﻿NO. 
  1125. 
  CESTODE 
  PARASITES 
  OF 
  FISHES— 
  LINTON. 
  445 
  

  

  strobile, 
  the 
  posterior 
  segments 
  being 
  crenulate 
  on 
  lateral 
  margins; 
  

   segments 
  at 
  first 
  broader 
  tlian 
  long, 
  becoming 
  square, 
  then 
  longer 
  than 
  

   broad. 
  

  

  Diinensioiis 
  of 
  a 
  specimen 
  (alcoholic): 
  Length, 
  8.5 
  mm.; 
  diameter 
  of 
  

   head, 
  0.44; 
  diameter 
  of 
  neck, 
  0.11; 
  distance 
  to 
  first 
  distinct 
  segment, 
  1; 
  

   length 
  of 
  first 
  distinct 
  segment, 
  0.08; 
  breadth 
  of 
  same, 
  0.14; 
  length 
  of 
  

   last 
  segment, 
  0.5G; 
  breadth 
  of 
  last 
  segment, 
  28. 
  

  

  The 
  strobiles 
  were 
  young 
  and 
  the 
  reproductive 
  apparatus 
  could 
  not 
  

   be 
  made 
  out 
  satisfactorily. 
  The 
  vitellaria 
  make 
  a 
  comparatively 
  nar- 
  

   row 
  border 
  along 
  the 
  margins 
  ; 
  ovary 
  at 
  posterior 
  end, 
  api^arently 
  single; 
  

   testes 
  centrally 
  placed, 
  mostly 
  forward 
  of 
  the 
  genital 
  cloaca; 
  the 
  geni- 
  

   tal 
  aperture 
  is 
  about 
  the 
  middle 
  or 
  a 
  little 
  in 
  front 
  of 
  the 
  middle 
  of 
  the 
  

   length 
  of 
  the 
  segment, 
  not 
  on 
  a 
  lateral 
  margin, 
  but 
  near 
  it. 
  (Plate 
  

   XXXIII, 
  fig. 
  12.) 
  

  

  Plate 
  XXXIV, 
  fig. 
  1, 
  is 
  from 
  a 
  sketch 
  of 
  a 
  longitudinal 
  section 
  

   through 
  the 
  head 
  of 
  one 
  of 
  the 
  specimens, 
  and 
  represents 
  the 
  relation 
  

   of 
  the 
  anterior 
  acetabulum 
  to 
  the 
  bothrium 
  proper 
  and 
  of 
  the 
  auxiliary 
  

   organ 
  of 
  circular 
  fibers. 
  The 
  two 
  former 
  organs 
  present 
  the 
  usual 
  

   appearance 
  made 
  by 
  the 
  strong 
  radiating 
  fibers 
  characteristic 
  of 
  such 
  

   organs; 
  the 
  latter 
  lies 
  superficially 
  to 
  the 
  larger 
  acetabulum 
  and 
  con- 
  

   sists 
  almost 
  entirely 
  of 
  strong 
  circular 
  fibers. 
  In 
  these 
  two 
  sjiecimens 
  

   these 
  fibers 
  were 
  strongly 
  contracted 
  into 
  a 
  circular 
  disk, 
  with 
  small 
  

   aperture. 
  The 
  disk 
  really 
  represents 
  the 
  border 
  of 
  the 
  bothria 
  proper, 
  

   and 
  when 
  relaxed 
  no 
  doubt 
  gives 
  to 
  the 
  bothrium 
  a 
  very 
  different 
  

   aspect 
  from 
  what 
  it 
  bears 
  in 
  these 
  specimens. 
  

  

  Plate 
  XXXIIl, 
  fig. 
  11, 
  is 
  a 
  hypothethical 
  sketch 
  giving 
  what 
  I 
  con- 
  

   ceive 
  to 
  be 
  the 
  relation 
  of 
  the 
  circular 
  fibers 
  to 
  the 
  acetabula 
  when 
  

   relaxed. 
  

  

  30. 
  CROSSOBOTHRIUM 
  LACINIATUM 
  Linton. 
  

  

  CroiiSohothrium 
  hi<iiiiatu)u 
  LiNTON, 
  U. 
  S. 
  Fisli 
  Com. 
  Kept., 
  1886, 
  pj). 
  469-474, 
  

   pi. 
  III. 
  iigs. 
  4-18 
  ; 
  1887, 
  pp. 
  799-802, 
  pi. 
  \n, 
  fig. 
  4. 
  

  

  Xos. 
  4718, 
  4723, 
  4731, 
  4738, 
  4780, 
  4781, 
  U.S.KM. 
  Several 
  lots 
  of 
  this 
  

   parasite 
  occur 
  in 
  the 
  United 
  States 
  National 
  Museum 
  collection. 
  All 
  

   were 
  collected 
  at 
  Woods 
  Holl, 
  Massachusetts, 
  the 
  host 
  in 
  each 
  case 
  

   being 
  the 
  sand 
  shark 
  [CarcJtarias 
  liftoralis 
  Mitchell). 
  The 
  parasites 
  

   were 
  usually 
  in 
  considerable 
  numbers 
  and 
  were 
  found 
  in 
  the 
  the 
  spiral 
  

   intestine. 
  

  

  These 
  specimens 
  were 
  collected 
  in 
  the 
  mouths 
  of 
  August, 
  Xovember, 
  

   and 
  December. 
  Collectors, 
  Vinal 
  X. 
  Edwards 
  and 
  Ealph 
  S. 
  Tarr. 
  

  

  Both 
  young 
  and 
  adult 
  specimens 
  were 
  found 
  together 
  in 
  the 
  Novem- 
  

   ber 
  collections, 
  appearing 
  much 
  as 
  I 
  have 
  seen 
  them 
  in 
  July. 
  

  

  One 
  specimen 
  was 
  found 
  which 
  had 
  an 
  elongated 
  first 
  joint, 
  or 
  neck, 
  

   like 
  that 
  noticed 
  and 
  figured 
  in 
  my 
  report 
  on 
  Cestodes 
  of 
  Marine 
  

   Fishes." 
  This 
  is 
  the 
  second 
  individual 
  of 
  the 
  kind 
  that 
  I 
  have 
  noticed 
  

   among 
  many 
  hundreds 
  of 
  individuals 
  from 
  many 
  different-hosts. 
  

  

  ' 
  U. 
  S. 
  Fish 
  Com. 
  Kept., 
  1887, 
  p. 
  800, 
  pi. 
  vii, 
  fit 
  

  

  