﻿AVD 
  AVES 
  OF 
  NORTH 
  AMERICA. 
  11 
  

  

  readily 
  determined. 
  When 
  the 
  postorbital 
  roof 
  bone 
  is 
  raised 
  up, 
  the 
  meeting 
  of 
  two 
  

   gular 
  dermal 
  bones, 
  as 
  I 
  interpret 
  them, 
  is 
  seen. 
  One 
  of 
  these 
  is 
  a 
  plate 
  directed 
  

   backwards 
  and 
  outwards, 
  bearing 
  minute 
  radiating 
  lines 
  on 
  its 
  upper 
  surface. 
  It 
  meets 
  a 
  

   similar 
  flat 
  plate 
  directed 
  forwards 
  and 
  outwards 
  with 
  similar 
  lines 
  radiating 
  to 
  the 
  

   circumference. 
  The 
  inner 
  margins 
  of 
  these 
  plates 
  were 
  not 
  seen. 
  

  

  The 
  orbits 
  are 
  remarkably 
  small, 
  and 
  situated 
  probably 
  near 
  the 
  middle 
  of 
  the 
  

   longitudinal 
  measurement 
  of 
  the 
  cranium. 
  The 
  external 
  nares 
  are 
  not 
  denned, 
  but 
  

   symmetrical 
  depressions 
  in 
  the 
  position 
  they 
  usually 
  occupy 
  in 
  Salamanders 
  are 
  distinct. 
  

  

  The 
  general 
  form 
  recalls 
  Menopoma, 
  particularly 
  the 
  small 
  orbits. 
  A 
  slender 
  curved 
  

   bone 
  with 
  a 
  slightly 
  dilated 
  and 
  truncate 
  extremity, 
  lying 
  by 
  the 
  cranium 
  in 
  connection 
  

   with 
  the 
  mandible, 
  is 
  like 
  a 
  branchihyal 
  of 
  that 
  genus. 
  Nevertheless 
  it 
  cannot 
  be 
  

   positively 
  assigned 
  to 
  that 
  genus, 
  as 
  numerous 
  cycloid 
  scales 
  of 
  fishes 
  are 
  on 
  the 
  same 
  

   block. 
  

  

  PARIOSTEGUS 
  MYOPS, 
  Cope. 
  

  

  The 
  surfaces 
  of 
  the 
  cranial 
  bones 
  are 
  little 
  sculptured 
  ; 
  there 
  are 
  small 
  tuberculiform 
  elevations 
  on 
  the 
  parietal 
  

   and 
  more 
  numerous 
  ones 
  on 
  the 
  preorbitals 
  . 
  The 
  postorbitals 
  show 
  the 
  strongest 
  markings 
  of 
  elongated 
  pits, 
  which 
  

   radiate 
  to 
  their 
  circumference, 
  leaving 
  a 
  smooth 
  obtuse 
  border. 
  The 
  nasals 
  present 
  a 
  series 
  of 
  small 
  warts 
  at 
  a 
  little 
  

   distance 
  on 
  each 
  side 
  of 
  their 
  common 
  suture, 
  and 
  transverse 
  to 
  it. 
  The 
  surface 
  of 
  the 
  maxillary 
  is 
  marked 
  with 
  

   longitudinal 
  grooves 
  and 
  shallow 
  pits. 
  

  

  No 
  suture 
  separating 
  maxillaries 
  and 
  premaxillaries 
  can 
  be 
  traced 
  with 
  certainty, 
  though 
  the 
  bones 
  of 
  the 
  jaw 
  

   are 
  interrupted 
  at 
  the 
  usual 
  place 
  of 
  suture, 
  opposite 
  the 
  nostril. 
  

  

  Measurements. 
  Lines. 
  

  

  Length 
  of 
  specimen 
  (including 
  mandible), 
  18 
  

  

  Width 
  between 
  outer 
  convexities 
  postorbitals, 
  17 
  

  

  Do. 
  do. 
  inner 
  borders 
  orbit, 
  11 
  

   Do. 
  of 
  same 
  without 
  preorbitals, 
  8 
  

  

  Do. 
  of 
  nasals 
  at 
  middle, 
  2.5 
  

  

  Do. 
  of 
  orbit, 
  1.5 
  

  

  Length 
  of 
  frontal 
  and 
  nasal 
  premaxillary, 
  11 
  

  

  Do. 
  of 
  supposed 
  branchihyal, 
  12 
  

  

  The 
  name 
  is 
  derived 
  from 
  the 
  roof-like 
  postorbitals 
  with 
  free 
  lateral 
  margin. 
  

  

  Locality. 
  — 
  Coal 
  bed 
  of 
  the 
  Keuper 
  Triassic, 
  Chatham 
  county, 
  North 
  Carolina. 
  The 
  

   species 
  was 
  discovered 
  by 
  Prof. 
  Jos. 
  Leidy, 
  who 
  handed 
  it 
  to 
  me 
  for 
  description. 
  It 
  is 
  in 
  

   the 
  Museum 
  of 
  the 
  Academy 
  Nat. 
  Sciences 
  of 
  this 
  city. 
  

  

  