﻿194 
  Mr. 
  M. 
  A. 
  C. 
  HJnton 
  on 
  

  

  " 
  Monkey 
  Gravel 
  " 
  * 
  — 
  the 
  uppermost 
  part 
  of 
  the 
  Upper 
  

   Freshwater-Bed 
  at 
  West 
  Ruuton, 
  Norfolk,— 
  Mr. 
  G. 
  White 
  

   was 
  fortunate 
  enough 
  to 
  find 
  a 
  minute 
  tooth 
  ; 
  its 
  small 
  size, 
  

   yellowish 
  colour, 
  and 
  form, 
  resembling 
  as 
  it 
  does 
  a 
  few 
  

   agglutinated 
  particles 
  of 
  the 
  sand 
  in 
  which 
  it 
  was 
  embedded, 
  

   says 
  much 
  for 
  the 
  sharp 
  sight 
  of 
  my 
  friend. 
  Mr. 
  White 
  

   very 
  generously 
  presented 
  the 
  specimen 
  to 
  me. 
  It 
  turns 
  out 
  

   to 
  be 
  the 
  right 
  Pii 
  of 
  a 
  squirrel. 
  It 
  differs 
  importantly 
  from 
  

   the 
  Pi* 
  of 
  S. 
  vulgaris, 
  and 
  indicates 
  a 
  species 
  which, 
  when 
  

   more 
  fully 
  known, 
  will 
  probably 
  not 
  be 
  able 
  to 
  find 
  a 
  place 
  

   within 
  the 
  genus 
  Sciurus 
  as 
  restricted 
  by 
  modern 
  mammalo- 
  

   gists. 
  For 
  this 
  Forest-Bed 
  species 
  I 
  have 
  pleasure 
  in 
  pro- 
  

   posing 
  the 
  name 
  of 
  S. 
  ivhitei. 
  

  

  In 
  S. 
  vulgaris 
  (PI. 
  VIIE. 
  lig. 
  9) 
  the 
  outer 
  border 
  of 
  Eii 
  is 
  

   formed 
  by 
  the 
  four 
  cusps 
  called 
  by 
  Winge 
  1, 
  4, 
  2, 
  and 
  5 
  ; 
  of 
  

   these 
  4 
  and 
  5 
  are 
  the 
  largest 
  and 
  most 
  lofty, 
  1 
  is 
  nearly 
  as 
  stout 
  

   tliough 
  lower 
  than 
  either, 
  while 
  2 
  is 
  minute 
  and 
  on 
  its 
  way 
  

   to 
  disappear. 
  The 
  inner 
  side 
  of 
  Eii 
  is 
  formed 
  by 
  a 
  single 
  

   very 
  large 
  and 
  lofty 
  cusp 
  (Wingers 
  6), 
  which 
  Forsyth 
  Majorf 
  

   has 
  shown 
  to 
  be 
  a 
  compound 
  of 
  at 
  least 
  three 
  inner 
  tubercles 
  

   which 
  have 
  fused 
  together. 
  Between 
  the 
  outer 
  cusps 
  and 
  the 
  

   inner 
  cone 
  is 
  a 
  series 
  of 
  transverse 
  ridges 
  (formed 
  out 
  of 
  a 
  

   modified 
  median 
  series 
  of 
  tubercles, 
  and 
  comprising, 
  inter 
  

   aUa, 
  the 
  " 
  proto-" 
  and 
  '' 
  meta-conules 
  "), 
  viz., 
  a 
  low 
  one 
  

   forming 
  the 
  anterior 
  border 
  of 
  the 
  tooth 
  from 
  cusp 
  1, 
  two 
  

   higher 
  ones 
  from 
  cusp 
  4, 
  and 
  the 
  anterior 
  edge 
  of 
  cusp 
  5 
  

   respectively, 
  and 
  a 
  low 
  one 
  forming 
  the 
  posterior 
  border 
  from 
  

   the 
  hinder 
  edge 
  of 
  5 
  ; 
  between 
  these 
  ridges 
  are 
  three 
  trans- 
  

   verse 
  valleys, 
  of 
  which 
  the 
  central 
  one, 
  for 
  the 
  reception 
  of 
  

   the 
  chief 
  cusp 
  of 
  the 
  opposed 
  tooth, 
  is 
  the 
  widest 
  and 
  deepest. 
  

   In 
  the 
  fossil 
  (PI. 
  VIII. 
  fig. 
  10) 
  the 
  same 
  elements 
  are 
  present, 
  

   but 
  the 
  transverse 
  arrangement 
  is 
  less 
  perfect. 
  (Jusp 
  1 
  is 
  much 
  

   smaller, 
  as 
  in 
  some 
  species 
  of 
  Tamias 
  ; 
  it 
  is 
  compressed 
  from 
  

   before 
  backwards, 
  and 
  prolonged 
  inwards 
  as 
  a 
  rounded 
  ridge 
  

   which 
  dies 
  out 
  with 
  the 
  first 
  transverse 
  valley 
  at 
  a 
  point 
  less 
  

   than 
  halfway 
  across 
  the 
  crown. 
  The 
  remainder 
  of 
  the 
  front 
  

   border 
  of 
  the 
  tooth 
  is 
  formed 
  by 
  the 
  " 
  proto-conule,'^ 
  which 
  

   here 
  retains 
  more 
  of 
  its 
  tubercular 
  character 
  and 
  indepen- 
  

   dence, 
  being 
  more 
  forwardly 
  placed 
  and 
  separated 
  from 
  

   cusp 
  4 
  by 
  a 
  conspicuous 
  cleft. 
  Cusp 
  2, 
  though 
  very 
  low, 
  is 
  

   stouter. 
  The 
  " 
  meta-conule 
  " 
  is 
  stouter 
  and 
  more 
  indepen- 
  

   dent; 
  externally 
  it 
  is 
  placed 
  fuither 
  buck, 
  the 
  hinder 
  trans- 
  

  

  * 
  Hinton, 
  Geol. 
  Ma^. 
  dec. 
  5, 
  vol. 
  v. 
  p. 
  440. 
  

   t 
  Forsyth 
  Major, 
  Proc. 
  Zool. 
  Soc. 
  1893, 
  p. 
  182. 
  

  

  