﻿British 
  Fossil 
  Crino'uh. 
  253 
  

  

  therefore 
  eliminate 
  the 
  monocyclic 
  S. 
  jacksoui. 
  Of 
  the 
  two 
  

   dicyclic 
  species 
  I 
  select 
  ;S^. 
  aiiapcptameuus 
  as 
  the 
  genotype; 
  

   and 
  if 
  reasons 
  for 
  this 
  course 
  be 
  required^ 
  tliere 
  are 
  two 
  good 
  

   ones 
  : 
  first, 
  it 
  was 
  the 
  species 
  chosen 
  for 
  reconstruction, 
  

   so 
  as 
  to 
  give 
  Austin^s 
  idea 
  of 
  the 
  genus 
  ; 
  secondly, 
  it 
  

   is 
  the 
  only 
  one 
  of 
  which 
  an 
  authentic 
  original 
  specimen 
  is 
  

   known, 
  which 
  specimen 
  1 
  have 
  above 
  selected 
  as 
  the 
  

   holotype. 
  

  

  Sycocrinus 
  therefore 
  stands, 
  with 
  genotype 
  S. 
  anapej)ta' 
  

   menus 
  ; 
  and 
  even 
  if 
  Austin's 
  account 
  was 
  not 
  perfectly 
  

   satisfactory, 
  the 
  essential 
  characters 
  of 
  the 
  genus 
  are 
  now^ 
  

   I 
  trust, 
  quite 
  intelligible. 
  

  

  To 
  this 
  genus 
  I 
  also 
  refer 
  " 
  Hypocrinus 
  " 
  piriformis 
  

   Rothpletz. 
  

  

  To 
  include 
  the 
  two 
  species 
  the 
  generic 
  diagnosis 
  drawn 
  up 
  

   to 
  receive 
  " 
  HP 
  jnriforinis 
  may 
  now 
  be 
  slightly 
  modified 
  

   (6/. 
  Proc. 
  Zool. 
  Soc. 
  1913, 
  p. 
  912). 
  

  

  Diagnosis 
  of 
  Sycocrinus. 
  — 
  A 
  Taxocrinid 
  with 
  no 
  radianal, 
  

   with 
  large 
  IB15 
  forming 
  a 
  conspicuous 
  part 
  of 
  the 
  cup, 
  with 
  

   left 
  post. 
  E, 
  and 
  arm 
  enlarged 
  and 
  all 
  others 
  reduced 
  in 
  size, 
  

   with 
  rectum 
  passing 
  out 
  between 
  13B 
  and 
  KR, 
  being 
  bounded 
  

   either 
  by 
  post. 
  B, 
  i. 
  post. 
  II, 
  and 
  r. 
  post. 
  R, 
  or 
  by 
  those 
  

   plates 
  and 
  by 
  r. 
  post. 
  B 
  and 
  r. 
  ant. 
  R 
  in 
  addition. 
  

  

  Habits. 
  — 
  The 
  asymmetry 
  of 
  Sycocrinus 
  suggests 
  that, 
  like 
  

   many 
  of 
  the 
  similarly 
  asymmetric 
  Eugeniacrmidre, 
  it 
  was 
  a 
  

   reef-dweller, 
  fixed 
  to 
  a 
  rocky 
  shore 
  by 
  a 
  short 
  stem, 
  and 
  

   exposed 
  to 
  a 
  food-bearing 
  current 
  of 
  some 
  force 
  flowing 
  in 
  

   one 
  direction. 
  The 
  cup, 
  one 
  supposes, 
  was 
  so 
  placed 
  that 
  

   the 
  inner 
  side 
  of 
  the 
  large 
  left 
  posterior 
  arm 
  faced 
  the 
  

   current. 
  The 
  same 
  current 
  that 
  brought 
  the 
  food-particles 
  

   would 
  have 
  swept 
  away 
  the 
  fcecal 
  stream 
  as 
  it 
  issued 
  from 
  

   the 
  laterally 
  projecting 
  anal 
  tube 
  (PI. 
  X. 
  fig. 
  1 
  d). 
  

  

  Geological 
  Age 
  — 
  The 
  limestone 
  at 
  Settle, 
  whence 
  all 
  the 
  

   Austins' 
  specimens 
  were 
  obtained, 
  is 
  in 
  the 
  Dibunopliylluiu 
  

   zone 
  ; 
  the 
  precise 
  horizon 
  from 
  which 
  they 
  were 
  collected 
  is 
  

   unknown. 
  

  

  I 
  cannot 
  close 
  this 
  note 
  without 
  recurring 
  to 
  the 
  question 
  

   of 
  the 
  age 
  of 
  the 
  Timor 
  pelmatozoa. 
  I 
  have 
  previously 
  

   remarked 
  on 
  the 
  Lower 
  Carboniferous 
  affinities 
  of 
  Schizo^ 
  

   blastus 
  (1908, 
  N. 
  Jahrb. 
  f. 
  Mineral., 
  Beil. 
  Bd. 
  xxv. 
  p. 
  318). 
  

   Sycocrinus 
  now 
  appears 
  both 
  in 
  Timor 
  and 
  in 
  our 
  Lower 
  

   Carboniferous. 
  And 
  perhaps 
  Dr. 
  Wanner 
  will 
  allow 
  me 
  to 
  

   state 
  that 
  in 
  my 
  coseval 
  Cydonocrinus 
  he 
  has 
  recognized 
  

   another 
  form 
  found 
  by 
  him 
  also 
  in 
  Timor. 
  Even 
  Hypo- 
  

   crinus 
  may 
  be 
  represented 
  in 
  Yorkshire 
  by 
  " 
  Sycocrinus 
  " 
  

  

  