﻿388 
  PROCEEDINGS 
  OF 
  THE 
  NATIONAL 
  MUSEUM 
  vor.. 
  98 
  

  

  of 
  basal 
  portion 
  of 
  hairs 
  is 
  extremely 
  variable 
  in 
  any 
  series 
  and 
  in 
  any 
  

   one 
  specimen. 
  Generally, 
  however, 
  these 
  are 
  darker 
  in 
  young 
  and 
  

   very 
  immature 
  individuals 
  than 
  in 
  adults. 
  Cranial 
  characters 
  are, 
  

   by 
  far, 
  most 
  variable. 
  Skull 
  characters 
  employed 
  by 
  Allen 
  for 
  sepa- 
  

   rating 
  various 
  forms 
  of 
  red 
  howlers 
  described 
  by 
  him 
  are 
  patently 
  

   individually 
  variable. 
  The 
  few 
  cranial 
  measurements, 
  and 
  the 
  exter- 
  

   nal 
  ones 
  as 
  well, 
  given 
  below 
  may 
  be 
  useful 
  for 
  comparisons 
  with 
  

   measurements 
  of 
  other 
  species 
  of 
  howlers. 
  They 
  are 
  of 
  no 
  value 
  for 
  

   differentiating 
  one 
  series 
  from 
  another. 
  In 
  the 
  majority 
  of 
  cases 
  indi- 
  

   vidual 
  measurements 
  represent 
  specimens 
  which, 
  though 
  all 
  adults, 
  

   are 
  not 
  strictly 
  comparable 
  because 
  of 
  the 
  many 
  peculiarities 
  of 
  the 
  

   individual, 
  the 
  family 
  or 
  the 
  clan 
  that 
  are 
  linked 
  to 
  them. 
  Highly 
  

   localized 
  environmental 
  conditions, 
  such 
  as 
  quality 
  and 
  availability 
  

   of 
  food 
  and 
  water, 
  are 
  of 
  greater 
  significance 
  in 
  growth 
  and 
  develop- 
  

   ment 
  of 
  these 
  very 
  sedentary 
  and 
  sluggish 
  monkeys 
  than 
  in 
  any 
  other 
  

   species 
  of 
  American 
  simian. 
  

  

  Cerro 
  de 
  la 
  Gvayta, 
  near 
  Cienaga 
  de 
  Gudjaro 
  (3 
  males, 
  1 
  subadult; 
  

   2 
  females): 
  Back, 
  between 
  shoulders 
  and 
  rump, 
  Ochraceous-Orange 
  

   to 
  Xanthine-Orange 
  with 
  the 
  yellower, 
  or 
  buffy, 
  subterminal 
  bands 
  

   of 
  hairs 
  showing 
  through 
  at 
  sm'face; 
  basal 
  portions 
  of 
  hahs 
  Ochraceous- 
  

   Tawny 
  to 
  Ciimamon-Brown. 
  Hairs 
  of 
  lateral 
  fringe 
  like 
  back 
  but 
  

   loager, 
  especially 
  the 
  Bm-nt 
  Sienna 
  terminal 
  portions 
  which 
  nearly 
  

   completely 
  cover 
  the 
  paler 
  proximal 
  portions. 
  Hairs 
  of 
  rump 
  San- 
  

   ford's 
  Brown 
  to 
  Bm'nt 
  Sienna 
  terminally, 
  becoming 
  increasingly 
  paler 
  

   basally 
  except 
  near 
  roots 
  which 
  may 
  be 
  brownish. 
  Interscapular 
  

   region 
  Biu-nt 
  Sienna 
  to 
  Mahogany 
  Red 
  or 
  Chestnut 
  in 
  appearance, 
  

   the 
  Orange-Rufous 
  to 
  Sanford's 
  Brown 
  terminal 
  halves 
  of 
  hairs 
  broken 
  

   by 
  a 
  Bm'nt 
  Sienna 
  to 
  Chestnut 
  subterminal 
  band, 
  upper 
  part 
  of 
  basal 
  

   portion 
  of 
  hairs 
  like 
  tips 
  or 
  slightly 
  paler, 
  lower 
  part 
  darker, 
  becoming 
  

   dark 
  brown 
  toward 
  roots. 
  Head, 
  chin, 
  fore 
  and 
  hind 
  limbs 
  more 
  or 
  

   less 
  uniformly 
  Burnt 
  Sienna 
  to 
  Chestnut. 
  Proximal 
  portion 
  of 
  tail 
  

   like 
  hind 
  limbs, 
  terminally 
  paler, 
  Mars 
  Orange 
  to 
  Xanthine 
  Orange. 
  

   Hairs 
  of 
  underparts 
  Burnt 
  Sienna 
  to 
  Chestnut. 
  

  

  Measurements.' 
  — 
  Those 
  of 
  an 
  adult 
  male 
  and 
  female, 
  respectively: 
  

   Head 
  and 
  body, 
  465, 
  475; 
  tail, 
  645, 
  646; 
  hind 
  foot, 
  146, 
  142; 
  greatest 
  

   length 
  of 
  skull, 
  118.3, 
  101.5; 
  condylobasal 
  length, 
  110.1, 
  93.6; 
  length 
  

   of 
  brain 
  case, 
  76.6, 
  63.4; 
  mastoidal 
  width 
  of 
  brain 
  case, 
  54.7, 
  — 
  ; 
  

   length 
  of 
  maxillary 
  tooth 
  row 
  (C-M^), 
  39.0, 
  35.4 
  mm. 
  

  

  Remarks.— 
  The 
  series 
  was 
  taken 
  in 
  the 
  low 
  hill 
  country 
  about 
  

   midway 
  between 
  Barranquilla 
  and 
  Cartagena 
  and 
  is 
  strictly 
  repre- 
  

   sentative 
  of 
  the 
  original 
  Lmnaean 
  seniculus. 
  All 
  skuUs 
  of 
  the 
  series 
  

   are 
  damaged. 
  The 
  foregoing 
  measurements 
  are 
  of 
  the 
  two 
  best- 
  

   preserved 
  specimens. 
  The 
  skull 
  of 
  one 
  adult 
  female 
  is 
  malformed 
  as 
  

   the 
  result 
  of 
  an 
  injury 
  it 
  must 
  have 
  received 
  in 
  early 
  life. 
  In 
  this 
  

  

  