﻿art 
  9 
  UNUSUAL 
  FORMS 
  OF 
  FOSSIL 
  CRINOIDS 
  SPRINGER 
  89 
  

  

  which 
  it 
  may 
  be 
  the 
  successor. 
  The 
  genus 
  belongs 
  typically 
  to 
  the 
  

   later 
  Lower 
  Carboniferous, 
  Hurlet 
  in 
  Britain 
  and 
  Chester 
  in 
  

   America, 
  and 
  ranges 
  up 
  into 
  the 
  Upper 
  Carboniferous. 
  

  

  The 
  British 
  species 
  of 
  the 
  genus 
  have 
  been 
  extensively 
  discussed 
  in 
  

   recent 
  years 
  by 
  Doctor 
  Bather 
  and 
  Mr. 
  Wright, 
  with 
  the 
  benefit 
  of 
  

   fine 
  newly 
  discovered 
  material 
  obtained 
  by 
  the 
  latter 
  gentleman 
  in 
  

   the 
  Hurlet 
  limestone 
  of 
  Scotland, 
  especially 
  of 
  the 
  species 
  H. 
  woodi- 
  

   anus, 
  in 
  which 
  the 
  structures 
  of 
  the 
  ventral 
  sac 
  and 
  arms 
  are 
  well 
  

   shown. 
  Along 
  with 
  a 
  careful 
  account 
  of 
  the 
  generic 
  characters, 
  

   Bather, 
  52 
  with 
  his 
  usual 
  lucid 
  diagrams 
  and 
  figures, 
  gives 
  the 
  most 
  

   particular 
  description 
  yet 
  published 
  of 
  the 
  ventral 
  sac 
  and 
  arms. 
  

   Of 
  the 
  latter 
  he 
  says 
  : 
  

  

  Only 
  one 
  ramus, 
  after 
  each 
  bifurcation, 
  bifurcates 
  again, 
  and 
  that 
  is 
  the 
  one 
  

   next 
  to 
  the 
  middle 
  line 
  of 
  the 
  ray; 
  all 
  branches 
  on 
  the 
  outer 
  side 
  continue 
  

   single 
  to 
  the 
  end. 
  

  

  This 
  excellent 
  description 
  of 
  the 
  mode 
  of 
  arm 
  branching 
  has 
  a 
  

   special 
  interest 
  in 
  relation 
  to 
  the 
  American 
  species. 
  As 
  to 
  the 
  ventral 
  

   sac 
  he 
  says: 
  

  

  No 
  anal 
  opening 
  is 
  yet 
  known, 
  but 
  it 
  probably 
  lay 
  at 
  the 
  base 
  of 
  the 
  ventral 
  

   sac 
  on 
  the 
  anterior 
  side, 
  where 
  Wachsmuth 
  and 
  Springer 
  have 
  found 
  it 
  in 
  

   other 
  fistulate 
  crinoids. 
  

  

  Professor 
  Wanner, 
  in 
  his 
  work 
  of 
  1916 
  on 
  Permischen 
  Echinod- 
  

   ermen 
  von 
  Timor 
  (pp. 
  150-166), 
  has 
  described 
  and 
  figured 
  several 
  

   species 
  under 
  this 
  genus, 
  53 
  some 
  of 
  which 
  seem 
  to 
  me 
  to 
  have 
  more 
  the 
  

   habitus 
  of 
  Coelioorinus, 
  with 
  the 
  rounded 
  inflated 
  ventral 
  sac. 
  

  

  HYDREIONOCRINUS 
  DEPRESSUS 
  (Hall 
  from 
  Troost) 
  

  

  Plate 
  26, 
  figs. 
  1-2 
  

  

  Zeacrinus 
  depressus 
  Hall, 
  Geol. 
  Iowa, 
  pt. 
  2, 
  1858, 
  p. 
  546. 
  

   Hydreionocrinus 
  armiger, 
  Wachsmuth 
  and 
  Springer, 
  Rev. 
  Pal., 
  pt. 
  1, 
  

  

  1879, 
  p. 
  31 
  ; 
  pt. 
  3, 
  p. 
  245. 
  — 
  Wetherby, 
  Journ. 
  Cincinnati 
  Soc. 
  Nat. 
  Hist., 
  

  

  1881, 
  p. 
  325, 
  pi. 
  9, 
  figs. 
  1-4, 
  6. 
  

   Upper 
  Chester 
  ; 
  Pulaski 
  and 
  Grayson 
  Counties, 
  Kentucky. 
  

  

  HYDREIONOCRINUS 
  WETHERBYI 
  Wachsmuth 
  and 
  Springer 
  

  

  Plate 
  25, 
  figs. 
  4-12 
  

  

  Hydreionocrinus 
  armiger, 
  Wachsmuth 
  and 
  Springer, 
  Rev. 
  Pal., 
  pt. 
  1, 
  

   1879, 
  p. 
  131. 
  — 
  Wetherby, 
  Journ. 
  Cincinnati 
  Soc. 
  Nat. 
  Hist., 
  1881, 
  p. 
  

   328, 
  pi. 
  9, 
  figs. 
  4-11. 
  

  

  Hydreionocrinus 
  tvetherbyi 
  Wachsmuth 
  and 
  Springer, 
  Rev. 
  Pal., 
  pt. 
  3, 
  

   1886, 
  p. 
  245. 
  

  

  Upper 
  Chester; 
  Pulaski 
  and 
  Grayson 
  Counties, 
  Kentucky. 
  

  

  52 
  Notes 
  on 
  Hydreionocrinus, 
  Trans. 
  Edinb. 
  Geol. 
  Soc, 
  vol. 
  10, 
  pt. 
  1, 
  1911-12, 
  pp. 
  61-76, 
  

   with 
  one 
  plate. 
  

  

  53 
  Now, 
  in 
  the 
  second 
  volume 
  of 
  his 
  work, 
  1924, 
  p. 
  250, 
  referred 
  to 
  a 
  new 
  genus, 
  Cado- 
  

   crinus, 
  which, 
  for 
  lack 
  of 
  radia,nal, 
  does 
  not 
  strictly 
  fall 
  within 
  this 
  subfamily. 
  

  

  