﻿526 
  rUOCEEIUNGS 
  OF 
  TEE 
  NATIOXAL 
  MISET'M. 
  

  

  in 
  length 
  to 
  the 
  pharynx. 
  Vitelline 
  glands 
  large, 
  globose, 
  extending 
  

   laterally 
  iVoni 
  tlie 
  tail 
  to 
  the 
  ventral 
  sucker. 
  Testes, 
  two 
  large, 
  remote 
  

   in 
  the 
  median 
  line. 
  Ovary 
  in 
  front 
  of 
  the 
  testes 
  trilobed 
  on 
  its 
  poste- 
  

   ricr 
  border. 
  Seminal 
  vescicle 
  ovate 
  immediately 
  in 
  front 
  of 
  ovary. 
  

   Cirrus 
  pouch 
  behind 
  ventral 
  sucker. 
  Genital 
  aperture 
  between 
  phar- 
  

   ynx 
  and 
  ventral 
  sucker. 
  Ova 
  not 
  numerous, 
  large. 
  Branches 
  of 
  intes- 
  

   tine 
  extending 
  to 
  posterior 
  end. 
  Excretory 
  vessel 
  single, 
  opening 
  by 
  

   terminal 
  pore. 
  Length, 
  3.9 
  mm. 
  | 
  Various 
  authors,] 
  

  

  Dujardin' 
  gives 
  the 
  length 
  1.25 
  to 
  2 
  mm. 
  for 
  one 
  and 
  3.6 
  for 
  another, 
  

   both 
  of 
  which 
  he 
  refers 
  to 
  this 
  si)ecies. 
  

  

  A 
  single 
  specimen, 
  No. 
  4847, 
  I'.S.N.M., 
  from 
  the 
  intestine 
  of 
  a 
  Tom- 
  

   cod 
  {Alkrogadns 
  tomcod), 
  Woods 
  Holl, 
  Massachusetts, 
  July 
  23, 
  1880. 
  

   yielded 
  during 
  life 
  the 
  following 
  measurements: 
  Length, 
  1.8 
  mm.; 
  

   breadth 
  at 
  anteiior 
  sucker, 
  0.14; 
  breadth 
  at 
  ventral 
  sucker, 
  0.34. 
  The 
  

   same 
  specimen, 
  after 
  killing 
  in 
  corrosive 
  sublinmte 
  and 
  preservation 
  in 
  

   alcohol, 
  when 
  placed 
  in 
  acetic 
  acid 
  for 
  examination 
  yielded 
  the 
  fol- 
  

   lowing 
  measurements 
  in 
  millimeters: 
  Length, 
  2.45: 
  diameter 
  of 
  oral 
  

   sucker, 
  0.15; 
  diameter 
  of 
  ventral 
  sucker, 
  0.28; 
  diameter 
  of 
  testes, 
  0.32. 
  

   In 
  both 
  cases 
  the 
  specimen 
  was 
  subjected 
  to 
  some 
  pressure 
  and 
  conse- 
  

   quently 
  more 
  or 
  less 
  distorted. 
  The 
  ova 
  in 
  this 
  specimen 
  were 
  few 
  

   (sixteen), 
  and 
  measured 
  0.084 
  and 
  0.04 
  in 
  the 
  two 
  principal 
  diameters. 
  

   Each 
  in 
  acetic 
  acid 
  showed 
  a 
  distinct 
  nucleus 
  near 
  one 
  end 
  (Fig. 
  4). 
  

  

  I 
  refer, 
  also, 
  to 
  this 
  species 
  three 
  lots 
  of 
  JH.stoma 
  belonging 
  to 
  the 
  

   United 
  States 
  Kational 
  Museum 
  collection, 
  all 
  from 
  the 
  sea 
  raven 
  {Hemi- 
  

   tripterus 
  americanus). 
  Four 
  specimens, 
  ISIo. 
  4863, 
  U.S.N.M., 
  Woods 
  

   Holl, 
  Massachusetts, 
  October 
  12, 
  1887, 
  V. 
  ]S\ 
  Edwards; 
  No. 
  4864, 
  

   U.S.N.M., 
  same 
  locality 
  and 
  collector, 
  December 
  1, 
  1887; 
  40 
  specimens, 
  

   Casco 
  Bay, 
  1873; 
  TTnited 
  States 
  Fish 
  Commission. 
  

  

  In 
  the 
  first 
  and 
  third 
  the 
  largest 
  specimens 
  are 
  about 
  2.5 
  mm. 
  in 
  

   length. 
  One 
  of 
  these 
  specimens, 
  the 
  second, 
  measures 
  4.1 
  mm. 
  in 
  

   length. 
  The 
  ventral 
  sucker, 
  0.34 
  mm. 
  in 
  diameter 
  in 
  one 
  specimen, 
  is 
  

   very 
  prominent, 
  and 
  in 
  many 
  of 
  the 
  specimens 
  the 
  neck 
  is 
  bent 
  back 
  

   dorsally, 
  making 
  an 
  acute 
  angle 
  with 
  the 
  body. 
  There 
  is 
  a 
  great 
  diver 
  

   sity 
  of 
  shape. 
  The 
  oral 
  sucker, 
  0.17 
  mm. 
  in 
  diameter, 
  has 
  a 
  posterior 
  

   notch. 
  Length 
  of 
  i^harynx, 
  0.10; 
  l)readth, 
  0.07 
  mm. 
  Vitellaria 
  mainly 
  

   lateral, 
  but 
  a 
  few 
  median 
  lobes 
  noticed 
  in 
  sections, 
  on 
  a 
  level 
  with 
  the 
  

   anterior 
  border 
  of 
  the 
  ovary. 
  

  

  20. 
  DISTOMUM 
  FALLENS 
  Rudolphi. 
  

  

  (Plate 
  XLVII, 
  iig.s. 
  <s, 
  !».) 
  

  

  THstomnm 
  paUvna 
  Du.jardin, 
  Hist. 
  Nat. 
  tl. 
  Hehu., 
  p. 
  457. 
  — 
  Difsixg, 
  Syst. 
  Hehn., 
  

   I, 
  p. 
  348. 
  — 
  COBBOLD, 
  Syuop.s. 
  Distoni., 
  p. 
  26. 
  — 
  Carus, 
  Pvodr. 
  Fauna- 
  Medi- 
  

   terr., 
  I, 
  p. 
  130. 
  — 
  .Srossicn, 
  Dist. 
  cL 
  Pesc, 
  p. 
  31; 
  Bull. 
  Soc. 
  Adriat. 
  Trieste, 
  

   IX, 
  1887, 
  (Extract) 
  p. 
  4. 
  

  

  A 
  single 
  specimen, 
  No. 
  48(»0, 
  TJ.S.N.]M., 
  of 
  a 
  Distonium 
  found 
  in 
  the 
  

   intestine 
  of 
  Alutera 
  schocpjii, 
  and 
  which 
  I 
  refer 
  with 
  some 
  doubt 
  to 
  D. 
  

  

  ' 
  Hist. 
  Nat. 
  d. 
  Helm., 
  1845, 
  p. 
  466. 
  

  

  