﻿NO. 
  1969. 
  FOUR 
  NEW 
  SPECIES 
  OF 
  FOSSIL 
  HORSES— 
  HAY. 
  581 
  

  

  specimen 
  figured 
  by 
  Gidley. 
  By 
  length 
  of 
  the 
  tooth 
  is. 
  meant, 
  here 
  

   as 
  elsewhere, 
  the 
  fore-and-aft 
  extent 
  of 
  the 
  crown, 
  not 
  the 
  height 
  of 
  

   the 
  tooth. 
  The 
  fore-and-aft 
  extent 
  of 
  the 
  protocones 
  is 
  also 
  given. 
  

   It 
  should 
  be 
  observed 
  that 
  in 
  comparing 
  the 
  dimensions 
  of 
  the 
  teeth, 
  

   the 
  lengths 
  of 
  pm.^, 
  pm.2, 
  m.^, 
  and 
  m.3 
  are 
  less 
  constant 
  than 
  those 
  of 
  

   the 
  other 
  teeth. 
  

  

  Measurements 
  of 
  teeth. 
  

  

  mm. 
  

  

  Length 
  of 
  the 
  upper 
  premolar-molar 
  series 
  190 
  

  

  Length 
  of 
  the 
  upper 
  premolar 
  series 
  107 
  

  

  Length 
  of 
  the 
  upper 
  molar 
  series 
  83 
  

  

  Pm.', 
  length 
  42 
  

  

  width 
  30 
  

  

  protocone 
  12 
  

  

  Pm.^, 
  length 
  32 
  

  

  width 
  30 
  

  

  protocone 
  17 
  

  

  Pm.*, 
  length 
  31 
  

  

  width 
  30 
  

  

  protocone 
  16 
  

  

  M.\ 
  length 
  30 
  

  

  width 
  27 
  

  

  protocone 
  14 
  

  

  M.^, 
  length 
  30 
  

  

  width 
  25 
  

  

  protocone 
  15 
  

  

  M.\ 
  length 
  25 
  

  

  width 
  20 
  

  

  protocone 
  15 
  

  

  Besides 
  the 
  maxilla 
  and 
  cheek 
  teeth 
  described 
  here 
  the 
  type 
  

   specimen 
  presents 
  the 
  premaxillse, 
  the 
  incisors 
  and 
  both 
  canines. 
  

   With 
  this 
  upper 
  jaw 
  there 
  is 
  present 
  also 
  a 
  part 
  of 
  a 
  lower 
  jaw 
  which 
  

   belonged 
  to 
  the 
  same 
  individual 
  and 
  which 
  presents 
  the 
  left 
  ramus 
  

   and 
  symphysis, 
  with 
  all 
  the 
  cheek 
  teeth 
  (fig. 
  21), 
  the 
  left 
  canine 
  

   and 
  all 
  the 
  incisors. 
  

  

  Measurements 
  of 
  teeth. 
  

  

  mm. 
  

  

  Length 
  of 
  premolar-molar 
  series 
  • 
  200 
  

  

  Length 
  of 
  premolar 
  series 
  110 
  

  

  Length 
  of 
  molar 
  series 
  90 
  

  

  Pm.2, 
  length 
  38 
  

  

  width 
  17 
  

  

  Pm.3, 
  length 
  33 
  

  

  wid 
  th 
  19 
  

  

  Pm.^, 
  length 
  32 
  

  

  width 
  18 
  

  

  M. 
  , 
  , 
  length 
  30 
  

  

  width 
  16 
  

  

  M.2, 
  length 
  32 
  

  

  width 
  15 
  

  

  if 
  .3, 
  length 
  31 
  

  

  width 
  11 
  

  

  