﻿.Nc..ii:r2. 
  XEJV 
  MAMMALS 
  FROM 
  THE 
  MEXICAN 
  BORDEE— 
  ME 
  ARSS. 
  503 
  

  

  tioii 
  of 
  the 
  tail 
  measures 
  285 
  by 
  155. 
  Adult 
  males 
  weigh 
  GO 
  pounds 
  and 
  

   upward; 
  females 
  40 
  to 
  50 
  pounds. 
  

  

  Cranial 
  characters. 
  — 
  The 
  skull 
  of 
  the 
  European 
  beaver 
  {Castor 
  fiber), 
  

   which 
  is 
  readily 
  distinguishable 
  from 
  tliat 
  of 
  the 
  Canadian 
  beaver 
  

   {C. 
  canadensis) 
  by 
  its 
  slender 
  build, 
  lengthened 
  nasal 
  bones, 
  and 
  elon- 
  

   gated 
  rostral 
  ijortion, 
  presents 
  still 
  greater 
  differences 
  when 
  compared 
  

   witli 
  the 
  beaver 
  of 
  Arizona 
  and 
  Sonera. 
  There 
  being 
  at 
  present 
  no 
  

   forest 
  connection 
  between 
  the 
  habitats 
  of 
  Castor 
  Jihcr 
  and 
  G. 
  canadensis 
  

   in 
  tlieir 
  respective 
  geographic 
  ranges, 
  and 
  consecpiently 
  no 
  continuity 
  

   of 
  habitat, 
  there 
  can 
  be 
  no 
  question 
  as 
  to 
  their 
  specific 
  distinctness. 
  

   The 
  skull 
  of 
  G. 
  canadensis 
  frondator 
  differs 
  from 
  that 
  of 
  G. 
  canadensis 
  

   (ty[>ical) 
  in 
  being 
  much 
  larger, 
  with 
  more 
  spreading 
  zygomata. 
  

  

  (ieofiraphical 
  range. 
  — 
  This 
  form 
  occupies 
  the 
  southern 
  interior 
  area 
  of 
  

   ]^orth 
  America, 
  ranging 
  north 
  from 
  Mexico 
  to 
  Wyoming 
  and 
  Montana. 
  

  

  NEOTOMA 
  CUMULATOR, 
  new 
  species. 
  

   COLORADO 
  KIVER 
  WOOD 
  RAT. 
  

  

  Tiipe. 
  — 
  Xo. 
  00348, 
  U.S.iS'.M. 
  (Collection 
  International 
  Boundary 
  Com- 
  

   mission.) 
  Skin 
  and 
  skull. 
  Adult 
  male 
  from 
  old 
  Fort 
  Yuma, 
  San 
  Diego 
  

   County, 
  California. 
  Collected 
  by 
  Doctor 
  Edgar 
  A. 
  Mearns, 
  A^jril 
  2, 
  

   1894. 
  Original 
  number, 
  3473. 
  

  

  Description 
  of 
  type. 
  — 
  Upper 
  parts 
  grayish 
  fulvous, 
  thickly 
  lined 
  with 
  

   black-tipped 
  hairs, 
  changing 
  to 
  gray 
  on 
  the 
  limbs, 
  and 
  ochraceous-buff 
  

   on 
  the 
  sides. 
  Tail 
  rather 
  long-haired, 
  almost 
  black 
  above, 
  and 
  white 
  

   below. 
  Feet, 
  a 
  small 
  patch 
  at 
  base 
  of 
  ear, 
  and 
  whole 
  under 
  surface 
  of 
  

   body 
  white. 
  Bars 
  scantily 
  clothed 
  with 
  gray 
  and 
  black 
  downy 
  hairs 
  

   on 
  concave 
  surface, 
  and 
  on 
  posterior 
  two 
  thirds 
  of 
  convex 
  surface; 
  

   anterior 
  third 
  of 
  convex 
  surface 
  coated 
  with 
  longer 
  black 
  hairs. 
  Whisk- 
  

   ers 
  long, 
  reaching 
  to 
  shoulder; 
  their 
  color, 
  mixed 
  black 
  and 
  white. 
  

   Orbital 
  area 
  dusky. 
  Length, 
  40 
  3 
  mm.; 
  tail 
  vertebne, 
  188 
  (to 
  end 
  of 
  

   hairs, 
  197); 
  ear 
  above 
  crown, 
  24.5; 
  ear 
  above 
  notch, 
  30.5; 
  distance 
  

   between 
  eyes, 
  18; 
  diameter 
  of 
  eye, 
  8; 
  length 
  of 
  longest 
  whisker, 
  75; 
  

   distance 
  from 
  tip 
  of 
  nose 
  to 
  eye, 
  25; 
  to 
  center 
  of 
  pupil, 
  31; 
  to 
  ear, 
  4G; 
  

   to 
  tip 
  of 
  ear, 
  81; 
  to 
  occiput, 
  5(); 
  to 
  end 
  of 
  outstretched 
  hinder 
  extrem- 
  

   ity, 
  292; 
  fore 
  limb, 
  from 
  olecranon 
  x>rocess 
  to 
  end 
  of 
  claws, 
  54; 
  length 
  

   of 
  fore 
  foot, 
  22; 
  longest 
  claw 
  of 
  fore 
  foot, 
  3.1; 
  hind 
  limb, 
  from 
  knee- 
  

   joint 
  to 
  end 
  of 
  claws, 
  76; 
  length 
  of 
  hind 
  foot, 
  37; 
  longest 
  claw 
  of 
  hind 
  

   foot, 
  4.7. 
  

  

  Bemarks. 
  — 
  This 
  is 
  one 
  of 
  the 
  largest 
  of 
  the 
  round-tailed 
  wood 
  rats. 
  

   The 
  coloration 
  is 
  similar 
  to 
  that 
  of 
  y. 
  intermedia 
  Ehoads, 
  but 
  is 
  paler 
  

   than 
  the 
  typical 
  form, 
  and 
  darker 
  than 
  the 
  desert 
  phase 
  {X. 
  intermedia 
  

   renusfa). 
  The 
  tail 
  is 
  more 
  sharply 
  bicolored, 
  nearly 
  black 
  above, 
  and 
  

   quite 
  heavily 
  coated 
  with 
  rather 
  long 
  hair. 
  It 
  requires 
  no 
  comparison 
  

   with 
  any 
  of 
  the 
  neighboring 
  forms, 
  but 
  is 
  closely 
  related 
  to 
  y. 
  leucodon, 
  

   recently 
  described 
  by 
  Doctor 
  Merriam, 
  from 
  San 
  Luis 
  Potosi, 
  Mexico, 
  

   and 
  extends 
  the 
  range 
  of 
  the 
  leucodon 
  group 
  to 
  within 
  the 
  United 
  

  

  