﻿ECHIUROID 
  WORMS 
  OF 
  NORTH 
  PACIFIC 
  — 
  FISHER 
  245 
  

  

  The 
  specimen 
  from 
  the 
  Cabrillo 
  Marine 
  Museum 
  was 
  taken 
  in 
  sand 
  

   and 
  is 
  notable 
  for 
  the 
  93-mm. 
  proboscis, 
  whicli 
  is 
  IG 
  mm. 
  broad 
  near 
  

   tne 
  base. 
  The 
  nerve 
  loop, 
  following 
  the 
  margin, 
  is 
  plainly 
  visible. 
  

  

  OCHETOSTOMA 
  EDAX, 
  new 
  species 
  

  

  Figure 
  14 
  

  

  Diagnosis. 
  — 
  Two 
  pairs 
  of 
  nephridia 
  situated 
  posterior 
  to 
  setae, 
  the 
  

   nephrostome 
  with 
  spiral 
  lips; 
  setae 
  with 
  interbasal 
  muscle 
  passing 
  

   through 
  a 
  small 
  loop 
  of 
  the 
  neurointestinal 
  blood 
  vessel; 
  longitudinal 
  

   muscle 
  bands 
  16 
  or 
  17, 
  with 
  very 
  narrow 
  interspaces; 
  rather 
  long 
  pre- 
  

   siphonal 
  intestine; 
  precloacal 
  coecum; 
  two 
  unbranched 
  anal 
  vesicles 
  

   capable 
  of 
  great 
  distension. 
  Body 
  wall 
  translucent 
  in 
  middle 
  region, 
  

   striped 
  with 
  narrow 
  dark 
  zones; 
  skin 
  papillae 
  numerous, 
  sometimes 
  

   whitish, 
  in 
  not 
  well-defined 
  transverse 
  lines, 
  and 
  usually 
  larger 
  on 
  

   posterior 
  third 
  or 
  fourth 
  of 
  body, 
  but 
  not 
  hard 
  to 
  the 
  touch; 
  proboscis 
  

   deciduous, 
  fleshy, 
  from 
  one-fourth 
  to 
  body 
  length. 
  Length 
  of 
  body 
  

   25 
  to 
  50 
  mm. 
  

  

  Description. 
  — 
  The 
  IG 
  or 
  17 
  muscle 
  bands 
  merge 
  into 
  a 
  continuous 
  

   sheet 
  in 
  ttie 
  posterior 
  fourth 
  of 
  body. 
  The 
  intervals 
  between 
  the 
  

   bands 
  are 
  narrower 
  than 
  in 
  octomyotum 
  and 
  transverse 
  oblique 
  fas- 
  

   cicles 
  of 
  the 
  inner 
  layer 
  are 
  decidedly 
  weaker. 
  The 
  ventral 
  muscle 
  

   band 
  under 
  the 
  nerve 
  cord 
  is 
  broader 
  than 
  the 
  others. 
  Sixteen 
  is 
  

   probably 
  the 
  normal 
  number 
  of 
  bundles, 
  the 
  extra 
  band 
  arising 
  from 
  

   the 
  incomplete 
  splitting 
  of 
  one 
  of 
  the 
  lateral 
  or 
  dorsal 
  bundles. 
  

  

  Nephridia 
  2 
  pairs, 
  opening 
  at 
  outer 
  margin 
  of 
  midventral 
  muscle 
  

   and 
  varying 
  greatly 
  in 
  size. 
  In 
  a 
  male 
  the 
  nephridia 
  are 
  very 
  large, 
  

   the 
  posterior 
  reaching 
  to 
  posterior 
  end 
  of 
  (contracted) 
  specimen, 
  

   while 
  in 
  a 
  smaller 
  female 
  they 
  have 
  the 
  relative 
  size 
  of 
  the 
  three 
  

   smaller 
  nephridia 
  of 
  figure 
  14. 
  The 
  ciliated 
  funnel 
  on 
  the 
  anterior 
  

   face 
  of 
  uephridium 
  has 
  long 
  coiled 
  lips. 
  The 
  two 
  anal 
  vesicles, 
  with- 
  

   out 
  branches, 
  are 
  covered 
  with 
  ciliated 
  funnels 
  and 
  are 
  capable 
  of 
  

   being 
  distended 
  to 
  a 
  large 
  size. 
  They 
  are 
  as 
  long 
  as 
  the 
  body 
  in 
  the 
  

   largest 
  specimen, 
  which 
  is, 
  however, 
  strongly 
  contracted. 
  

  

  Ali.ment.\ry 
  canal. 
  Forcgut 
  relatively 
  short, 
  ending 
  with 
  the 
  

   ring 
  blood 
  vessel 
  (IP). 
  Oidy 
  two 
  parts 
  are 
  clearly 
  difi'erentinted, 
  the 
  

   phar}-nx-esophagus 
  and 
  stomach, 
  with 
  longitudiiud 
  folds. 
  The 
  

   gizzard 
  of 
  0. 
  octomyotum 
  appears 
  to 
  be 
  lacking. 
  The 
  intestine 
  is 
  

   long, 
  highly 
  convoluted, 
  witii 
  a 
  very 
  much 
  longer 
  presiphonal 
  segment 
  

   than 
  in 
  octomyotum, 
  being 
  lojiger 
  than 
  the 
  foregut. 
  The 
  wall 
  is 
  thin 
  

   and 
  in 
  the 
  type 
  is 
  greatly 
  distended 
  with 
  coarse 
  sand; 
  in 
  another 
  

   specimen, 
  with 
  sizable 
  fragments 
  of 
  shells 
  and 
  miscellaneous 
  hard 
  

   deV>ris. 
  In 
  the 
  type 
  the 
  presiphonal 
  intestijie 
  measmes 
  roughly 
  

   30 
  mm., 
  the 
  siphonal 
  part 
  120 
  mm. 
  and 
  postsiphonal 
  90 
  mm. 
  The 
  

  

  