﻿246 
  PROCEEDINGS 
  OF 
  THE 
  NATIONAL 
  MUSEUM 
  vol.96 
  

  

  latter 
  has 
  a 
  ciliated 
  groove 
  terminating 
  at 
  the 
  coecum 
  just 
  in 
  front 
  

   of 
  the 
  cloaca. 
  The 
  walls 
  of 
  the 
  coecum 
  are 
  much 
  thinner 
  than 
  in 
  

   octomyotum 
  and 
  lack 
  heavy 
  longitudinal 
  folds. 
  

  

  Blood-vascular 
  system 
  (fig. 
  14, 
  B^-B^). 
  This 
  is 
  on 
  the 
  same 
  

   plan 
  as 
  in 
  octomyotum, 
  but 
  in 
  two 
  specimens 
  the 
  left 
  dorsoventral 
  

   connective 
  from 
  the 
  ring 
  vessel 
  was 
  much 
  longer 
  than 
  the 
  right. 
  

   Passing 
  through 
  the 
  small 
  loop 
  where 
  these 
  connectives 
  join 
  the 
  

   ventral 
  vessel 
  is 
  an 
  interbasal 
  muscle 
  of 
  the 
  setae, 
  not 
  present 
  in 
  

   octomyotum. 
  The 
  ventral 
  vessel 
  ends 
  posteriorly 
  in 
  the 
  coecum 
  

   without 
  branching. 
  

  

  Color. 
  "Specimens 
  were 
  elongate 
  to 
  grape-shaped, 
  smooth 
  and 
  

   thin-skinned, 
  greenish, 
  with 
  obvious 
  and 
  comparatively 
  large 
  spoon- 
  

   shaped 
  proboscis" 
  (Steinbeck 
  and 
  Ricketts). 
  

  

  T2/2?e.— 
  U.S.N.M. 
  No. 
  20606. 
  

  

  Type 
  locality. 
  — 
  Gulf 
  of 
  California: 
  Pichalingue 
  Bay, 
  near 
  La 
  Paz, 
  

   Baja 
  California, 
  February 
  1920, 
  Luis 
  G. 
  Rubio. 
  

  

  Specimens 
  examined. 
  As 
  follows: 
  

  

  Coronado 
  Island, 
  Gulf 
  of 
  California, 
  March 
  27, 
  1940, 
  Steinbeck 
  and 
  Ricketts, 
  

   3 
  specimens, 
  under 
  and 
  among 
  slightly 
  subtidal 
  rocks 
  on 
  white 
  sand. 
  

  

  Point 
  Lobos, 
  Espiritu 
  Santo 
  Island, 
  Baja 
  California, 
  March 
  3, 
  1940, 
  Steinbeck 
  

   and 
  Ricketts, 
  1 
  specimen, 
  under 
  boulders 
  of 
  tide 
  flats. 
  

  

  Puerto 
  Refugio, 
  Angel 
  de 
  la 
  Guarda 
  Island, 
  April 
  2, 
  1940, 
  Steinbeck 
  and 
  Ricketts, 
  

   10 
  specimens; 
  under 
  boulders 
  on 
  beach. 
  All 
  these 
  are 
  smaller 
  than 
  the 
  type. 
  

  

  Same 
  locality, 
  Allan 
  Hancock 
  Foundation, 
  1 
  specimen. 
  

  

  Remarks. 
  — 
  The 
  type 
  is 
  without 
  proboscis. 
  The 
  sketch 
  of 
  the 
  en- 
  

   tire 
  animal 
  is 
  from 
  an 
  example 
  taken 
  at 
  Puerto 
  Refugio. 
  As 
  some 
  of 
  

   the 
  specimens 
  lack 
  a 
  proboscis 
  and 
  others 
  have 
  only 
  a 
  small 
  one 
  it 
  is 
  

   probable 
  that 
  the 
  organ 
  is 
  soon 
  regenerated. 
  The 
  wide 
  difference 
  in 
  

   size 
  seems 
  hardly 
  to 
  be 
  due 
  to 
  accidents 
  of 
  fixation. 
  

  

  The 
  great 
  disparity 
  in 
  size 
  of 
  the 
  nephridia 
  in 
  the 
  two 
  specimens 
  

   dissected 
  shows 
  that 
  size 
  is 
  of 
  no 
  particular 
  value 
  as 
  a 
  character, 
  

   depending 
  as 
  it 
  does 
  on 
  the 
  amount 
  of 
  conta'ined 
  material. 
  There 
  is 
  

   a 
  wide 
  difference 
  also 
  in 
  the 
  size 
  of 
  the 
  anal 
  vesicles 
  in 
  the 
  two 
  specimens. 
  

  

  0. 
  edax 
  feeds 
  upon 
  the 
  sand 
  or 
  coarser 
  material 
  in 
  which 
  it 
  lives. 
  

   This 
  is 
  not 
  molded 
  into 
  definite 
  fecal 
  pellets. 
  The 
  specimen 
  from 
  

   Puerto 
  Refugio 
  had 
  eaten 
  very 
  coarse 
  material, 
  which 
  formed 
  irregular 
  

   masses 
  in 
  the 
  intestine. 
  Among 
  the 
  miscellaneous 
  material 
  could 
  be 
  

   recognized 
  fragments 
  of 
  pelecypod 
  and 
  gastropod 
  shells 
  and 
  small 
  

   whole 
  gastropod 
  shells; 
  serpulid 
  tubes, 
  calcareous 
  bryozoans, 
  barnacle 
  

   shells; 
  chelae 
  of 
  small 
  crab; 
  fragments 
  of 
  crab 
  carapace, 
  sea-urchin 
  

   spines, 
  and 
  brown 
  algae; 
  many 
  straight 
  sUiceous 
  sponge 
  spicules 
  and 
  

   fragments 
  of 
  volcanic 
  rock. 
  Some 
  of 
  the 
  sponge 
  spicules 
  were 
  in 
  

   bundles. 
  Others 
  had 
  perforated 
  the 
  intestinal 
  wall 
  and 
  were 
  lying 
  

   in 
  the 
  coelomic 
  cavity. 
  A 
  few 
  were 
  in 
  the 
  anal 
  vesicles. 
  

  

  