﻿122 
  

  

  ME. 
  W. 
  H. 
  SHEUBS0LE 
  ON 
  THE 
  

  

  Prof. 
  Hackel, 
  respecting 
  which 
  he 
  wrote, 
  on 
  Dec. 
  6, 
  1885 
  : 
  — 
  " 
  The 
  

   Kadiolarians 
  of 
  the 
  London 
  Clay, 
  the 
  sketches 
  of 
  which 
  I 
  return 
  

   enclosed, 
  are 
  not 
  identical 
  with 
  any 
  species 
  known, 
  living 
  or 
  fossil. 
  

   I 
  can 
  therefore 
  give 
  only 
  the 
  names 
  of 
  genera 
  enumerated 
  in 
  my 
  

   ' 
  Prodromus,' 
  published 
  in 
  1881 
  *. 
  

  

  " 
  Pig. 
  11, 
  Cenosphoer 
  a, 
  sp. 
  (Monosphaerida) 
  ; 
  figs. 
  2 
  and 
  26, 
  Spongo- 
  

   cliscus. 
  Pigs. 
  1, 
  8, 
  and 
  10 
  are 
  Cyrtida, 
  probably 
  Monocyrtida 
  (with 
  

   a 
  single 
  joint); 
  Pig. 
  1 
  perhaps 
  the 
  upper 
  part 
  of 
  a 
  Gyrtocalpis, 
  figs. 
  

   8 
  and 
  10 
  of 
  an 
  Anthocyrtis 
  or 
  Cornutella. 
  

  

  " 
  But 
  when 
  there 
  are 
  two 
  joints 
  separated 
  by 
  a 
  transverse 
  stricture 
  

   or 
  an 
  internal 
  flange 
  (as 
  you 
  describe), 
  it 
  may 
  belong 
  to 
  Dicyrtida 
  

   (Sethocorys 
  or 
  Anthocyrtis, 
  the 
  latter 
  with 
  a 
  corona 
  of 
  terminal 
  

   spines). 
  The 
  large 
  spines 
  in 
  your 
  figs. 
  5a 
  and 
  56 
  may 
  be 
  apical 
  

   spines 
  of 
  those 
  or 
  of 
  other 
  Cyrtida, 
  or 
  perhaps 
  radial 
  spines 
  of 
  

   Sphserida. 
  

  

  " 
  If 
  the 
  apex 
  and 
  the 
  mouth 
  of 
  the 
  shell 
  is 
  not 
  complete, 
  it 
  is 
  not 
  

   possible 
  to 
  determine 
  with 
  certainty 
  the 
  genus 
  of 
  Cyrtida. 
  

  

  " 
  Since 
  Radiolaria 
  occur 
  in 
  great 
  numbers 
  in 
  all 
  seas 
  (in 
  warmer, 
  

   however, 
  more 
  frequently 
  than 
  in 
  colder), 
  and 
  in 
  open 
  seas 
  as 
  well 
  

   as 
  near 
  the 
  shore, 
  no 
  certain 
  inferences 
  can 
  be 
  drawn 
  from 
  their 
  

   presence 
  in 
  the 
  London 
  Clay." 
  

  

  Prom 
  the 
  above 
  correspondence, 
  it 
  appears 
  more 
  than 
  probable 
  

   that 
  in 
  the 
  material 
  sent 
  to 
  Prof. 
  Hackel 
  there 
  were 
  some 
  forms 
  

   that 
  I 
  had 
  not 
  seen. 
  In 
  the 
  absence 
  of 
  specimens 
  or 
  further 
  infor- 
  

   mation, 
  nothing 
  more 
  can 
  now 
  be 
  said 
  respecting 
  tbem, 
  and 
  attention 
  

   must 
  therefore 
  be 
  restricted 
  to 
  those 
  forms 
  of 
  which 
  we 
  have 
  the 
  

   representations. 
  

  

  Nos. 
  1, 
  8, 
  and 
  10 
  evidently 
  belong 
  to 
  the 
  same 
  species, 
  No. 
  1 
  

   having 
  been 
  less 
  perfectly 
  preserved 
  than 
  the 
  others. 
  These, 
  in 
  some 
  

   washings, 
  were 
  more 
  abundant 
  than 
  the 
  other 
  forms, 
  and 
  were 
  first 
  

   found 
  alone 
  at 
  a 
  slightly 
  higher 
  level. 
  

  

  The 
  shell 
  may 
  be 
  described 
  as 
  being 
  conical, 
  with 
  a 
  curved 
  out- 
  

   line, 
  terminating 
  in 
  a 
  solid 
  apical 
  spine 
  tapering 
  to 
  a 
  point, 
  this 
  

   spine 
  in 
  many 
  specimens 
  being 
  longer 
  than 
  in 
  those 
  figured. 
  

   Whereas 
  in 
  many 
  of 
  the 
  Cyrtoidea 
  the 
  apical 
  spine 
  is 
  set 
  obliquely 
  

   to 
  the 
  centre 
  of 
  the 
  shell, 
  in 
  all 
  specimens 
  of 
  the 
  species 
  under 
  con- 
  

   sideration 
  that 
  I 
  have 
  examined 
  the 
  spine 
  is 
  a 
  direct 
  prolongation 
  of 
  

   the 
  longitudinal 
  axis. 
  

  

  Basal 
  mouth 
  a 
  simple 
  wide 
  opening. 
  Skeletal 
  shell 
  built 
  up 
  of 
  

   lattice-work, 
  having 
  openings 
  which 
  are 
  hexagonal 
  on 
  the 
  exterior, 
  

   and 
  circular 
  on 
  the 
  interior 
  surface, 
  and 
  which 
  increase 
  in 
  size 
  

   towards 
  the 
  mouth. 
  Near 
  the 
  open 
  end 
  is 
  a 
  broad 
  internal 
  flange, 
  

   pierced 
  with 
  circular 
  holes 
  proportionately 
  large, 
  as 
  if 
  to 
  combine 
  

   lightness 
  with 
  strength. 
  In 
  many 
  instances 
  the 
  mouth 
  is 
  orna- 
  

   mented 
  with 
  a 
  corona 
  of 
  short 
  spines, 
  which 
  seem 
  to 
  have 
  been 
  

   removed 
  from 
  others 
  (and 
  from 
  those 
  figured) 
  by 
  abrasion 
  ; 
  and 
  in 
  

   a 
  few 
  I 
  observed 
  traces 
  of 
  a 
  probable 
  further 
  extension 
  of 
  the 
  frame- 
  

   work 
  on 
  a 
  larger 
  scale. 
  

  

  * 
  Jenaische 
  Zeitschrift 
  fur 
  JNaturwissenschaften, 
  vol. 
  xv. 
  

  

  