﻿714 
  REPORT 
  OF 
  COMMISSIONER 
  OF 
  FISH 
  AND 
  FISHERIES. 
  [8 
  J 
  

  

  jured 
  for 
  description. 
  At 
  Eastport 
  we 
  found 
  but 
  one 
  adult 
  specimen, 
  

   aud 
  before 
  figures 
  were 
  made 
  the 
  anterior 
  part 
  was 
  accidentally 
  lost; 
  

   but 
  a 
  number 
  of 
  half-grown 
  specimens, 
  evidently 
  of 
  the 
  same 
  species, 
  

   were 
  taken. 
  

  

  In 
  the 
  adult 
  form 
  the 
  head 
  is 
  somewhat 
  more 
  quadrangular 
  than 
  in 
  

   fig. 
  1G 
  (young); 
  the 
  antennae 
  relatively 
  a 
  little 
  longer, 
  and 
  there 
  are 
  no 
  

   eyes. 
  The 
  unpaired 
  antenna 
  arises 
  near 
  the 
  posterior 
  margin 
  of 
  the 
  

   head, 
  and 
  is 
  a 
  little 
  shorter 
  than 
  the 
  superior 
  paired 
  antenna'. 
  

  

  The 
  first 
  segment 
  is 
  shorter 
  than 
  the 
  second 
  and 
  third 
  and 
  is 
  hardly 
  

   visible 
  dorsally, 
  except 
  at 
  the 
  sides. 
  The 
  tentacular 
  cirri 
  have 
  long 
  

   basal 
  articles, 
  are 
  from 
  two 
  to 
  three 
  times 
  the 
  width 
  of 
  the 
  body 
  in 
  

   length, 
  taper 
  uniformly, 
  becoming 
  quite 
  delicate 
  near 
  their 
  outer 
  end. 
  

  

  The 
  dorsal 
  cirri 
  (fig. 
  14) 
  are 
  in 
  all 
  respects 
  similar 
  to 
  the 
  tentacular 
  

   cirri 
  and 
  nearly 
  as 
  long. 
  The 
  dorsal 
  ramus 
  is 
  a 
  small 
  but 
  well 
  defined 
  

   papilla. 
  The 
  ventral 
  ramus 
  is 
  large, 
  its 
  inner 
  two-thirds 
  (fig. 
  14) 
  cyl- 
  

   indrical, 
  outer 
  third 
  bluntly 
  conical. 
  The 
  ventral 
  cirrus 
  arises 
  at 
  the 
  

   outer 
  third 
  of 
  the 
  ventral 
  ramus, 
  is 
  stout, 
  conical, 
  and 
  projects 
  beyond 
  

   its 
  ramus. 
  

  

  The 
  chief 
  peculiarity 
  of 
  this 
  species 
  is 
  in 
  the 
  structure 
  of 
  the 
  anal 
  

   segment. 
  The 
  anal 
  opening 
  is 
  large, 
  dorsal, 
  surrounded 
  by 
  a 
  thin 
  mem- 
  

   brane, 
  with 
  scolloped 
  margin. 
  Attached 
  to 
  the 
  posterior 
  ventral 
  margin 
  

   of 
  this 
  segment 
  (fig. 
  15) 
  is 
  a 
  membranous, 
  horizontal 
  plate, 
  nearly 
  double 
  

   the 
  width 
  of 
  its 
  segmeut, 
  and 
  with 
  its 
  lateral 
  margins 
  rounded. 
  The 
  

   free 
  margin 
  has 
  a 
  series 
  of 
  lateral 
  papillae 
  or 
  digitations, 
  bluntly 
  rounded 
  

   at 
  apex, 
  better 
  defined 
  at 
  the 
  sides 
  than 
  behind. 
  In 
  the 
  young 
  forms 
  

   there 
  are 
  two 
  anal 
  cirri 
  which 
  arise 
  at 
  the 
  outer 
  posterior 
  angles 
  of 
  the 
  

   anal 
  segment, 
  run 
  across 
  the 
  anal 
  plate 
  (fig. 
  17), 
  and 
  extend 
  far 
  beyond 
  

   it. 
  There 
  were 
  no 
  anal 
  cirri 
  on 
  our 
  adult 
  form, 
  but 
  it 
  seems 
  probable 
  

   that 
  they 
  had 
  fallen 
  off. 
  

  

  The 
  form 
  of 
  the 
  ventral 
  seta3 
  is 
  shown 
  in 
  fig. 
  20; 
  their 
  arrangement 
  

   in 
  fig. 
  18. 
  The 
  dorsal 
  setae 
  (fig. 
  19) 
  are 
  short, 
  stout, 
  simple, 
  six 
  to 
  eight 
  

   in 
  each 
  bundle. 
  

  

  The 
  anterior 
  division 
  of 
  the 
  alimentary 
  canal 
  extends 
  back 
  to 
  the 
  sixth 
  

   or 
  seventh 
  segment, 
  where 
  it 
  suddenly 
  passes 
  into 
  a 
  much 
  wider 
  tube, 
  

   which 
  uearly 
  fills 
  the 
  cavity 
  of 
  the 
  body. 
  The 
  proboscis 
  ends 
  in 
  a 
  cir- 
  

   cle 
  of 
  conical 
  papilla'. 
  

  

  The 
  body 
  is 
  convex 
  above, 
  nearly 
  flat 
  below 
  ; 
  the 
  segments 
  increase 
  

   in 
  width 
  and 
  slightly 
  in 
  length 
  to 
  the 
  middle 
  of 
  the 
  body, 
  after 
  which 
  

   they 
  gradually 
  become 
  smaller, 
  the 
  posterior 
  segments 
  being 
  very 
  short. 
  

  

  Head 
  and 
  body, 
  white; 
  appendages, 
  colorless; 
  alimentary 
  canal, 
  white, 
  

   the 
  anterior, 
  narrow 
  part 
  margined, 
  with 
  a 
  wide, 
  colorless 
  band. 
  

  

  Length, 
  ( 
  J""". 
  

  

  Width, 
  1 
  

  

  Most 
  of 
  our 
  specimens 
  appear 
  to 
  be 
  about 
  half-grown. 
  In 
  these 
  the 
  

   head 
  is 
  rounded 
  (lig. 
  1G); 
  there 
  are 
  two 
  minute, 
  lateral, 
  red 
  eyes; 
  the 
  

   tentacular, 
  dorsal, 
  and 
  ventral 
  cirri 
  are 
  much 
  shorter 
  than 
  in 
  the 
  adult; 
  

  

  