﻿10 
  THE 
  EXTINCT 
  BATRACHIA, 
  REPTILIA 
  

  

  PARIOSTEGTJS, 
  Cope. 
  

   Proceed. 
  Acad. 
  Nat. 
  Sci. 
  1868, 
  p. 
  211. 
  

  

  This 
  genus 
  is 
  represented 
  by 
  a 
  large 
  part 
  of 
  the 
  cranium 
  of 
  a 
  batrachian 
  from 
  the 
  

   triassic 
  coal 
  measures 
  of 
  Chatham 
  county, 
  North 
  Carolina. 
  If 
  not 
  a 
  batrachian, 
  it 
  could 
  

   only 
  belong 
  to 
  a 
  Ganoid 
  fish, 
  but 
  though 
  some 
  of 
  its 
  characters 
  are 
  somewhat 
  ichthyic, 
  it 
  

   lacks 
  the 
  following 
  important 
  elements 
  of 
  the 
  Ganoid 
  structure, 
  i. 
  e. 
  post 
  and 
  suborbital 
  

   bones; 
  postnareal 
  cavities, 
  branchiostegal, 
  and 
  arched 
  branchihyal 
  bones. 
  On 
  the 
  other 
  

   hand 
  it 
  has 
  a 
  large 
  preorbital, 
  bounding 
  the 
  frontal 
  and 
  maxillary 
  to 
  the 
  nares, 
  and 
  the 
  

   inner 
  border 
  of 
  the 
  orbit, 
  as 
  in 
  Stegocephalous 
  Batrachia; 
  also 
  a 
  postorbital 
  element, 
  

   contributing 
  to 
  the 
  formation 
  of 
  an 
  extended 
  supratemporal 
  roof. 
  

  

  Contrary 
  to 
  what 
  has 
  been 
  found 
  the 
  case 
  in 
  most 
  genera 
  of 
  Stegocephali, 
  the 
  

   maxillary 
  appears 
  to 
  extend 
  posteriorly 
  to 
  a 
  free 
  termination, 
  as 
  in 
  modern 
  Salamanders, 
  

   and 
  the 
  supratemporal 
  bone 
  presents 
  a 
  very 
  prominent, 
  obtuse, 
  arched 
  margin. 
  This 
  

   margin 
  extends 
  from 
  the 
  orbits 
  on 
  each 
  side, 
  and 
  is 
  inclined 
  towards 
  the 
  posterior 
  part 
  of 
  

   the 
  cranium. 
  There 
  is 
  therefore 
  no 
  quadratojugal 
  piece. 
  

  

  The 
  maxillary 
  and 
  mandibular 
  pieces 
  are 
  slender, 
  flat 
  bones, 
  as 
  in 
  Menopoma; 
  the 
  

   form 
  of 
  the 
  posterior 
  or 
  articular 
  portion 
  of 
  the 
  latter 
  cannot 
  be 
  ascertained 
  from 
  the 
  

   specimen. 
  The 
  more 
  or 
  less 
  exposed 
  part 
  of 
  the 
  median 
  region 
  of 
  the 
  latter, 
  exhibits 
  a 
  

   succession 
  of 
  shallow 
  transverse 
  notches, 
  enclosing 
  thirteen 
  obtuse 
  elevations. 
  The 
  

   former 
  resemble 
  rudimental 
  lateral 
  alveolae 
  for 
  minute 
  pleurodont 
  teeth. 
  A 
  few 
  other 
  

   similar 
  minute 
  ribs, 
  and, 
  perhaps, 
  a 
  minute 
  curved 
  cone 
  without 
  sculpture, 
  are 
  the 
  only 
  

   other 
  indications 
  of 
  dentition. 
  

  

  The 
  bones 
  of 
  the 
  upper 
  surface 
  of 
  the 
  cranium 
  are 
  more 
  readily 
  interpreted 
  by 
  

   reference 
  to 
  those 
  of 
  Menopoma. 
  A 
  pair 
  of 
  narrow 
  nasals, 
  acuminate 
  behind, 
  penetrate 
  

   between 
  the 
  frontals 
  as 
  far 
  posteriorly 
  as 
  the 
  posterior 
  margins 
  of 
  the 
  orbits. 
  The 
  suture 
  

   between 
  these 
  is 
  very 
  distinct, 
  and 
  entirely 
  straight. 
  The 
  preorbitals 
  extend 
  to 
  above 
  

   the 
  orbit, 
  and 
  then 
  appear 
  to 
  cease 
  with 
  a 
  transverse 
  suture. 
  Between 
  these 
  and 
  the 
  

   nasals 
  a 
  broad 
  triangular 
  element 
  enters 
  on 
  each 
  side, 
  not 
  attaining 
  the 
  probable 
  position 
  

   of 
  the 
  nostrils. 
  Each 
  is 
  divided 
  by 
  a 
  longitudinal 
  groove, 
  which 
  is 
  probably 
  a 
  suture, 
  and 
  

   which 
  would 
  then 
  divide 
  the 
  frontals 
  from 
  the 
  parietals. 
  The 
  frontal 
  woidd 
  then 
  divide 
  

   the 
  parietals 
  entirely, 
  as 
  they 
  do 
  in 
  Menopoma, 
  for 
  the 
  anterior 
  half 
  of 
  their 
  length. 
  This 
  

   would 
  give 
  the 
  frontals 
  a 
  narrow 
  form, 
  acuminate 
  in 
  front, 
  and 
  bounded 
  behind 
  by 
  a 
  

   regular 
  coarse, 
  zig-zag 
  transverse 
  suture. 
  The 
  cranium 
  behind 
  this 
  point 
  is 
  rugose, 
  and 
  

   the 
  surface 
  not 
  well 
  preserved, 
  and 
  it 
  can 
  only 
  be 
  said, 
  that 
  two 
  peculiar 
  grooves 
  converge 
  

   to 
  a 
  point 
  between 
  the 
  posterior 
  extremities 
  of 
  the 
  frontals, 
  like 
  the 
  boundaries 
  of 
  the 
  

   supraoccipitals. 
  The 
  posterior 
  boundary 
  of 
  the 
  cranium 
  with 
  the 
  condyles 
  cannot 
  be 
  

  

  