﻿CANYON 
  FERRY 
  FOSSIL 
  VERTEBRATES 
  — 
  ^WHITE 
  427 
  

  

  Frick 
  (1937, 
  p. 
  625) 
  synonomized 
  i.? 
  esulcatus 
  Matthew 
  (1903, 
  

   p. 
  222, 
  fig, 
  15) 
  with 
  L. 
  transmontanus 
  Douglass. 
  On 
  the 
  following 
  

   page 
  he 
  indicates 
  that 
  the 
  specimens 
  referred 
  by 
  Matthew 
  (1903, 
  p. 
  

   224) 
  to 
  L. 
  mammifer 
  Cope 
  should 
  be 
  considered 
  a 
  large 
  variant 
  of 
  

   this 
  species, 
  and 
  on 
  page 
  629 
  he 
  refers 
  the 
  specimens 
  figured 
  by 
  

   Matthew 
  as 
  Z.? 
  esulcatus 
  Cope 
  to 
  L. 
  evansi 
  Leidy. 
  The 
  upper 
  denti- 
  

   tions 
  of 
  Leptomeryx 
  in 
  the 
  U. 
  S. 
  National 
  Museum 
  and 
  in 
  the 
  Carnegie 
  

   Museum 
  from 
  Pipestone 
  Springs 
  and 
  Lower 
  Oligocene 
  of 
  Canyon 
  

   Ferry 
  agree 
  with 
  the 
  figure 
  and 
  published 
  measurements 
  given 
  by 
  

   Douglass 
  (1903, 
  p. 
  167, 
  fig. 
  11) 
  for 
  the 
  type 
  of 
  L. 
  transmontanus. 
  

   Also, 
  a 
  comparison 
  of 
  this 
  material 
  with 
  the 
  type 
  (USNM 
  157) 
  and 
  

   referred 
  material 
  of 
  L. 
  evansi 
  Leidy 
  from 
  the 
  Middle 
  Oligocene 
  reveal 
  

   a 
  number 
  of 
  differences 
  which 
  are 
  fairly 
  constant 
  and 
  are 
  presented 
  

   in 
  table 
  2. 
  As 
  far 
  as 
  it 
  was 
  possible 
  to 
  do 
  so 
  the 
  characters 
  of 
  

   L. 
  evansi 
  were 
  taken 
  from 
  the 
  type. 
  

  

  Table 
  2. 
  — 
  Contrasting 
  characters 
  of 
  Leptomeryx 
  evansi 
  Leidy 
  and 
  

   L. 
  transmontanus 
  Douglass. 
  

  

  Matthew 
  (1903, 
  p. 
  223) 
  stressed 
  the 
  differences 
  in 
  the 
  length 
  of 
  the 
  

   posterior 
  ridges 
  on 
  the 
  protoconid 
  of 
  the 
  third 
  lower 
  premolar 
  as 
  the 
  

   distinguishing 
  characteristic 
  of 
  this 
  species 
  and 
  it 
  is 
  valid 
  for 
  the 
  

   majority 
  of 
  the 
  specimens 
  I 
  have 
  examined. 
  Normally, 
  there 
  are 
  an 
  

   inner 
  and 
  an 
  outer 
  cusp 
  on 
  the 
  heel 
  of 
  P3, 
  each 
  with 
  a 
  short 
  ridge 
  ex- 
  

   tending 
  antero-medially 
  (axis 
  of 
  the 
  tooth). 
  These 
  ridges 
  usually 
  

   meet 
  and 
  fuse 
  near 
  the 
  middle 
  of 
  the 
  heel. 
  Normally, 
  the 
  inner 
  ridge 
  

   from 
  the 
  protoconid 
  is 
  united 
  with 
  this 
  common 
  meeting 
  point. 
  In 
  

   the 
  material 
  at 
  my 
  disposal 
  the 
  outer 
  ridge 
  from 
  the 
  protoconid 
  is 
  

   variable 
  in 
  length, 
  is 
  usually 
  bifid, 
  and 
  in 
  one 
  specimen 
  it 
  joins 
  the 
  

   heel 
  at 
  the 
  common 
  meeting 
  point 
  mentioned 
  above. 
  Occasionally 
  

   the 
  ridge 
  from 
  one 
  of 
  the 
  cusps 
  on 
  the 
  heel 
  does 
  not 
  develop, 
  or 
  the 
  

   ridge 
  may 
  extend 
  directly 
  anteriorly. 
  In 
  two 
  specimens 
  the 
  ridges 
  

   of 
  both 
  heel 
  cusps 
  have 
  gi-own 
  anteriorly 
  and 
  met 
  the 
  posterior 
  ridges 
  

   from 
  the 
  protoconid, 
  giving 
  P3 
  the 
  appearance 
  of 
  P4. 
  

  

  Leptomeryx 
  evansi 
  Leidy 
  

  

  USNM 
  18924-18926, 
  three 
  maxillary 
  fragments; 
  USNM 
  18923, 
  

   18927-18930, 
  five 
  mandibular 
  fragments; 
  and 
  seven 
  unnumbered 
  

  

  