﻿Mr. 
  O. 
  Thomas 
  on 
  a 
  new 
  Species 
  of 
  Mus. 
  433 
  

  

  Dr. 
  Jullien's 
  critical 
  remarks 
  on 
  the 
  classification 
  of 
  the 
  

   Pedicellinidse 
  I 
  hope 
  to 
  notice 
  on 
  some 
  future 
  occasion. 
  

  

  EXPLANATION 
  OF 
  PLATE 
  XXI. 
  

  

  Fig. 
  1. 
  Scrwpocellaria 
  scabra, 
  Van 
  Beneden. 
  Form 
  destitute 
  of 
  vibracul 
  a. 
  

  

  Fig. 
  2. 
  Smittia 
  producta, 
  Packard. 
  

  

  Fig. 
  3. 
  Mucronella 
  spimdifera, 
  n. 
  sp. 
  

  

  Fig. 
  4. 
  Poretta 
  concinna, 
  Busk, 
  var. 
  

  

  Fig. 
  5. 
  Porella 
  acutirostris, 
  Smitt. 
  a. 
  Orifice 
  of 
  zooecium. 
  b. 
  That 
  of 
  P. 
  

  

  concinna. 
  

   Fig. 
  6. 
  lihainphosfomclla 
  costata, 
  Lorenz, 
  var. 
  cristata. 
  

   Fig. 
  7. 
  The 
  same. 
  Group 
  of 
  marginal 
  cells. 
  

   Fig. 
  8. 
  The 
  same. 
  Young 
  cells, 
  showing 
  the 
  superficial 
  costre. 
  

   Fig. 
  9. 
  Pedicellina 
  nutans, 
  Dalyell. 
  

   Fig. 
  10. 
  Barentsia 
  gracilis, 
  Sara. 
  (For 
  comparison 
  with 
  B. 
  my'or, 
  Hincks, 
  

  

  'Annals' 
  for 
  March 
  1838, 
  pi. 
  xv. 
  fig. 
  2.) 
  

  

  LIII. 
  — 
  Description 
  of 
  a 
  new 
  Species 
  of 
  Mus 
  from 
  South 
  

   Australia. 
  By 
  Oldfield 
  Thomas. 
  

  

  Mus 
  arguruSj 
  sp. 
  n. 
  

  

  Size 
  about 
  equal 
  to 
  that 
  of 
  a 
  small 
  Mus 
  nanus 
  or 
  large 
  M. 
  

   albo-cinereus. 
  Fur 
  crisp 
  or 
  even 
  slightly 
  spinous. 
  General 
  

   colour 
  above 
  pale 
  sandy 
  rufous, 
  the 
  hairs 
  slate-coloured 
  at 
  

   their 
  bases. 
  Ears 
  very 
  thinly 
  covered 
  with 
  tine 
  white 
  hairs, 
  

   rounded, 
  laid 
  forward 
  they 
  reach 
  just 
  beyond 
  the 
  middle 
  of 
  

   the 
  eye. 
  Muzzle 
  and 
  underside 
  of 
  body 
  white, 
  the 
  line 
  of 
  

   demarcation 
  on 
  sides 
  not 
  sharply 
  marked 
  ; 
  hairs 
  of 
  chest 
  and 
  

   belly 
  pale 
  rufous 
  basally. 
  Hands 
  and 
  feet 
  pure 
  white. 
  Soles 
  

   smooth, 
  naked, 
  with 
  six 
  well-developed 
  rounded 
  pads, 
  the 
  

   posterior 
  one 
  elongated. 
  Tail 
  rather 
  longer 
  than 
  the 
  head 
  

   and 
  body, 
  quite 
  uniform 
  in 
  colour 
  above 
  and 
  below, 
  more 
  

   thickly 
  covered 
  with 
  hairs 
  than 
  usual, 
  the 
  hairs 
  pure 
  white 
  

   the 
  scales 
  (which 
  average 
  about 
  thirteen 
  or 
  fourteen 
  to 
  the 
  

   centimetre) 
  pale 
  flesh-coloured 
  ; 
  tip 
  of 
  tail 
  slightly 
  pen- 
  

   cilled. 
  Palate-ridges 
  nine, 
  three 
  anterior 
  undivided 
  and 
  six 
  

   divided, 
  interdental, 
  of 
  which 
  the 
  anterior 
  is 
  directly 
  trans- 
  

   verse, 
  while 
  the 
  others 
  are 
  slanted 
  backwards 
  mesially. 
  

  

  Skull 
  smooth 
  and 
  unridged. 
  Nasal 
  and 
  interorbital 
  regions 
  

   flat, 
  evenly 
  convex 
  when 
  viewed 
  in 
  profile 
  ; 
  supraorbital 
  

   edges 
  sharply 
  square, 
  but 
  not 
  beaded 
  or 
  ridged. 
  Inter- 
  

   parietal 
  broad 
  antero- 
  posteriorly, 
  its 
  diameter 
  in 
  this 
  direction 
  

   more 
  than 
  half 
  its 
  transverse 
  breadth. 
  Anterior 
  ed^-e 
  of 
  

  

  