﻿E. 
  L. 
  Troxell 
  — 
  An 
  Oligocene 
  Camel. 
  383 
  

  

  comes 
  quickly 
  to 
  a 
  thin 
  edge 
  and 
  flares 
  outward 
  ; 
  the 
  process 
  

   itself, 
  which 
  is 
  a 
  sharp 
  point 
  about 
  6 
  mm 
  long, 
  is 
  directed 
  

   slightly 
  backward. 
  A 
  deep 
  fossa 
  separates 
  this 
  from 
  the 
  occip- 
  

   ital 
  condyle. 
  

  

  The 
  glenoid 
  cavity 
  consists 
  of 
  two 
  flat 
  surfaces 
  at 
  right 
  

   angles 
  and 
  completely 
  united. 
  Such 
  an 
  articulation 
  with 
  the 
  

   small 
  condyle 
  of 
  the 
  ramus 
  allows 
  very 
  free 
  motion 
  of 
  the 
  jaw 
  

   and 
  the 
  spacing 
  of 
  the 
  teeth 
  requires 
  a 
  different 
  position 
  of 
  the 
  

   condyle 
  for 
  interlocking 
  the 
  front 
  teeth 
  and 
  the 
  molar-premolar 
  

   series 
  respectively. 
  

  

  In 
  the 
  occipital 
  condyles 
  there 
  is 
  no 
  anterior 
  basal 
  facet 
  as 
  

   an 
  accessory 
  articulation 
  with 
  the 
  inferior 
  border 
  of 
  the 
  atlas 
  

   and 
  consequently 
  the 
  lower 
  border 
  of 
  the 
  latter 
  shows 
  no 
  

   rounded 
  articular 
  edge. 
  The 
  condyle 
  is 
  situated 
  forward 
  and 
  

   is 
  overhung 
  slightly 
  by 
  the 
  su 
  preoccipital. 
  For 
  more 
  than 
  half 
  

   its 
  extent 
  the 
  crest 
  is 
  strong 
  and 
  single; 
  then 
  it 
  bifurcates 
  and 
  

   leads 
  to 
  the 
  supraorbital, 
  bony 
  shelf 
  extending 
  over 
  the 
  eye. 
  

   Lateral 
  ridges 
  from 
  the 
  supraoccipital 
  prominence 
  extend 
  to 
  

   the 
  external, 
  auditory 
  meatus 
  and 
  thence 
  a 
  sharp 
  border 
  fol- 
  

   lows 
  the 
  temporal 
  groove 
  and 
  joins 
  the 
  superior 
  border 
  of 
  the 
  

   zygomatic 
  arch. 
  

  

  The 
  width 
  across 
  the 
  supraorbitals 
  is 
  6'3 
  mm 
  . 
  The 
  rear 
  border 
  

   of 
  the 
  post-orbital 
  process 
  is 
  at 
  right 
  angles 
  to 
  the 
  long 
  axis, 
  

   causing 
  an 
  abrupt 
  narrowing 
  of 
  the 
  skull 
  posteriorly 
  and 
  a 
  

   widening 
  of 
  the 
  forehead 
  over 
  the 
  eyes. 
  This 
  is 
  characteristic 
  

   of 
  camels 
  and 
  gives 
  the 
  head 
  a 
  triangular 
  appearance. 
  

   Anteriorly 
  there 
  is 
  an 
  ins 
  weep 
  of 
  the 
  orbital 
  margin, 
  directing 
  

   the 
  eyes 
  somewhat 
  forward. 
  

  

  In 
  place 
  of 
  the 
  usual 
  supraorbital 
  notch 
  of 
  other 
  specimens, 
  

   in 
  the 
  present 
  skull 
  there 
  is 
  an 
  inclosed 
  foramen 
  on 
  one 
  side; 
  

   on 
  the 
  other, 
  there 
  is 
  a 
  very 
  narrow 
  slit 
  in 
  the 
  outer 
  margin 
  of 
  

   the 
  bony 
  shelf 
  leading 
  into 
  the 
  pseudo-foramen. 
  Over 
  the 
  

   middle 
  of 
  P 
  4 
  and 
  the 
  length 
  of 
  the 
  tooth 
  above 
  it 
  is 
  the 
  mental 
  

   foramen 
  : 
  the 
  postpalatine 
  foramen 
  lies 
  between 
  P 
  3 
  and 
  P\ 
  

  

  In 
  this 
  specimen 
  as 
  in 
  all 
  the 
  species 
  of 
  Po'ebr 
  other 
  ium, 
  the 
  

   orbit 
  is 
  not 
  inclosed 
  behind 
  ; 
  this 
  is 
  a 
  primitive 
  character 
  and 
  

   distinguishes 
  the 
  genus 
  from 
  Gompholherium. 
  The 
  orbits 
  are 
  

   so 
  close 
  together 
  that 
  only 
  a 
  thin 
  septum 
  intervenes. 
  The 
  

   lower 
  border 
  of 
  the 
  jugal 
  is 
  a 
  straight 
  line, 
  sloping 
  downward 
  

   and 
  forward 
  ; 
  its 
  posterior 
  notch, 
  which 
  receives 
  the 
  squa- 
  

   mosal, 
  is 
  not 
  deep. 
  There 
  is 
  a 
  parapet 
  or 
  flange 
  along 
  the 
  

   lower 
  rim 
  of 
  the 
  orbit. 
  In 
  front 
  the 
  zygomatic 
  arch 
  ends 
  

   definitely 
  above 
  a 
  point 
  between 
  M 
  2 
  , 
  M 
  3 
  and 
  there 
  is 
  a 
  slight 
  

   pit 
  over 
  M 
  2 
  . 
  The 
  pit 
  over 
  P 
  2 
  , 
  near 
  the 
  top 
  of 
  the 
  maxillary, 
  

   measures 
  over 
  a 
  centimeter 
  in 
  diameter; 
  it 
  constricts 
  the 
  nasal 
  

   passage 
  considerably 
  and 
  gives 
  this 
  region 
  of 
  the 
  skull 
  a 
  nar- 
  

   row 
  appearance. 
  The 
  suture 
  scar 
  on 
  the 
  upper 
  inner 
  edge 
  

  

  