﻿846 
  PALEONTOLOGY 
  OF 
  ILLINOIS. 
  

  

  ON 
  A 
  NEW 
  GENUS 
  AND 
  SPECIES 
  

  

  OF 
  

  

  BLASTOIDS, 
  

  

  WITH 
  OH8EBVATION8 
  

  

  THE 
  STRUCTURE 
  OF 
  THE 
  BA8AL 
  PLATES 
  IN 
  CODA8TEB 
  

   AND 
  PENTREMITE8. 
  

  

  BY 
  OH 
  A. 
  RLE 
  3 
  WACHSMTJTH. 
  

  

  Among 
  sum, 
  interesting 
  new 
  Blastoids, 
  lately 
  Bent 
  to 
  me 
  for 
  in- 
  

   vestigation 
  by 
  Rev. 
  W. 
  II. 
  Barris, 
  of 
  Davenport, 
  Iowa, 
  collected 
  by 
  

   him 
  in 
  Northern 
  Michigan, 
  I 
  found 
  one 
  type, 
  which 
  » 
  to 
  me 
  

  

  of 
  unusual 
  inte] 
  representing 
  a 
  form 
  intermediate 
  

  

  Codaster. 
  McCoy, 
  and 
  the 
  new 
  genua 
  PfumtAckuma, 
  Ether, 
  and 
  c';irp. 
  

   A; 
  my 
  request, 
  Mr. 
  Harris 
  not 
  only 
  kindly 
  permitted 
  me 
  to 
  describe 
  

   the 
  a 
  bu( 
  he 
  very 
  liberally 
  furnished 
  me 
  a 
  number 
  of 
  B] 
  

  

  mens, 
  which 
  he 
  allowed 
  to 
  be 
  oul 
  for 
  sections. 
  I 
  iving 
  the 
  

  

  ription 
  of 
  t 
  ho 
  form, 
  I 
  wish 
  t.> 
  make 
  a 
  few 
  remarks 
  upon 
  the 
  

   tenninology 
  employed 
  in 
  this 
  and 
  thi 
  ling 
  paper 
  by 
  Mr. 
  k 
  

  

  Binoe 
  the 
  appearance 
  of 
  Prof. 
  F. 
  Roemer'i 
  ical 
  work 
  upon 
  

  

  tin- 
  Blastoidea, 
  his 
  terms, 
  with 
  Blighl 
  variations, 
  were 
  osed, 
  both 
  in 
  

   this 
  country 
  and 
  in 
  Europe, 
  by 
  all 
  the 
  leading 
  palsontolo 
  

   Roemer's 
  trim- 
  are 
  no 
  doubt 
  appropriate, 
  but 
  they 
  hi 
  

  

  of 
  giving 
  new 
  nan* 
  srtain 
  part- 
  which 
  in 
  allied 
  

  

  groups 
  had 
  previously 
  n 
  propel 
  • 
  • 
  n. 
  \n 
  parts 
  thai 
  

  

  are 
  founded 
  upon 
  identity 
  of 
  plan, 
  or 
  which 
  are 
  analogous 
  in 
  their 
  

   fund 
  ouid 
  always 
  be 
  called 
  by 
  the 
  same 
  nam.. 
  

  

  . 
  unnecessarily 
  introduced, 
  lead 
  to 
  the 
  impression 
  that 
  the 
  

   differ 
  r 
  than 
  I 
  mid 
  

  

  they 
  form 
  a 
  -.nous 
  ,„ 
  nis;i 
  ] 
  () 
  f 
  t 
  |„. 
  , 
  , 
  ( 
  | 
  lf 
  . 
  

  

  