﻿446 
  rEOCEEDINGS 
  OF 
  THE 
  NATIONAL 
  MUSEUM. 
  

  

  In 
  this 
  lot 
  were 
  some 
  with 
  attenuated 
  anterior 
  ends 
  and 
  distorted 
  

   heads 
  which 
  would 
  be 
  very 
  jnizzling 
  to 
  one 
  who 
  has 
  not 
  seen 
  the 
  living 
  

  

  worm. 
  

  

  Since 
  reporting 
  on 
  this 
  worm 
  1 
  have 
  encountered 
  it 
  at 
  Woods 
  Holl, 
  

   Massachusetts, 
  July 
  8, 
  1880, 
  where 
  in 
  iibout 
  one 
  hundred 
  and 
  seventy- 
  

   five 
  specimens, 
  young 
  and 
  adult, 
  it 
  was 
  found 
  in 
  spiral 
  intestine 
  of 
  

   sand 
  shark. 
  The 
  young 
  worms 
  were 
  found 
  in 
  the 
  anterior 
  part 
  of 
  the 
  

   intestine 
  near 
  the 
  pyloric 
  division 
  of 
  the 
  stomach. 
  Again 
  on 
  July 
  12, 
  

   1889, 
  numerous 
  specimens 
  found 
  in 
  spiral 
  intestine 
  of 
  each 
  of 
  two 
  sand 
  

   sharks, 
  and 
  on 
  July 
  13, 
  1880, 
  a 
  few 
  specimens 
  were 
  found 
  in 
  a 
  mutilated 
  

   intestine 
  of 
  sand 
  shark 
  which 
  had 
  been 
  brought 
  into 
  the 
  laboratory. 
  

  

  In 
  July, 
  1889, 
  I 
  received 
  from 
  Doctor 
  E. 
  A. 
  Andrews 
  a 
  vial 
  contain- 
  

   ing 
  a 
  single 
  example 
  of 
  C. 
  laciniatio)i, 
  which 
  was 
  found 
  by 
  him, 
  in 
  a 
  pail 
  

   containing 
  specimens 
  of 
  ^MgnUv. 
  August 
  16, 
  1889, 
  one 
  specimen 
  of 
  

   C. 
  laciniatum 
  in 
  intestine 
  of 
  sand 
  shark. 
  

  

  31. 
  ONCHOBOTHRIUM 
  UNCINATUM 
  Diesing. 
  

   (Plate 
  XXXIV, 
  tigs. 
  2-5.) 
  

  

  Oiichohothrium 
  iincinatiiin 
  Diesing, 
  Eevis. 
  cl. 
  Cephal., 
  Param., 
  pp. 
  269-270. 
  — 
  Ols- 
  

   sox, 
  Luud's 
  Univers. 
  Arsskrift, 
  III, 
  p. 
  45, 
  pi 
  ii, 
  figs. 
  30-34. 
  

  

  Xo. 
  1795, 
  U.S.I^.M,, 
  is 
  from 
  intestine 
  of 
  sting 
  ray 
  {Basi/atis 
  centnira)', 
  

   two 
  specimens, 
  in 
  poor 
  state 
  of 
  preservation. 
  Heads 
  much 
  distorted 
  

   and 
  details 
  of 
  structure 
  difficult 
  to 
  make 
  out; 
  bothria, 
  four, 
  in 
  marginal 
  

   pairs, 
  apparently 
  triloculare 
  the 
  largest 
  loculus 
  near 
  apex, 
  and 
  sur- 
  

   rounded 
  by 
  a 
  pair 
  of 
  dark-brown, 
  nearly 
  black 
  hooks; 
  neck 
  long; 
  

   broadest 
  segment 
  some 
  distance 
  from 
  i)osterior 
  end, 
  toward 
  which 
  they 
  

   become 
  narrower; 
  genital 
  apertures 
  marginal, 
  irregularly 
  alternate. 
  

  

  Dimensions 
  : 
  Length 
  of 
  largest, 
  Gl 
  mm. 
  ; 
  breadth 
  of 
  broadest 
  segments, 
  

   2 
  ; 
  length 
  of 
  same, 
  0.3 
  ; 
  length 
  of 
  posterior 
  segments, 
  0.8 
  ; 
  breadth 
  of 
  pos- 
  

   terior 
  segments, 
  1; 
  thickness 
  of 
  head, 
  0.6; 
  breadth 
  of 
  head, 
  0.8 
  ; 
  breadth 
  

   of 
  neck, 
  0.6; 
  length 
  of 
  bothrium, 
  0.4; 
  breadth 
  of 
  bothrium, 
  0.35. 
  

  

  One 
  of 
  the 
  specimens 
  was 
  quite 
  attenuate, 
  and 
  34 
  mm. 
  in 
  length 
  with- 
  

   out 
  any 
  indication 
  of 
  segments. 
  The 
  details 
  of 
  structure 
  of 
  hooks 
  were 
  

   not 
  made 
  out 
  with 
  entire 
  satisfaction. 
  One 
  hook 
  of 
  each 
  pair 
  bears 
  a 
  

   small 
  tubercular 
  hook 
  at 
  its 
  base. 
  The 
  hooks 
  are 
  in 
  pairs, 
  whether 
  

   united 
  at 
  base 
  not 
  certain; 
  in 
  one 
  case 
  the 
  hooks 
  of 
  a 
  pair 
  were 
  united 
  

   by 
  a 
  slender 
  chitinous 
  bar, 
  a 
  blending 
  of 
  their 
  broad 
  bases. 
  In 
  another 
  

   case 
  tlie 
  bases, 
  while 
  contiguous, 
  Avere 
  not 
  united. 
  The 
  hooks 
  were 
  more 
  

   or 
  less 
  broken, 
  so 
  that 
  lengths 
  could 
  not 
  be 
  obtained 
  exactly. 
  

  

  Dimensions 
  of 
  hooks 
  : 
  Length, 
  measured 
  from 
  top 
  to 
  opposite 
  of 
  base, 
  

   about 
  0.17 
  mm. 
  ; 
  breadth 
  of 
  base, 
  0.1 
  ; 
  length 
  of 
  hook 
  proper, 
  0.08. 
  

  

  While 
  the 
  hooks 
  do 
  not 
  agree 
  in 
  detail 
  with 
  descriptions 
  of 
  this 
  

   species, 
  none 
  of 
  them 
  maintaining 
  the 
  tubercular 
  hook 
  which 
  is 
  born 
  by 
  

   one 
  hook 
  in 
  each 
  pair, 
  I 
  do 
  not 
  feel 
  justified 
  in 
  making 
  a 
  new 
  specific 
  

   name, 
  particularly 
  when 
  the 
  small 
  amount 
  of 
  material 
  and 
  its 
  poor 
  state 
  

   of 
  preservation 
  are 
  taken 
  into 
  consideration. 
  

  

  