﻿328 
  

  

  PROCEEDINGS 
  OF 
  THE 
  NATIONAL 
  MUSEUM 
  

  

  VOL. 
  98 
  

  

  Cebus 
  albifrons 
  partially 
  resembles 
  pale, 
  or 
  erythristic, 
  members 
  of 
  the 
  

   "tufted" 
  group, 
  while 
  C. 
  nigrivittatus 
  could 
  be 
  confused 
  with 
  dark 
  

   browD 
  or 
  blackish 
  "tufted" 
  monkeys. 
  Superficial 
  characters 
  sepa- 
  

   rating 
  albifrons 
  from 
  nigrivittatus 
  are 
  outlined 
  below 
  and 
  may 
  be 
  of 
  

   additional 
  service 
  in 
  distinguishing 
  them 
  from 
  "tufted" 
  forms. 
  

  

  Cebus 
  albifrons 
  

   (Fig. 
  52, 
  a~b) 
  

  

  1. 
  Cap 
  in 
  males 
  (and 
  females 
  without 
  

   superciliary 
  brush 
  or 
  frontal 
  diadem), 
  

   usually 
  well 
  rounded, 
  extending 
  from 
  

   crown 
  to 
  back 
  of 
  head, 
  and 
  broadly 
  out- 
  

   lined 
  in 
  front 
  by 
  whitish 
  to 
  buflfy 
  super- 
  

   ciliary 
  or 
  transverse 
  frontal 
  band; 
  height 
  

   of 
  superciliary 
  band 
  equal 
  to 
  about 
  one- 
  

   half 
  distance 
  between 
  ears, 
  and 
  with 
  or 
  

   without 
  a 
  dark 
  median 
  line 
  from 
  cap 
  to 
  

   root 
  of 
  nose. 
  

  

  2. 
  Back 
  and 
  sides 
  of 
  body 
  more 
  or 
  

   less 
  uniformly 
  yellowish 
  to 
  reddish 
  or 
  

   brown; 
  median 
  dorsal 
  band, 
  if 
  present, 
  

   poorly 
  defined; 
  hairs 
  uniformly 
  colored 
  

   or 
  with 
  bases 
  paler 
  and 
  never 
  with 
  

   sharply 
  contrasting 
  paler 
  tips. 
  

  

  3. 
  Tail 
  never 
  blackish, 
  upper 
  side 
  

   like 
  back 
  or 
  with 
  hairs 
  punctulated, 
  

   usually 
  becoming 
  paler 
  terminally. 
  

  

  4. 
  Hairs 
  of 
  outer 
  side 
  of 
  forearm 
  and 
  

   foreleg 
  uniformly 
  yellowish 
  to 
  reddish 
  

   or 
  brown 
  or 
  gradually 
  becoming 
  paler 
  

   from 
  tip 
  to 
  base; 
  sometimes 
  with 
  dis- 
  

   tinct 
  annulations 
  or 
  paler 
  tips; 
  wrist, 
  

   ankle, 
  and 
  upper 
  surface 
  of 
  hand 
  and 
  

   foot 
  not 
  markedly 
  darker. 
  

  

  5. 
  Hairs 
  of 
  chest 
  and 
  belly 
  usually 
  

   paler 
  than 
  terminal 
  portions 
  of 
  hairs 
  

   of 
  back. 
  

  

  6. 
  Pelage 
  generally 
  smoothly 
  ad- 
  

   pressed 
  and 
  of 
  a 
  soft, 
  silky 
  texture. 
  

  

  Cebus 
  nigrivittatus 
  

   (Fig. 
  52, 
  d) 
  

  

  1. 
  Cap 
  in 
  males 
  (and 
  untufted 
  fe- 
  

   males) 
  smaller, 
  narrower, 
  triangular 
  or 
  

   wedge-shaped 
  with 
  apex 
  in 
  front, 
  usu- 
  

   ally 
  restricted 
  to 
  crown 
  and 
  sharply 
  

   outlined 
  from 
  sides 
  of 
  head; 
  pale 
  super- 
  

   ciliary 
  band 
  narrower, 
  height 
  at 
  mid- 
  

   frontal 
  line 
  about 
  one 
  fourth 
  or 
  less 
  dis- 
  

   tance 
  between 
  ears 
  and 
  usually 
  with 
  a 
  

   line 
  or 
  wedge 
  of 
  dark 
  hairs 
  from 
  cap 
  to 
  

   root 
  of 
  nose. 
  

  

  2. 
  Back 
  and 
  sides 
  yellowish 
  to 
  nearly 
  

   black, 
  median 
  dorsal 
  band, 
  when 
  pres- 
  

   ent 
  usually 
  moderately 
  well 
  defined; 
  

   hairs 
  at 
  least 
  of 
  sides 
  of 
  back 
  usually 
  

   conspicuously 
  annulated, 
  the 
  wide 
  pale 
  

   terminal 
  bands 
  contrasting 
  with 
  darker 
  

   subterminal 
  portions. 
  

  

  3. 
  Tail 
  above 
  like 
  back 
  proximally, 
  

   usually 
  becoming 
  darker 
  terminally, 
  

  

  4. 
  Hairs 
  of 
  outer 
  side 
  of 
  forearm 
  and 
  

   foreleg 
  dark 
  brown 
  or 
  gray 
  basally 
  or 
  

   subterminally, 
  sharply 
  paler 
  terminally; 
  

   wrist, 
  ankle, 
  and 
  upper 
  surface 
  of 
  hand 
  

   and 
  foot 
  usually 
  contrastingly 
  darker, 
  

   or 
  blackish. 
  

  

  5. 
  Hairs 
  of 
  chest 
  and 
  belly 
  usually 
  

   darker 
  than 
  terminal 
  portions 
  of 
  hairs 
  

   of 
  back. 
  

  

  6. 
  Pelage 
  generally 
  lax 
  and 
  of 
  a 
  

   coarser 
  texture. 
  

  

  In 
  general, 
  C. 
  albifrons 
  is 
  delicately 
  built 
  and 
  brightly 
  colored, 
  with 
  

   forearms, 
  legs, 
  and 
  tail 
  never 
  blackish 
  as 
  in 
  the 
  "tufted" 
  species. 
  In 
  

   contrast, 
  nigrivittatus 
  is 
  larger, 
  more 
  robust 
  and 
  somberly 
  colored, 
  and 
  

   approaches 
  the 
  "tufted" 
  forms 
  in 
  color 
  of 
  limbs 
  and 
  tail. 
  Its 
  skull 
  is 
  

   larger 
  and 
  more 
  dolichocephalic 
  than 
  thai 
  oi 
  albifrons. 
  Amore 
  detailed 
  

   description 
  of 
  Cebus 
  albifrons 
  is 
  given 
  later 
  under 
  specific 
  and 
  sub- 
  

   specific 
  headings. 
  

  

  