﻿LITTLE-KNOWN 
  JUEASSIC 
  CEINOIDS. 
  33 
  

  

  calyx 
  retains 
  its 
  cirrhi. 
  In 
  the 
  Lansdown 
  Encrinite, 
  however, 
  there 
  

   are 
  none 
  of 
  these 
  organs 
  upon 
  the 
  stem 
  ; 
  and 
  the 
  evidence 
  as 
  to 
  the 
  

   presence 
  of 
  a 
  root 
  is 
  very 
  incomplete. 
  The 
  short-stemmed 
  forms 
  

   (PL 
  I. 
  figs. 
  2, 
  4, 
  10-13, 
  23), 
  at 
  any 
  rate, 
  must 
  have 
  been 
  more 
  

   " 
  free 
  " 
  than 
  most 
  Comatulce, 
  though 
  they 
  find 
  a 
  parallel 
  among 
  

   those 
  species, 
  such 
  as 
  Actinometra 
  Jukesii, 
  in 
  which 
  the 
  cirrhi 
  

   entirely 
  disappear 
  from 
  the 
  centrodorsal 
  when 
  maturity 
  is 
  

   reached*. 
  

  

  There 
  are 
  other 
  types 
  among 
  the 
  Pelmatozoa 
  which, 
  although 
  

   stalked, 
  seem 
  to 
  have 
  been 
  practically 
  free 
  in 
  their 
  mode 
  of 
  life, 
  

   e. 
  g. 
  Woodocrinus, 
  Ghjptocystites, 
  and 
  some 
  (all 
  ?) 
  species 
  of 
  Pentre- 
  

   mites. 
  In 
  all 
  of 
  these 
  the 
  stem 
  tapers 
  downwards 
  to 
  a 
  point 
  and 
  bears 
  

   few 
  or 
  no 
  cirrhi. 
  Hence 
  the 
  distinction 
  between 
  the 
  stalked 
  types 
  

   and 
  those 
  which 
  merely 
  retain 
  the 
  top 
  stem 
  -joint, 
  though 
  of 
  consi- 
  

   derable 
  morphological 
  importance, 
  does 
  not 
  necessarily 
  involve 
  corre- 
  

   sponding 
  physiological 
  differences. 
  

  

  b. 
  The 
  intercalated 
  Stem-joints. 
  

  

  Several 
  individuals 
  (PL 
  I. 
  figs. 
  1, 
  7, 
  10) 
  have 
  small 
  incomplete 
  

   lenticular 
  joints 
  intercalated 
  among 
  the 
  larger 
  stem-joints. 
  This 
  

   peculiarity 
  has 
  been 
  noted 
  by 
  de 
  Loriol 
  in 
  other 
  species 
  of 
  Milleri- 
  

   crinus 
  and 
  also 
  of 
  Apiocrinus, 
  some 
  of 
  which 
  he 
  has 
  figured 
  t. 
  The 
  

   lenticular 
  joints 
  were 
  regarded 
  by 
  him, 
  rightly, 
  as 
  I 
  believe, 
  as 
  new 
  

   joints 
  in 
  process 
  of 
  formation. 
  QuenstedtJ, 
  however, 
  who 
  has 
  met 
  

   with 
  the 
  same 
  peculiarity 
  in 
  Pentacrinus, 
  speaks 
  of 
  it 
  as 
  a 
  " 
  kleine 
  

   Missbildung." 
  The 
  peculiarities 
  of 
  the 
  sixth 
  and 
  subjacent 
  joints 
  of 
  

   the 
  individual 
  represented 
  in 
  fig. 
  7 
  seem 
  to 
  represent 
  the 
  later 
  

   stages 
  of 
  this 
  intercalation 
  of 
  new 
  joints. 
  

  

  c. 
  The 
  top 
  

  

  It 
  has 
  been 
  already 
  mentioned 
  that 
  the 
  top 
  stem-joint 
  is 
  some- 
  

   what 
  variable 
  in 
  its 
  appearance. 
  It 
  is 
  sometimes 
  relatively 
  thick 
  

   and 
  almost 
  uniformly 
  so 
  all 
  round 
  (PL 
  I. 
  figs. 
  1, 
  3, 
  4, 
  13) 
  ; 
  while 
  

   it 
  is 
  sometimes 
  comparatively 
  thin 
  immediately 
  beneath 
  the 
  basals, 
  

   with 
  a 
  strong 
  ascending 
  process 
  between 
  the 
  lower 
  angles 
  of 
  every 
  

   pair 
  (figs. 
  6-8, 
  10, 
  12). 
  Judging 
  from 
  what 
  is 
  shown 
  in 
  the 
  

   original 
  of 
  fig. 
  21, 
  I 
  cannot 
  help 
  suspecting 
  that 
  the 
  appearance 
  of 
  

   large 
  upper 
  stem-joints 
  may 
  sometimes 
  be 
  a 
  secondary 
  condition. 
  

   On 
  one 
  side 
  of 
  this 
  specimen 
  two 
  large 
  stem-joints 
  are 
  visible 
  just 
  

   below 
  the 
  basals 
  ; 
  but 
  they 
  are 
  broken 
  away 
  on 
  the 
  other 
  side, 
  and 
  

   it 
  then 
  becomes 
  manifest 
  that 
  they 
  enclose 
  a 
  central 
  core 
  of 
  much 
  

   thinner 
  and 
  narrower 
  joints, 
  which 
  seem 
  to 
  extend 
  upwards 
  to 
  the 
  

   basals 
  and 
  to 
  have 
  been 
  continuous 
  with 
  those 
  lower 
  down 
  the 
  stem. 
  

   There 
  appears 
  therefore 
  to 
  have 
  been 
  a 
  secondary 
  deposit 
  of 
  lime- 
  

  

  * 
  Proc. 
  Eoy. 
  Soc. 
  1879, 
  no. 
  194, 
  p. 
  390. 
  

  

  t 
  " 
  Monographie 
  des 
  Orinoides 
  fossiles 
  de 
  la 
  Suisse," 
  Menu 
  de 
  la 
  Soc. 
  Pal. 
  

   Suisse, 
  1877-79, 
  pp. 
  40, 
  42, 
  82, 
  94, 
  pi. 
  v. 
  fig. 
  9, 
  pi. 
  vi. 
  fig. 
  7, 
  pi. 
  vii. 
  fig. 
  2, 
  pl.xi. 
  

   fig. 
  21, 
  pi. 
  xii. 
  fig. 
  27. 
  

  

  % 
  ' 
  Petrefactenkunde 
  Deutschlands,' 
  Bd. 
  iv., 
  Asteriden 
  und 
  Encriniden, 
  

   p. 
  247, 
  Taf. 
  98. 
  fig. 
  118, 
  Taf. 
  99. 
  fig. 
  44. 
  

  

  Q. 
  J. 
  G. 
  S. 
  No. 
  149. 
  d 
  

  

  