 
  width 
  across 
  maxillary 
  tooth 
  

   row, 
  28.7, 
  27.0, 
  27.9; 
  length, 
  upper 
  canine 
  to 
  M^ 
  26.8, 
  24.2, 
  25.9; 
  

   length, 
  lower 
  canine 
  to 
  Ms, 
  30.3, 
  27.6, 
  29.6; 
  mandibular 
  depth 
  at 
  

   condyle, 
  28.9, 
  25.3, 
  29.4 
  mm. 
  

  

  Remarks. 
  — 
  The 
  geographically 
  nearest 
  race 
  is 
  hypoleucus 
  of 
  the 
  

   Rio 
  Simi 
  region. 
  Where 
  the 
  ranges 
  of 
  hypoleucus 
  and 
  pleei 
  meet 
  

   cannot 
  be 
  ascertained. 
  Differences 
  between 
  the 
  two 
  forms 
  are 
  great, 
  

   and 
  it 
  must 
  be 
  assumed 
  that 
  the 
  Rio 
  Cauca 
  (and 
  the 
  San 
  Jorge) 
  acts 
  

   as 
  a 
  very 
  nearly 
  complete 
  barrier 
  to 
  intergradation 
  between 
  them. 
  

   Differences 
  between 
  pleei 
  and 
  the 
  considerably 
  paler 
  cesarae 
  are 
  of 
  a 
  

   comparable 
  magnitude. 
  Here 
  separation 
  between 
  the 
  two 
  forms 
  is 
  

   effected 
  by 
  the 
  Rio 
  Magdalena. 
  

  

  Unavailability 
  of 
  the 
  name 
  chrysopus 
  for 
  micos 
  of 
  the 
  lower 
  Cauca- 
  

   Magdalena 
  Valley 
  has 
  aheady 
  been 
  discussed 
  (p. 
  342). 
  The 
  pale 
  

   " 
  Chrysope^' 
  originally 
  figiu-ed 
  and 
  described 
  by 
  Cuvier 
  bears 
  no 
  close 
  

   resemblance 
  to 
  the 
  extremely 
  warmly 
  colored 
  pleei. 
  

  

  As 
  noted 
  elsewhere 
  (p. 
  342), 
  the 
  first 
  specimens 
  of 
  pleei, 
  erroneously 
  

   identified 
  as 
  chrysopus 
  by 
  authors, 
  were 
  collected 
  by 
  Flee. 
  One 
  of 
  his 
  

   micos 
  in 
  the 
  Museum 
  d'Histoire 
  Naturelle 
  des 
  Fays-Bas, 
  acquired 
  

   from 
  the 
  Faris 
  Museum, 
  was 
  recorded 
  by 
  Schlegel 
  (1876, 
  p. 
  196) 
  as 
  

   Cebus 
  albifrons. 
  The 
  label 
  of 
  the 
  specimen 
  bore 
  the 
  name 
  "carita 
  

   blanca." 
  Very 
  little 
  is 
  known 
  of 
  the 
  collector 
  for 
  whom 
  the 
  present 
  

   monkey 
  is 
  named. 
  He 
  was 
  one 
  of 
  three 
  young 
  students 
  selected 
  by 
  

   the 
  faculty 
  of 
  the 
  Museum 
  National 
  d'Histoire 
  Naturelle, 
  Faris, 
  and 
  

  

  