﻿THE 
  ANATOMY 
  OF 
  P(EC1L0CHJ;TUS, 
  CLAPAKEDE. 
  83 
  

  

  Habits. 
  

  

  Pceciloclia^tus 
  serpens 
  constructs 
  U-sliaped 
  tubes 
  in 
  

   fine 
  sand. 
  These 
  tubes 
  are 
  lined 
  Avitli 
  a 
  stiff 
  layer 
  of 
  line 
  

   particles 
  of 
  mud 
  or 
  clay 
  held 
  together 
  with 
  mucus. 
  The 
  

   worm 
  in 
  its 
  tube 
  is 
  shown 
  in 
  fig. 
  12 
  (PI. 
  9). 
  This 
  

   drawing, 
  of 
  natural 
  size, 
  was 
  made 
  from 
  a 
  tube 
  which 
  had 
  

   been 
  constructed 
  by 
  a 
  Avorm 
  in 
  a 
  glass 
  cell 
  formed 
  of 
  two 
  

   glass 
  plates 
  lying 
  about 
  yL 
  inch 
  apart 
  and 
  partially 
  filled 
  with 
  

   sand. 
  The 
  process 
  of 
  burrowing 
  was 
  carefully 
  watched, 
  and 
  

   the 
  animal 
  remained 
  under 
  observation 
  in 
  its 
  tube 
  for 
  some 
  

   hours. 
  The 
  burrowing 
  was 
  accomplished 
  with 
  the 
  head 
  end 
  

   of 
  the 
  worm, 
  more 
  particularly 
  with 
  the 
  forwardly 
  directed 
  

   parapodial 
  cirri 
  of 
  the 
  first 
  segment 
  and 
  the 
  long 
  bristles 
  

   belonging 
  to 
  it. 
  During 
  the 
  process 
  the 
  anterior 
  part 
  of 
  the 
  

   body 
  was 
  constantly 
  waved 
  to 
  and 
  fro 
  in 
  a 
  transverse 
  

   direction. 
  The 
  burrowing 
  movement 
  was 
  persisted 
  in 
  until 
  

   the 
  complete 
  U-shaped 
  tube 
  had 
  been 
  formed. 
  

  

  When 
  at 
  rest 
  the 
  animal 
  lies 
  in 
  its 
  tube 
  either 
  with 
  the 
  

   two 
  long 
  palps 
  extended 
  in 
  front, 
  the 
  ends 
  being 
  often 
  pro- 
  

   truded 
  for 
  some 
  distance 
  beyond 
  the 
  opening 
  of 
  the 
  tube, 
  or 
  

   with 
  the 
  palps 
  lying 
  in 
  a 
  number 
  of 
  loose 
  coils 
  immediately 
  

   in 
  front 
  of 
  the 
  head. 
  A 
  constant 
  current 
  of 
  water, 
  drawing 
  

   small 
  particles 
  with 
  it, 
  is 
  kept 
  up 
  through 
  the 
  tube 
  by 
  means 
  

   of 
  an 
  undulatory 
  movement 
  of 
  the 
  body 
  and 
  of 
  a 
  fan-like 
  

   movement 
  of 
  the 
  parapodia 
  and 
  bristles. 
  The 
  movement 
  of 
  

   the 
  numerous 
  feather-like 
  bristles 
  in 
  the 
  posterior 
  part 
  of 
  the 
  

   body 
  (PI. 
  9, 
  fig. 
  10) 
  plays 
  an 
  important 
  part 
  in 
  the 
  production 
  

   of 
  the 
  current 
  that 
  enters 
  the 
  tube 
  at 
  the 
  end 
  towards 
  

   which 
  the 
  head 
  of 
  the 
  Avorm 
  is 
  directed, 
  and 
  passes 
  back- 
  

   wards 
  over 
  the 
  body. 
  If 
  the 
  animal 
  reverses 
  its 
  position 
  

   in 
  the 
  tube, 
  which 
  frequently 
  happened 
  in 
  the 
  specimen 
  

   under 
  observation, 
  the 
  direction 
  of 
  the 
  current 
  is 
  immediately 
  

   reversed. 
  

  

  As 
  the 
  worm 
  possesses 
  no 
  jaws, 
  it 
  seems 
  probable 
  that 
  its 
  

   food 
  consists 
  entirely 
  of 
  fine 
  organic 
  particles 
  and 
  of 
  small 
  

   organisms 
  carried 
  in 
  the 
  current 
  which 
  it 
  sets 
  up. 
  This 
  is 
  

  

  