﻿Gatty 
  Marine 
  Laboratory, 
  St. 
  Andrews. 
  167 
  

  

  thicker, 
  are 
  developed. 
  The 
  shaft 
  dilates 
  in 
  its 
  progress 
  

   upward, 
  then 
  gradually 
  diminishes 
  to 
  the 
  slightly 
  curved 
  tip, 
  

   which 
  is 
  rather 
  blunt. 
  At 
  the 
  twentieth 
  bristled 
  foot 
  the 
  

   bristles 
  are 
  still 
  longer 
  but 
  more 
  slender, 
  and 
  two 
  crotchets 
  

   are 
  present 
  ventrally, 
  whilst 
  dorsally 
  there 
  are 
  four 
  con- 
  

   siderably 
  stouter, 
  and 
  the 
  bristles 
  are 
  very 
  long, 
  stretching 
  

   far 
  beyond 
  the 
  body. 
  A 
  considerable 
  number 
  of 
  bristles 
  

   occur 
  ventrally 
  between 
  the 
  hooks, 
  whilst 
  there 
  are 
  three 
  

   dorsally. 
  At 
  "the 
  fortieth 
  foot 
  (PI. 
  VI. 
  fig. 
  5 
  d) 
  four 
  large 
  

   crotchets 
  are 
  present 
  in 
  each 
  division 
  — 
  now 
  closely 
  approxi- 
  

   mated, 
  the 
  ventral 
  being 
  shaped 
  like 
  a 
  scapel 
  set 
  in 
  its 
  

   handle, 
  with 
  a 
  slight 
  constriction 
  and 
  bend 
  at 
  the 
  end 
  of 
  the 
  

   handle 
  ; 
  both 
  shaft 
  and 
  tip 
  are 
  longitudinally 
  striated. 
  The 
  

   dorsal 
  crotchets 
  still 
  are 
  the 
  stronger 
  (PI. 
  VI. 
  fig. 
  5 
  e) 
  and 
  

   the 
  tip 
  (or 
  blade) 
  is 
  more 
  distinctly 
  curved. 
  Four 
  long 
  

   bristles 
  occur 
  between 
  the 
  third 
  and 
  fourth 
  (that 
  is, 
  toward 
  

   the 
  ventral 
  edge) 
  ; 
  whilst 
  ventrally 
  two 
  bristles 
  lie 
  between 
  

   the 
  first 
  and 
  second 
  and 
  two 
  between 
  the 
  second 
  and 
  third. 
  

  

  These 
  posterior 
  crotchets 
  differ 
  from 
  those 
  of 
  C. 
  setosa 
  in 
  

   their 
  great 
  size 
  and 
  in 
  the 
  absence 
  of 
  longer 
  intermediate 
  

   forms, 
  as 
  well 
  as 
  in 
  their 
  occurrence 
  anteriorly. 
  

  

  Chaetozone 
  7i. 
  

  

  A 
  fragment 
  of 
  the 
  posterior 
  end 
  of 
  a 
  form 
  not 
  hitherto 
  seen, 
  

   and 
  having 
  the 
  shape 
  of 
  a 
  gradually 
  widening 
  and 
  spathulate 
  

   tail 
  with 
  the 
  broad 
  end 
  posteriorly. 
  The 
  posterior 
  border 
  is 
  

   bluntly 
  rounded, 
  with 
  a 
  median 
  ridge 
  dorsally 
  and 
  ventrally, 
  

   the 
  former 
  curving 
  downward 
  to 
  terminate 
  in 
  the 
  ventral 
  anus 
  

   which 
  has 
  a 
  peak 
  anteriorly. 
  The 
  region 
  in 
  front 
  of 
  the 
  broad 
  

   tail 
  is 
  considerably 
  narrower, 
  the 
  dorsal 
  surface 
  being 
  rounded 
  

   and 
  the 
  ventral 
  flattened. 
  The 
  segments 
  are 
  numerous 
  and 
  

   narrow, 
  and 
  have 
  dorsal 
  and 
  ventral 
  tufts 
  of 
  slender 
  

   capillary 
  bristles 
  (PI. 
  VI. 
  fig. 
  6 
  a) 
  of 
  a 
  pale 
  yellow 
  colour 
  

   and 
  nearly 
  straight. 
  It 
  was 
  procurved 
  in 
  the 
  ' 
  Porcupine 
  ' 
  

   Expedition 
  of 
  1870/ 
  no 
  locality 
  being 
  given. 
  

  

  A 
  peculiar 
  form, 
  which 
  may 
  temporarily 
  be 
  termed 
  Cirra- 
  

   tulispio, 
  was 
  dredged 
  in 
  the 
  ' 
  Porcupine 
  ' 
  Expedition 
  of 
  1869 
  

   in 
  378 
  fathoms 
  in 
  sticky 
  mud 
  off 
  the 
  coast 
  of 
  Ireland. 
  The 
  

   mud 
  contained 
  fragments 
  of 
  foraminifera, 
  coccoliths, 
  and 
  

   sandy 
  debris. 
  

  

  The 
  head 
  (PI. 
  VI. 
  fig. 
  7) 
  is 
  bluntly 
  conical 
  and 
  the 
  sides 
  

   of 
  the 
  cone 
  slightly 
  hollowed. 
  A 
  pair 
  of 
  slender 
  tentacles 
  

   pass 
  from 
  the 
  bristled 
  segment 
  immediately 
  behind, 
  and 
  

   therefore 
  apparently 
  posterior 
  to 
  the 
  buccal 
  ring. 
  

  

  