﻿PROCEEDINGS 
  OF 
  THE 
  UNITED 
  STATES 
  NATIONAL 
  MUSEUM 
  

  

  issued 
  

  

  SMITHSONIAN 
  INSTITUTION 
  

  

  U. 
  S. 
  NATIONAL 
  MUSEUM 
  

   Vol. 
  98 
  Washington: 
  1948 
  No. 
  3221 
  

  

  MAMMALS 
  OF 
  NORTHERN 
  COLOMBIA 
  

  

  PRELIMINARY 
  REPORT 
  NO. 
  3: 
  WATER 
  RATS 
  (GENUS 
  NECTOMYS), 
  

   WITH 
  SUPPLEMENTAL 
  NOTES 
  ON 
  RELATED 
  FORMS 
  

  

  By 
  Philip 
  Hershkovitz 
  

  

  Water 
  rats 
  obtained 
  in 
  northern 
  Colombia 
  by 
  the 
  author 
  during 
  his 
  

   1941-1943 
  tenure 
  of 
  the 
  Walter 
  Rathbone 
  Bacon 
  Traveling 
  Scholar- 
  

   ship 
  number 
  12 
  specimens 
  of 
  an 
  undescribed 
  race 
  of 
  Nectomys 
  

   squavilpeH 
  and 
  4 
  specimens 
  of 
  Nectomys 
  alfari 
  russulus. 
  Both 
  series 
  

   were 
  taken 
  in 
  the 
  same 
  trap 
  line 
  in 
  the 
  Rio 
  Tarra 
  region, 
  upper 
  Rio 
  

   Catatumbo, 
  department 
  of 
  Norte 
  de 
  Santander. 
  This 
  is 
  the 
  first 
  

   recorded 
  occurrence 
  of 
  two 
  species 
  of 
  Nectomys 
  in 
  the 
  same 
  locality 
  

   and 
  supplies 
  further 
  evidence 
  that 
  the 
  Lake 
  Maracaibo 
  drainage 
  

   basin 
  is 
  an 
  area 
  where 
  interchange 
  between 
  trans- 
  and 
  cis-Andean 
  

   mammalian 
  faunas 
  takes 
  place. 
  Extensive 
  trapping 
  for 
  small 
  rodents 
  

   failed 
  to 
  yield 
  water 
  rats 
  in 
  other 
  Colombian 
  localities 
  where 
  collect- 
  

   ing 
  was 
  done. 
  However, 
  several 
  specimens 
  of 
  Nectomys 
  squamipes 
  

   from 
  the 
  Cauca 
  and 
  upper 
  Meta 
  regions, 
  generously 
  donated 
  by 
  

   Hermano 
  Niceforo 
  Maria, 
  of 
  the 
  Instituto 
  de 
  La 
  Salle, 
  Bogota, 
  furnisli 
  

   important 
  additions. 
  

  

  Present 
  material 
  serves 
  to 
  dispose 
  of 
  some 
  taxonomic 
  problems 
  

   left 
  unclarified 
  in 
  the 
  writer's 
  review 
  (1944) 
  of 
  the 
  genus 
  Nectomys. 
  

   In 
  addition, 
  the 
  types 
  of 
  the 
  species 
  described 
  by 
  Thomas 
  as 
  Nectomys 
  

   dimidiatus, 
  Nectomys 
  hammondi,, 
  and 
  Nectomys 
  saturatus^ 
  which 
  were 
  

   referred 
  to 
  the 
  '"''incertae 
  sedis 
  group" 
  (1944, 
  p. 
  80), 
  have 
  been 
  exam- 
  

   ined 
  recently 
  in 
  the 
  British 
  Museum. 
  The 
  first 
  two 
  prove 
  to 
  be 
  unique 
  

   members 
  of 
  the 
  genus 
  Oryzom^ys. 
  The 
  last 
  is 
  a 
  subspecies 
  of 
  N. 
  

  

  778064—48 
  49 
  

  

  