﻿8 
  SUPPLEMENT 
  TO 
  THE 
  EXTINCT 
  BATKACH1A 
  

  

  OESTOCEPHALUS 
  EEMEX, 
  Cope. 
  

   Transac. 
  Amer. 
  Pbilos. 
  Soc, 
  XIV, 
  1869, 
  p. 
  17. 
  

  

  OESTOCEPHALUS 
  RECTLDENS, 
  Cope, 
  Sp. 
  Nov. 
  

  

  Indicated 
  by 
  a 
  left 
  dentary 
  bone 
  witb 
  its 
  teetb 
  and 
  external 
  surface 
  preserved. 
  Tbe 
  latter 
  is 
  nearly 
  smooth 
  

   and 
  without 
  sculpture. 
  The 
  outer 
  face 
  is 
  convex, 
  and 
  the 
  general 
  form 
  is 
  slender, 
  but 
  not 
  curved 
  upwards 
  at 
  the 
  

   extremity. 
  Teeth 
  straight 
  and 
  conic, 
  apex 
  acute 
  ; 
  no 
  visible 
  grooves 
  of 
  the 
  surface 
  ; 
  eleven 
  in 
  m. 
  .005, 
  closely 
  

   placed, 
  and 
  of 
  equal 
  lengths. 
  The 
  extremity 
  of 
  the 
  dentary 
  does 
  not 
  exhibit 
  teeth, 
  but 
  they 
  may 
  be 
  concealed. 
  

  

  M. 
  

   Length 
  of 
  dentary, 
  0.022 
  

  

  " 
  tooth 
  line, 
  .0152 
  

  

  Depth 
  dentary 
  at 
  last 
  tooth, 
  .0027 
  

  

  This 
  represents 
  a 
  smaller 
  animal 
  than 
  does 
  the 
  skull 
  of 
  0. 
  curvidens, 
  and 
  differs 
  much 
  from 
  the 
  latter 
  in 
  the 
  

   more 
  closely 
  placed 
  and 
  perfectly 
  straight 
  teeth. 
  

  

  I 
  describe 
  here 
  a 
  specimen 
  which 
  is 
  closely 
  related 
  as 
  to 
  size 
  to 
  the 
  0. 
  rectidens, 
  and 
  is 
  probably 
  a 
  member 
  

   of 
  this 
  genus 
  ; 
  but 
  the 
  specific 
  reference 
  will 
  remain 
  uncertain 
  till 
  other 
  portions 
  of 
  the 
  skeleton 
  are 
  discovered. 
  

   Those 
  preserved 
  consist 
  of 
  twenty-five 
  caudal 
  vertebrae, 
  probably 
  from 
  the 
  anterior 
  part 
  of 
  the 
  column. 
  There 
  are 
  

   therefore 
  no 
  ribs 
  nor 
  ventral 
  armature. 
  The 
  centra 
  are 
  rather 
  elongate 
  and 
  expanded 
  at 
  the 
  extremities. 
  The 
  neural 
  

   arches 
  have 
  a 
  close 
  union. 
  There 
  are 
  no 
  diapophyses, 
  but 
  the 
  fan 
  shaped 
  and 
  striate 
  neural 
  and 
  haemal 
  spines 
  are 
  

   present. 
  They 
  are, 
  however, 
  shorter 
  than 
  in 
  0. 
  remex, 
  and 
  not 
  so 
  expanded 
  as 
  in 
  the 
  species 
  of 
  Ptyonias. 
  The 
  

   bases 
  are 
  quite 
  narrow. 
  Their 
  reduced 
  size 
  maybe 
  derived 
  from 
  the 
  following 
  measurements. 
  Length 
  of 
  three 
  

   centra, 
  m. 
  .0086 
  ; 
  extent 
  of 
  neural 
  and 
  haemal 
  spines, 
  .0087. 
  The 
  same 
  dimensions 
  in 
  0. 
  remex 
  are 
  .012 
  ; 
  extent 
  of 
  

   spines, 
  .02. 
  While 
  this 
  species 
  is 
  smaller 
  than 
  the 
  latter, 
  it 
  is 
  larger 
  than 
  any 
  known 
  Ptyonius, 
  its 
  elongate 
  vertebrae 
  

   are 
  most 
  like 
  those 
  of 
  OestocepJialus. 
  

  

  BRACHYDECTES, 
  Cope. 
  

  

  Proceed. 
  Acad. 
  Nat. 
  Sci., 
  Philadelphia, 
  1868, 
  214. 
  Transac. 
  Amer. 
  Philos. 
  Soc, 
  1868, 
  XIV., 
  p. 
  14. 
  

  

  This 
  genus 
  is 
  indicated 
  by 
  two 
  rami 
  of 
  a 
  mandible 
  and 
  a 
  portion 
  of 
  a 
  premaxil- 
  

   lary 
  only. 
  These, 
  when 
  compared 
  with 
  those 
  of 
  OestocepJialus 
  and 
  Dendrerpeton, 
  

   from 
  the 
  same 
  locality, 
  and 
  with 
  others 
  described 
  by 
  authors, 
  are 
  so 
  much 
  stouter, 
  i. 
  e., 
  

   shorter 
  and 
  more 
  elevated, 
  that 
  they 
  evidently 
  belong 
  to 
  a 
  peculiar 
  genus. 
  The 
  

   genus 
  further 
  differs 
  from 
  O'estoceplialus 
  'in 
  having 
  the 
  teeth 
  of 
  equal 
  size 
  to 
  the 
  

   posterior 
  parts 
  of 
  the 
  series, 
  that 
  is, 
  to 
  the 
  base 
  of 
  the 
  elevated 
  coronoid 
  process. 
  

   The 
  teeth 
  are 
  elongate 
  cylindric 
  cones, 
  with 
  their 
  acute 
  tips 
  turned 
  a 
  little 
  poste- 
  

   riorly. 
  The 
  fractured 
  ones 
  display 
  a 
  large 
  pulp 
  cavity. 
  The 
  three 
  premaxillaries 
  

   preserved 
  are 
  similar, 
  but 
  without 
  curvature 
  of 
  the 
  tips. 
  They 
  do 
  not 
  exhibit 
  striae 
  

   or 
  any 
  other 
  sculpture. 
  

  

  So 
  far 
  as 
  the 
  remains 
  known 
  go, 
  the 
  genus 
  is 
  nearer 
  Hylerpeton 
  than 
  any 
  other. 
  

   According 
  to 
  Dawson 
  that 
  genus 
  is 
  provided 
  with 
  a 
  large 
  canine-like 
  tooth, 
  at 
  the 
  

   anterior 
  extremity 
  of 
  the 
  maxillary, 
  on 
  the 
  inner 
  row, 
  which 
  is 
  inserted 
  into 
  a 
  dis- 
  

   tinct 
  socket. 
  No 
  such 
  tooth 
  appears 
  among 
  those 
  of 
  this 
  genus. 
  The 
  latter 
  does 
  

   not 
  give 
  any 
  indication 
  of 
  the 
  very 
  elevated 
  coronoid 
  process 
  of 
  BracJiydectes, 
  though 
  

  

  