﻿art 
  9 
  IX 
  USUAL 
  FORMS 
  OF 
  FOSSIL 
  CRINOIDS 
  SPRINGER 
  53 
  

  

  Genus 
  AGASSIZOCRINUS 
  Owen 
  and 
  Shumard 
  

  

  Plate 
  15 
  

  

  [ffassizocrinus 
  Troost, 
  Ms., 
  Proc. 
  Amer. 
  Assn. 
  Adv. 
  Sci., 
  1850, 
  p. 
  60. 
  Not 
  

   defined, 
  nomen 
  nudum. 
  — 
  Owen 
  and 
  Shumard, 
  Journ. 
  Acad. 
  Nat. 
  Sci. 
  

   Phila., 
  ser. 
  2, 
  1852, 
  p. 
  93.— 
  Shumard, 
  Marcy's 
  Red 
  River 
  Exped., 
  1854, 
  

   p. 
  173. 
  

  

  Astylocrinus 
  Roemer, 
  Lethaea 
  Geognost, 
  1855, 
  vol. 
  1, 
  pi. 
  2, 
  p. 
  229. 
  

  

  Agassizocrinus, 
  Wachsmuth 
  and 
  Springer, 
  Rev. 
  Pal., 
  pt. 
  3, 
  18S6. 
  p. 
  2G2. 
  — 
  

   S. 
  A. 
  Miller, 
  N. 
  A. 
  Geol. 
  and 
  Pal., 
  1889, 
  p. 
  221.— 
  Bathee, 
  Lankester 
  

   Zoology, 
  pt. 
  3, 
  1900, 
  p. 
  103.— 
  Zittel-Eastman, 
  Textb. 
  Pal., 
  1913, 
  p. 
  224. 
  35 
  

  

  Mississippian, 
  Upper 
  Chester. 
  

  

  The 
  following 
  species, 
  in 
  chronological 
  order, 
  have 
  been 
  described 
  

   under 
  this 
  genus, 
  or 
  referred 
  to 
  it; 
  all 
  upper 
  Chester 
  unless 
  other- 
  

   wise 
  stated 
  : 
  

  

  1852. 
  Agassizocrinus 
  conicus 
  Owen 
  and 
  Shumard, 
  Journ. 
  Acad. 
  Nat. 
  Sci. 
  Phila., 
  

   ser. 
  2, 
  vol. 
  2, 
  p. 
  93, 
  pi. 
  11, 
  fig. 
  G 
  ; 
  Geol. 
  Sur. 
  Iowa, 
  Wis. 
  and 
  Minn., 
  

   1852, 
  p. 
  597, 
  pi. 
  5B, 
  fig. 
  6.— 
  Meek 
  and 
  Worthen, 
  Geol. 
  Surv. 
  111., 
  vol. 
  

   5, 
  1873, 
  pi. 
  21, 
  fig. 
  S. 
  

  

  Elongate 
  conical; 
  no 
  marks 
  for 
  insertion 
  of 
  column; 
  base 
  (IBB) 
  

   composed 
  of 
  5 
  pieces 
  closely 
  adhering, 
  usually 
  anchylosed 
  ; 
  IBB 
  cone 
  ex- 
  

   tremely 
  high, 
  higher 
  than 
  in 
  any 
  species 
  subsequently 
  described 
  ; 
  

   height 
  to 
  width 
  to 
  height 
  of 
  IBB, 
  in 
  mm., 
  25/17/15. 
  Chester, 
  Illinois. 
  

  

  1852. 
  Also 
  described 
  in 
  the 
  same 
  publication 
  as 
  Poteri-ocrinus, 
  and 
  referred 
  by 
  

   subsequent 
  authors 
  to 
  this 
  genus: 
  A 
  tumidus 
  (Owen 
  and 
  Shumard), 
  

   p. 
  90, 
  pi. 
  11; 
  figs. 
  3a, 
  b. 
  A. 
  Occident 
  alls 
  (Owen 
  and 
  Shumard), 
  p. 
  92, 
  

   pi. 
  11, 
  figs. 
  5a, 
  b. 
  Both 
  Chester, 
  Illinois. 
  

  

  1854. 
  A 
  dactyliformis 
  Shumard, 
  Marcy's 
  Red 
  River 
  Exped., 
  p. 
  173, 
  pi. 
  1, 
  fig. 
  7. 
  

  

  Washington 
  county, 
  Arkansas. 
  

  

  1855. 
  A. 
  laevis 
  (Roemer), 
  Lethaea 
  Geogn., 
  vol. 
  1, 
  pi. 
  2, 
  p. 
  229, 
  pi. 
  4, 
  figs. 
  

  

  13ar-d 
  (as 
  Astylocrinus). 
  Figs, 
  b, 
  c, 
  d 
  are 
  from 
  the 
  small 
  basal 
  cones 
  

   found 
  in 
  great 
  abundance 
  on 
  Prairie 
  du 
  Long 
  creek 
  in 
  Randolph 
  

   county, 
  Illinois 
  ; 
  fig. 
  a 
  from 
  a 
  nearly 
  complete 
  specimen 
  said 
  by 
  the 
  

   author 
  to 
  be 
  from 
  Indiana, 
  but 
  the 
  authentic 
  type 
  is 
  from 
  Chester, 
  

   Illinois.— 
  Pictet, 
  Traite 
  d. 
  Pal., 
  1S57, 
  vol. 
  4, 
  p. 
  291, 
  pi. 
  99, 
  fig. 
  8; 
  

   copied 
  from 
  Roemer 
  with 
  some 
  changes, 
  among 
  them 
  inserting 
  a 
  

   circlet 
  of 
  divided 
  plates 
  above 
  the 
  basal 
  cone, 
  making 
  4 
  ranges 
  of 
  

   plates. 
  — 
  (As 
  A. 
  dactyliformis 
  Troost), 
  Meek 
  and 
  Worthen, 
  111., 
  vol. 
  5, 
  

   1873, 
  pi. 
  21, 
  figs, 
  la, 
  b.— 
  S. 
  A. 
  Miller, 
  North 
  Amer. 
  Geol. 
  and 
  Pal., 
  

   18S9, 
  p. 
  221, 
  fig. 
  240. 
  — 
  Troost, 
  Ms., 
  nomen 
  nudum. 
  Proc. 
  Amer. 
  Assn. 
  

   Adv. 
  Sci., 
  1S50, 
  p. 
  60; 
  Bull. 
  64, 
  U. 
  S. 
  Nat. 
  Mus., 
  1909, 
  p. 
  96, 
  pi. 
  12, 
  

   ng. 
  1. 
  

  

  Large, 
  broadly 
  rounded 
  ovate 
  ; 
  base 
  fused, 
  with 
  traces 
  of 
  sutures 
  in 
  

   upper 
  part 
  ; 
  IBB 
  more 
  than 
  Va 
  total 
  height 
  of 
  calyx 
  ; 
  H 
  to 
  W 
  to 
  IBB 
  

   21/19/9. 
  Chester, 
  Illinois. 
  

   185S. 
  A. 
  gibbosus 
  Hall, 
  Geol. 
  Iowa, 
  pt. 
  2, 
  p. 
  686, 
  pi. 
  25, 
  fig. 
  6.— 
  Worthen, 
  111., 
  

   vol. 
  5, 
  p. 
  556, 
  pi. 
  21, 
  fig. 
  11. 
  

  

  Small, 
  broadly 
  conical; 
  base 
  fused, 
  IBB 
  not 
  over 
  % 
  total 
  height 
  

   of 
  calyx 
  : 
  12/11/4. 
  Chester, 
  Illinois. 
  

  

  55 
  I 
  am 
  not 
  attempting 
  to 
  give 
  complete 
  synonymy 
  under 
  any 
  of 
  the 
  genera, 
  but 
  only 
  

   such 
  references 
  as 
  will 
  indicate 
  the 
  chief 
  sources 
  of 
  Information 
  and 
  facilitate 
  the 
  consid- 
  

   eration 
  of 
  the 
  forms 
  under 
  discussion. 
  

  

  