﻿22 
  ATELEUS 
  

  

  with 
  an 
  unshakable 
  firmness 
  anything 
  and 
  everything 
  it 
  may 
  touch, 
  and 
  

   fulfilling 
  in 
  the 
  highest 
  degree 
  and 
  with 
  an 
  admirable 
  service, 
  the 
  

   purposes 
  of 
  a 
  fifth 
  hand. 
  By 
  it, 
  fruits 
  or 
  other 
  desirable 
  objects 
  other- 
  

   wise 
  unattainable 
  are 
  seized 
  and 
  brought 
  within 
  reach 
  of 
  the 
  mouth 
  

   or 
  hands, 
  and 
  it 
  also 
  can 
  hold 
  its 
  possessor 
  suspended 
  in 
  the 
  air, 
  and 
  

   allow 
  the 
  hands 
  and 
  feet 
  to 
  act 
  with 
  complete 
  freedom. 
  While 
  mem- 
  

   bers 
  of 
  other 
  genera 
  of 
  the 
  Order 
  possess 
  prehensile 
  tails, 
  in 
  com- 
  

   parison 
  with 
  that 
  of 
  Ateleus 
  they 
  perform 
  but 
  a 
  restricted 
  service. 
  

   Another 
  feature 
  of 
  this 
  group 
  is 
  the 
  absence 
  of 
  the 
  thumb, 
  existing 
  in 
  

   a 
  rudimentary 
  condition 
  in 
  one 
  or 
  two 
  forms, 
  and 
  this 
  probably 
  is 
  an 
  

   advantage 
  to 
  the 
  animal 
  as 
  it 
  travels 
  through 
  the 
  forest, 
  permitting 
  

   without 
  hindrance 
  the 
  long 
  hand 
  to 
  slide 
  over 
  and 
  grasp 
  the 
  branches 
  

   in 
  its 
  swift 
  progress, 
  which 
  the 
  opposing 
  thumb, 
  might 
  at 
  times 
  prevent. 
  

   Against 
  this 
  theory, 
  however, 
  is 
  the 
  fact 
  that 
  the 
  members 
  of 
  Hylo- 
  

   bates, 
  of 
  the 
  Old 
  World 
  Apes, 
  which 
  are 
  strictly 
  arboreal 
  animals, 
  

   and 
  whose 
  flight 
  through 
  the 
  forest 
  can 
  only 
  be 
  compared 
  in 
  ease 
  and 
  

   swiftness 
  to 
  the 
  passage 
  of 
  a 
  bird, 
  possess 
  very 
  long 
  thumbs. 
  The 
  

   limbs 
  of 
  Ateleus 
  are 
  long, 
  the 
  arms 
  exceeding 
  the 
  legs 
  in 
  length 
  ; 
  the 
  

   body 
  is 
  comparatively 
  small, 
  with 
  the 
  stomach 
  protruding, 
  and 
  

   covered 
  with 
  rather 
  coarse 
  long 
  hair, 
  but 
  without 
  any 
  woolly 
  under 
  

   fur. 
  The 
  lumbar 
  region 
  of 
  the 
  skeleton 
  is 
  short, 
  but 
  the 
  dorsal 
  segment 
  

   attains 
  a 
  greater 
  relative 
  length 
  than 
  in 
  any 
  other 
  Monkey. 
  

  

  The 
  tail 
  has 
  twenty-three 
  vertebrae, 
  flattened 
  beneath, 
  and 
  with 
  

   processes 
  present 
  for 
  the 
  attachment 
  of 
  muscles 
  for 
  increasing 
  its 
  

   efficiency 
  as 
  a 
  prehensile 
  organ. 
  A 
  median 
  air 
  sac 
  is 
  situated 
  in 
  the 
  

   back 
  of 
  the 
  larynx, 
  but 
  there 
  is 
  no 
  such 
  provision 
  for 
  increasing 
  the 
  

   power 
  of 
  the 
  voice 
  as 
  witnessed 
  in 
  the 
  vocal 
  apparatus 
  of 
  the 
  Howling 
  

   Monkeys. 
  

  

  LITERATURE 
  OF 
  THE 
  SPECIES 
  AND 
  SUBSPECIES. 
  

  

  1758. 
  Linnceus, 
  Sy 
  sterna 
  Natures. 
  

  

  Ateleus 
  paniscus 
  described 
  as 
  Simla 
  paniscus. 
  

   1777. 
  Erxleben, 
  Sy 
  sterna 
  Regni 
  Animalis. 
  

  

  In 
  the 
  list 
  here 
  given 
  one 
  species, 
  Ateleus 
  paniscus, 
  is 
  included 
  

  

  in 
  the 
  genus 
  Cebus. 
  

   1806. 
  E. 
  Geoffroy 
  St. 
  Hilaire, 
  in 
  Annates 
  du 
  Museum 
  d'Histoire 
  

  

  Naturelle, 
  Paris. 
  

  

  In 
  this 
  Memoir 
  five 
  species 
  are 
  included 
  in 
  the 
  genus 
  Ateleus, 
  

  

  viz.: 
  Le 
  Chamek, 
  A. 
  pentadactylus 
  = 
  A. 
  paniscus; 
  La 
  Coaita, 
  

  

  A. 
  paniscus 
  ; 
  L'arachnoide, 
  A. 
  arachnoides 
  = 
  Brachyteleus 
  

  

  