﻿THK 
  ANATOMY 
  OF 
  PrECH.OOHJlTUS, 
  C'LAPAREDE. 
  143 
  

  

  P. 
  fnlgoris. 
  Here^ 
  ag;iiD, 
  imperfect 
  preservatiou 
  may 
  

   account 
  for 
  the 
  difference. 
  

  

  o. 
  The 
  tnbercles 
  (openings 
  of 
  epithelial 
  glands), 
  which 
  

   cover 
  both 
  the 
  dorsal 
  and 
  ventral 
  snrfaces 
  of 
  Poeci 
  lochtetus 
  

   fulgoris, 
  are 
  scarcely 
  represented 
  on 
  the 
  dorsal 
  surface 
  of 
  

   Plymouth 
  specimens, 
  thongh 
  moderately 
  common 
  on 
  the 
  

   ventral. 
  

  

  4. 
  Only 
  one 
  pair 
  (dorsal 
  or 
  posterior) 
  of 
  eyes 
  is 
  described 
  

   by 
  Claparede, 
  the 
  ventral 
  (anterior) 
  pair 
  not 
  having 
  been 
  

   observed. 
  

  

  5. 
  Claparede 
  describes 
  the 
  bnccal 
  segment 
  as 
  having 
  a 
  

   single 
  cirrus 
  on 
  each 
  side. 
  The 
  rudimentary 
  dorsal 
  cirrus 
  was 
  

   either 
  not 
  present 
  or 
  was 
  overlooked. 
  

  

  6. 
  The 
  long 
  dorsal 
  cirrus 
  of 
  segment 
  5 
  is 
  not 
  described 
  or 
  

   figured 
  by 
  Claparede. 
  The 
  cirri 
  of 
  the 
  seventh 
  to 
  the 
  eleventh 
  

   segments 
  differ 
  in 
  shape 
  from 
  the 
  others, 
  being 
  flask 
  shaped 
  

   with 
  long, 
  stiff 
  necks 
  in 
  Claparede's 
  specimen, 
  whilst 
  in 
  the 
  

   Plymouth 
  specimens 
  this 
  chai-acter 
  is 
  constant 
  for 
  segments 
  

   from 
  the 
  seventh 
  to 
  the 
  thirteenth. 
  As, 
  however, 
  all 
  larv£B 
  

   seen 
  at 
  Plymouth 
  agree 
  with 
  P. 
  fnlgoris 
  in 
  this 
  respect, 
  the 
  

   difference 
  may 
  be 
  due 
  to 
  the 
  fact 
  that 
  Claparede's 
  specimens 
  

   were 
  not 
  adult. 
  

  

  7. 
  The 
  second, 
  the 
  third, 
  and 
  the 
  fourth 
  segments 
  of 
  the 
  

   " 
  Lightning 
  " 
  specimens 
  have 
  short, 
  stout 
  spines 
  in 
  the 
  

   neuropodium; 
  in 
  the 
  Plymouth 
  specimens 
  such 
  spines 
  are 
  

   confined 
  to 
  the 
  second 
  and 
  third 
  segments. 
  

  

  The 
  differences 
  expressed 
  under 
  the 
  headings 
  (3), 
  (6) 
  and 
  

   (7) 
  appear 
  to 
  render 
  it 
  necessary 
  to 
  regard 
  the 
  Plymouth 
  

   specimens, 
  at 
  least 
  provisionally, 
  as 
  belonging 
  to 
  a 
  new 
  

   species 
  for 
  which 
  I 
  propose 
  the 
  name 
  Poecilochaatus 
  

   serpens. 
  

  

  Dkfinitions. 
  

  

  Family 
  Disomidse, 
  Mesnil. 
  

  

  Polyeh^eta 
  having 
  a 
  simple 
  prostoniiuui 
  without 
  tentacles 
  or 
  

   with 
  one 
  median 
  tentacle, 
  and 
  with 
  four 
  simple 
  eyes. 
  A 
  pan* 
  

  

  