﻿306 
  PAL2EONTOLOGTC 
  OP 
  ILLINOIS. 
  

  

  GteHDfl 
  PLATYCKIM'S. 
  Miller. 
  

  

  PiATYORnroa 
  Mohboxbsis, 
  Worthen. 
  

  

  n. 
  xxx. 
  fit. 
  

  

  Plain 
  

  

  Bulletin 
  No. 
  lot 
  the 
  nilnob 
  * 
  Hatarel 
  History. 
  P. 
  «. 
  

  

  Body 
  small, 
  cup-shaped, 
  about 
  once 
  and 
  a 
  half 
  as 
  wide 
  

   Basal 
  plates 
  extending 
  about 
  one-half 
  their 
  length 
  beyond 
  tl 
  

   oolamnar 
  joints, 
  the 
  lower 
  margin 
  projectim. 
  

   row 
  rim 
  to 
  the 
  base. 
  Radiale 
  wider 
  than 
  high, 
  the 
  articulating 
  

   scar 
  occupying 
  only 
  about 
  one-third 
  to 
  one-half 
  id 
  their 
  

  

  width. 
  

  

  Brachials 
  single, 
  narrow, 
  Bubtriangolar, 
  sharply 
  cuneat* 
  

   and 
  supporting 
  on 
  their 
  upper 
  Bides 
  the 
  first 
  arm 
  plat- 
  

   two 
  rays 
  visible 
  in 
  the 
  BpeciraeD 
  under 
  examination, 
  the 
  arms, 
  

   after 
  their 
  first 
  division 
  on 
  the 
  brachials, 
  divide 
  again, 
  both 
  divisi< 
  

   onee 
  on 
  the 
  second 
  plate 
  above 
  the 
  brachials, 
  and 
  one 
  of 
  them 
  the 
  

   second 
  time 
  on 
  the 
  second 
  arm 
  plate 
  above, 
  giving 
  nve 
  

  

  each 
  ray. 
  

  

  arms 
  composed 
  at 
  first 
  of 
  long, 
  rounded 
  joints, 
  that 
  ar 
  

   what 
  zigzag 
  and 
  projecting 
  on 
  their 
  me 
  when 
  tl 
  off 
  

  

  strong 
  pinnules, 
  but 
  towards 
  their 
  extremities 
  th 
  I 
  of 
  

  

  rt. 
  triangular 
  pieces 
  that 
  also 
  sustain 
  pinnules 
  on 
  tl 
  

   margins. 
  Pinnules 
  quite 
  stout, 
  their 
  diameter 
  bt 
  

   one-third 
  of 
  the 
  width 
  oi 
  the 
  plates 
  to 
  which 
  they 
  are 
  attached. 
  

   Hon 
  and 
  localitie$: 
  St. 
  Louis 
  tin 
  unty 
  lb.. 
  

  

  Blounl 
  county. 
  Trim. 
  

   No. 
  2,461, 
  Illinois 
  State 
  collection. 
  

  

  (.1 
  m 
  a 
  BRETMOCEIETUS, 
  L, 
  and 
  I 
  

   \ 
  >nsovn 
  mm, 
  Wortl 
  

  

  Will. 
  1 
  .• 
  14. 
  

  

  Bal 
  ' 
  -no. 
  

  

  Miull 
  and 
  turbi] 
  101 
  'be 
  

  

  si,. 
  ntlv 
  projecting 
  on 
  th. 
  ii 
  lower 
  I 
  wll 
  

  

  i 
  run 
  around 
  th< 
  

  

  