﻿NO. 
  1125. 
  CESTODE 
  PARASITES 
  OF 
  FISHES— 
  LINTON. 
  427 
  

  

  Dimensions 
  of 
  one 
  of 
  the 
  larger 
  specimens: 
  Length, 
  14.5 
  mm.; 
  

   breadth 
  of 
  liead, 
  0.72; 
  breadth 
  immediately 
  back 
  of 
  head, 
  0.68; 
  great- 
  

   est 
  breadth, 
  1; 
  breadth 
  near 
  posterior 
  end, 
  0.7; 
  breadth 
  at 
  posterior 
  

   end, 
  0.3; 
  length 
  of 
  head, 
  0.7. 
  

  

  Genital 
  apertnre, 
  2.8 
  mm. 
  from 
  posterior 
  end. 
  Ova 
  collected 
  in 
  folds 
  

   of 
  the 
  uterus 
  near 
  the 
  posterior 
  end 
  of 
  the 
  body, 
  0.038 
  to 
  0.040 
  mm. 
  in 
  

   larger 
  diameter 
  and 
  about 
  0.2 
  in 
  shorter 
  diameter. 
  

  

  Bothrium 
  terminal, 
  somewhat 
  two-lobed, 
  lobes 
  lateral, 
  namely, 
  cor- 
  

   responding 
  to 
  flat 
  [Surfaces 
  of 
  body; 
  each 
  lobe 
  divided 
  by 
  two 
  longi- 
  

   tudinal 
  ribs 
  into 
  three 
  loculi. 
  The 
  six 
  locnli 
  meet 
  at 
  the 
  apex 
  of 
  the 
  

   head 
  and 
  form 
  a 
  central 
  papilla 
  which 
  may 
  project 
  forward 
  as 
  a 
  sharp 
  

   conical 
  elevation 
  or 
  be 
  contracted 
  to 
  a 
  low 
  eminence; 
  doubtless 
  other 
  and 
  

   diverse 
  shapes 
  may 
  be 
  assumed 
  by 
  this 
  versatile 
  organ; 
  body 
  flattened, 
  

   not 
  divided 
  into 
  segments. 
  In 
  specimen 
  made 
  transparent 
  by 
  oil 
  of 
  

   cloves 
  the 
  anatomy 
  of 
  the 
  reproductive 
  organs 
  was 
  seen 
  to 
  agree 
  

   closely 
  with 
  that 
  made 
  out 
  for 
  Monohothrium 
  terebrans 
  Linton, 
  found 
  

   in 
  a 
  sucker 
  {Catostomns 
  ardens) 
  from 
  Heart 
  Lake, 
  Yellowstone 
  National 
  

   Park, 
  Wyoming.' 
  Testes 
  arranged 
  along 
  central 
  space 
  ; 
  vitelline 
  gland 
  

   along 
  lateral 
  margins 
  and 
  at 
  posterior 
  end; 
  both 
  vitellaria 
  and 
  testes 
  

   beginning 
  near 
  the 
  head; 
  ovary 
  with 
  lateral 
  folds 
  extending 
  nearly 
  to 
  

   cirrus; 
  uterus 
  with 
  ova 
  lying 
  in 
  folds 
  behind 
  the 
  genital 
  aperture, 
  also 
  

   a 
  few 
  folds 
  near 
  the 
  posterior 
  end 
  behind 
  ovary; 
  genital 
  aperture 
  about 
  

   posterior 
  fifth; 
  cirrus 
  about 
  0.1 
  mm. 
  in 
  diameter; 
  cirrus-bulb 
  about 
  0.27 
  

   in 
  diameter. 
  Cirrus 
  extended 
  in 
  one 
  specimen 
  presented 
  the 
  following 
  

   dimensions: 
  Length, 
  1 
  mm.; 
  diameter 
  at 
  apex, 
  0.043; 
  diameter 
  near 
  

   middle, 
  0.055; 
  diameter 
  at 
  tumid 
  base, 
  0.080. 
  Lateral 
  vessels 
  commu- 
  

   nicate 
  with 
  a 
  posterior 
  terminal 
  pore. 
  

  

  The 
  ovary 
  lies 
  nearest 
  the 
  tace 
  on 
  which 
  the 
  genital 
  ai)erture 
  is 
  situ- 
  

   ated, 
  the 
  median 
  portion 
  showing 
  first 
  in 
  longitudiiml 
  sections. 
  Calling 
  

   this 
  side 
  ventral 
  then 
  at 
  the 
  posterior 
  end 
  the 
  vitelline 
  gland 
  is 
  dorsal 
  

   to 
  the 
  posterior 
  folds 
  of 
  the 
  uterus, 
  which 
  in 
  turn 
  pass 
  dorsally 
  to 
  the 
  

   central 
  portion 
  of 
  the 
  ovary. 
  

  

  5. 
  SCHISTOCEPHALUS 
  DIMORPHUS 
  Crepin 
  (?) 
  

   (Plate 
  XXVIII, 
  tigs. 
  4-.5.) 
  

  

  Schiatocephahts 
  dimorphus 
  Diesing, 
  Syst. 
  Helm., 
  I, 
  pp. 
  484— 
  185; 
  Revis. 
  d. 
  Ceph. 
  

   Par., 
  pp. 
  232-233.— 
  WiLtKMOES-SuHM, 
  Zeitsebr. 
  f. 
  w. 
  Zool., 
  XIX, 
  p. 
  469-i"2, 
  

   pi. 
  XXXV, 
  tigs. 
  1-3. 
  — 
  Shauinsland, 
  Embrvoualentwicklnug, 
  pp. 
  36-39, 
  pi. 
  in, 
  

   tigs. 
  8-10. 
  

  

  No. 
  4727, 
  U.S.jST.M. 
  From 
  abdominal 
  cavity 
  of 
  the 
  blob 
  {Coitus 
  

   hairdii). 
  Swan 
  River, 
  Montana, 
  August 
  3, 
  1891 
  ; 
  B. 
  AV. 
  Everman, 
  

   collector. 
  

  

  Three 
  specimens, 
  32, 
  30, 
  and 
  5 
  mm. 
  in 
  length 
  and 
  0, 
  5, 
  and 
  1.5 
  in 
  

   breadth, 
  respectively. 
  Dimensions 
  of 
  larger 
  specimen: 
  Length, 
  32 
  

   mm.; 
  greatest 
  breadtli, 
  middle, 
  0; 
  breadth, 
  2.5, 
  from 
  anterior 
  end, 
  3; 
  

  

  'TJ. 
  S. 
  Fish 
  Com. 
  Rept., 
  1889-1891, 
  pp. 
  548-552, 
  pis. 
  lxiii-lxv, 
  figs. 
  1-21. 
  

  

  