﻿1874.] 
  

  

  f 
  Challenger' 
  Soundings 
  in 
  the 
  Southern 
  Sea. 
  

  

  47 
  

  

  the 
  tubes 
  of 
  a 
  tube-building 
  annelid, 
  several 
  of 
  them 
  3 
  to 
  4 
  inches 
  long, 
  

   and 
  containing 
  the 
  worm, 
  a 
  species 
  of 
  Myriochele, 
  still 
  living. 
  The 
  

   worm-tubes, 
  like 
  all 
  the 
  tests 
  of 
  Foraminifera 
  from 
  the 
  same 
  dredging, 
  

   were 
  made 
  up 
  of 
  particles 
  of 
  the 
  red 
  clay 
  alone. 
  

  

  It 
  seems 
  evident, 
  from 
  the 
  observations 
  here 
  recorded, 
  that 
  clay, 
  which 
  

   we 
  have 
  hitherto 
  looked 
  upon 
  as 
  essentially 
  the 
  product 
  of 
  the 
  dis- 
  

   integration 
  of 
  older 
  rocks, 
  under 
  certain 
  circumstances, 
  maybe 
  an 
  organic 
  

   formation 
  like 
  chalk 
  ; 
  that, 
  as 
  a 
  matter 
  of 
  fact, 
  an 
  area 
  on 
  the 
  surface 
  of 
  

   the 
  globe, 
  which 
  we 
  have 
  shown 
  to 
  be 
  of 
  vast 
  extent, 
  although 
  we 
  are 
  

   still 
  far 
  from 
  having 
  ascertained 
  its 
  limits, 
  is 
  being 
  covered 
  by 
  such 
  a 
  

   deposit 
  at 
  the 
  present 
  day. 
  

  

  It 
  is 
  impossible 
  to 
  avoid 
  associating 
  such 
  a 
  formation 
  with 
  the 
  fine, 
  

   smooth, 
  homogeneous 
  clays 
  and 
  schists, 
  poor 
  in 
  fossils, 
  but 
  showing 
  

   worm-tubes 
  and 
  tracks, 
  and 
  bunches 
  of 
  doubtful 
  branching 
  things, 
  such 
  

   as 
  Oldhamia, 
  siliceous 
  sponges, 
  and 
  thin-shelled 
  peculiar 
  shrimps. 
  Such 
  

   formations, 
  more 
  or 
  less 
  metamorphosed, 
  are 
  very 
  familiar, 
  especially 
  to 
  

   the 
  student 
  of 
  palaeozoic 
  geology, 
  and 
  they 
  often 
  attain 
  a 
  vast 
  thickness. 
  

   One 
  is 
  inclined, 
  from 
  this 
  great 
  resemblance 
  between 
  them 
  in 
  composition 
  

   and 
  in 
  the 
  general 
  character 
  of 
  the 
  included 
  fauna, 
  to 
  suspect 
  that 
  these 
  

   may 
  be 
  organic 
  formations, 
  like 
  the 
  modern 
  red 
  clay 
  of 
  the 
  Atlantic 
  and 
  

   Southern 
  Sea, 
  accumulations 
  of 
  the 
  insoluble 
  ashes 
  of 
  shelled 
  creatures. 
  

  

  The 
  dredging 
  in 
  the 
  red 
  clay 
  on 
  the 
  13th 
  of 
  March 
  was 
  unusually 
  

   rich. 
  The 
  bag 
  contained 
  examples, 
  those 
  with 
  calcareous 
  shells 
  rather 
  

   stunted, 
  of 
  most 
  of 
  the 
  characteristic 
  deep-water 
  groups 
  of 
  the 
  Southern 
  

   Sea, 
  including 
  Umbellularia, 
  Euplectella, 
  Pterocrinus, 
  Brisinga, 
  Ophio- 
  

   glypha, 
  Pourtalesia, 
  and 
  one 
  or 
  two 
  Mollusca. 
  This 
  is, 
  however, 
  very 
  

   rarely 
  the 
  case. 
  Generally 
  the 
  " 
  red 
  clay 
  " 
  is 
  barren, 
  or 
  contains 
  only 
  a 
  

   very 
  small 
  number 
  of 
  forms. 
  

  

  On 
  the 
  11th 
  of 
  February, 
  lat. 
  60° 
  52' 
  S., 
  long. 
  80° 
  20' 
  E., 
  and 
  March 
  3, 
  

   lat. 
  53° 
  55' 
  S., 
  long. 
  108° 
  35' 
  E., 
  the 
  sounding-instrument 
  came 
  up 
  filled 
  

   with 
  a 
  very 
  fine 
  cream-coloured 
  paste, 
  which 
  scarcely 
  effervesced 
  with 
  

   acid, 
  and 
  dried 
  into 
  a 
  very 
  light 
  impalpable 
  white 
  powder. 
  This, 
  when 
  

   examined 
  under 
  the 
  microscope, 
  was 
  found 
  to 
  consist 
  almost 
  entirely 
  of 
  

   the 
  frustules 
  of 
  Diatoms, 
  some 
  of 
  them 
  wonderfully 
  perfect 
  in 
  all 
  the 
  

   details 
  of 
  their 
  ornament, 
  and 
  many 
  of 
  them 
  broken 
  up. 
  The 
  species 
  of 
  

   diatoms 
  entering 
  into 
  this 
  deposit 
  have 
  not 
  yet 
  been 
  worked 
  up, 
  but 
  they 
  

   appear 
  to 
  be 
  referable 
  chiefly 
  to 
  the 
  genera 
  Fragillaria, 
  Coscinodiscus, 
  

   Chcetoceros, 
  Asteromphalus, 
  and 
  Dictyocha, 
  with 
  fragments 
  of 
  the 
  sepa- 
  

   rated 
  rods 
  of 
  a 
  singular 
  siliceous 
  organism, 
  with 
  which 
  we 
  were 
  un- 
  

   acquainted, 
  and 
  which 
  made 
  up 
  a 
  large 
  proportion 
  of 
  the 
  finer 
  matter 
  of 
  

   this 
  deposit. 
  Mixed 
  with 
  the 
  Diatoms 
  there 
  were 
  a 
  few 
  small 
  Globig 
  evince, 
  

   some 
  of 
  the 
  tests 
  and 
  spicules 
  of 
  E-adiolarians, 
  and 
  some 
  sand 
  particles 
  ; 
  

   but 
  these 
  foreign 
  bodies 
  were 
  in 
  too 
  small 
  proportion 
  to 
  affect 
  the 
  

   formation 
  as 
  consisting 
  practically 
  of 
  diatoms 
  alone. 
  On 
  the 
  4th 
  of 
  

   February, 
  in 
  lat, 
  52° 
  29' 
  S., 
  long. 
  71° 
  36' 
  E., 
  a 
  little 
  to 
  the 
  north 
  of 
  the 
  

  

  