﻿Mammals 
  from 
  British 
  East 
  Africa. 
  523 
  

  

  effect 
  produced 
  being 
  that 
  of 
  a 
  reddish-brown 
  tail, 
  and 
  not 
  of 
  

   a 
  black 
  one. 
  

  

  Skull 
  a 
  great 
  deal 
  smaller 
  than 
  that 
  of 
  nigricauda, 
  shorter 
  

   and 
  narrower 
  ; 
  markedly 
  shorter 
  nasals 
  and 
  narrower 
  brain- 
  

   case. 
  Auditory 
  bulla? 
  much 
  smaller 
  and 
  shorter. 
  

  

  Dimensions 
  of 
  the 
  type 
  (measured 
  in 
  the 
  flesh) 
  : 
  — 
  

  

  Head 
  and 
  body 
  164- 
  mm. 
  ; 
  tail 
  208 
  ; 
  hind 
  foot 
  40'5 
  ; 
  ear 
  22. 
  

  

  Skull: 
  greatest 
  length 
  48 
  ; 
  basilar 
  length 
  36*8 
  ; 
  condylo- 
  

   incisive 
  length 
  42; 
  zygomatic 
  breadth 
  24 
  - 
  7 
  ; 
  interorbital 
  

   breadth 
  86 
  ; 
  breadth 
  of 
  brain-case 
  (across 
  squamosal 
  

   region) 
  17'5; 
  length 
  of 
  nasals 
  20 
  - 
  5 
  ; 
  palatilar 
  length 
  21*5 
  ; 
  

   width 
  of 
  palate 
  (inside 
  m 
  1 
  ) 
  4*3 
  ; 
  length 
  of 
  palatal 
  foramina 
  9 
  ; 
  

   greatest 
  diameter 
  of 
  bullae 
  12*5 
  ; 
  alveolar 
  length 
  of 
  upper 
  

   cheek-teeth 
  7"2. 
  

  

  Hub. 
  Nyama 
  Nyango, 
  Eusso 
  Nyiro. 
  Altitude 
  3000 
  feet. 
  

  

  Type. 
  Old 
  male. 
  Original 
  number 
  1798. 
  Collected 
  on 
  

   January 
  27th, 
  1911. 
  

  

  The 
  much 
  smaller 
  size 
  of 
  the 
  skull 
  and 
  lighter-coloured 
  

   tail 
  are 
  the 
  chief 
  points 
  wherein 
  this 
  new 
  form 
  differs 
  from 
  

   the 
  Mombasa 
  species. 
  I 
  have 
  taken 
  as 
  representing 
  T. 
  nigri- 
  

   cauda 
  a 
  long 
  series 
  of 
  specimens 
  recently 
  obtained 
  by 
  

   Mr. 
  Kemp 
  at 
  Voi 
  and 
  Taveta. 
  The 
  following 
  are 
  the 
  cranial 
  

   dimensions 
  of 
  an 
  adult 
  male 
  : 
  — 
  

  

  Greatest 
  length 
  51 
  mm.; 
  basilar 
  length 
  40; 
  condylo- 
  

   incisive 
  length 
  45'3 
  ; 
  zygomatic 
  breadth 
  26*8 
  ; 
  interorbital 
  

   breadth 
  9; 
  breadth 
  of 
  brain-case 
  (across 
  squamosal 
  region) 
  20 
  ; 
  

   length 
  of 
  nasals 
  23 
  ; 
  palatilar 
  length 
  236; 
  length 
  of 
  palatal 
  

   foramina 
  10; 
  greatest 
  diameter 
  of 
  bullae 
  14; 
  alveolar 
  length 
  

   of 
  upper 
  cheek-teeth 
  75. 
  

  

  Tatera 
  varia, 
  described 
  by 
  Heller 
  from 
  the 
  Eusso 
  Nyiro 
  

   River, 
  Sotik 
  District, 
  would 
  appear 
  to 
  be 
  the 
  only 
  other 
  

   member 
  of 
  the 
  genus 
  described 
  from 
  this 
  district. 
  T. 
  varia 
  

   belongs 
  to 
  the 
  fallax 
  group 
  with 
  the 
  white-tipped 
  tails, 
  and 
  

   is 
  in 
  no 
  way 
  related 
  to 
  nigricauda 
  or 
  the 
  form 
  here 
  described. 
  

  

  Otomys 
  irroratus 
  elgonis, 
  Wrought. 
  

  

  $. 
  1523, 
  1526, 
  1527,1531,1567,1571,1582, 
  1583,1595, 
  

   1596, 
  1617, 
  1618, 
  1637, 
  1641, 
  1642,1655, 
  1663, 
  1668,1714, 
  

   1715 
  ; 
  ? 
  . 
  1522, 
  1572, 
  1597, 
  1658, 
  1710. 
  Solai, 
  Mt. 
  Kenya. 
  

  

  Otomys 
  angoniensis 
  elassodon, 
  Osg. 
  

  

  (J. 
  1312, 
  1315, 
  1316 
  ; 
  ? 
  . 
  1307, 
  1314. 
  Nakuru. 
  

  

  c? 
  . 
  1421, 
  1423, 
  1438, 
  1448, 
  1450, 
  1457, 
  1478, 
  1481, 
  1502, 
  

   1514, 
  1506; 
  ? 
  . 
  1422, 
  1458, 
  1459, 
  1475, 
  1485, 
  1497, 
  1498, 
  

   1499, 
  1515, 
  1516. 
  Rumruti, 
  Laikipia 
  Plateau. 
  

  

  