﻿AND 
  AYES 
  OF 
  NORTH 
  AMERICA. 
  

  

  225 
  

  

  In. 
  

  

  Length 
  basi-occipital, 
  

  

  " 
  sphenoid 
  (oblique), 
  

  

  Width 
  of 
  basi-occipital 
  condyle, 
  

  

  " 
  between 
  basi-occipital 
  processes, 
  

   " 
  of 
  sphenoid 
  medially, 
  below, 
  

   " 
  between 
  processes 
  of 
  sphenoid, 
  

   " 
  of 
  quadratum 
  antero-externally, 
  

   " 
  " 
  postero- 
  " 
  

  

  " 
  " 
  (greatest) 
  quadratum, 
  condyle, 
  

   " 
  " 
  meatus 
  auditorius, 
  

  

  Length 
  quadratum, 
  

   " 
  ramus 
  mandibuli, 
  

   " 
  to 
  splenial 
  joint, 
  

   ' 
  ' 
  to 
  coronoid 
  process, 
  

   " 
  to 
  cotylus 
  (anterior 
  margin) 
  

  

  Width 
  of 
  angle 
  at 
  base, 
  

  

  Depth 
  at 
  coronoid 
  process, 
  

   " 
  " 
  splenial 
  joint, 
  

   " 
  "at 
  twelfth 
  tooth, 
  

  

  Length 
  of 
  o. 
  palatinum, 
  

  

  Width 
  " 
  " 
  

  

  Length 
  pterygoid 
  to 
  transverse 
  process, 
  

   " 
  transverse 
  process, 
  

  

  Width 
  pterygoid 
  at 
  do., 
  

  

  " 
  " 
  " 
  palatine 
  suture, 
  

  

  Elevation 
  mandibular 
  tooth 
  above 
  dentary, 
  

   " 
  crown 
  only, 
  

  

  Antero-posterior 
  diameter 
  crown 
  do. 
  at 
  base, 
  

  

  15 
  

  

  10 
  

   12 
  

   14 
  

   11 
  

  

  2 
  

  

  1 
  

  

  4 
  

   1 
  

  

  Lin. 
  

   13.7 
  

   17 
  

  

  9.9 
  

   17.3 
  

   10.3 
  

   13.5 
  

   15 
  

  

  9 
  

   13.3 
  

  

  2.4 
  

   18.5 
  

  

  8 
  

  

  2 
  

  

  4 
  

  

  4.5 
  

  

  3 
  

  

  10 
  

   10 
  

   11 
  

  

  6.4 
  

  

  3.5 
  

  

  6 
  

   12.5 
  

  

  5.6 
  

  

  5 
  

  

  3.2 
  

  

  The 
  lateral 
  processes 
  of 
  the 
  basi-occipital 
  are 
  ovate, 
  broadly 
  behind, 
  and 
  narrowed 
  anteriorly; 
  they 
  are 
  flat-faced, 
  

   and 
  marked 
  with 
  concentric 
  ruga? 
  on 
  the 
  same; 
  they 
  are 
  connected 
  by 
  a 
  cross-ridge, 
  which 
  forms 
  the 
  boundary 
  of 
  a 
  

   median 
  obtuse 
  ridge 
  in 
  front 
  of 
  it. 
  The 
  sphenoid 
  is 
  marked 
  by 
  two 
  weak 
  parallel 
  median 
  ridges. 
  Its 
  lateral 
  margins 
  

   project 
  and 
  are 
  angulate. 
  The 
  anterior 
  processes 
  for 
  the 
  pterygoids 
  are 
  flat, 
  and 
  obliquely 
  transverse. 
  The 
  articular 
  

   faces 
  are 
  directed 
  but 
  little 
  forwards. 
  

  

  There 
  are 
  seventeen 
  teeth 
  on 
  each 
  pterygoid, 
  the 
  posterior 
  smaller 
  and 
  more 
  closely 
  spaced. 
  The 
  anterior 
  tooth 
  

   is 
  close 
  to 
  the 
  suture 
  with 
  the 
  palatine. 
  The 
  tooth 
  series 
  is 
  everywhere 
  nearer 
  the 
  outer 
  than 
  the 
  inner 
  margin. 
  The 
  

   palatine 
  suture 
  extends 
  forwards 
  and 
  inwards. 
  Anteriorly 
  the 
  inner 
  margin 
  is 
  more 
  prolonged 
  than 
  the 
  outer, 
  and 
  is 
  

   connected 
  with 
  it 
  by 
  a 
  concave 
  margin. 
  The 
  surface 
  of 
  the 
  bone 
  is 
  concave 
  medially 
  and 
  elevated 
  on 
  the 
  inner 
  and 
  

   outer 
  margins. 
  

  

  The 
  vomers 
  each 
  have 
  an 
  elevated 
  middle 
  line, 
  which 
  produces 
  two 
  longitudinal 
  ribs 
  on 
  the 
  median 
  line, 
  as 
  in 
  

   many 
  lacertilians. 
  Their 
  surface 
  is 
  not 
  striate. 
  

  

  The 
  scapular 
  arch 
  is 
  only 
  represented 
  by 
  scapula 
  and 
  coracoid; 
  the 
  other 
  elements, 
  if 
  existing, 
  have 
  been 
  lost. 
  

   The 
  convex 
  margin 
  of 
  the 
  coracoid 
  is 
  very 
  thin, 
  thickest 
  posteriorly. 
  The 
  outer 
  anterior 
  margin 
  has 
  two 
  angles, 
  one 
  

   above 
  and 
  one 
  below, 
  the 
  former 
  running 
  out 
  on 
  the 
  plate. 
  

  

  The 
  two 
  extremities 
  of 
  the 
  humerus 
  are 
  in 
  nearly 
  the 
  same 
  plane, 
  the 
  inferior 
  condyle 
  being 
  directed 
  backwards 
  

   from 
  it. 
  The 
  head 
  is 
  thick, 
  with 
  superior 
  and 
  inferior 
  tuberosities 
  more 
  prominent 
  than 
  the 
  articular 
  face. 
  The 
  latter 
  

   is 
  especially 
  large, 
  acuminate 
  anteriorly, 
  and 
  the 
  bordering 
  portions 
  of 
  the 
  shank 
  coarsely 
  striate. 
  The 
  greater 
  tuber- 
  

   osity 
  projects 
  posteriorly; 
  its 
  margin 
  is 
  convex. 
  It 
  is 
  separated 
  by 
  a 
  deep 
  groove 
  from 
  the 
  lesser 
  tuberosity, 
  which 
  is 
  

   equally 
  prominent, 
  but 
  much 
  narrower 
  and 
  more 
  prolonged 
  on 
  the 
  posterior 
  face 
  of 
  the 
  bone. 
  It 
  occupies 
  the 
  summit 
  

  

  AMERT. 
  PHILO. 
  SOC. 
  — 
  VOT,. 
  XIV. 
  57 
  

  

  