﻿MAMMALS 
  OF 
  NORTHERN 
  COLOMBIA 
  — 
  HERSHKOVITZ 
  399 
  

  

  c. 
  A. 
  belzebul 
  belzebul. 
  

  

  Male: 
  As 
  in 
  male 
  seniculus 
  but 
  mouth 
  of 
  bulla 
  larger, 
  sagittal 
  diameter 
  

   about 
  half 
  greatest 
  depth 
  of 
  hyoid 
  bone, 
  tentorium 
  less 
  developed, 
  

   without 
  lateral 
  partitions; 
  rudimentary 
  cornua 
  present; 
  inner 
  surface 
  

   of 
  hyoid 
  nearly 
  entirely 
  smooth, 
  

  

  d. 
  A. 
  belzebul 
  nigerriina. 
  

  

  Female: 
  As 
  in 
  female 
  straminea 
  but 
  tentorium 
  more 
  inflated 
  (as 
  in 
  female 
  

   seniculus), 
  cornua 
  obsolete. 
  

  

  e. 
  A. 
  fusca.^ 
  

  

  Male: 
  As 
  in 
  male 
  belzebul 
  but 
  rudimentary 
  cornua 
  absent, 
  articular 
  

  

  depressions 
  for 
  stylohyal 
  as 
  in 
  seniculus. 
  

   Female: 
  As 
  in 
  female 
  seniculus 
  but 
  mouth 
  of 
  bulla 
  larger, 
  occupying 
  

  

  about 
  one-half 
  or 
  more 
  posterior 
  surface 
  of 
  drum; 
  tentorium 
  less 
  

  

  modified 
  than 
  in 
  seniculus, 
  little 
  inflated 
  and 
  hardly 
  or 
  not 
  at 
  all 
  

  

  forming 
  a 
  distinct 
  chamber. 
  

  

  2. 
  A. 
  car 
  ay 
  a 
  

  

  Male: 
  Smaller 
  than 
  in 
  A. 
  seniculus 
  group; 
  mouth 
  of 
  bulla 
  large, 
  occupy- 
  

   ing 
  more 
  than 
  one-half 
  postero 
  ventral 
  surface 
  of 
  hyoid; 
  rudimentary 
  

   tentorium 
  an 
  extended 
  plate 
  with 
  dorsal 
  edge 
  slightly 
  bent 
  or 
  folded 
  

   posteriorly 
  but 
  not 
  inflated 
  and 
  without 
  lateral 
  partitions; 
  rudimentary 
  

   cornua 
  present; 
  cornicula 
  approximately 
  as 
  in 
  seniculus; 
  outer 
  dorsal 
  

   surface 
  of 
  bulla 
  angular 
  and 
  arched; 
  inner 
  surface 
  of 
  bulla 
  smooth. 
  

  

  3. 
  A. 
  palliata 
  

  

  As 
  described 
  in 
  text, 
  p. 
  396. 
  

  

  Remarks. 
  — 
  The 
  most 
  highly 
  specialized 
  hyoid 
  apparatus 
  is 
  found 
  in 
  

   male 
  A. 
  seniculus. 
  The 
  female 
  hyoid 
  of 
  A. 
  palliata 
  is 
  least 
  modified 
  

   and 
  may 
  be 
  nearest 
  that 
  of 
  the 
  ancestral 
  type 
  of 
  howler. 
  The 
  male 
  

   hyoid 
  of 
  A. 
  caraya 
  is 
  intermediate. 
  Here 
  a 
  rudimentary 
  tentorium 
  

   appears 
  and 
  from 
  this 
  type, 
  the 
  male 
  hyoid 
  of 
  A. 
  belzebul 
  can 
  be 
  

   derived. 
  The 
  male 
  hyoid 
  of 
  A.fusca 
  is 
  more 
  specialized, 
  its 
  tentorium 
  

   more 
  inflated, 
  and 
  it 
  shows 
  a 
  tendency 
  to 
  develop 
  the 
  trabeculae 
  

   and 
  partitions 
  on 
  inner 
  surface 
  of 
  bulla 
  noted 
  in 
  male 
  hyoid 
  of 
  

   A. 
  seniculus. 
  Relationship 
  between 
  sexes 
  in 
  size 
  of 
  hyoid 
  is 
  about 
  

   the 
  same 
  in 
  all 
  species 
  and 
  out 
  of 
  all 
  proportions 
  to 
  sexual 
  differences 
  

   in 
  external 
  and 
  cranial 
  characters. 
  Throughout, 
  the 
  female 
  hyoid 
  is 
  

   less 
  modified 
  than 
  that 
  of 
  the 
  male. 
  Greatest 
  structural 
  differences 
  

   between 
  the 
  sexes 
  are 
  found 
  in 
  hyoids 
  of 
  A. 
  seniculus, 
  the 
  least 
  in 
  

   those 
  of 
  A. 
  palliata. 
  

  

  GENUS 
  AOTUS 
  ILLIGER: 
  NIGHT 
  MONKEYS, 
  OR 
  MICOS 
  DE 
  NOCHE 
  

  

  Ten 
  specimens 
  of 
  night 
  monkeys 
  were 
  secured 
  in 
  northern 
  Colombia. 
  

   Five 
  are 
  from 
  Norosi, 
  department 
  of 
  Bolivar, 
  three 
  from 
  the 
  Sierra 
  

   Negra, 
  Sierra 
  de 
  Perijd, 
  the 
  remaining 
  two 
  from 
  El 
  Orinoco, 
  Rio 
  

   Cesar. 
  Each 
  series 
  differs 
  markedly 
  in 
  many 
  external 
  and 
  cranial 
  

   characters 
  from 
  the 
  other 
  two. 
  Abundant 
  comparable 
  material 
  

  

  » 
  Subspecies 
  of 
  fusca 
  include 
  beniensis 
  and 
  clamitans 
  (A. 
  fusca 
  guariha 
  Ihering, 
  preoccupied 
  by 
  guariba 
  

   Humboldt, 
  replaced 
  by 
  damitans 
  Cabrera, 
  1940 
  [antedates 
  iheringi 
  Lonnberg, 
  1941, 
  also 
  proposed 
  as 
  a 
  sub" 
  

   atitute]). 
  

  

  