﻿CANYON 
  FERRY 
  FOSSIL 
  VERTEBRATES 
  — 
  ^WHITE 
  425 
  

  

  (carnivore 
  or 
  herbivore) 
  the 
  probability 
  of 
  dealing 
  with 
  a 
  purely 
  local 
  

   fauna 
  is 
  in 
  inverse 
  ratio 
  to 
  the 
  size. 
  

  

  This 
  is 
  not 
  an 
  attempt 
  to 
  justify 
  the 
  multitudinous 
  species 
  of 
  

   Mesohippiis 
  or 
  the 
  subspecies 
  of 
  Trigonias 
  osborni 
  but 
  to 
  point 
  out, 
  

   as 
  did 
  Matthew, 
  that 
  we 
  must 
  utilize 
  the 
  principles 
  of 
  distribution 
  

   and 
  ecology, 
  which 
  have 
  been 
  worked 
  out 
  by 
  the 
  neozoologists, 
  in 
  in- 
  

   terpreting 
  the 
  fossil 
  faunas. 
  

  

  Family 
  Rhinoceratidae 
  

  

  Caenopus 
  cf. 
  mitis 
  (Cope) 
  

  

  USNM 
  19026, 
  right 
  mandibular 
  fragment 
  with 
  P4-M3, 
  from 
  

   locahty 
  No. 
  24BW18. 
  

  

  This 
  specimen 
  is 
  referred 
  to 
  this 
  genus 
  and 
  species 
  on 
  the 
  measure- 
  

   ments 
  of 
  the 
  teeth 
  which 
  agree 
  with 
  those 
  of 
  the 
  type. 
  The 
  teeth 
  

   of 
  this 
  specimen 
  are 
  well 
  worn 
  and 
  it 
  may 
  not 
  be 
  identifiable. 
  

  

  Order 
  ARTIODACTYLA 
  

   Family 
  Leptochoeridae 
  

  

  Leptochoerus 
  sp. 
  

  

  USNM 
  18919, 
  right 
  mandibular 
  fragment 
  with 
  P4-M3, 
  from 
  Lower 
  

   Oligocene 
  of 
  locahty 
  No. 
  24LC16. 
  

  

  The 
  teeth 
  on 
  this 
  specimen 
  are 
  so 
  badly 
  worn 
  that 
  only 
  provisional 
  

   reference 
  is 
  possible. 
  However, 
  it 
  is 
  sufficient 
  to 
  record 
  the 
  presence 
  

   of 
  this 
  group 
  in 
  these 
  deposits. 
  

  

  Family 
  Merycoidodontidae 
  

  

  Merycoidodon? 
  sp. 
  

  

  Only 
  maxillary 
  and 
  mandibular 
  fragments 
  were 
  obtained 
  from 
  the 
  

   Oligocene 
  deposits 
  and 
  these 
  are 
  inadequate 
  for 
  certain 
  generic 
  

   reference. 
  The 
  size 
  of 
  these 
  specimens 
  indicate 
  an 
  animal 
  of 
  about 
  

   the 
  size 
  of 
  Merycoidodon 
  cidbertsoni 
  (Leidy). 
  Nothing 
  in 
  the 
  size 
  

   range 
  of 
  the 
  small 
  and 
  poorly 
  known 
  genera 
  has 
  yet 
  been 
  found. 
  

  

  Mesoreodon 
  chelonyx 
  Scott 
  

  

  USNM 
  19091, 
  skull, 
  jaws 
  and 
  greater 
  part 
  of 
  the 
  skeleton; 
  USNM 
  

   19092, 
  skull 
  and 
  jaws; 
  both 
  from 
  the 
  Lower 
  Miocene 
  of 
  locality 
  

   No. 
  24LC18. 
  

  

  These 
  specimens 
  are 
  slightly 
  larger 
  than 
  those 
  recorded 
  by 
  Schultz 
  

   and 
  Falkenbach 
  (1949, 
  p. 
  154) 
  from 
  the 
  same 
  locality, 
  but 
  are 
  still 
  

   within 
  the 
  limits 
  of 
  individual 
  variation. 
  

  

  