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

  

  579 
  

  

  the 
  valley 
  is 
  usually 
  extended 
  somewhat 
  farther 
  toward 
  the 
  outward 
  

   face. 
  Here, 
  as 
  in 
  other 
  characters, 
  deviations 
  from 
  the 
  rule 
  are 
  to 
  

   be 
  expected. 
  

  

  Figs. 
  19-21.— 
  19, 
  Equus 
  i^obbarensis. 
  X 
  i- 
  Uppee 
  ja-w, 
  left 
  side. 
  Type. 
  4g99, 
  U. 
  S. 
  Nat. 
  Mus. 
  

   20, 
  Left 
  lower 
  jaw. 
  Type. 
  4999, 
  U. 
  S. 
  Nat. 
  Mus. 
  21, 
  Left 
  lower 
  jaw. 
  2725, 
  Amer. 
  Mus. 
  

  

  In 
  the 
  lower 
  cheek 
  teeth, 
  both 
  premolars 
  and 
  molars 
  (fig. 
  20), 
  the 
  

   loop 
  of 
  enamel 
  which 
  enters 
  the 
  crown 
  at 
  the 
  middle 
  of 
  the 
  outer 
  

  

  