﻿art 
  9 
  UNUSUAL, 
  FORMS 
  OF 
  FOSSIL 
  CRINOIDS 
  SPRINGER 
  73 
  

  

  here 
  shown, 
  but 
  I 
  am 
  figuring 
  it 
  because 
  enough 
  of 
  the 
  sac 
  can 
  be 
  

   seen 
  on 
  the 
  opposite 
  side, 
  although 
  too 
  much 
  shattered 
  for 
  drawing, 
  

   to 
  show 
  that 
  it 
  was 
  substantially 
  like 
  that 
  of 
  the 
  other 
  species 
  figured, 
  

   with 
  the 
  opening 
  about 
  midway. 
  

  

  ABROTOCRINUS 
  UNICUS 
  (Hall) 
  

  

  Plate 
  17, 
  figs. 
  1-3 
  

  

  » 
  

   PoteriocHnus 
  (Scaphiocrinus) 
  unicus 
  Hall, 
  Boston 
  Journ. 
  Nat. 
  Hist., 
  

   1861, 
  p. 
  313. 
  — 
  Meek 
  and 
  Worthen, 
  Geol. 
  Surv. 
  111., 
  vol. 
  5, 
  pi. 
  15, 
  fig. 
  

   5. 
  — 
  Wachsmuth 
  and 
  Springer, 
  North 
  Ainer. 
  Crin. 
  Cam., 
  1S97, 
  pi. 
  7, 
  

  

  fig. 
  6. 
  

   Keokuk 
  limestone 
  ; 
  Crawfordsville, 
  Indiana. 
  

  

  One 
  of 
  the 
  very 
  prominent 
  species 
  of 
  its 
  celebrated 
  locality, 
  in 
  

   Avhich 
  the 
  sac 
  with 
  its 
  midway 
  opening 
  is 
  shown 
  by 
  numerous 
  speci- 
  

   mens, 
  quite 
  constant 
  throughout. 
  The 
  pentagonal 
  stem, 
  at 
  least 
  

   next 
  to 
  the 
  calyx, 
  is 
  distinct 
  in 
  more 
  than 
  fifty 
  specimens. 
  

  

  Genus 
  CULMICRINUS 
  Jaekel 
  

  

  Plate 
  18 
  

  

  Culmicrinus 
  Jaekel, 
  Philogenie 
  und 
  System 
  der 
  Polmatozen, 
  Pal. 
  Deut- 
  

   schl., 
  Berlin, 
  vol. 
  3, 
  191S, 
  p. 
  62. 
  Untercarb. 
  (Kulm). 
  Pro 
  Poterio- 
  

   crinus 
  regularis 
  H. 
  von 
  Meyer, 
  Herborn. 
  To 
  include 
  Poteriocr. 
  mis- 
  

   souriensis 
  Sbumard. 
  

  

  Devonian 
  to 
  upper 
  Chester. 
  

  

  Under 
  this 
  name 
  Professor 
  Jaekel 
  has 
  included 
  a 
  form 
  which 
  I 
  

   have 
  had 
  set 
  apart 
  in 
  my 
  collection 
  for 
  many 
  years 
  as 
  a 
  new 
  genus, 
  

   containing 
  species 
  from 
  at 
  least 
  four 
  different 
  formations. 
  The 
  

   dominant 
  character 
  is 
  that 
  it 
  has 
  more 
  than 
  two 
  primibrachs, 
  the 
  

   number 
  actually 
  ranging 
  from 
  five 
  to 
  ten 
  before 
  the 
  first 
  bifurcation, 
  

   after 
  which 
  the 
  arms 
  branch 
  a 
  few 
  times 
  at 
  long 
  intervals, 
  with 
  

   rather 
  sparse 
  pinnules 
  borne 
  on 
  cuneiform 
  brachials. 
  The 
  calyx 
  is 
  

   elongate, 
  turbinate, 
  with 
  round 
  stem. 
  The 
  remarkable 
  thing 
  about 
  

   this 
  form 
  is 
  its 
  extremely 
  large 
  sac, 
  rising 
  to 
  the 
  full 
  height 
  of 
  the 
  

   arms, 
  with 
  the 
  anal 
  opening 
  at 
  the 
  very 
  base. 
  

  

  The 
  form 
  with 
  extra 
  primibrachs, 
  varying 
  considerably 
  in 
  other 
  

   characters, 
  ranges 
  in 
  America 
  from 
  the 
  Chemung 
  through 
  the 
  

   Waverly 
  or 
  its 
  equivalent 
  into 
  the 
  St. 
  Louis, 
  ending 
  in 
  the 
  upper 
  

   formation 
  of 
  the 
  Chester. 
  Several 
  Chemung 
  and 
  Portage 
  species 
  

   have 
  been 
  described 
  by 
  Miss 
  Winifred 
  Goldring 
  under 
  Liimrocrinus 
  

   and 
  three 
  other 
  new 
  genera 
  in 
  the 
  Monograph 
  of 
  the 
  Devonian 
  

   Crinoids 
  just 
  published 
  by 
  the 
  State 
  Museum 
  of 
  New 
  York, 
  and 
  

   received 
  too 
  late 
  for 
  detailed 
  consideration 
  here. 
  The 
  species 
  from 
  

   the 
  Waverly 
  equivalent, 
  or 
  basal 
  Mississippian, 
  as 
  yet 
  undescribed, 
  

   occurs 
  in 
  the 
  form 
  of 
  imperfect 
  impressions 
  in 
  western 
  Pennsylvania. 
  

   The 
  other 
  two 
  are 
  figured 
  herewith. 
  

   23832—26 
  6 
  

  

  