﻿246 
  Mr. 
  F. 
  A. 
  Batlier 
  on 
  

  

  or 
  figured. 
  It 
  is, 
  however, 
  possible 
  to 
  glean 
  some 
  facts 
  con- 
  

   cerning 
  the 
  genus 
  from 
  tlie 
  position 
  to 
  which 
  it 
  was 
  assigned. 
  

   Being 
  in 
  the 
  Class 
  Adelostella 
  (Austin), 
  it 
  had 
  a 
  " 
  body 
  

   covered 
  with 
  closely-jointed 
  calcareous 
  plates, 
  not 
  lobed, 
  and 
  

   without 
  arms." 
  Being 
  in 
  the 
  Order 
  Columnidoe 
  (Austin'), 
  

   its 
  body 
  was 
  ''attached 
  by 
  a 
  jointed 
  . 
  . 
  . 
  column.-" 
  Of 
  the 
  

   two 
  Families 
  : 
  SpliBeronoideae 
  ((J 
  ray) 
  and 
  Echinocrinoidea 
  

   (Austin) 
  into 
  which 
  that 
  Order 
  was 
  divided, 
  Sycocrinus 
  was 
  

   placed 
  in 
  the 
  former 
  ; 
  we 
  may 
  therefore 
  infer 
  that 
  " 
  pores 
  ^' 
  

   were 
  eitlier 
  '' 
  wanting 
  " 
  or 
  " 
  scattered 
  irrcgulai'ly 
  among 
  

   the 
  plates," 
  and 
  that 
  the 
  "surface" 
  was 
  ''smooth/' 
  i.e. 
  

   devoid 
  of 
  spines. 
  

  

  In 
  March, 
  1843, 
  the 
  " 
  Descriptions 
  of 
  several 
  new 
  Genera 
  

   and 
  Species 
  of 
  Crinoidca," 
  whose 
  names 
  had 
  been 
  introduced 
  

   in 
  the 
  previous 
  paper, 
  were 
  published 
  by 
  the 
  Austins, 
  and 
  

   among 
  them 
  the 
  definitions 
  of 
  Sycocrinus 
  and 
  its 
  three 
  

   species 
  (Ann. 
  & 
  Mag. 
  Nat. 
  Hist. 
  vol. 
  xi. 
  p. 
  20G). 
  It 
  is 
  not 
  

   necessary 
  to 
  reprint 
  these 
  definitions, 
  but, 
  translating 
  them 
  

   into 
  more 
  modern 
  terminology, 
  we 
  can 
  state 
  the 
  following 
  

   further 
  facts 
  alleged 
  concerning 
  the 
  genus. 
  In 
  two 
  out 
  

   of 
  the 
  three 
  species 
  at 
  any 
  rate, 
  the 
  plates 
  of 
  the 
  cup 
  

   are 
  in 
  three 
  circlets, 
  corresponding 
  apparently 
  to 
  the 
  cup- 
  

   plates 
  of 
  a 
  simple 
  crinoid 
  with 
  dicyclic 
  base. 
  Each 
  of 
  these 
  

   circlets 
  consists 
  of 
  five 
  plates, 
  except 
  the 
  proximal 
  circlet 
  

   (IBB); 
  in 
  which 
  there 
  are 
  three, 
  doubtless 
  formed 
  as 
  usual 
  

   by 
  fusion 
  of 
  two 
  pairs. 
  The 
  mouth 
  is 
  central 
  and 
  surrounded 
  

   or 
  covered, 
  in 
  one 
  of 
  these 
  dicyclic 
  species, 
  by 
  five 
  plates 
  

   corresponding 
  to 
  the 
  so-called 
  orals, 
  in 
  the 
  other 
  dicyclic 
  

   species 
  by 
  (it 
  is 
  suggested) 
  a 
  plated 
  integument. 
  Supposed 
  

   orals 
  are 
  also 
  present 
  in 
  the 
  third 
  species. 
  The 
  anus 
  is 
  

   lateral 
  ; 
  its 
  position 
  is 
  given 
  more 
  precisely 
  for 
  only 
  one 
  

   species, 
  and 
  there 
  it 
  is 
  said 
  to 
  be 
  between 
  what 
  we 
  should 
  

   call 
  the 
  basal 
  and 
  radial 
  circlets. 
  

  

  Analysing 
  the 
  definitions 
  of 
  the 
  three 
  species 
  given 
  on 
  the 
  

   same 
  page, 
  we 
  deduce- 
  the 
  following 
  : 
  — 
  

  

  S. 
  clausus 
  : 
  dicyclic 
  ; 
  oral 
  aspect 
  covered 
  by 
  5 
  plates 
  ; 
  anus 
  

  

  between 
  BB 
  and 
  RB. 
  

   S.jacksoni: 
  monocyclic; 
  oral 
  aspect 
  covered 
  by 
  5 
  plates 
  ; 
  

  

  anus 
  lateral 
  ; 
  stem-facet 
  small. 
  

   S. 
  anapeptamenus 
  : 
  dicyclic; 
  oral 
  aspect 
  not 
  covered, 
  so 
  

  

  far 
  as 
  known 
  ; 
  anus 
  projecting 
  at 
  the 
  side. 
  

  

  The 
  alleged 
  distinction 
  between 
  S. 
  clausus 
  and 
  S 
  anapepta- 
  

   menus 
  is 
  not 
  great, 
  since 
  the 
  anus 
  may 
  have 
  been 
  in 
  the 
  

   same 
  position 
  in 
  the 
  two 
  species. 
  S. 
  jacksoni, 
  on 
  the 
  other 
  

   hand, 
  clearly 
  belonged 
  to 
  a 
  different 
  genus. 
  

  

  