﻿Gatty 
  Marine 
  Laboratory 
  } 
  St. 
  Andrews. 
  151 
  

  

  make 
  its 
  tunnel 
  in 
  shells. 
  In 
  Nevaya 
  a 
  fully 
  developed 
  foot 
  

   with 
  lamellae 
  and 
  bristles 
  occurs 
  in 
  front 
  of 
  that 
  with 
  the 
  

   four 
  great 
  golden 
  bristles 
  inserted 
  in 
  the 
  massive 
  setigerous 
  

   region. 
  Moreover, 
  no 
  bifid 
  or 
  fork-like 
  bristles 
  occur 
  in 
  

   Nevaya 
  so 
  far 
  as 
  the 
  single 
  example 
  shows. 
  Both 
  Sclero- 
  

   cheilus 
  and 
  Nevaya 
  present 
  a 
  remarkable 
  development 
  of 
  

   certain 
  anterior 
  ventral 
  bristles 
  which 
  must 
  in 
  some 
  way 
  be 
  

   connected 
  with 
  their 
  dwellings, 
  whether 
  in 
  tubes 
  or 
  burrows; 
  

   yet 
  the 
  divergences 
  in 
  the 
  position 
  and 
  structure 
  of 
  these 
  

   organs 
  in 
  each 
  case 
  indicate 
  noteworthy 
  differences 
  in 
  

   function. 
  In 
  Polydora 
  the 
  great 
  hook-like 
  bristles 
  occur 
  on 
  

   the 
  fifth 
  segment, 
  whereas 
  homologous 
  forms 
  are 
  on 
  the 
  

   third 
  foot 
  of 
  Disoma. 
  De 
  St. 
  Joseph 
  after 
  a 
  careful 
  survey 
  

   of 
  the 
  structure 
  of 
  Sclerocheilus 
  concludes 
  that 
  it 
  belongs 
  to 
  

   the 
  Scalibregmidae. 
  

  

  3. 
  On 
  the 
  British 
  Cirratulidae. 
  

  

  Four 
  species 
  representing 
  the 
  Cirratulidae 
  are 
  given 
  in 
  

   Dr. 
  Johnston's 
  ' 
  Catalogue 
  of 
  Worms 
  in 
  the 
  British 
  Museum/ 
  

   viz. 
  Cirratulus 
  tentaculatus, 
  Montagu, 
  Cirratulus 
  cirratus, 
  

   O. 
  F. 
  Miiller 
  (under 
  the 
  name 
  of 
  C. 
  borealis), 
  Aonis 
  vittata, 
  

   Grube, 
  and 
  Dodecaceria 
  concharum, 
  (Ersted. 
  

  

  By 
  De 
  Quatrefages 
  the 
  Cirratulids 
  were 
  classified 
  chiefly 
  

   by 
  the 
  arrangement 
  of 
  their 
  branchiae, 
  which 
  either 
  occurred 
  

   throughout 
  or 
  were 
  confined 
  to 
  the 
  anterior 
  segment 
  ; 
  but 
  

   subsequent 
  authors 
  took 
  into 
  consideration 
  the 
  structure 
  of 
  

   the 
  bristles 
  and 
  hooks, 
  as 
  shown, 
  for 
  instance, 
  by 
  Langer- 
  

   hans, 
  Levinsen, 
  Claparede, 
  and 
  others. 
  Thus 
  two 
  great 
  

   divisions 
  of 
  the 
  Cirratulids 
  are 
  made 
  by 
  De 
  St. 
  Joseph, 
  viz. 
  : 
  

   (1) 
  those 
  devoid 
  of 
  large 
  prehensile 
  tentacles, 
  and 
  (2) 
  those 
  

   having 
  such. 
  Further, 
  they 
  may 
  be 
  grouped 
  : 
  (1) 
  into 
  those 
  

   having 
  capillary 
  bristles 
  in 
  both 
  divisions 
  of 
  the 
  foot 
  

   throughout, 
  (2) 
  those 
  having 
  only 
  capillary 
  bristles 
  in 
  the 
  

   dorsal 
  division 
  and 
  crotchets 
  in 
  a 
  certain 
  number 
  of 
  the 
  

   ventral 
  divisions, 
  and 
  (3) 
  those 
  having 
  capillary 
  bristles 
  and 
  

   crotchets 
  in 
  a 
  certain 
  number 
  of 
  both 
  dorsal 
  and 
  ventral 
  

   divisions. 
  The 
  majority 
  of! 
  the 
  British 
  forms 
  fall 
  under 
  the 
  

   third 
  group, 
  such 
  as 
  Cirratulus 
  cirratus, 
  C. 
  tentaculatus, 
  

   C. 
  bioculatus, 
  Dodecaceria 
  concharum, 
  and 
  Chcetozone. 
  

  

  C. 
  tentaculatus 
  is 
  everywhere 
  distributed 
  round 
  our 
  shores 
  

   from 
  Shetland 
  to 
  the 
  Channel 
  Islands, 
  and 
  is 
  abundant 
  

   under 
  stones 
  on 
  muddy 
  and 
  sandy 
  ground 
  between 
  tide- 
  

   marks. 
  Such 
  muddy 
  sand, 
  indeed, 
  is 
  often 
  furrowed 
  by 
  

   them 
  and 
  their 
  trailing 
  tentacles, 
  which 
  stretch 
  as 
  orange 
  

   threads 
  in 
  every 
  direction 
  ; 
  and, 
  besides, 
  they 
  are 
  found 
  in 
  

  

  