﻿Gatty 
  Marine 
  Laboratory, 
  St. 
  Andrews. 
  157 
  

  

  length, 
  slightly 
  tapered 
  toward 
  the 
  snout 
  and 
  distinctly 
  

   diminished 
  toward 
  the 
  tail 
  and 
  more 
  or 
  less 
  rounded 
  

   throughout. 
  The 
  segments 
  are 
  60 
  or 
  more, 
  and 
  when 
  the 
  

   body 
  is 
  extended 
  the 
  anterior 
  region 
  is 
  nearly 
  as 
  narrow 
  as 
  

   the 
  snout. 
  The 
  tentacles 
  are 
  12 
  in 
  number, 
  six 
  on 
  each 
  

   side, 
  arise 
  on 
  the 
  dorsal 
  surface 
  opposite 
  each 
  other, 
  and 
  the 
  

   bases 
  of 
  the 
  pairs 
  approach 
  quite 
  as 
  closely 
  as 
  in 
  Dodecaceria 
  

   ater. 
  They 
  commence 
  on 
  the 
  anterior 
  part 
  of 
  the 
  second 
  

   segment, 
  the 
  first 
  pair 
  being 
  longer 
  than 
  the 
  others. 
  As 
  a 
  

   rule 
  they 
  are 
  of 
  a 
  pale 
  green 
  colour, 
  with 
  darker 
  pigment 
  at 
  

   the 
  tip, 
  but 
  they 
  may 
  be 
  dull 
  orange. 
  A 
  coiled 
  blood-vessel 
  

   proceeds 
  along 
  the 
  centre 
  of 
  each, 
  and 
  the 
  edges 
  of 
  the 
  

   tentacle 
  are 
  often 
  crenated, 
  and 
  when 
  extended 
  frequently 
  

   show 
  a 
  dilatation 
  at 
  the 
  tip, 
  but 
  no 
  cilia. 
  When 
  sickly 
  the 
  

   tentacles 
  assume 
  a 
  dull 
  brown 
  hue. 
  

  

  The 
  first 
  seven 
  bristled 
  segments 
  have 
  on 
  each 
  side 
  two 
  

   fascicles 
  of 
  simple 
  bristles 
  which 
  taper 
  to 
  very 
  delicate 
  tips. 
  

   In 
  the 
  eighth 
  segment 
  the 
  ventral 
  division 
  has 
  a 
  few 
  of 
  the 
  

   peculiar 
  bill-hook 
  crotchets 
  amongst 
  the 
  bristles, 
  and 
  at 
  the 
  

   tenth 
  the 
  latter 
  only 
  occur 
  in 
  the 
  ventral 
  series, 
  whilst 
  some 
  

   show 
  dorsally 
  a 
  few 
  of 
  the 
  simple 
  tapering 
  bristles 
  and 
  about 
  

   three 
  stouter 
  bristles, 
  the 
  tips 
  of 
  which 
  have 
  been 
  abraded, 
  

   so 
  that 
  an 
  oblique 
  surface 
  remains. 
  The 
  typical 
  crotchet 
  or 
  

   hook 
  has 
  a 
  slightly 
  curved 
  shaft, 
  which 
  somewhat 
  increases 
  

   in 
  diameter 
  from 
  the 
  base 
  to 
  the 
  distal 
  third, 
  then 
  gently 
  

   bends 
  backward 
  to 
  the 
  neck, 
  where 
  the 
  dorsal 
  line 
  again 
  has- 
  

   a 
  backward 
  curve, 
  and 
  then 
  goes 
  forward 
  to 
  the 
  tip. 
  The 
  

   anterior 
  curve, 
  which 
  at 
  the 
  neck 
  is 
  also 
  slightly 
  backward, 
  

   is 
  abruptly 
  broken 
  by 
  a 
  bold 
  conical 
  projection, 
  from 
  the 
  

   apex 
  of 
  which 
  the 
  distal 
  curve 
  runs 
  to 
  the 
  stout 
  tip. 
  It 
  thus 
  

   differs 
  in 
  all 
  respects 
  from 
  the 
  tip 
  of 
  the 
  southern 
  Dodeca- 
  

   ceria 
  ater 
  of 
  De 
  Quatrefages. 
  

  

  In 
  the 
  posterior 
  part 
  of 
  the 
  body 
  the 
  dorsal 
  setigerous 
  

   cone 
  bears 
  a 
  few 
  of 
  the 
  long 
  slender 
  tapering 
  bristles, 
  and 
  

   one 
  or 
  two 
  stout 
  hook-like 
  bristles 
  bevelled 
  at 
  the 
  tip 
  and 
  

   representing 
  a 
  modified 
  type 
  of 
  the 
  ventral 
  series, 
  for 
  they 
  

   present 
  no 
  enlargement 
  on 
  the 
  anterior 
  face 
  below 
  the 
  

   bevelled 
  region. 
  The 
  ventral 
  division 
  likewise 
  has 
  a 
  bristle 
  

   or 
  two 
  of 
  a 
  shorter 
  type 
  than 
  the 
  dorsal, 
  which 
  are 
  con- 
  

   spicuous 
  in 
  a 
  lateral 
  view 
  from 
  above, 
  and 
  one 
  or 
  two 
  of 
  the 
  

   characteristic 
  crotchets, 
  the 
  only 
  peculiarities 
  being 
  their 
  

   shortness 
  and 
  the 
  more 
  marked 
  curve 
  of 
  the 
  less 
  robust 
  hook 
  

   at 
  the 
  tip. 
  The 
  conical 
  projection 
  at 
  the 
  anterior 
  base 
  of 
  

   the 
  curve 
  of 
  the 
  tip 
  is 
  marked. 
  

  

  In 
  a 
  young 
  example 
  3-4 
  mm. 
  in 
  length, 
  procured 
  along 
  

  

  