﻿160 
  Prof. 
  M'Intosh's 
  Notes 
  from 
  the 
  

  

  their 
  gradual 
  increase 
  in 
  length 
  from 
  before 
  backward 
  

   corroborates 
  this 
  view. 
  In 
  some, 
  when 
  seen 
  antero- 
  poste- 
  

   riorly, 
  the 
  tips 
  are 
  spatula- 
  shaped, 
  a 
  slight 
  constriction 
  

   occurring 
  at 
  the 
  neck. 
  One 
  or 
  two 
  capillary 
  bristles, 
  with 
  a 
  

   slight 
  flattening 
  of 
  the 
  tapered 
  and 
  serrated 
  tip, 
  accompany 
  

   the 
  dorsal 
  hooks. 
  Several 
  procured 
  at 
  Guernsey 
  and 
  Herm 
  

   in 
  July 
  and 
  August 
  had 
  well-developed 
  eggs. 
  Moreover, 
  an 
  

   epitokous 
  male 
  more 
  than 
  2 
  inches 
  long 
  occurred 
  amongst 
  

   the 
  others. 
  In 
  this 
  the 
  anterior 
  region 
  of 
  about 
  twenty-two 
  

   segments 
  (exclusive 
  of 
  the 
  head 
  and 
  six 
  or 
  seven 
  segments) 
  is 
  

   modified, 
  whilst 
  the 
  caudal 
  of 
  about 
  thirty 
  segments 
  is 
  not 
  

   materially 
  changed. 
  The 
  pigmented 
  area 
  of 
  the 
  eyes 
  is 
  

   perhaps 
  a 
  little 
  larger, 
  and 
  the 
  dorsal 
  tuberosity 
  of 
  the 
  head 
  

   somewhat 
  more 
  prominent, 
  whilst 
  the 
  tentacles 
  and 
  branchiae 
  

   are 
  normal. 
  The 
  whole 
  of 
  the 
  anterior 
  and 
  middle 
  regions 
  

   are 
  enlarged 
  and 
  softer, 
  and 
  have 
  long 
  resplendent 
  dorsal 
  

   swimming-bristles 
  which 
  in 
  length 
  exceed 
  the 
  diameter 
  of 
  

   the 
  body. 
  They 
  are 
  smooth, 
  simple, 
  tapering 
  bristles 
  with 
  

   very 
  faint 
  longitudinal 
  lines, 
  and 
  of 
  a 
  pale 
  yellow 
  hue, 
  best 
  

   seen 
  by 
  transmitted 
  light, 
  and 
  their 
  tips 
  are 
  remarkably 
  

   attenuate. 
  The 
  anterior 
  dorsal 
  bristles 
  are 
  little 
  altered, 
  but 
  

   from 
  the 
  eighth 
  to 
  the 
  thirty-first 
  they 
  form 
  conspicuous 
  

   tufts 
  on 
  each 
  side. 
  This 
  bristled 
  region, 
  with 
  the 
  head, 
  is 
  

   probably 
  thrown 
  off 
  and 
  discharges 
  the 
  sexual 
  elements, 
  

   whilst 
  the 
  unchanged 
  and 
  flattened 
  moiety 
  of 
  about 
  thirty 
  

   segments 
  reproduces 
  a 
  head 
  and 
  anterior 
  region. 
  The 
  fact 
  

   that 
  this 
  example, 
  which 
  was 
  not 
  quite 
  ripe, 
  still 
  occupied 
  its 
  

   tube 
  in 
  Lithothamnion 
  would 
  indicate 
  that 
  up 
  to 
  the 
  period 
  

   of 
  "swarming" 
  the 
  oar-shaped 
  posterior 
  region 
  and 
  its 
  

   series 
  of 
  powerful 
  hooks 
  would 
  be 
  of 
  material 
  service 
  to 
  the 
  

   form, 
  and, 
  further, 
  after 
  the 
  separation 
  of 
  the 
  sexual 
  region, 
  

   if 
  such 
  is 
  found 
  to 
  occur, 
  the 
  remnant 
  would 
  be 
  ready 
  for 
  

   the 
  emergencies 
  of 
  its 
  life 
  in 
  the 
  calcareous 
  crusts 
  and 
  

   masses. 
  The 
  great 
  size 
  of 
  the 
  hooks 
  or 
  crotchets 
  throughout, 
  

   and 
  especially 
  in 
  the 
  posterior 
  region, 
  shows 
  that 
  the 
  form 
  is 
  

   adult 
  and 
  that 
  the 
  shovel-shaped 
  and 
  abraded 
  posterior 
  hooks 
  

   have 
  been 
  in 
  constant 
  use. 
  In 
  the 
  dorsal 
  division 
  one 
  or 
  

   two 
  of 
  the 
  tapering 
  capillary 
  bristles 
  with 
  the 
  anterior 
  edge 
  

   of 
  the 
  tip 
  serrated 
  are 
  present. 
  

  

  The 
  great 
  size 
  of 
  the 
  hooks 
  in 
  Dodecaceria 
  ater 
  and 
  their 
  

   special 
  structure 
  at 
  once 
  attract 
  attention, 
  especially 
  when 
  

   contrasted 
  with 
  those 
  of 
  D. 
  concharum. 
  

  

  A 
  form 
  (Chatozone 
  dunmanni), 
  which 
  appears 
  to 
  be 
  inter- 
  

   mediate 
  between 
  Cirratulus 
  and 
  Chatozone, 
  comes 
  from 
  

  

  