﻿CANYON 
  FERRY 
  FOSSIL 
  VERTEBRATES 
  — 
  ^WHITE 
  419 
  

  

  of 
  the 
  hypoconid. 
  A 
  metaconulid 
  and 
  a 
  protoconulid 
  are 
  present 
  as 
  

   in 
  Nothocyon 
  and 
  Tomarctos. 
  There 
  is 
  a 
  small 
  but 
  distinct 
  entoconid 
  

   on 
  M2. 
  

  

  An 
  unusual 
  feature 
  of 
  this 
  specimen 
  is 
  that 
  both 
  teeth 
  show 
  evidence 
  

   of 
  dental 
  caries. 
  On 
  Mi 
  there 
  is 
  a 
  major 
  lesion 
  on 
  the 
  hypoconid 
  

   (fig. 
  49) 
  with 
  a 
  minor 
  lesion 
  on 
  the 
  entoconid, 
  protoconid, 
  metaconid 
  

   and 
  metaconulid. 
  On 
  M2 
  there 
  is 
  a 
  major 
  lesion 
  on 
  the 
  protoconid 
  

   with 
  a 
  minor 
  lesion 
  on 
  the 
  metaconid 
  and 
  hypoconid. 
  Among 
  the 
  

   recent 
  carnivores 
  the 
  only 
  evidence 
  of 
  dental 
  caries 
  I 
  have 
  seen 
  was 
  

   in 
  the 
  teeth 
  of 
  the 
  grizzly 
  bears 
  (Ursus 
  horribilis 
  Ord) 
  in 
  the 
  Museum 
  

   of 
  Comparative 
  Zoology 
  and 
  in 
  the 
  U. 
  S. 
  National 
  Museum. 
  Meas- 
  

   urements 
  of 
  teeth 
  (in 
  millimeters): 
  

  

  width 
  

  

  Length 
  

  

  Trigoni 
  

  

  Mi__ 
  

  

  Mj 
  

  

  Nothocyon 
  cf. 
  geismarianus 
  (Cope) 
  

  

  USNM 
  19097, 
  right 
  mandible 
  with 
  P2-M2, 
  from 
  locaUty 
  No. 
  

   24LC19. 
  

  

  This 
  specimen 
  is 
  shghtly 
  smaller 
  than 
  the 
  one 
  described 
  by 
  Cope 
  

   (1884, 
  p. 
  920) 
  but 
  agrees 
  in 
  other 
  details. 
  

  

  Family 
  Ursidae 
  

   Subfamily 
  amphicynodontinae 
  

  

  Daphoenocyon 
  cf. 
  dodgei 
  (Scott) 
  

  

  USNM 
  19094, 
  left 
  mandibular 
  fragment 
  (fig. 
  50) 
  with 
  dP3-4 
  and 
  

   Mi_2, 
  from 
  locaHty 
  No. 
  24LC16. 
  

  

  This 
  specimen 
  is 
  badly 
  fractured 
  but 
  it 
  is 
  possible 
  to 
  make 
  out 
  the 
  

   essential 
  details 
  of 
  the 
  teeth. 
  The 
  deciduous 
  teeth 
  are 
  more 
  canidlike 
  

   in 
  the 
  cusp 
  arrangement 
  than 
  are 
  the 
  permanent 
  teeth, 
  but 
  are 
  low 
  

   crowned. 
  In 
  dPa 
  the 
  anterior 
  and 
  posterior 
  cusps 
  are 
  well 
  developed, 
  

   the 
  posterior 
  accessory 
  cusp 
  present 
  and 
  distinct, 
  heel 
  broad 
  with 
  pro- 
  

   nounced 
  internal 
  and 
  external 
  cinguli. 
  In 
  dP4 
  the 
  trigonid 
  does 
  not 
  

   differ 
  from 
  that 
  of 
  the 
  permanent 
  tooth 
  except 
  in 
  size, 
  hypoconid 
  and 
  

   and 
  entoconid 
  subequal 
  with 
  entoconid 
  slightly 
  larger, 
  a 
  distinct 
  

   hypoconulid 
  slightly 
  smaller 
  than 
  the 
  hypoconid 
  present. 
  The 
  per- 
  

   manent 
  teeth, 
  being 
  in 
  an 
  unworn 
  condition, 
  exhibit 
  features 
  on 
  the 
  

   heels 
  of 
  Mi 
  and 
  M2 
  which 
  appear 
  to 
  be 
  common 
  to 
  many 
  members 
  of 
  

   this 
  subfamily, 
  namely, 
  in 
  the 
  breaking 
  up 
  of 
  the 
  principal 
  conids 
  into 
  

   smaller 
  cusps. 
  In 
  this 
  specimen, 
  while 
  the 
  conids 
  on 
  the 
  heel 
  of 
  Mi 
  

   are 
  quite 
  distinct, 
  the 
  hypoconid 
  has 
  two 
  apices 
  and 
  the 
  entoconid 
  

   has 
  three. 
  The 
  heel 
  of 
  M2 
  is 
  a 
  further 
  exaggeration 
  of 
  this 
  phenome- 
  

  

  