﻿THE 
  ANATOMY 
  OF 
  P(EGlL0CHiETU8, 
  CLAPAEEDE. 
  81 
  

  

  and 
  the 
  specific 
  name 
  being 
  new. 
  He 
  was 
  still 
  nnable 
  to 
  

   include 
  it 
  in 
  any 
  known 
  family, 
  and 
  thought 
  it 
  not 
  improbable 
  

   that 
  a 
  special 
  family 
  would 
  have 
  to 
  be 
  made 
  to 
  receive 
  it. 
  

   Figures 
  are 
  given 
  (loc. 
  cit., 
  Taf 
  . 
  i^ 
  fig. 
  1, 
  a^ 
  b, 
  c, 
  and 
  d) 
  of 
  the 
  

   head 
  end 
  from 
  the 
  dorsal 
  and 
  ventral 
  surfaces, 
  of 
  several 
  

   chsette, 
  of 
  a 
  parapodium, 
  and 
  of 
  the 
  external 
  opening 
  of 
  one 
  

   of 
  the 
  epithelial 
  glands, 
  the 
  latter 
  being 
  described 
  as 
  " 
  petits 
  

   tubercules 
  grannleux.^' 
  

  

  Levinsen 
  (1883, 
  p. 
  106) 
  gives 
  some 
  further 
  details 
  of 
  the 
  

   structure 
  of 
  late 
  larval 
  stages 
  of 
  Poecilocha3tus 
  from 
  obser- 
  

   vations 
  upon 
  specimens 
  which 
  had 
  been 
  taken 
  by 
  the 
  " 
  Hauch" 
  

   Expedition 
  in 
  the 
  Skager 
  Hack. 
  He 
  also 
  discusses 
  the 
  rela- 
  

   tions 
  of 
  Poecilochaetus 
  with 
  Disoma 
  multisetosum, 
  

   Oersted, 
  and 
  points 
  out 
  that 
  the 
  two 
  genera 
  are 
  closely 
  allied. 
  

   He 
  places 
  both 
  genera 
  in 
  the 
  family 
  Spionidffi. 
  

  

  Mcintosh 
  (1894) 
  furnishes 
  some 
  notes, 
  accompanied 
  by 
  

   four 
  figures, 
  on 
  the 
  larva 
  described 
  by 
  Claparede. 
  He 
  con- 
  

   siders 
  that 
  the 
  first 
  notice 
  of 
  this 
  larva 
  is 
  due 
  to 
  Maximillian 
  

   Miiller 
  (1852), 
  but 
  reference 
  to 
  Miiller 
  s 
  paper 
  has 
  not 
  con- 
  

   vinced 
  me 
  that 
  the 
  tail 
  end 
  of 
  a 
  larva 
  which 
  he 
  figures 
  is 
  

   really 
  the 
  same 
  as 
  Claparede's 
  larva. 
  

  

  Mcintosh 
  makes 
  no 
  mention 
  of 
  Claparede's 
  discovery 
  of 
  the 
  

   adult 
  Pcecilochastus, 
  nor 
  of 
  Levinsen's 
  discussion 
  of 
  the 
  

   subject. 
  He 
  states 
  that 
  the 
  larva 
  occurs 
  in 
  considerable 
  

   numbers 
  in 
  the 
  bottom-nets 
  at 
  St. 
  Andrews 
  from 
  July 
  to 
  

   October. 
  Mcintosh 
  gives 
  a 
  figure 
  of 
  an 
  advanced 
  larval 
  

   stage, 
  showing 
  the 
  two 
  palps 
  well 
  developed. 
  

  

  Mesnil 
  (1897), 
  in 
  his 
  monograph 
  on 
  the 
  Spioiiida?, 
  discusses 
  

   the 
  position 
  of 
  Pcecilochastus 
  in 
  relation 
  to 
  that 
  family. 
  

   He 
  proposes 
  to 
  place 
  it 
  with 
  Disoma 
  in 
  a 
  new 
  family, 
  the 
  

   Disomidge 
  (see 
  further, 
  p. 
  140). 
  

  

  OCCURRKNCE 
  AT 
  PLYMOUTH. 
  

  

  The 
  larva 
  of 
  Poecilochj^tus 
  has 
  been 
  constantly 
  and 
  

   regularly 
  taken 
  for 
  many 
  years 
  in 
  the 
  plankton 
  collected 
  at 
  

   Plymouth 
  during 
  the 
  summer 
  months, 
  though 
  I 
  believe 
  no 
  

  

  