﻿410 
  PROCEEDINGS 
  OF 
  THE 
  NATIONAL 
  MUSEUM 
  vol.98 
  

  

  bare-faced 
  Seniocebus 
  as 
  a 
  genus. 
  His 
  key 
  to 
  the 
  genera 
  Leontocebus, 
  

   Mystax, 
  Seniocebus, 
  and 
  Oedipomidas 
  was 
  based 
  on 
  length 
  of 
  fingers, 
  

   size 
  of 
  ears, 
  and 
  color 
  of 
  tail 
  and 
  limbs. 
  A 
  list 
  of 
  the 
  "species" 
  of 
  

   each 
  genus 
  was 
  given. 
  Tate 
  (1939, 
  pp. 
  207-209) 
  discussed 
  the 
  nomen- 
  

   clature 
  and 
  replaced 
  the 
  preoccupied 
  generic 
  name 
  Mystax 
  with 
  

   Tamarin. 
  He 
  combined 
  Seniocebus 
  with 
  Oedipomidas 
  as 
  a 
  subgenus 
  

   of 
  Tamarin. 
  Leontocebus 
  was 
  retained 
  as 
  a 
  full 
  genus. 
  Cruz 
  Lima 
  

   (1945, 
  pp. 
  203-253) 
  made 
  use 
  of 
  the 
  earlier 
  name 
  Marikina 
  Lesson 
  

   for 
  the 
  bare-faced 
  marmosets 
  heretofore 
  included 
  in 
  Oedipomidas 
  and 
  

   Seniocebus. 
  He 
  also 
  recognized 
  the 
  genera 
  Tamarin 
  and 
  Leontocebus. 
  

   No 
  species 
  were 
  listed 
  under 
  the 
  latter 
  genus, 
  but 
  all 
  Amazonian 
  

   marmosets 
  referable 
  to 
  Tamarin 
  and 
  Marikina 
  were 
  keyed 
  and 
  de- 
  

   scribed, 
  many 
  of 
  them 
  figured 
  in 
  color. 
  

  

  It 
  is 
  apparent 
  that 
  subdivisions 
  of 
  marmosets 
  with 
  normal 
  lower 
  

   canine-incisor 
  relationship 
  include 
  four 
  recognizable 
  species 
  groups. 
  

   At 
  times 
  these 
  groups 
  have 
  been 
  combined 
  into 
  one 
  genus; 
  at 
  others, 
  

   separated 
  into 
  genera. 
  Leontocebus 
  {s. 
  s.), 
  the 
  least 
  known 
  and 
  poorest 
  

   represented 
  in 
  collections, 
  has 
  been 
  most 
  generally 
  separated 
  from 
  

   the 
  others. 
  Its 
  larger 
  size 
  and 
  distinctive 
  external 
  and 
  cranial 
  char- 
  

   acters 
  justify 
  its 
  generic 
  distinction. 
  Seniocebus 
  (= 
  Marikina 
  s. 
  s.) 
  

   has 
  been 
  combined 
  at 
  times 
  with 
  Oedipomidas; 
  at 
  others, 
  with 
  Tamarin, 
  

   As 
  long 
  as 
  diagnostic 
  characters 
  of 
  each 
  of 
  these 
  three 
  categories 
  are 
  

   not 
  found 
  to 
  be 
  weightier, 
  it 
  is 
  best 
  to 
  treat 
  each 
  as 
  a 
  subgenus 
  of 
  

   Marikina, 
  the 
  oldest 
  available 
  name. 
  No 
  consistent 
  cranial 
  characters 
  

   distinguish 
  any 
  one 
  subgenus 
  of 
  Marikina 
  from 
  another. 
  Externally 
  

   the 
  bare-faced, 
  large-eared 
  M. 
  (Marikina) 
  is 
  annectant 
  between 
  the 
  

   equally 
  large 
  eared 
  M. 
  (Tamarin) 
  and 
  the 
  bare-faced 
  but 
  small-eared 
  

   M. 
  (Oedipomidas). 
  

  

  The 
  following 
  key 
  may 
  aid 
  in 
  distinguishing 
  Leontocebus 
  from 
  

   Marikina 
  and 
  the 
  subgenera 
  of 
  the 
  latter 
  from 
  one 
  another: 
  

  

  I. 
  Hand 
  elongated, 
  palm 
  narrow, 
  digits 
  long; 
  first 
  phalanges 
  of 
  second 
  and 
  

   third 
  fingers 
  and 
  third 
  and 
  fourth 
  fingers 
  closely 
  united 
  by 
  webbing; 
  

   length 
  of 
  longest 
  finger 
  (with 
  claw) 
  more 
  than 
  twice 
  width 
  of 
  palm; 
  head 
  

   and 
  sides 
  of 
  face 
  completely 
  covered, 
  the 
  long 
  hairs 
  forming 
  a 
  mane 
  con- 
  

   cealing 
  ears; 
  sphenoidal 
  pits 
  or 
  vacuities 
  large 
  Leontocebus 
  (p. 
  423) 
  

  

  II. 
  Hands 
  normal; 
  palm 
  broad, 
  digits 
  not 
  markedly 
  elongated; 
  first 
  phalanges 
  

   of 
  middle 
  digits 
  usually 
  free, 
  webbing, 
  if 
  present, 
  extremely 
  narrow; 
  

   length 
  of 
  longest 
  finger 
  (with 
  claw) 
  less 
  than 
  twice 
  width 
  of 
  palm; 
  sides 
  

   of 
  crown 
  and 
  sides 
  of 
  face 
  completely 
  covered 
  with 
  hair 
  or 
  nearly 
  bare; 
  

   ears 
  entirely 
  or 
  partially 
  exposed. 
  Sphenoidal 
  pits 
  or 
  vacuities 
  obsolete 
  or 
  

  

  absent 
  Marikina 
  (genus) 
  

  

  A. 
  Side 
  of 
  head 
  from 
  brow 
  to 
  ear, 
  cheeks, 
  and 
  chin 
  covered 
  with 
  black, 
  brown 
  

   or 
  reddish 
  hairs 
  "; 
  arms, 
  at 
  least 
  to 
  wrists, 
  black, 
  brown, 
  or 
  red; 
  tail, 
  at 
  

   least 
  for 
  terminal 
  three-fourths, 
  uniformly 
  black 
  or 
  dark 
  brown, 
  with 
  or 
  

   without 
  a 
  grayish 
  or 
  rufous 
  overlay; 
  ears 
  large. 
  

  

  Tamarin 
  (subgenus, 
  p. 
  411) 
  

  

  '• 
  For 
  the 
  white 
  tamarin, 
  see 
  arrangement 
  of 
  species 
  in 
  subgenus 
  Tamarin. 
  

  

  