﻿644 
  Mr. 
  A. 
  H. 
  Clark 
  on 
  a 
  new 
  

  

  LXXVI. 
  — 
  A 
  new 
  UnstaJked 
  Crinoid 
  from 
  Christmas 
  Island. 
  

   By 
  Austin 
  Hobart 
  Claek. 
  

  

  While 
  visiting 
  the 
  British 
  Museum 
  recently 
  I 
  found 
  among 
  

   the 
  collections 
  there 
  a 
  curious 
  little 
  comasterid 
  which 
  had 
  

   been 
  obtained 
  at 
  Christmas 
  Island. 
  I 
  urged 
  Professor 
  Bell 
  

   to 
  describe 
  it 
  in 
  order 
  that 
  I 
  might 
  mention 
  it 
  in 
  my 
  report 
  

   upon 
  the 
  ' 
  Investigator 
  ' 
  crinoids, 
  but 
  with 
  his 
  characteristic 
  

   generosity 
  he 
  suggested 
  that 
  it 
  would 
  be 
  more 
  fitting 
  were 
  

   I 
  to 
  do 
  it, 
  as 
  I 
  had 
  become 
  so 
  deeply 
  engrossed 
  in 
  the 
  study 
  

   of 
  these 
  animals. 
  

  

  This 
  little 
  comasterid 
  represents 
  a 
  new 
  species 
  of 
  the 
  

   genus 
  Comissia, 
  a 
  genus 
  including 
  eight 
  species, 
  occurring 
  

   from 
  South-eastern 
  Africa 
  to 
  Ceylon 
  and 
  thence 
  eastward 
  to 
  

   the 
  Philippine 
  Islands, 
  all 
  of 
  which 
  have 
  been 
  described 
  

   since 
  the 
  publication 
  of 
  the 
  ' 
  Challenger 
  ' 
  report. 
  

  

  The 
  species 
  of 
  the 
  genus 
  Comissia 
  never 
  have 
  more 
  than 
  

   ten 
  arms 
  ; 
  the 
  cirri 
  are 
  always 
  numerous 
  and 
  well-developed, 
  

   and 
  the 
  distal 
  cirrus 
  segments 
  always 
  bear 
  spines 
  or 
  tubercles 
  

   on 
  the 
  dorsal 
  surface, 
  this 
  serving 
  to 
  differentiate 
  them 
  at 
  

   once 
  from 
  the 
  species 
  of 
  Comatula 
  and 
  Cominia, 
  the 
  cirri 
  of 
  

   which 
  are 
  invariably 
  smooth. 
  

  

  Comissia 
  has 
  no 
  very 
  close 
  relatives 
  in 
  the 
  East 
  Indian 
  

   region, 
  though 
  it 
  falls 
  in 
  the 
  same 
  subfamily, 
  Capillasterinae, 
  

   as 
  Capillaster 
  and 
  Comatella, 
  but 
  in 
  the 
  West 
  Indies 
  it 
  is 
  

   represented 
  by 
  the 
  allied 
  Leptonemaster 
  and 
  Comatilia. 
  

  

  The 
  species 
  of 
  Comissia 
  are 
  all 
  sublittoral, 
  occurring 
  

   between 
  17 
  and 
  100 
  fathoms 
  ; 
  though 
  none 
  of 
  them 
  inhabit 
  

   water 
  of 
  any 
  great 
  depth, 
  none 
  have 
  ever 
  been 
  found 
  at 
  the 
  

   surface. 
  

  

  The 
  new 
  form 
  described 
  below 
  differs 
  somewhat 
  abruptly 
  

   from 
  all 
  the 
  others 
  in 
  the 
  genus 
  in 
  the 
  great 
  length 
  of 
  the 
  

   teeth 
  of 
  the 
  comb 
  on 
  the 
  earlier 
  pinnules, 
  and 
  by 
  the 
  large 
  

   proportion 
  of 
  pinnulars 
  occupied 
  by 
  the 
  comb. 
  It 
  may 
  be 
  

   described 
  as 
  follows 
  : 
  — 
  

  

  Comissia 
  pectinifer, 
  sp. 
  n. 
  

  

  Description. 
  — 
  Centrodorsal 
  moderately 
  large, 
  with 
  a 
  mode- 
  

   rately 
  large 
  flat 
  dorsal 
  pole 
  and 
  three 
  closely 
  crowded 
  

   marginal 
  rows 
  of 
  cirrus 
  sockets. 
  

  

  Cirri 
  xxxiv. 
  14-16 
  (usually 
  16), 
  14 
  mm. 
  long; 
  the 
  eighth 
  

   is 
  a 
  transition 
  segment 
  ; 
  the 
  longer 
  proximal 
  segments 
  are 
  

   nearly 
  twice 
  as 
  long 
  as 
  broad, 
  slightly 
  constricted 
  centrally 
  ; 
  

  

  