﻿384 
  G. 
  B. 
  VINE 
  ON 
  THE 
  ANNELIDA 
  TTJBICOLA 
  

  

  5. 
  Oetonia 
  seepttlieormis, 
  ii. 
  sp. 
  (Plate 
  XY. 
  fig. 
  4.) 
  

  

  Tube 
  minute, 
  attenuated-flexuous 
  ; 
  adherent 
  to 
  species 
  of 
  corals 
  ; 
  

   varying 
  in 
  length 
  from 
  one 
  and 
  half 
  to 
  two 
  lines, 
  but 
  much 
  more 
  

   delicate 
  in 
  every 
  respect 
  than 
  the 
  last 
  species. 
  Tube 
  adherent 
  by 
  

   its 
  whole 
  length 
  ; 
  and 
  in 
  one 
  specimen, 
  in 
  which 
  the 
  coral 
  was 
  too 
  

   small, 
  the 
  distal 
  part 
  of 
  the 
  tube, 
  gradually 
  adapting 
  itself 
  to 
  cir- 
  

   cumstances, 
  turned 
  over, 
  and 
  became 
  adherent 
  to 
  the 
  cross 
  section 
  

   of 
  the 
  coral. 
  

  

  Loc. 
  Middle 
  \Venlock 
  Shales, 
  Coalbrookdale 
  beds, 
  no. 
  43 
  ; 
  Upper 
  

   Wenlock 
  Shales, 
  Tickwood 
  beds, 
  no. 
  25. 
  

  

  Specimens 
  of 
  this 
  species 
  are 
  rare, 
  and 
  I 
  have 
  not 
  found 
  it 
  in 
  any 
  

   of 
  the 
  washings 
  except 
  the 
  above, 
  and 
  only 
  on 
  corals. 
  I 
  cannot 
  

   identify 
  it 
  with 
  any 
  of 
  the 
  species 
  described 
  by 
  Prof. 
  Nicholson 
  ; 
  and 
  

   as 
  it 
  closely 
  resembles 
  the 
  attenuated 
  proximal 
  end 
  of 
  Serpula 
  ver- 
  

   micularis 
  of 
  Brown's 
  ' 
  Conchologist's 
  Text-Book,' 
  pi. 
  xix. 
  fig. 
  14, 
  

   I 
  give 
  it 
  the 
  above 
  specific 
  name. 
  I 
  do 
  not 
  know 
  the 
  recent 
  

   species 
  : 
  and 
  without 
  having 
  details 
  of 
  the 
  species 
  figured, 
  I 
  have 
  no 
  

   desire 
  to 
  make 
  any 
  comparison 
  between 
  the 
  recent 
  and 
  the 
  fossil 
  

   type. 
  

  

  Genus 
  Spieorbis, 
  Lamarck. 
  

  

  6. 
  Spirorbis 
  arkonensis, 
  Nicholson. 
  

  

  New 
  Devonian 
  Fossils, 
  Geol. 
  Mag. 
  1874. 
  

  

  Tube 
  minute, 
  dextral, 
  of 
  two 
  turns, 
  the 
  last 
  turned 
  upwards. 
  

   Aperture 
  circular. 
  The 
  diameter 
  of 
  the 
  entire 
  spiral 
  is 
  about 
  one 
  

   third 
  of 
  a 
  line. 
  Surface 
  sparingly 
  marked 
  with 
  annulations. 
  

  

  Loc. 
  Buildwas 
  beds, 
  no. 
  22 
  ; 
  Tickwood 
  beds, 
  no. 
  25. 
  In 
  this 
  bed 
  

   there 
  is 
  only 
  a 
  section 
  of 
  the 
  tube 
  preserved. 
  

  

  I 
  have 
  adopted 
  Nicholson's 
  name 
  S. 
  arkonensis 
  for 
  this 
  most 
  

   delicate 
  Annelid. 
  In 
  my 
  description 
  I 
  have 
  accepted 
  in 
  part 
  the 
  

   diagnosis 
  of 
  the 
  American 
  Devonian 
  fossil. 
  There 
  is 
  a 
  slight 
  differ- 
  

   ence 
  in 
  the 
  two 
  forms, 
  but 
  so 
  slight 
  indeed 
  that, 
  unless 
  one 
  wanted 
  

   to 
  be 
  very 
  scrupulously 
  exact, 
  the 
  two 
  may 
  pass 
  unnoticed 
  under 
  

   one 
  name. 
  In 
  measurement, 
  but 
  not 
  in 
  ornamentation, 
  the 
  two 
  

   species 
  are 
  as 
  nearly 
  as 
  can 
  be 
  the 
  same. 
  

  

  Species 
  belonging 
  to 
  this 
  genus 
  are 
  exceedingly 
  rare 
  in 
  the 
  shale- 
  

   washings. 
  Only 
  two 
  out 
  of 
  the 
  eleven 
  localities 
  have 
  as 
  yet 
  yielded 
  

   me 
  specimens. 
  One 
  specimen 
  from 
  no. 
  22 
  is 
  tolerably 
  perfect 
  and 
  

   on 
  a 
  fragment 
  of 
  shell 
  ; 
  the 
  other 
  is 
  a 
  section 
  (base) 
  of 
  the 
  tube 
  on 
  

   the 
  tube 
  of 
  Conchicolites 
  NicJiolsoni. 
  The 
  specimen 
  from 
  no. 
  25 
  is 
  

   on 
  a 
  fragment 
  of 
  coral 
  ; 
  and 
  this, 
  too, 
  is 
  only 
  a 
  section. 
  

  

  The 
  record 
  of 
  Spirorbis 
  as 
  a 
  Silurian 
  fossil 
  is 
  very 
  meagre. 
  No 
  

   evidence 
  is 
  afforded 
  by 
  the 
  collection 
  in 
  the 
  School 
  of 
  Mines 
  that 
  it 
  

   existed 
  prior 
  to 
  the 
  period 
  of 
  the 
  Wenlock 
  Shales. 
  As 
  the 
  shales 
  

   are 
  derived 
  from 
  rocks 
  of 
  a 
  previous 
  age, 
  its 
  true 
  home 
  is 
  not 
  yet 
  

   found. 
  Very 
  little 
  additional 
  detail 
  is 
  given 
  in 
  Mr. 
  Robert 
  Ethe- 
  

   ridge's 
  famous 
  address 
  to 
  the 
  Geological 
  Society. 
  For 
  specific 
  de- 
  

   tails 
  Sowerby's, 
  so 
  far 
  as 
  I 
  am 
  aware, 
  is 
  the 
  only 
  British 
  species 
  

   described. 
  The 
  following 
  are 
  the 
  recorded 
  Silurian 
  species 
  : 
  — 
  

  

  