﻿PALEOCRINOIDEA. 
  

  

  GENUS 
  ALLAGECRINUS, 
  Carp, 
  and 
  Ether. 
  

   Allagecrinus 
  Carpenteri, 
  Wacbsmuth. 
  

  

  PL 
  XXIX, 
  Fig. 
  14. 
  

  

  Allagecrinus 
  Carpenteri, 
  Wachsmuth, 
  February. 
  1882. 
  

  

  Bulletin 
  No. 
  1, 
  of 
  the 
  Illinois 
  State 
  Museum 
  of 
  Natural 
  History, 
  p. 
  40. 
  

  

  The 
  unique 
  specimen 
  upon 
  which 
  this 
  species 
  is 
  founded 
  is 
  from 
  

   the 
  collection 
  of 
  Prof. 
  Worthen, 
  who 
  kindly 
  permitted 
  me 
  to 
  describe 
  

   it. 
  It 
  is 
  partly 
  imbedded 
  in 
  the 
  rock, 
  but 
  only 
  a 
  small 
  portion 
  is 
  

   covered 
  by 
  the 
  matrix. 
  It 
  consists 
  of 
  a 
  two-inch 
  column, 
  the 
  calyx 
  

   and 
  arms. 
  The 
  calyx 
  is 
  somewhat 
  pressed 
  out 
  of 
  shape, 
  but 
  with 
  

   this 
  exception 
  is 
  excellently 
  preserved. 
  The 
  specimen 
  is 
  small, 
  its 
  

   length 
  measuring 
  from 
  the 
  basal 
  disk 
  to 
  the 
  tips 
  of 
  the 
  arms 
  80.100 
  

   parts 
  of 
  an 
  inch, 
  to 
  the 
  arm 
  bases 
  16.100 
  parts, 
  of 
  which 
  the 
  basal 
  

   disk 
  occupies 
  only 
  4.100 
  parts. 
  

  

  Specific 
  Diagnosis: 
  The 
  calyx 
  is 
  of 
  small 
  size, 
  the 
  form 
  is 
  cylin- 
  

   dro-conical 
  ; 
  it 
  is 
  composed 
  of 
  two 
  rings 
  of 
  plates, 
  the 
  upper 
  sup- 
  

   porting 
  the 
  arms. 
  There 
  are 
  no 
  interradials, 
  and 
  no 
  azygous 
  side. 
  

   Plates 
  strong, 
  without 
  ornamentation. 
  

  

  Basal 
  disk 
  undivided, 
  at 
  least 
  without 
  visible 
  suture 
  lines 
  ; 
  it 
  is 
  

   short, 
  three 
  times 
  wider 
  than 
  high, 
  saucer-shaped 
  — 
  the 
  upper 
  side 
  

   but 
  little 
  wider 
  than 
  the 
  bottom 
  part, 
  with 
  very 
  obtuse 
  upper 
  angles. 
  

  

  Kadials 
  1x5, 
  differing 
  somewhat 
  in 
  width, 
  — 
  wider 
  at 
  the 
  top, 
  — 
  

   quadrangular 
  in 
  outline, 
  but 
  actually 
  pentangular; 
  axillary, 
  with 
  

   very 
  obtuse 
  upper 
  angles, 
  the 
  sloping 
  sides 
  slightly 
  excavated 
  and 
  

   supporting 
  the 
  free 
  arms. 
  

  

  Arms 
  two 
  from 
  each 
  ray, 
  simple 
  throughout, 
  unequal 
  in 
  size, 
  — 
  

   some 
  of 
  them 
  one-half 
  thicker 
  than 
  others 
  — 
  not 
  tapering; 
  nearly 
  as 
  

   thick 
  at 
  the 
  distal 
  end 
  as 
  at 
  the 
  base. 
  The 
  arms 
  are 
  constructed 
  

  

  