﻿331 
  

  

  ON 
  SOME 
  NEW 
  SPECIES 
  OF 
  MAEINE 
  MOLLUSC 
  A 
  FROM 
  

   CHRISTMAS 
  ISLAND, 
  INDIAN 
  OCEAN. 
  

  

  By 
  Tom 
  Iredale. 
  

  

  Bead 
  8th 
  June, 
  1917. 
  

  

  PLATE 
  XIII. 
  

  

  Some 
  years 
  ago 
  Mr. 
  R. 
  Kirkpatrick, 
  of 
  the 
  British 
  Museum, 
  made 
  

   au 
  expedition 
  to 
  Christmas 
  Iskiud, 
  Indian 
  Ocean, 
  for 
  tlie 
  purpose 
  of 
  

   securing 
  living 
  examples 
  of 
  a 
  peculiar 
  murine 
  sponge. 
  In 
  this 
  quest 
  

   he 
  was 
  successful 
  after 
  tedious 
  and 
  difficult 
  dredging, 
  and 
  lie 
  brought 
  

   buck 
  a 
  few 
  samples 
  of 
  the 
  sand 
  dredged 
  which 
  have 
  just 
  recently 
  

   been 
  lianded 
  to 
  me 
  for 
  examination 
  for 
  small 
  molluscan 
  forms. 
  The 
  

   results 
  have 
  been 
  so 
  extruoniinury 
  that 
  I 
  hope 
  later, 
  under 
  more 
  

   favourable 
  circumstances, 
  to 
  furnish 
  a 
  full 
  account 
  of 
  them. 
  I 
  suggest 
  

   that 
  200-300 
  species 
  are 
  represented 
  in 
  the 
  small 
  quantity 
  of 
  sand 
  

   available, 
  and 
  many 
  are 
  of 
  great 
  systematic 
  interest. 
  I 
  herewith 
  

   describe 
  a 
  few 
  of 
  remarkable 
  aspect 
  and 
  unknown 
  relationship. 
  

   These 
  were 
  all 
  sorted 
  from 
  a 
  parcel 
  labelled 
  " 
  Rich 
  Foraminiferal 
  

   sand, 
  with 
  shells 
  and 
  corallines, 
  100 
  fathoms 
  off 
  North-East 
  Point, 
  

   Christmas 
  Island 
  . 
  . 
  ." 
  The 
  matter 
  is 
  all 
  very 
  dead, 
  but 
  a 
  very 
  

   few 
  live 
  shells 
  occur 
  which 
  are 
  obviously 
  living 
  in 
  that 
  depth. 
  I 
  do 
  

   not 
  consider 
  that 
  the 
  majority 
  of 
  the 
  dead 
  shells 
  had, 
  however, 
  lived 
  

   there, 
  but 
  had 
  been 
  washed 
  down 
  from 
  less 
  depths. 
  In 
  consequence 
  

   of 
  this 
  result 
  Mr. 
  Kirkpatrick 
  lianded 
  over 
  to 
  me 
  a 
  second 
  parcel 
  of 
  

   the 
  same 
  depth 
  but 
  another 
  place, 
  when 
  most 
  of 
  the 
  previouslv 
  

   recognized 
  shells 
  were 
  again 
  observed, 
  with 
  many 
  additional 
  forms. 
  

   Dr. 
  C. 
  W, 
  Andrews, 
  who 
  made 
  large 
  collections 
  at 
  Christmas 
  Island, 
  

   and 
  upon 
  whoso 
  researches 
  the 
  Sfonograph 
  of 
  Christmas 
  Island 
  

   was 
  based, 
  has 
  interested 
  himself, 
  and 
  through 
  his 
  intervention, 
  

   which 
  is 
  here 
  gratefully 
  acknowledged, 
  I 
  hope 
  to 
  receive 
  new 
  and 
  

   better 
  material 
  whereby 
  tliis 
  most 
  interesting 
  fauna 
  can 
  be 
  studied. 
  

   The 
  peculiar 
  novelties 
  hereafter 
  described 
  may 
  not 
  be 
  in 
  any 
  sense 
  

   local, 
  but 
  may 
  be 
  widel}^ 
  distributed 
  throughout 
  the 
  Indo-Pacific 
  

   Region, 
  as 
  I 
  have 
  already 
  noted 
  species 
  not 
  hitherto 
  recorded 
  from 
  

   the 
  Indian 
  Ocean. 
  

  

  Sheeboenia. 
  mirabilis, 
  gen. 
  et 
  sp. 
  nov. 
  (PI. 
  XIII, 
  Figs. 
  1-4.) 
  

   Shell 
  small, 
  commencing 
  life 
  regularly 
  as 
  a 
  dextral 
  fusiform 
  shell 
  

   with 
  a 
  short 
  open 
  canal, 
  and 
  upon 
  approaching 
  maturity 
  developing 
  

   tubular 
  apertures 
  whilst 
  the 
  canal 
  recurves. 
  Thereafter, 
  from 
  the 
  

   oral 
  aperture, 
  two 
  tubular 
  apertures 
  being 
  persistent 
  at 
  the 
  side 
  

   opposite 
  and 
  the 
  canal 
  being 
  closed 
  and 
  left 
  also 
  as 
  an 
  aperture, 
  

   a 
  shelly 
  plate 
  develops 
  in 
  concentric 
  circles 
  forming 
  a 
  platform. 
  

   This 
  new 
  genus 
  is 
  a 
  further 
  development 
  along 
  the 
  evolutionary 
  

   lines 
  of 
  the 
  Triphoridse, 
  and 
  has 
  so 
  many 
  peculiar 
  features 
  that 
  

   I 
  have 
  no 
  hesitation 
  in 
  proposing 
  for 
  it 
  alone 
  a 
  new 
  familv 
  

   Sherborniidre, 
  which 
  may 
  temporarily 
  be 
  placed 
  next 
  the 
  Triphoridge, 
  

   but 
  I 
  do 
  not 
  suggest 
  that 
  this 
  is 
  its 
  true 
  taxonomic 
  position. 
  I 
  am 
  

  

  VOL. 
  XII. 
  — 
  NOVEMBER, 
  1917. 
  23 
  

  

  