﻿74 
  PROCEEDINGS 
  OF 
  THE 
  NATIONAL 
  MUSEUM 
  vol. 
  0,7 
  

  

  CULMICRINUS 
  MISSOURIENSIS 
  (Shumard) 
  

  

  Plate 
  IS, 
  fig. 
  3 
  

  

  Poteriocrinus 
  mis 
  sour 
  iensis 
  Shumard, 
  Geol. 
  Rep. 
  Missouri, 
  1S57, 
  p. 
  188, 
  

  

  pi. 
  B, 
  figs. 
  a-c. 
  

   St. 
  Louis 
  limestone 
  ; 
  St. 
  Louis, 
  Missouri. 
  

  

  One 
  of 
  the 
  best 
  known 
  fossils 
  in 
  the 
  St. 
  Louis 
  limestone, 
  of 
  which 
  

   many 
  good 
  specimens 
  have 
  been 
  found 
  with 
  the 
  elongate 
  ventral 
  

   sac 
  preserved, 
  but 
  it 
  is 
  only 
  in 
  the 
  one 
  herewith 
  figured 
  that 
  the 
  

   position 
  of 
  the 
  anal 
  opening 
  is 
  definitely 
  fixed 
  at 
  the 
  anterior 
  side 
  

   close 
  down 
  to 
  the 
  base. 
  The 
  species 
  is 
  notable 
  for 
  the 
  slender, 
  grace- 
  

   ful 
  contour 
  of 
  the 
  crown. 
  

  

  In 
  the 
  Revision 
  of 
  Palaeocrinoidea 
  (pt. 
  1, 
  1879, 
  p. 
  114), 
  Wach- 
  

   smuth 
  and 
  Springer 
  called 
  attention 
  to 
  the 
  fact 
  that 
  this 
  species 
  

   " 
  differs 
  from 
  all 
  others 
  in 
  this 
  group 
  in 
  having 
  a 
  single 
  arm 
  to 
  each 
  

   ray, 
  the 
  first 
  bifurcation 
  taking 
  place 
  at 
  the 
  tenth 
  or 
  twelfth 
  plate." 
  

  

  CULMICRINUS 
  ELEGANS 
  (Wachsmuth 
  and 
  Springer) 
  

  

  Plate 
  18, 
  figs. 
  1, 
  la 
  

  

  " 
  Scapliiocrinus 
  " 
  elegans, 
  Wachsmuth 
  and 
  Springer, 
  North 
  Amer. 
  Crin- 
  

  

  Cam., 
  1897, 
  pi. 
  7, 
  figs. 
  1, 
  2. 
  

   Chester 
  group, 
  Glen 
  Dean 
  formation 
  ; 
  Sloan's 
  Valley, 
  Kentucky. 
  

  

  I 
  have 
  figured 
  at 
  full 
  length 
  the 
  type 
  specimen, 
  of 
  which 
  only 
  a 
  

   partial 
  figure 
  was 
  given 
  in 
  1897, 
  in 
  order 
  to 
  show 
  the 
  great 
  size 
  of 
  

   the 
  sac, 
  this 
  being 
  the 
  best 
  known 
  example 
  of 
  the 
  lowest 
  position 
  of 
  

   the 
  opening. 
  The 
  tube 
  is 
  actually 
  a 
  little 
  longer 
  than 
  is 
  here 
  shown, 
  

   as 
  it 
  appears 
  in 
  a 
  second 
  specimen 
  from 
  the 
  same 
  locality 
  otherwise 
  

   not 
  so 
  perfect, 
  which 
  has 
  some 
  nodose 
  plates 
  to 
  mark 
  the 
  change 
  of 
  

   direction. 
  As 
  in 
  many 
  of 
  the 
  genera 
  of 
  this 
  group, 
  the 
  anterior 
  

   ray 
  differs 
  from 
  the 
  others, 
  in 
  this 
  case 
  being 
  unbranched. 
  

  

  Genus 
  AULOCRINUS 
  Wachsmuth 
  and 
  Springer 
  

  

  Plate 
  19. 
  

  

  AULOCRINUS 
  AGASSIZI 
  Wachsmuth 
  and 
  Springer 
  

  

  Aulocrinus 
  agassisi 
  Wachsmuth 
  and 
  Springer, 
  North 
  Amer. 
  Crin. 
  Uain., 
  

  

  1S97, 
  pi. 
  7, 
  fig. 
  9.— 
  Springer, 
  Amer. 
  Geol., 
  vol. 
  26, 
  1900, 
  pi. 
  16, 
  figs. 
  11, 
  12. 
  

  

  Mississippian 
  ; 
  Keokuk 
  group, 
  Indian 
  creek, 
  Montgomery 
  County, 
  Indiana. 
  

  

  A 
  monotypic 
  genus 
  founded 
  on 
  the 
  species 
  A. 
  agassizi, 
  figured 
  as 
  

   above 
  without 
  definition, 
  or 
  description, 
  but 
  based 
  solety 
  upon 
  the 
  

   extraordinary 
  form 
  of 
  the 
  ventral 
  sac, 
  which 
  with 
  its 
  lateral 
  spout 
  

   exhibits 
  a 
  specialization 
  without 
  precedent 
  among 
  the 
  crinoids. 
  Aside 
  

   from 
  this 
  the 
  form 
  is 
  essentially 
  that 
  of 
  Decadocrinus 
  as 
  to 
  calyx 
  and 
  

   arms, 
  but 
  differs 
  in 
  the 
  stem 
  and 
  cirri. 
  

  

  