﻿289 
  PALEONTOLOGY 
  OF 
  ILLlNo; 
  

  

  <>nly 
  one 
  of 
  the 
  rays 
  i> 
  partially 
  preserved. 
  In 
  this 
  then 
  

   five 
  brachials, 
  the 
  last 
  one 
  of 
  which 
  is 
  an 
  axillary 
  plate, 
  and 
  sup- 
  

   port- 
  the 
  first 
  divisions 
  of 
  the 
  ray. 
  one 
  of 
  which 
  divides 
  again 
  on 
  

   the 
  third 
  plate, 
  beyond 
  which 
  the 
  arm- 
  are 
  not 
  pn 
  The 
  

  

  anus 
  are 
  composed 
  of 
  long, 
  Blender, 
  ronnded 
  joints, 
  generally 
  twice 
  

   as 
  long 
  as 
  wide. 
  

  

  Column 
  unknown. 
  

  

  rition 
  and 
  locality 
  : 
  Keokuk 
  limestone, 
  Warsaw, 
  111. 
  

  

  No. 
  2,464, 
  Illinois 
  Stale 
  collection. 
  

  

  PoTKBXOcanrcrB 
  Nauvooensis, 
  Worthen. 
  

  

  PL 
  XXVIII. 
  Fig. 
  10. 
  

  

  Pob 
  IVl.piary. 
  1882. 
  

  

  Bulk-tin 
  N... 
  1. 
  of 
  thi 
  ry 
  . 
  ,,. 
  ):i 
  . 
  

  

  Body 
  Bmall, 
  cup-shaped; 
  the 
  plates 
  being 
  displaced 
  Bomewhat 
  by 
  

   crashing, 
  prevents 
  a 
  complete 
  diagnosis. 
  

  

  Basale 
  small, 
  and 
  hidden 
  hy 
  the 
  first 
  columnar 
  joints. 
  Sul. 
  ra- 
  

   dial- 
  as 
  high 
  or 
  higher 
  than 
  wide, 
  and 
  aharply 
  angular 
  al 
  

   Radials 
  pentagonal, 
  wider 
  than 
  long. 
  First 
  brachial 
  quadrangular, 
  

   id 
  brachial 
  pentagonal, 
  and 
  both 
  as 
  wide 
  or 
  a 
  little 
  wider 
  than 
  

   (he 
  radials 
  In 
  low. 
  

  

  The 
  arms 
  of 
  only 
  one 
  of 
  the 
  rays, 
  the 
  h 
  ft 
  antero-lateral, 
  

   I 
  BO 
  that 
  it- 
  -tincture 
  can 
  be 
  made 
  out. 
  Th 
  

   the 
  second 
  brachial, 
  and 
  the 
  1. 
  ft 
  branch 
  twice 
  more 
  on 
  the 
  Birth 
  

   and 
  eighth 
  plate 
  above, 
  while 
  the 
  right 
  branch 
  divides 
  at 
  least 
  four 
  

   times 
  on 
  the 
  sixth 
  and 
  eighth 
  plates, 
  making 
  at 
  lit 
  arms 
  

  

  to 
  this 
  ray. 
  Anal 
  -. 
  1 
  ic- 
  cannot 
  DC 
  Been 
  clearly 
  eUOUgfa 
  to 
  DC 
  fully 
  

  

  determined; 
  they 
  are 
  apparently 
  arranged 
  as 
  canal 
  in 
  this 
  genus. 
  

  

  Column 
  round, 
  and 
  composed 
  of 
  thin, 
  unequal 
  joint-. 
  

  

  This 
  species 
  is 
  evidently 
  nearly 
  related 
  to 
  Hair- 
  ; 
  - 
  

   aqualis, 
  bul 
  differs 
  from 
  that 
  in 
  the 
  relative 
  bibs 
  of 
  its 
  Bubradial 
  

   plates, 
  and 
  m 
  the 
  number 
  and 
  mode 
  of 
  bifurcation 
  of 
  the 
  arm-. 
  

   ition 
  '111,1 
  locality: 
  Keokuk 
  hm. 
  in. 
  

  

  No. 
  2, 
  166, 
  Illinois 
  State 
  coll< 
  etion. 
  

  

  