﻿734 
  REPORT 
  OF 
  COMMISSIONER 
  OF 
  FISH 
  AND 
  FISHERIES. 
  [2 
  8 
  J 
  

  

  first 
  three 
  segments 
  this 
  cirrus 
  is 
  close 
  to 
  the 
  ventral 
  ramus 
  (fig. 
  77), 
  

   but 
  recedes 
  gradually 
  till 
  on 
  the 
  segments 
  4-7 
  it 
  is 
  about 
  half-way 
  be- 
  

   tween 
  this 
  ramus 
  and 
  the 
  branchia 
  (fig. 
  80). 
  

  

  Tbe 
  ventral 
  ramus 
  on 
  segments 
  1-3 
  is 
  a 
  fleshy, 
  lateral 
  plate, 
  some- 
  

   what 
  quadrangular, 
  and 
  with 
  a 
  small 
  conical 
  lobe 
  projecting 
  from 
  its 
  

   lower 
  margin 
  (fig. 
  77). 
  On 
  the 
  fourth 
  segment 
  (fig. 
  78), 
  in 
  place 
  of 
  

   this 
  single 
  lobe, 
  there 
  is 
  a 
  second 
  plate 
  not 
  so 
  thick 
  as 
  the 
  setigerous 
  

   plate, 
  but 
  not 
  membranous, 
  with 
  its 
  outer 
  margin 
  divided 
  into 
  4-G 
  

   stout 
  conical 
  processes. 
  Segments 
  5 
  and 
  (5 
  have 
  the 
  setigerous 
  lobe 
  

   much 
  smaller 
  (fig. 
  79), 
  while 
  a 
  membranous, 
  elevated 
  plate, 
  starting 
  

   from 
  about 
  the 
  middle 
  of 
  this 
  lobe, 
  runs 
  downward, 
  encroaching 
  on 
  the 
  

   ventral 
  surface. 
  This 
  membrane 
  has 
  its 
  outer 
  margin 
  convex 
  and 
  mi- 
  

   nutely 
  digitate, 
  or 
  beset 
  with 
  numerous 
  minute 
  cylindrical 
  papillae 
  On 
  

   the 
  seventh 
  segment 
  this 
  membrane 
  is 
  longer,entirely 
  replaces 
  the 
  setig- 
  

   erous 
  lobe, 
  aud 
  its 
  margin 
  (fig. 
  SO) 
  is 
  divided 
  into 
  conical 
  lobes 
  similar 
  

   to 
  those 
  on 
  the 
  fourth 
  segment, 
  but 
  larger 
  and 
  irregular. 
  On 
  these 
  

   seven 
  segments 
  the 
  setaj 
  arc 
  practically 
  all 
  of 
  one 
  kind 
  (fig. 
  84), 
  wide 
  

   at 
  base, 
  regularly 
  and 
  rapidly 
  tapering, 
  flattened. 
  They 
  are 
  very 
  numer- 
  

   ous 
  and 
  in 
  several 
  series 
  on 
  segments 
  1-4; 
  less 
  numerous 
  on 
  segments 
  

   5-7. 
  

  

  Segments 
  8-12, 
  formiug 
  the 
  middle 
  region 
  of 
  the 
  body, 
  have 
  their 
  ven- 
  

   tral 
  rami 
  elongated, 
  conical 
  (figs. 
  81,82), 
  carrying 
  a 
  few 
  very 
  long, 
  delicate 
  

   seta? 
  (fig. 
  85). 
  On 
  the 
  eighth 
  segment 
  a 
  membrane 
  starting 
  from 
  the 
  

   middle 
  of 
  the 
  ramus 
  runs 
  down 
  the 
  side 
  of 
  the 
  body 
  (fig. 
  81) 
  ; 
  the 
  outer 
  

   margin 
  of 
  this 
  membrane 
  is 
  finely 
  denticulated. 
  A 
  similar 
  membrane 
  

   exists 
  on 
  segments 
  9-12, 
  but 
  it 
  is 
  longer, 
  arising 
  nearer 
  the 
  apex 
  of 
  the 
  

   ramus, 
  and 
  encroaching 
  on 
  the 
  ventral 
  surface 
  (fig. 
  82). 
  On 
  the 
  eleventh 
  

   segment 
  the 
  denticulations 
  are 
  larger 
  than 
  on 
  the 
  others, 
  approaching 
  

   in 
  form 
  and 
  size 
  those 
  found 
  on 
  the 
  fourth 
  and 
  seventh 
  segments. 
  

  

  The 
  segments 
  of 
  the 
  posterior 
  third 
  of 
  the 
  body 
  are 
  numerous. 
  The 
  

   ventral 
  rami 
  on 
  these 
  segments 
  are 
  rather 
  cylindrical 
  than 
  conical 
  

   (fig. 
  83), 
  and 
  they 
  lack 
  the 
  lateral 
  membrane, 
  but 
  are 
  furnished 
  with 
  a 
  

   variable 
  number 
  of 
  conical 
  papilla'. 
  The 
  setae 
  are 
  like 
  those 
  of 
  the 
  mid- 
  

   dle 
  region. 
  

  

  Back 
  of 
  the 
  seventh 
  segment 
  the 
  branchiae 
  become 
  somewhat 
  elon- 
  

   gated 
  and 
  delicate 
  ; 
  they 
  are 
  found 
  on 
  all 
  except 
  a 
  few 
  of 
  the 
  posterior 
  

   segments, 
  where, 
  however, 
  all 
  the 
  appendages 
  become 
  much 
  smaller, 
  

   or 
  even 
  disappear. 
  

  

  Only 
  two 
  of 
  our 
  specimens 
  had 
  the 
  extreme 
  posterior 
  segments; 
  

   only 
  one 
  the 
  anal 
  cirri. 
  Anal 
  segment 
  obliquely 
  truncated, 
  at 
  a 
  small 
  

   angle; 
  anal 
  opening 
  situated 
  dorsally, 
  on 
  the 
  truncated 
  surface. 
  Anal 
  

   cirri 
  two, 
  delicate, 
  filiform, 
  lateroventral, 
  as 
  long 
  as 
  the 
  last 
  six 
  seg- 
  

   ments. 
  

  

  Our 
  specimens 
  were 
  for 
  the 
  most 
  part 
  badly 
  broken, 
  and 
  have 
  not 
  

   kept 
  well 
  in 
  alcohol. 
  It 
  seems 
  probable 
  that 
  they 
  live 
  in 
  tubes, 
  but 
  we 
  

   always 
  found 
  them 
  free. 
  

  

  