﻿NO. 
  1133. 
  TREMJTODE 
  PARASITES 
  OF 
  FISHES— 
  LINTON. 
  529 
  

  

  \ 
  iduals 
  holding: 
  on 
  to 
  one 
  another 
  by 
  their 
  ventral 
  suckers. 
  When 
  

   sei)arated 
  from 
  this 
  tangled 
  mass, 
  they 
  were 
  lound 
  to 
  be 
  much 
  distorted. 
  

   Where 
  a 
  ventral 
  sucker 
  of 
  one 
  individual 
  had 
  beeu 
  applied 
  to 
  the 
  body 
  

   of 
  another, 
  there 
  was 
  a 
  knob-like 
  protuberance 
  which 
  represented 
  the 
  

   portion 
  that 
  had 
  been 
  embraced 
  by 
  the 
  sucker. 
  Sometimes 
  the 
  bodies 
  

   and 
  som»-times 
  the 
  necks 
  were 
  strangulated 
  to 
  a 
  slender 
  filament 
  where 
  

   they 
  had 
  been 
  compressed. 
  Fortunately, 
  two 
  or 
  three 
  worms 
  were 
  

   found 
  which 
  had 
  not 
  beeu 
  distorted 
  in 
  any 
  other 
  way 
  than 
  by 
  contrac- 
  

   tion. 
  The 
  ventral 
  suckers 
  were 
  globular, 
  prominent, 
  and 
  in 
  some 
  cases 
  

   decidedly 
  pediceled. 
  Those 
  which 
  were 
  not 
  distinctly 
  pediceled 
  showed 
  

   by 
  their 
  wrinkled 
  condition 
  that 
  they 
  were 
  capable 
  of 
  considerable 
  

   extension. 
  

  

  Body 
  cylindrical, 
  trausverselj^ 
  wrinkled 
  (a 
  contraction 
  character), 
  

   tai)ering 
  from 
  median 
  region 
  in 
  each 
  direction, 
  but 
  most 
  posteriorly. 
  

   Posterior 
  end 
  somewhat 
  bluntly 
  pointed: 
  greatest 
  diameter 
  back 
  of 
  

   ventral 
  sucker. 
  Neck 
  rather 
  short, 
  arcuate 
  excavated 
  on 
  ventral 
  sur- 
  

   face, 
  convex 
  on 
  dorsal 
  surface. 
  Dorsal 
  surface 
  and 
  lateral 
  margins 
  

   armed 
  with 
  spheroidal 
  tuberculate 
  spines. 
  Ventral 
  sucker 
  much 
  larger 
  

   than 
  oral, 
  aperture 
  about 
  twice 
  the 
  diameter 
  of 
  the 
  mouth. 
  Slight 
  

   constriction 
  back 
  of 
  oral 
  sucker, 
  making 
  a 
  rounded 
  head. 
  Oral 
  aper- 
  

   ture 
  subterminal, 
  with 
  flat 
  spines 
  surrounding 
  it 
  on 
  inner 
  margin, 
  with 
  

   lip 
  projecting 
  anteriorly 
  in 
  a 
  blunt 
  i)oint. 
  The 
  subglobose 
  head 
  with 
  

   sparse 
  spines 
  on 
  dorsal 
  surface, 
  llenital 
  aperture 
  immediately 
  behind 
  

   mouth. 
  The 
  dark-brown 
  branching 
  vitellaria 
  show 
  through 
  the 
  body 
  

   wall 
  along 
  the 
  sides, 
  from 
  a 
  little 
  in 
  front 
  of 
  the 
  posterior 
  end 
  to 
  a 
  point 
  

   about 
  halfway 
  between 
  the 
  posterior 
  end 
  and 
  the 
  ventral 
  sucker. 
  The 
  

   anterior 
  portion 
  of 
  the 
  body, 
  including 
  the 
  ventral 
  sucker 
  and 
  neck, 
  

   yellowish 
  white. 
  The 
  oesophagus 
  opens 
  by 
  a 
  conical 
  papilla 
  into 
  the 
  

   oral 
  sucker. 
  (Figs. 
  -A, 
  6.) 
  This 
  papilla 
  is 
  0.21* 
  mm. 
  in 
  length, 
  0.14 
  

   and 
  0.08 
  in 
  diameter 
  at 
  base 
  and 
  apex, 
  respectively. 
  There 
  are 
  twenty 
  

   flat 
  spines, 
  more 
  or 
  less, 
  on 
  the 
  inner 
  margin 
  of 
  the 
  oral 
  aperture. 
  The 
  

   spines 
  on 
  the 
  neck 
  are 
  spheroidal, 
  with 
  from 
  four 
  to 
  six 
  small 
  round 
  

   tubercles 
  ijointing 
  posteriorly 
  and 
  postero-laterally. 
  (Fig. 
  5.) 
  

  

  The 
  specimens 
  were 
  so 
  much 
  distorted 
  that 
  the 
  measurements 
  ob- 
  

   tained 
  can 
  not 
  be 
  of 
  much 
  service. 
  One 
  of 
  the 
  least 
  distorted 
  exam- 
  

   ples 
  yielded 
  the 
  following 
  measurements: 
  Length, 
  8 
  mm.; 
  diameter 
  of 
  

   head, 
  0.3; 
  diameter 
  of 
  body 
  at 
  ventral 
  sucker, 
  0.55; 
  greatest 
  diameter, 
  

   0.72; 
  diameter 
  at 
  posterior 
  end, 
  0.2; 
  longitudinal 
  diameter 
  of 
  oral 
  

   sucker, 
  0.6; 
  longitudinal 
  diameter 
  of 
  ventral 
  sucker, 
  0.7; 
  diameter 
  of 
  

   oral 
  aperture, 
  0.15; 
  diameter 
  of 
  ventral 
  aperture, 
  0.3: 
  length 
  of 
  neck, 
  

   to 
  middle 
  of 
  ventral 
  sucker, 
  1.(5. 
  Measurements 
  made 
  of 
  si)ecimen 
  

   lying 
  on 
  its 
  side. 
  

  

  Three 
  ova 
  measured 
  0.036, 
  0,033, 
  and 
  0.030 
  mm., 
  respectively, 
  in 
  

   length, 
  and 
  0.020 
  in 
  shorter 
  diameter. 
  

  

  The 
  longest 
  of 
  these 
  specimens 
  measured 
  about 
  12 
  mm. 
  in 
  length, 
  but 
  

   had 
  been 
  capable, 
  evidently, 
  of 
  much 
  greater 
  elongation. 
  

   Proc. 
  N. 
  M. 
  vol. 
  XX 
  34 
  

  

  i 
  

  

  