﻿Oatty 
  Marine 
  Laboratory 
  } 
  St. 
  Andrews. 
  163 
  

  

  animal. 
  A 
  median 
  streak 
  occupies 
  the 
  centre 
  of 
  the 
  dorsum 
  

   and 
  another 
  the 
  mid-ventral 
  line. 
  Apparently 
  three 
  achse- 
  

   tous 
  segments 
  follow 
  the 
  head, 
  the 
  third 
  and 
  broadest 
  being 
  

   tessellated 
  or 
  crenate 
  A 
  r 
  entrally 
  as 
  well 
  as 
  dorsally, 
  the 
  latter 
  

   surface 
  being 
  so 
  broad 
  as 
  to 
  reach 
  the 
  area 
  of 
  the 
  next 
  

   segment 
  toward 
  the 
  middle 
  line, 
  the 
  lateral 
  region 
  being 
  

   occupied 
  by 
  the 
  elongated 
  scar 
  for 
  the 
  tentacles, 
  only 
  traces 
  

   of 
  which 
  are 
  present 
  in 
  the 
  examples. 
  The 
  outer 
  edge 
  of 
  

   each 
  tentacular 
  area 
  abuts 
  on 
  the 
  prominence 
  of 
  the 
  dorsal 
  

   division 
  of 
  the 
  first 
  bristled 
  foot, 
  which 
  occupies 
  a 
  dorso- 
  

   lateral 
  position, 
  the 
  dorsal 
  divisions 
  of 
  the 
  succeeding 
  feet 
  

   forming 
  a 
  well-marked 
  oblique 
  ridge 
  on 
  each 
  side 
  and 
  

   causing 
  the 
  body 
  to 
  appear 
  as 
  if 
  sheathed 
  in 
  the 
  anterior 
  

   region 
  (snout 
  and 
  achsetous 
  segments). 
  This 
  arrangement 
  

   is 
  due 
  to 
  the 
  greater 
  distance 
  between 
  the 
  dorsal 
  and 
  ventral 
  

   divisions 
  of 
  the 
  first 
  feet, 
  the 
  oblique 
  region 
  including 
  about 
  

   fifteen 
  feet. 
  Thereafter 
  the 
  dorsal 
  and 
  ventral 
  divisions 
  

   approach 
  more 
  closely, 
  the 
  space 
  between 
  them, 
  however, 
  

   remaining 
  distinct 
  to 
  the 
  posterior 
  end. 
  Each 
  division 
  of 
  

   the 
  foot 
  carries 
  a 
  tuft 
  of 
  long, 
  pale 
  golden, 
  capillary 
  bristles 
  

   (PI. 
  VI. 
  fig. 
  3) 
  issuing 
  from 
  a 
  distinct 
  setigerous 
  process, 
  and 
  

   no 
  change 
  in 
  the 
  structure 
  of 
  these 
  organs 
  occurs 
  from 
  front 
  

   to 
  rear. 
  The 
  dorsal 
  bristles, 
  as 
  a 
  rule, 
  are 
  longer 
  than 
  the 
  

   ventral 
  and 
  are 
  curved 
  outward 
  and 
  backward, 
  the 
  length 
  

   being 
  less 
  than 
  half 
  the 
  diameter 
  of 
  the 
  body 
  anteriorly. 
  

   Each 
  consists 
  of 
  a 
  long 
  basal 
  region 
  or 
  shaft 
  slightly 
  

   narrowed 
  proximally, 
  remaining 
  of 
  the 
  same 
  diameter 
  for 
  

   some 
  distance, 
  and 
  then 
  gradually 
  tapering 
  to 
  a 
  fine 
  point. 
  

   Posteriorly 
  one 
  of 
  the 
  dorsal 
  bristles 
  in 
  each 
  tuft 
  is 
  con- 
  

   siderably 
  larger 
  than 
  the 
  rest, 
  the 
  tip 
  stretching 
  outward 
  as 
  

   a 
  long 
  delicate 
  hair. 
  The 
  tips 
  of 
  all, 
  indeed, 
  in 
  this 
  region 
  

   are 
  very 
  fine. 
  The 
  ventral 
  bristles 
  are 
  shorter 
  and 
  slightly 
  

   broader, 
  but 
  also 
  have 
  delicately 
  tapered 
  tips. 
  The 
  ventral 
  

   setigerous 
  processes 
  and 
  tufts 
  are 
  really 
  ventral 
  in 
  position, 
  

   for 
  in 
  the 
  preparations 
  they 
  are 
  visible 
  only 
  in 
  ventral 
  and 
  

   lateral 
  views. 
  

  

  The 
  structure 
  of 
  the 
  bristles 
  of 
  this 
  form 
  distinguishes 
  it 
  

   from 
  the 
  Chatozone 
  macrophthalma 
  of 
  Langerhans 
  *, 
  and, 
  

   moreover, 
  the 
  skin 
  of 
  the 
  species 
  from 
  Madeira 
  is 
  smooth. 
  

   The 
  Hrierocirrus 
  marioni 
  of 
  De 
  St. 
  Joseph 
  f 
  from 
  Dinard 
  

   has 
  no 
  crotchets, 
  capillary 
  bristles 
  occurring 
  throughout 
  

   both 
  divisions, 
  but 
  the 
  ventral 
  bristle 
  is 
  flattened 
  at 
  the 
  tip 
  

   and 
  with 
  a 
  hair-like 
  termination. 
  

  

  * 
  Zeitschr. 
  f. 
  wiss. 
  Zool. 
  Bd. 
  xxxiv. 
  p 
  98, 
  Taf. 
  iv. 
  fig- 
  10. 
  

   ■\ 
  Ann. 
  Sc. 
  Nat. 
  8 
  e 
  s£r. 
  t. 
  xvii. 
  p. 
  56, 
  pi. 
  iii. 
  figs. 
  62-64. 
  

  

  11* 
  

  

  