﻿114 
  On 
  new 
  South- 
  American 
  Mammals. 
  

  

  Teeth 
  about 
  as 
  in 
  M. 
  cerastes, 
  the 
  canines 
  longer 
  and 
  

   heavier. 
  

  

  Dimensions 
  of 
  the 
  type 
  (measured 
  in 
  skin) 
  : 
  — 
  

  

  Forearm 
  49 
  mm.; 
  third 
  finger, 
  metacarpus 
  49, 
  first 
  

   phalanx 
  20; 
  fifth 
  finger, 
  metacarpus 
  26, 
  first 
  phalanx 
  11*5. 
  

  

  Skull: 
  greatest 
  length, 
  gnathion 
  to 
  tip 
  of 
  occipital 
  crest 
  

   23'8 
  ; 
  condylo-basal 
  length 
  22'3 
  ; 
  zygomatic 
  breadth 
  16'5 
  ; 
  

   breadth 
  of 
  muzzle 
  11 
  ; 
  interorbital 
  breadth 
  5*5 
  ; 
  mastoid 
  

   breadth 
  15*5 
  ; 
  height 
  of 
  canine 
  4*8 
  ; 
  front 
  of 
  canine 
  to 
  back 
  

   of 
  m 
  9 
  8'8. 
  Height 
  of 
  lower 
  jaw 
  beltfw 
  m 
  x 
  3'5. 
  

  

  Hob. 
  Demerara. 
  Type 
  from 
  Bartica 
  Grove, 
  Lower 
  

   Essequibo. 
  

  

  Type. 
  Old 
  male. 
  B.M. 
  no. 
  10. 
  11. 
  10. 
  3. 
  Collected 
  by 
  

   Cozier 
  and 
  presented 
  by 
  F. 
  V. 
  McConnell, 
  Esq. 
  

  

  Related 
  to 
  M. 
  brachymeles 
  of 
  Peru 
  an 
  1 
  M. 
  cerastes 
  of 
  

   Paraguay 
  and 
  S. 
  Brazil, 
  but 
  markedly 
  larger 
  than 
  either. 
  

  

  Rhipidomys 
  bovallii, 
  sp. 
  n. 
  

  

  A 
  very 
  large 
  species, 
  with 
  grey-based 
  belly-hairs. 
  

   Size, 
  as 
  judged 
  by 
  the 
  length 
  of 
  the 
  tooth-row, 
  larger 
  than 
  

   in 
  any 
  other 
  species. 
  Fur 
  long 
  and 
  thick, 
  hairs 
  of 
  back 
  

   about 
  11 
  mm. 
  in 
  length, 
  the 
  long 
  bristle-hairs 
  surpassing 
  

   them 
  by 
  4-5 
  mm. 
  General 
  colour 
  above 
  the 
  usual 
  dull 
  

   fulvous 
  grey, 
  darker 
  along 
  the 
  median 
  dorsal 
  area, 
  clearer 
  on 
  

   sides. 
  Under 
  surface 
  dull 
  creamy, 
  the 
  hairs 
  slaty 
  for 
  rather 
  

   more 
  than 
  half 
  their 
  length; 
  lateral 
  line 
  of 
  demarcation 
  little 
  

   marked. 
  Hands 
  and 
  feet 
  dark, 
  the 
  hallucal 
  edges 
  whitish. 
  

   Tail 
  dark 
  brown 
  as 
  usual, 
  very 
  heavily 
  haired, 
  especially 
  at 
  

   ihe 
  tip, 
  where 
  the 
  hairs 
  attain 
  a 
  length 
  of 
  25 
  mm. 
  

  

  Skull 
  with 
  rather 
  narrow 
  nasals 
  and 
  narrow 
  interorbital 
  

   space. 
  Palate 
  much 
  less 
  broad 
  than 
  in 
  lih. 
  lucullus. 
  

   Dimensions 
  of 
  the 
  type 
  (measured 
  on 
  the 
  skin) 
  : 
  — 
  

   Head 
  and 
  body 
  180 
  mm.; 
  tail 
  198 
  ; 
  hind 
  foot 
  33. 
  

   JSkull 
  : 
  nasals 
  15; 
  interorbital 
  breadth 
  5*6 
  ; 
  diastema 
  1T2 
  ; 
  

   palatal 
  foramina 
  8'6 
  ; 
  breadth 
  across 
  outside 
  m 
  2 
  8'2 
  ; 
  length 
  

   of 
  upper 
  molar 
  series 
  6'8. 
  

  

  Bab. 
  Potaro 
  Highlands, 
  towards 
  Mt. 
  Roraima, 
  British 
  

   Guiana. 
  Alt. 
  2000'. 
  

  

  Type. 
  Adult. 
  B.M. 
  no. 
  7. 
  6. 
  10. 
  3. 
  Collected 
  10th 
  

   November, 
  1905, 
  and 
  presented 
  by 
  Dr. 
  Carl 
  Bovallius. 
  

  

  This 
  fine 
  species 
  appears 
  to 
  be 
  a 
  Guianan 
  representative 
  of 
  

   the 
  Rh. 
  leucodactylus 
  group 
  of 
  Peru. 
  From 
  lih. 
  sc/ateri, 
  the 
  

   only 
  other 
  Guianan 
  species 
  at 
  all 
  allied 
  to 
  it, 
  it 
  differs 
  by 
  its 
  

   larger 
  size, 
  longer 
  coarser 
  fur, 
  and 
  more 
  fulvous 
  colour. 
  

  

  