﻿542 
  PEOCEEDINCS 
  OF 
  THE 
  NATIONAL 
  MUSEUM. 
  

  

  oesophagus, 
  from 
  the 
  mouth 
  to 
  the 
  pharynx, 
  was 
  not 
  very 
  clearly 
  shown. 
  

   So 
  lar 
  as 
  it 
  could 
  be 
  made 
  out, 
  it 
  is 
  as 
  shown 
  in 
  the 
  sketch. 
  (Fig. 
  3, 
  ph.) 
  

  

  The 
  ova 
  are 
  nearly 
  globular, 
  0.018 
  and 
  O.Ol."") 
  mm. 
  in 
  the 
  two 
  diameters 
  

   in 
  life, 
  0.17 
  and 
  0.15 
  in 
  the 
  two 
  diameters 
  in 
  alcoholic 
  specimens. 
  

  

  Ova 
  were 
  observed 
  making 
  their 
  escai)e 
  from 
  the 
  right 
  side 
  of 
  the 
  

   terminal 
  pore 
  of 
  a 
  living 
  specimen. 
  

  

  The 
  bodies 
  of 
  all 
  the 
  specimens 
  were 
  tlat, 
  depressed, 
  and 
  somewhat 
  

   convex 
  above. 
  

  

  EXPLANATION 
  OF 
  PLATES. 
  

  

  i 
  

  

  a. 
  oral 
  sucker. 
  p 
  g. 
  prostate 
  jjlaud 
  

  

  c. 
  cirrus. 
  l>h. 
  pharynx. 
  

  

  c 
  p. 
  cirrus 
  pouch. 
  s 
  g. 
  shell 
  uland. 
  

  

  ex. 
  excretory 
  vessel. 
  s 
  r. 
  seniiual 
  receptacle. 
  

   g. 
  uteriue 
  gland. 
  t. 
  testis. 
  

  

  ). 
  intestine. 
  n. 
  ulerus. 
  

  

  m. 
  mouth. 
  r 
  d. 
  vas 
  deferens. 
  

  

  0. 
  ovary. 
  rd'. 
  vitelline 
  duct. 
  

  

  OP. 
  oesophagus. 
  v 
  g. 
  vitelline 
  gland. 
  

  

  r 
  s. 
  ventral 
  sucker. 
  

  

  Sketches 
  on 
  which 
  the 
  enlargement 
  is 
  not 
  otherwise 
  noted 
  were 
  made 
  with 
  an 
  

   Abbe 
  camera 
  lucida 
  and 
  Zeiss 
  objectives 
  and 
  eyepieces, 
  as 
  indicated 
  in 
  the 
  explana- 
  

   tions. 
  They 
  were 
  reduced 
  about 
  one-fourth 
  in 
  linear 
  dimensions 
  in 
  the 
  process 
  of 
  

   printing. 
  Except 
  where 
  otherwise 
  stated, 
  all 
  sketches 
  are 
  by 
  the 
  author. 
  

  

  Plate 
  XL. 
  

  

  NitzscMa 
  papiUosa, 
  new 
  species, 
  from 
  gills 
  of 
  Acipen.ser 
  siiirio. 
  

  

  Fig. 
  1. 
  Sketch 
  of 
  alcoholic 
  specimen, 
  distorted, 
  posterior 
  third 
  side 
  view, 
  anterior 
  

   two-thirds 
  ventral 
  view. 
  Enlarged 
  about 
  eighteen 
  times. 
  

  

  2. 
  Ventral 
  view 
  of 
  another 
  specimen, 
  alcoholic. 
  Enlarged 
  about 
  eighteen 
  

   ' 
  times. 
  

  

  3. 
  Ventral 
  view 
  of 
  head 
  greatly 
  enlarged. 
  Enlarged 
  about 
  two 
  hundred 
  and 
  

  

  twenty-five 
  times; 
  m, 
  mouth; 
  /) 
  s, 
  buccal 
  sucker. 
  

  

  4. 
  Everted 
  cirrus. 
  Enlarged 
  about 
  two 
  hundred 
  and 
  twenty-five 
  times. 
  

  

  5. 
  Transverse 
  section 
  through 
  ovary. 
  Zeiss 
  2/ 
  A, 
  draw- 
  tube 
  open. 
  

  

  6. 
  Longitudinal, 
  horizontal 
  section 
  through 
  ovary 
  and 
  testis. 
  Zeiss 
  2/A, 
  

  

  draw-tube 
  open. 
  

  

  Trisfoiuiim 
  Uvve 
  Verrill, 
  from 
  gills 
  of 
  Otinmosarda 
  pehnmjs. 
  

  

  7. 
  Dorsal 
  view, 
  alcoholic 
  specimen. 
  Enlarged 
  about 
  six 
  times. 
  

  

  8. 
  Ventral 
  view, 
  alcoholic 
  specimen. 
  Enlarged 
  about 
  six 
  times. 
  

  

  Tristomum 
  coccinexm 
  Cuvier, 
  from 
  gills 
  of 
  Niphias 
  gJadiufi. 
  

  

  9. 
  Ventral 
  view 
  of 
  portion 
  of 
  anterior. 
  Enlarged 
  about 
  six 
  times; 
  from 
  sketch 
  

  

  of 
  living 
  specimen 
  by 
  Margaret 
  B. 
  Linton. 
  

  

  /*. 
  .s., 
  buccal 
  sucker; 
  p., 
  granules 
  of 
  marginal 
  papilLc 
  ; 
  r., 
  vagina. 
  

  

  Octoplectanum 
  affine, 
  new 
  species, 
  from 
  month 
  of 
  Parriliclifhys 
  dentatus. 
  

  

  10. 
  Ventral 
  view 
  of 
  alcoholic 
  specimen. 
  Enlarged 
  about 
  three 
  times. 
  

  

  11. 
  Single 
  plectanum 
  of 
  same. 
  Zeiss 
  2/A, 
  draw-tnbe 
  open. 
  

  

  12. 
  Hooks 
  from 
  genital 
  atrium 
  : 
  a, 
  Zeiss 
  2/D, 
  draw-tube 
  open 
  ; 
  h 
  and 
  <■ 
  still 
  more 
  

  

  highly 
  magnified. 
  

   II-?. 
  Ovum. 
  Enlarjjed 
  one 
  hundri'd 
  aiul 
  eightv 
  times. 
  

  

  