﻿INVEBTEBKATES. 
  311 
  

  

  Column 
  round, 
  very 
  strong 
  at 
  the 
  base 
  of 
  the 
  calyx, 
  decreasing 
  

   about 
  one-half 
  in 
  diameter 
  a 
  half 
  inch 
  below, 
  and 
  composed 
  of 
  rather 
  

   thin, 
  even 
  joints. 
  

  

  Position 
  and 
  locality: 
  Kinderhook 
  group, 
  Marshalltown, 
  Iowa. 
  

  

  The 
  author's 
  collection. 
  

  

  GENUS 
  EUPACHYCRINUS, 
  Meek 
  andWorthen. 
  

  

  Eupachycrinus 
  asperatus, 
  Worthen. 
  

  

  PI. 
  XXIX. 
  Fig. 
  4. 
  

  

  Eupachycrinus 
  asperatus, 
  Wokthen, 
  February, 
  1882. 
  

  

  Bulletin 
  No. 
  1, 
  of 
  the 
  Illinois 
  State 
  Museum 
  of 
  Natural 
  History, 
  p. 
  34. 
  

  

  Body 
  of 
  medium 
  size, 
  basin-shaped, 
  composed 
  of 
  very 
  massive 
  

   angular 
  plates. 
  Base 
  deeply 
  concave 
  and 
  basals 
  concealed 
  by 
  the 
  

   column. 
  

  

  Subradials 
  very 
  massive, 
  projecting 
  outward 
  and 
  downward, 
  

   slightly 
  excavated 
  below 
  from 
  their 
  outer 
  sides 
  to 
  the 
  point 
  where 
  

   they 
  join 
  the 
  basals, 
  and 
  forming 
  five 
  prominent 
  angular 
  nodes 
  on 
  

   which 
  the 
  body 
  would 
  rest 
  when 
  divested 
  of 
  its 
  column. 
  

  

  Badials 
  nearly 
  twice 
  as 
  wide 
  as 
  long, 
  four 
  of 
  them 
  pentagonal, 
  

   the 
  right 
  posterior 
  one 
  quadrangular, 
  and 
  all 
  produced 
  into 
  obtuse 
  

   nodes 
  or 
  ridges 
  that 
  on 
  three 
  of 
  them 
  extend 
  nearly 
  across 
  the 
  plate, 
  

   nearer 
  to 
  the 
  lower 
  than 
  the 
  upper 
  margin, 
  leaving 
  a 
  broad, 
  sloping 
  

   surface 
  between 
  the 
  ridges 
  and 
  the 
  upper 
  margin 
  of 
  the 
  radial 
  

   plates. 
  

  

  Brachials 
  on 
  each 
  of 
  the 
  anterior 
  and 
  tbe 
  antero-lateral 
  rays, 
  

   shorter 
  and 
  about 
  the 
  same 
  width 
  as 
  the 
  radials, 
  and 
  like 
  them 
  

   produced 
  into 
  a 
  distinct 
  ridge 
  on 
  their 
  upper 
  margins. 
  

  

  The 
  right 
  posterior 
  brachial 
  supports 
  two 
  shorter 
  brachials, 
  and 
  

   these 
  support 
  above 
  two 
  arms 
  each, 
  making 
  four 
  arms 
  to 
  this 
  ray. 
  

   The 
  left 
  posterior 
  brachial 
  supports 
  an 
  additional 
  brachial 
  on 
  one 
  

   side, 
  that 
  gives 
  support 
  to 
  two 
  arms, 
  while 
  a 
  single 
  arm 
  is 
  supported 
  

   on 
  the 
  other 
  side, 
  making 
  three 
  arms 
  to 
  this 
  ray. 
  The 
  other 
  

   brachials 
  give 
  support 
  to 
  two 
  arms 
  each, 
  making 
  thirteen 
  altogether 
  

   for 
  this 
  species. 
  The 
  first 
  three 
  or 
  four 
  plates 
  of 
  each 
  arm 
  are 
  quad- 
  

   rangular, 
  but 
  they 
  soon 
  pass 
  into 
  a 
  series 
  of 
  wedge-formed 
  interlock- 
  

   ing 
  pieces, 
  gradually 
  becoming 
  narrower 
  toward 
  their 
  extremities. 
  

  

  