﻿368 
  PROCEEDINGS 
  OF 
  THE 
  NATIONAL 
  MUSEUM 
  vol. 
  sa 
  

  

  25.8; 
  length, 
  upper 
  canine 
  to 
  M^, 
  26.1, 
  25.1; 
  length, 
  lower 
  canine 
  to 
  

   Ma, 
  23.7, 
  24.4; 
  mandibular 
  depth 
  at 
  condyle, 
  27.1, 
  25.8 
  mm. 
  

  

  Remarks. 
  — 
  Distinction 
  of 
  leucocephalus 
  from 
  versicolor 
  was 
  originally- 
  

   premised 
  on 
  the 
  presence 
  of 
  a 
  midfrontal 
  line 
  in 
  the 
  former 
  and 
  its 
  

   absence 
  in 
  the 
  latter. 
  The 
  nature 
  of 
  this 
  character, 
  shown 
  repeatedly 
  

   to 
  be 
  individually 
  variable, 
  together 
  with 
  the 
  Colombian 
  habitat 
  of 
  

   both 
  leucocephalus 
  and 
  versicolor, 
  induced 
  most 
  authors 
  to 
  regard 
  the 
  

   two 
  as 
  identical. 
  Each 
  form, 
  however, 
  occupies 
  a 
  distinct 
  geographi- 
  

   cal 
  area, 
  and 
  leucocephalus 
  is 
  much 
  the 
  darker 
  monkey. 
  

  

  The 
  detailed 
  description 
  of 
  the 
  "Bogotd" 
  monkey 
  recorded 
  as 
  

   hypoleucus 
  by 
  Martinez 
  (op. 
  cit.) 
  agrees 
  with 
  leucocephalus. 
  The 
  

   true 
  habitat 
  of 
  this 
  individual 
  was 
  probably 
  somewhere 
  in 
  the 
  Andean 
  

   forests 
  north 
  of 
  Bogotd 
  and 
  is, 
  no 
  doubt, 
  the 
  same 
  specimen 
  assigned 
  

   to 
  leucocephalus 
  by 
  Cabrera 
  (op. 
  cit.). 
  The 
  Orope, 
  Venezuela, 
  series 
  

   includes 
  specimen 
  No. 
  16567 
  (C.N.H.M.) 
  that 
  Osgood 
  (1910, 
  p. 
  32) 
  

   compared 
  with 
  the 
  type 
  of 
  leucocephalus. 
  The 
  nearly 
  complete 
  agree- 
  

   ment 
  noted 
  by 
  Osgood 
  between 
  his 
  specimen 
  and 
  the 
  type, 
  applies 
  

   equally 
  well 
  to 
  the 
  individual 
  described 
  above 
  from 
  El 
  Tambor, 
  

   Colombia. 
  Hence, 
  restriction 
  of 
  type 
  locality 
  to 
  this 
  last 
  place 
  con- 
  

   forms 
  both 
  to 
  the 
  country 
  originally 
  stated 
  to 
  be 
  the 
  habitat 
  as 
  well 
  

   as 
  to 
  that 
  part 
  of 
  Osgood's 
  suggestion 
  that 
  the 
  " 
  exact 
  locality 
  was 
  at 
  

   least 
  in 
  northeastern 
  Colombia." 
  

  

  Fischer 
  (1829, 
  pp. 
  57, 
  545) 
  listed 
  Pithecia 
  leucocephala 
  Geoffroy 
  as 
  

   Cebus 
  leucocephalus. 
  The 
  result 
  of 
  this 
  action 
  may 
  be 
  regarded 
  by 
  

   some 
  as 
  a 
  "preoccupation" 
  of 
  Cebus 
  leucocephalus 
  Gray. 
  Article 
  35 
  

   of 
  the 
  International 
  Code, 
  as 
  here 
  interpreted, 
  relates 
  primarily 
  to 
  

   names 
  given 
  to 
  species 
  and 
  subspecies 
  described 
  as 
  new 
  and 
  not 
  to 
  

   secondary 
  combinations 
  resulting 
  from 
  transfer 
  of 
  species 
  and 
  sub- 
  

   species 
  to 
  genera 
  other 
  than 
  those 
  under 
  which 
  they 
  were 
  originally 
  

   described. 
  However, 
  in 
  the 
  event 
  that 
  two 
  identical 
  specific 
  names 
  

   each 
  originally 
  assigned 
  to 
  a 
  different 
  genus 
  are 
  subsequently 
  included 
  

   in 
  the 
  same 
  genus, 
  the 
  more 
  recent 
  specific 
  name 
  is 
  rejected 
  but 
  not 
  

   suppressed. 
  Such 
  "secondary 
  homonyms" 
  revert 
  to 
  their 
  original 
  

   status 
  when 
  generically 
  removed 
  from 
  preoccupying 
  specific 
  names. 
  

   Names 
  substituted 
  for 
  such 
  "secondary 
  homonyms" 
  then 
  become 
  

   absolute 
  synonyms 
  of 
  them. 
  The 
  status 
  of 
  Cebus 
  nigrivittatus 
  Wagner 
  

   (=Cebus 
  leporinus 
  Pusch, 
  cf. 
  supra 
  p. 
  345) 
  is 
  a 
  case 
  in 
  point. 
  The 
  

   name 
  Cebus 
  leucocephalus 
  Gray 
  cannot 
  be 
  construed 
  as 
  either 
  a 
  pri- 
  

   mary 
  or 
  a 
  secondary 
  homonym 
  under 
  any 
  circumstance. 
  

  

  Specimens 
  examined. 
  — 
  Eleven. 
  Type 
  of 
  leucocephalus 
  Gray 
  (B.M.) 
  ; 
  

   El 
  Tambor, 
  Santander, 
  Colombia, 
  2 
  (CM.) 
  ; 
  Bella 
  Vista, 
  Rio 
  Tarra, 
  

   Norte 
  de 
  Santander, 
  Colombia, 
  1 
  (U.S.N.M.) 
  ; 
  Orope, 
  Zulia, 
  Venezuela, 
  

   7 
  (C.N.H.M.). 
  

  

  