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THE 


INSTITUTED   MDCCCXLIV. 


This  volume  is  issued  to  the  Siibawibers  to  the  RAY  SOCIETY  for 
the  Year  \M:1. 


LONDON: 
MCMXIII. 


THE 

BRITISH 
PARASITIC  COPEPODA 


BY 

THOMAS    SCOTT,   LL.D,   F.L.S. 

AND 

ANDREW    SCOTT,  A.L.S. 


VOLUME    I 
COPEPODA    PARASITIC    ON    FISHES 

(Mi£47 

TEXT  f^Z&°     %v 


LONDON 
PRINTED    FOR    THE    RAY    SOCIETY 

AND    SOLD    BY 

DULAU    &   CO.,  LTD.,   37,   SOHO   SQUARE,   W. 
1913 


PRINTKD   BY   ADLARD   AND   SON 
LONDON   AND   DORKING 


THE    AUTHORS 

DESIRE,    WITH    THE    MOST    SINCERE    RESPECT, 

TO    DEDICATE    THIS    WORK 

TO    THE 

REV.    CANON    A.    M.    NORMAN,    M.A., 

D.C.L.,    LL.D.,   F.R.S.,    F.L.«.,    ETC., 
IN    GRATITUDE    FOR    HIS    UNFAILING 

KINDNESS   AND   ASSISTANCE 
EXTENDED   TO   THEM    FOR   MANY   TEARS. 


PREFACE. 


DR.  BAIRD'S  work  on  c  The  Natural  History  of  the 
British  Entomostraca,'  published  by  the  Ray  Society 
in  1850,  marked  an  important  stage  in  British  Natural 
History  research,  and  forms  the  basis  of  the  present 
volume.  That  work  contains  a  complete  account  of 
the  Copepoda  found  living  as  parasites  on  British 
fishes,  so  far  as  then  known.  Much  has  been  done 
since  then  to  extend  our  knowledge  of  these  organisms, 
and  many  species  have  been  added  to  the  number 
recorded  by  Dr.  Baird.  His  work  naturally  tended  to 
produce  such  results,  for  it  placed  before  British 
students,  in  a  concise  manner,  a  large  amount  of 
interesting  information  concerning  these  parasitic 
forms,  and,  by  showing  the  successful  results  which 
had  already  been  accomplished  in  other  countries 
among  such  curious  animals,  led  to  an  increased 
interest  in  their  study. 

'  A  Monograph  of  the  Free  and  Semi-Parasitic 
Copepoda,'  by  Dr.  Gr.  S.  Brady,  was  published  by  the 
Ray  Society  in  1878-1880.  That  work,  which  con- 
sists of  three  volumes,  marked  a  second  important 
stage  in  the  study  of  these  minute  crustaceans,  and 
was  an  evidence  of  the  increasing  attention  their  study 
was  receiving.  But  though  several  groups  of  the  non- 
freeliving  species  were  described  in  that  Monograph, 
those  found  parasitic  on  fishes  were  expressly  omitted. 
The  author  in  his  Introduction  states :  "  The  truly 
parasitic  forms — fish-lice,  etc. — are  excluded  as  not 
coming  within  the  scope  of  my  work.  They  are  of 
themselves  sufficient  to  occupy  an  independent  volume, 


Vlll  PREFACE. 

and  to  afford  abundant  work  to  any  naturalist  whose 
time  and  opportunities  allow  of  his  taking  them  in 
hand"  (Vol.  I,  p.  2).  The  present  Monograph  is  the 
result  of  an  endeavour  to  enumerate  and  describe  the 
species  which  Dr.  Brady  has  excluded,  and  may  there- 
fore be  regarded  as  supplementary  to  that  author's 
work. 

The  Copepoda  recorded  by  Dr.  Baird  as  parasites 
on  British  fishes  number  thirty-four  species ;  this 
number  is  now  increased  to  one  hundred  and  thirteen. 
Many  of  the  new  records  are  scattered  through  various 
publications,  and  it  has  been  considered  by  the  Council 
of  the  Ray  Society  that,  for  the  convenience  of 
students,  these  should  be  brought  together  and 
combined  with  those  described  by  Dr.  Baird,  and  thus 
made  more  accessible.  This  work,  which  has  been 
intrusted  to  us,  we  have  endeavoured  to  carry  out, 
and  we  hope,  while  conscious  of  its  imperfections,  that 
it  may  be  found  useful  and  tend  to  create  a  still 
greater  interest  in  the  study  of  these  remarkable 
organisms. 

In  the  preparation  of  this  Monograph  we  have  been 
indebted  for  valuable  assistance  to  numerous  friends, 
and  to  none  more  so  than  the  Rev.  Canon  A.  M. 
Norman.  Indeed  but  for  his  encouragement  and 
assistance  it  is  doubtful  if  we  could  have  ventured  to 
undertake  it.  We  therefore  embrace  this  opportunity 
of  expressing  our  gratitude  to  him,  not  only  for  his 
helpfulness  in  this  special  work,  but  also  for  kindness 
shewn  to  us  in  many  other  ways.  We  are  also 
indebted  to  Dr.  Williamson  and  Dr.  Bowman  of  the 
Scientific  Staff  of  the  Fishery  Board  for  Scotland  for  a 
number  of  rare  and  interesting  specimens;  and  to 
our  friend  Mr.  John  Lindsay  (of  Messrs.  Blackwood  & 
Sons,  Edinburgh)  for  assistance  in  revising  the  proof- 
sheets  and  other  useful  help.  Our  grateful  acknow- 
ledgments are  also  due  to  Mr.  John  Hopkinson, 
Secretary  of  the  Ray  Society,  for  the  great  labour  and 
interest  he  has  taken  in  seeing  the  work  through  the 


PREFACE.  IX 

press.  Our  obligations  to  other  friends  who  have 
assisted  us  with  information  or  specimens  are  grate- 
fully acknowledged  in  the  body  of  the  work. 

The  drawings  have,  with  some  few  exceptions,  all 
been  prepared  from  recent  specimens,  examined  by  our- 
selves, and  wherever  possible  careful  dissections  have 
been  made.*  There  are  a  few  species,  however,  of 
which  we  have  been  unable  to  obtain  specimens,  such 
for  example  as  Demolens  paradoxa,  Lemseocera  cypri- 
nacea,  Brachiella  pastinaca,  and  perhaps  one  or  two 
others,  figures  of  which  have,  with  due  acknowledg- 
ment, been  reproduced  from  published  works  men- 
tioned in  the  sequel.  In  a  considerable  proportion  of 
the  species  dealt  with  in  this  work  the  ovisacs  are 
frequently  greatly  elongated,  and  we  have  followed 
Dr.  C.  B.  Wilson  in  adopting  the  term  "  egg-strings  " 
to  describe  them.  The  coloured  figures  of  the  para- 
sites represent  them  as  observed  by  us  in  the  particular 
specimen  illustrated.  The  colours  vary  considerably 
according  to  the  condition  of  the  parasite,  the  place 
where  it  was  attached,  and  the  freshness  of  the  host. 
External  parasites  lose  their  colours  much  more 
rapidly  than  those  that  are  found  under  the  oper- 
culum  or  attached  to  the  gills,  and  it  is  not  always 
possible  to  obtain  perfectly  fresh  fish. 


THOMAS   AND   ANDREW   SCOTT. 


ABERDEEN, 

31st  March,  1913. 


*  NOTE  BY  THOMAS  SCOTT. — The  drawings  and  dissections  referred 
to  above  are  entirely  the  work  of  my  son  Andrew  Scott,  who  has 
otherwise  assisted  in  the  preparation  of  the  Monograph. 


CONTENTS. 


PAGE 

INTRODUCTION  .......        1 

SYSTEMATIC  LIST  OF  THE  SPECIES  .  .  .  .  .30 

DESCRIPTIONS  OF  THE  SPECIES       .  .  .  .  .33 

TRIBE  I.  CTCLOPOIDA  .      33 

FAM.  i.  ERGASiLiixas  .  .  .  .  .33 

TRIBE  II.  CALIGOIDA  .      43 

FAM.  n.  CALIGID^  .  .  .  .  .  .44 

FAM.  in.  DICHELESTIID^E  .....    105 

FAM.  iv.  PHILICHTHYID.E  .....    137 

TRIBE  III.  LERN^EOIDA       .  .     141 

FAM.  v.  LERN^ID^  .  .  .    141 

FAM.  vi.  CHONDRACANTHID.E        .  .  .    166 

FAM.  vn.  LERN.SOPODID.E  ....     186 

Argulus  foliaceus  .......     227 

Tripaphylus  musteli  (amended  description  of  male)      .  .     229 

LIST  OF  THE  FISHES  ON  WHICH  PARASITIC   COPEPODA  WERE 

OBTAINED  ......    230 

BIBLIOGRAPHY  OF  MEMOIRS  REFERRED  TO  IN  THE  TEXT         .    233 
INDEX  .  .  .248 

ERRATA  :>o2 


45S14 


BRITISH    PARASITIC    COPEPODA. 


INTRODUCTION. 

PARASITIC  habits  are  not  peculiar  to  any  class  of 
organisms,  but  are  met  with  in  all  departments  of  life, 
vegetable  as  well  as  animal.  Nevertheless  there  are 
certain  groups  both  of  plants  and  animals  whose  en- 
vironment seems  to  be  specially  favourable  for  the 
adoption  of  habits  of  a  parasitic  or  semi-parasitic 
kind.  Such  habits  seem  to  prevail  to  a  considerable 
extent  among  the  Crustacea,  and  particularly  among 
the  so-called  lower  forms  belonging  to  that  class. 
Many  kinds  of  animals  are  required  to  act  as  hosts  for 
these  crustaceans,  and  curiously  enough  not  a  few  of 
them  belong  to  the  same  class  as  that  to  which  the 
parasites  themselves  belong.  Many  fishes  are  also 
infested  by  these  crustacean  parasites.  Fishes  live  in 
a  medium  where  on  every  side  they  are  exposed  to  the 
attacks  of  all  kinds  of  parasitic  forms,  so  that  very 
few  of  the  fishes  examined  by  us  are  found  to  be 
entirely  free  from  these  organisms. 

At  a  fish-market  where  quantities  of  fishes  of  various 
kinds  are  being  landed,  crustacean  parasites  may  be 
frequently  observed  on  the  skin  of  the  fishes,  or  found 
adhering  to  their  fins,  their  gills,  or  on  the  inside  of 

VOL.  i.  1 


2  BRITISH    PARASITIC    COPEPODA. 

the  gill-covers ;  sometimes  they  may  be  found  clinging 
to  the  roof  and  sides  of  the  mouth,  as  well  as  on  the 
tongue,  especially  the  under  side  of  it,  and  also  in  the 
nasal  fossae.  At  other  times  they  make  excavations  in 
the  flesh  of  the  fish,  causing  sores  of  a  more  or  less 
serious  nature,  and  they  may  even  penetrate  into 
the  abdominal  cavity,  as  occasionally  happens  with 
Lernasan  parasites. 

The  degree  of  parasitism  varies  greatly  even  among 
closely  allied  species.  In  somes  cases  the  relationship 
of  the  crustacean  to  the  fish  is  decidedly  that  of  a 
parasite,  while  in  others  it  would  scarcely  be  accurate 
to  describe  the  position  of  the  crustacean  to  the  fish 
as  truly  parasitic.  Sometimes,  however,  it  is  more 
convenient  to  use  the  terms  "  parasite"  or  "  parasitic  " 
in  the  wider  sense  to  avoid  any  confusion  which  might 
arise  by  trying  to  define  in  each  particular  case  the 
degree  of  relationship  of  the  one  to  the  other,  and  it  is 
in  the  wider  sense  that  these  terms  are  used  here. 

The  study  of  the  Parasitic  Crustacea  is  in  some 
respects  more  difficult,  if  also  more  interesting,  than 
that  of  the  species  which  live  under  normal  conditions. 
Their  structure  has  become  more  or  less  altered  by 
reason  of  their  parasitic  habits,  and  the  forms  which 
some  of  them  assume  are  greatly  at  variance  with 
those  of  free-living  species.  The  forms  of  some  of 
these  parasites  are  so  abnormal  arid  grotesque  that 
even  experienced  investigators  have  been  deceived,  ami 
have  failed  to  recognize  their  relationship  to  the 
Crustacea,  and  only  by  the  study  of  their  life-histories 
have  their  true  affinities  been  determined. 

Among  the  crustacean  parasites  of  fishes  the  Cope- 
poda  are  probably  more  numerously  represented  than 
any  other  of  the  crustacean  Orders,  and  what  we  pro- 


INTRODUCTION.  d 

pose  in  the  first  volume  of  the  present  work  is  to  give 
descriptions  of  the  various  parasitic  Copepoda  known 
to  occur  on  British  fishes.  The  second  volume  will 
contain  the  figures. 

We  have  not  considered  it  necessary  to  enter  into 
a  lengthened  discussion  on  the  structure  and  develop- 
ment of  the  parasitic  Copepoda  ;  this  has  already  been 
done  by  Dr.  Baird  and  some  other  writers.  Mr.  C.  B. 
Wilson,  in  his  various  contributions  dealing  with  the 
Xorth  American  parasitic  Copepods,has  described  them 
very  fully  both  in  their  histological  and  physiological 
aspects.  Moreover  one  of  the  authors  of  the  present 
volume  (A.  Scott)  has  published  a  Memoir  con- 
taining detailed  accounts  of  a  Lepeophtheirus  and  a 
Lernaea,  representing  two  important  and  diverse  types 
of  the  parasitic  species.* 

G-ENERAL  REMARKS  ON  DEVELOPMENT,  ETC. 

The  following  general  remarks  concerning  the 
development  and  structure  of  these  organisms  are 
derived  chiefly  from  the  works  referred  to  above. 

The  Copepod  parasites  of  fishes  are  roughly  divided 
into  two  groups — viz.,  those  which  in  the  adult  stage 
are  free,  that  is,  they  can  move  about,  at  least  to  some 
extent,  from  one  part  of  the  fish  to  another;  while 
the  others  are  permanently  fixed.  Lepeophtheirus 
pectoralis  may  be  taken  as  representing  the  first,  and 
Lernsea  branchialis  the  second. 

The  two  groups  taken  together  form  a  series  which 
exhibits  remarkable  variation  in  habits  and  structure. 
While  there  is  little  to  distinguish  some  of  the 
species  at  the  one  end  of  the  series  from  free-living 
non-parasitic  Copepods,  those  at  the  other  end  exhibit 

*  Liverpool  Marine  Biology  Committee,  Memoir  No.  VI :  '  Lepeophtheirus 
and  Lernsea '  (1901). 


4  BRITISH    PARASITIC    COPEPODA. 

forms  so  abnormal  and  grotesque  that,  as  already 
observed,  it  is  difficult  without  a  knowledge  of  their 
life-histories  to  regard  them  as  belonging  to  the 
Crustacea. 

The  young  Copepod,  no  matter  how  abnormal  it 
may  be  when  adult,  begins  life  as  a  free-swimming 
nauplius ;  it  is  of  an  oval  form,  with  a  single  median 
eye  and  three  pairs  of  limbs  arranged  round  the 
mouth ;  there  are  no  frontal  appendages  and  no 
proper  mouth-organs. 

The  young  parasite  passes  through  numerous 
ecdyses  and  increases  in  size.  The  various  append- 
ages make  their  appearance  in  regular  order,  and 
the  animal  gradually  takes  on  the  adult  condition. 
In  the  case  of  those  parasites  which  retain  their  active 
habits  throughout  life,  the  appendages  become  com- 
pletely developed  when  the  adult  form  is  assumed. 
On  the  other  hand,  the  appendages  of  the  parasites 
that  are  more  or  less  permanently  attached  to  their 
host  are  comparatively  well  developed  early  in  life, 
and  then  continue  in  a  stationary  condition  or  are 
gradually  suppressed.  One  finds  on  carefully  dissect- 
ing the  head  of  an  adult  Lernasa  from  the  gills  of  its 
host  that  the  four  pairs  of  swimming-feet  which  were 
developed  at  an  early  period  of  its  life  are  present, 
and  retain  the  characters  they  had  during  the 
cyclops  stage,  although  they  are  not  of  any  use  to 
the  animal.  The  four  pairs  of  feet  are  buried  with 
the  head  in  the  tissues,  and  if  by  any  means  the  animal 
could  detach  itself  from  its  host,  they  obviously  would 
not  enable  it  to  swim  through  the  water.  In  some 
parasites  certain  appendages  used  as  anchors,  such 
as  the  antennae  and  second  maxillipeds,  become 
greatly  developed  and  are  conspicuous  even  to  the 


INTRODUCTION.  5 

naked  eye.  In  others  the  cephalic  segment  becomes 
highly  chitinised,  and  is  frequently  expanded  into 
horn-like  processes  which  are  buried  in  the  tissues  of 
the  host.  Certain  members  of  the  Caligoida  are  able 
to  live  apart  from  their  hosts  and  lead  a  more  or  less 
pelagic  life  in  the  water  for  a  time,  but  whether  adult 
females  voluntarily  detach  themselves  from  healthy 
and  living  hosts  is  doubtful.  They  appear,  however, 
to  leave  the  host  when  it  dies  in  an  aquarium  tank. 
One  rarely  finds  LepeopJitheirus  pectoralis  on  dead 
flounders  which  have  been  allowed  to  remain  in  a  tank 
for  a  day  or  two  after  death,  although  it  was  quite 
certain  they  were  present  when  the  host  was  alive. 
We  have  kept  LepeopJitheirus  pectoralis  alive  in  vessels 
of  sea- water  for  periods  of  six  weeks  after  removal  from 
flounders.  Adult  males  of  Caligus  rapax  are  often 
met  with  in  collections  of  plankton,  but  the  females 
are  less  frequently  noticed.  The  members  of  the 
genera  Chondr acanthus  and  Clavella  sometimes  live  for 
a  couple  of  days  after  being  removed  from  their  hosts, 
but  the  Lern&a,  quickly  perishes.  It  is  almost  certain 
that,  with  the  exception  of  a  few  members  of  the 
Caligoida,  all  the  copepod  parasites  of  fishes  die  soon 
after  the  death  of  their  host,  even  although  the  body 
remains  in  the  water.  On  one  occasion  we  dissected 
the  spiracles  of  a  large  grey  skate  (Raia  hatis)  which 
had  evidently  died  in  the  sea  and  was  afterwards 
washed  up  partly  macerated  on  the  beach.  A  full- 
grown  specimen  of  Charopinus  dalmanni  was  found  in 
one  of  the  spiracles  and  was  in  a  perfect  condition, 
but  there  was  no  sign  of  life  in  it. 

The  sexes  are  separate,  the  males  as  a  rule  being 
much  smaller  than  the  females.  In  many  cases  the 
males  are  simply  parasites  on  the  females,  especially 


6  BRITISH    PARASITIC    COPEPODA. 

those  of  Chondr acanthus,  Lerneopoda,  and  Clavella. 
The  fact  that  males  are  found  upon  egg-bearing 
females  of  these  genera  is  due  to  their  power  of  loco- 
motion having  been  lost  when  they  reached  the  adult 
condition.  When  once  they  have  settled  down  on  a 
female  and  matured  they  are  unable  to  change  their 
position  to  any  extent.  Fertilization  of  the  female  is 
effected  early  in  its  life,  before  the  metamorphoses  are 
completed.  The  resulting  embryos  pass  out  from  the 
two  oviducts  and  remain  attached  to  the  external 
apertures  either  in  single  or  multiserial  columns,  each 
being  enclosed  in  a  sac,  until  they  hatch.  In  Chondra- 
canihus  zei  the  columns  are  very  much  compressed  and 
resemble  miniature  oval  biscuits.  The  period  of  incu- 
bation extends  over  several  weeks.  The  young  para- 
sites hatch  out  as  free-swimming  nauplii.  These 
undergo  metamorphoses,  which  in  some  forms,  after  a 
particular  stage  is  attained,  are  retrogressive,  finally 
leading  to  the  adult  condition. 

The  following  is  a  short  account  of  the  anatomy  of 
two  members  of  very  different  families,  the  Caligoida 
and  the  Lernseoida.  For  fuller  details  the  Memoir 
published  by  the  Liverpool  Marine  Biology  Committee 
and  the  reports  by  C.  B.  Wilson  on  North  American 
Parasitic  Copepods  should  be  consulted. 

TRIBE  CALIGOIDA. 

The  species  chosen  to  represent  this  tribe  is  Lepeo- 
phtheirus  pecioralis  (Miiller).  This  parasite  is  some- 
times very  common  on  the  fins  and  body  of  the 
flounder  or  "white  fluke"  (Pleuronectes  flesus).  It 
also  occurs  on  other  members  of  the  Pleuronectidge. 
Although  Lepeophtheirus  pectoralis  does  not  confine 
itself  to  any  particular  part  of  the  exterior  of  its  host, 


INTRODUCTION.  7 

and  though  adult  and  immature  specimens  of  both 
sexes  may  be  found  scattered  all  over  the  body,  mature 
egg-bearing  females  are  most  frequently  met  with 
under  the  pectoral  fins.  (See  Plate  A.)  It  is  possible 
to  collect  a  fairly  complete  series  of  stages  of  develop- 
ment from  the  one  host.  The  average  length  of  a 
mature  egg-bearing  female  is  one-fifth  of  an  inch,  and 
of  a  male  one-ninth  of  an  inch.  The  parasites  attach 
themselves  to  the  fish  by  means  of  their  powerful 
second  maxillipeds  assisted  by  the  antennae,  and  a 
decided  pull  has  to  be  applied  before  they  can  be 
removed.  By  depressing  the  edge  of  the  carapace 
and  applying  it  closely  to  the  skin,  the  parasite  is  able 
to  increase  its  holding  power  to  such  an  extent  that 
the  posterior  portion  can  be  torn  off  from  the  anterior 
without  detaching  it.  The  anterior  portion  wrhe'n  thus 
separated  will  sometimes  remain  alive  for  twenty-four 
hours.  It  is  even  capable  of  swimming  about 
vigorously,  but  eventually  its  movements  become 
erratic  and  finally  it  dies.  Lepeophtheirus  pectoralis 
can  be  kept  alive  in  sea  water  for  about  six  weeks  after 
removal  from  the  host.  The  parasites  live  for  a  con- 
siderable time  after  the  fish  has  been  caught  and  re- 
moved from  the  water,  if  they  are  not  allowed  to  dry  up. 
Increase  of  temperature  to  16°  C.  is  fatal  to  them. 
Decrease  of  temperature  to  even  below  freezing-point 
does  not  appear  to  incommode  them.  If  the  aquaria 
are  kept  cool,  the  sea-water  in  which  the  parasites 
are  placed  after  removal  from  the  host  need  only  be 
changed  at  long  intervals. 

EXTERNAL  APPEARANCE  AND  STRUCTURE. 
The    animal   is    depressed    dorso-ventrally   and    is 
divided   into  four  parts.     The  first  and  usually  the 


BRITISH    PARASITIC   COPEPODA. 

largest  is  almost  circular  in  outline.  It  bears  all  the 
appendages  with  the  exception  of  the  fourth  and  fifth 
pairs  of  feet.  This  part  is  known  as  the  cephalo-thorax. 
The  second  part  is  very  small  and  represents  the  fourth 
thoracic  segment  of  the  pelagic  Copepoda.  It  bears 
the  fourth  thoracic  feet.  The  third  part  of  the  body 
is  of  variable  size  and  shape,  and  is  known  as  the 
genital  segment.  Its  size  and  shape  depend  largely 
upon  the  degree  of  maturity  of  the  reproductive  organs. 
The  fourth  part  is  short  and  narrow.  It  is  only  about 
one-fourth  the  width  of  the  genital  segment.  It  repre- 
sents the  abdomen  of  the  pelagic  Copepoda,  and  bears 
at  its  apex  two  short  papillae  known  as  the  f  urcal  joints 
or  caudal  stylets. 

Viewed  from  above,  the  cephalo-thorax  is  seen  to  be 
slightly  convex  and  divided  into  four  portions  by  im- 
perfect sutures.  The  frontal  margin  is  indented.  The 
greatest  depth  is  in  the  middle  line.  In  the  centre  of 
the  hollow,  situated  on  the  ventral  surface,  is  an  oval- 
shaped  opening  with  a  chitinous  fringe.  This  opening 
is  apparently  a  rudimentary  sucker,  and  is  the  remains 
of  a  median  sucker  which  is  greatly  developed  in  the 
early  life  of  the  parasite.  This  rudimentary  sucker  can 
be  traced  in  all  the  members  of  the  Caligoida.  No 
other  suckers  are  present  in  the  members  of  the  genus 
Lepeophtheirus.  The  frontal  and  lateral  margins  of 
the  segment  are  surrounded  by  a  transparent  mem- 
brane with  faint  transverse  lines.  This  membrane  is 
simply  an  extension  of  the  chitinous  exoskeleton 
which  covers  the  whole  animal.  The  edges  have  fre- 
quently a  serrated  appearance,  but  this  is  due  to  the 
membrane  being  damaged.  The  eyes  appear  as  a 
reddish  spot  in  the  living  animal.  They  are  placed  on 
the  dorsal  surface  mid\vav  between  the  anterior  and 


h 


INTRODUCTION.  9 

posterior  margins.  When  the  spot  is  examined  micro- 
scopically it  is  found  to  consist  of  two  distinct  eyes 
closely  approximated  and  embedded  in  a  mass  of 
reddish-black  pigment.  The  eyes  are  wholly  under 
the  carapace.  Each  eye  has  a  simple,  spherical,  crys- 
talline lens  beneath  a  thin  cornea.  Behind  the  lens 
lies  a  row  of  retinal  cells  of  fairly  large  size  and  lined 
internally  with  a  layer  of  pigment.  A  chitin  division 
deeply  pigmented  w^ith  red  separates  the  two  eyes. 

THE  APPENDAGES. 

There  are  twelve  pairs  of  appendages,  as  follows  : — 
One  pair  of  antennules,  one  pair  of  antenna,  one  pair 
of  mandibles,  two  pairs  of  maxilla?,  two  pairs  of  maxil- 
_  lipeds,  and  five  pairs  of  feet.  The  first  three  pairs 
ot-.feet  only  are  adapted  for  swimming.  The  fifth  pair 
of  feet  is  very  small  and  is  attached  to  the  postero- 
l^eral  margins  of  the  genital  segment.  A  sixth  pair 
of  feet  is  usually  present  in  the  male,  appearing  as 
small  papilla?  immediately  behind  the  fifth  pair. 

The  antennules  are  placed  on  the  frontal  margin  of 
the  cephalo-thorax  and  are  two-jointed.  The  basal 
joint  is  usually  moderately  broad  and  is  furnished  with 
a  number  of  plumose  seta?.  The  seta?  are  well  supplied 
with  nerves  and  evidently  act  as  sensory  organs.  The 
other  appendages  are  all  on  the  ventral  surface.  The 
first  in  order  are  the  antenna?.  These  are  two-jointed. 
The  apical  joint  is  a  strongly-prehensile  claw  which  is 
used  for  holding  on  to  the  host.  The  mandibles  are 
stylet-shaped  and  are  enclosed  in  the  suctorial  mouth. 
The  apical  joint  is  flattened  and  curved.  The  inner 
margin  is  distinctly  serrate  at  the  distal  end,  the 
serrations  being  sometimes  more  or  less  irregular. 

The  mandibles  of  all  the  copepod  parasites  of  fishes 


10  BRITISH    PARASITIC    COPEPODA. 

with  the  exception  of  Chondracanthus  are  of  a  some- 
what similar  type  to  that  of  Lepeopktheirus.  The  first 
maxillae  are  one-jointed  and  are  situated  near  the 
lateral  margins,  slightly  posterior  to  the  base  of  the 
antennas.  The  second  maxillae  are  also  one- jointed  and 
are  placed  at  the  sides  of  the  suctorial  tube  which 
carries  the  mouth  at  its  apex.  The  first  maxillipeds 
consist  of  two-jointed  appendages  and  are  situated  just 
behind  the  second  pair  of  maxillae.  The  apical  joint  is 
claw-like  and  prehensile.  The  second  pair  arise  mid- 
way between  the  first  and  the  first  pair  of  feet.  They 
are  composed  of  two  joints.  The  basal  joint  is  much 
inflated,  and  the  apical  is  in  the  form  of  a  powerful 
claw  which  closes  upon  the  basal  joint  and  provides 
the  animal  with  a  strong  grasping  appendage.  The 
first  three  pairs  of  feet  consist  of  an  endopodite  and  an 
exopodite  attached  to  a  two-jointed  protopodite.  The 
endopodite  of  the  first  pair  is  rudimentary  and  is 
represented  by  a  minute  joint  bearing  a  few  setae. 
The  exopodite  is  two-jointed.  In  the  second  pair  both 
the  endopodite  and  the  exopodite  are  three- jointed. 
The  protopodite  of  the  third  pair  is  greatly  developed 
and  forms  a  prominent  lamella.  The  exopodite  and 
endopodite  are  very  small,  the  former  being  com- 
posed of  two  and  the  latter  of  three  joints.  Each  of 
the  first  three  pairs  of  feet  is  attached  to  a  sternal 
plate.  The  protopodite  of  the  fourth  pair  of  feet  is 
two-jointed  and  the  exopodite  is  also  two-jointed,  but 
there  is  no  trace  of  an  endopodite.  A  strong  chitinous 
plate  with  a  bifid  apex  arises  from  the  middle  line 
between  the  second  pair  of  maxillipeds.  This  is 
known  as  the  sternal  fork.  Its  function  is  not  clearly 
established.  It  has  been  suggested  that  it  acts  as  a 
crutch  to  raise  the  body  of  the  animal  from  that  of  the 


INTRODUCTION.  1 1 

host  to  enable  either  the  mouth-organs  or  swimming 
feet  to  have  free  play.  The  sternal  fork,  however,  is 
not  articulated,  neither  is  it  flexible.* 

The  external  openings  are  the  mouth,  the  vulvas  and 
apertures  of  the  oviducts  in  the  female,  the  vasa 
deferentia  in  the  male,  and  the  anus.  The  mouth  is 
situated  on  the  ventral  surface  of  the  cephalo-thorax, 
and  is  placed  at  the  apex  of  a  short,  conical,  movable 
tube.  The  vulvas  are  situated  on  each  side  of  the 
middle  line  at  the  posterior  end  of  the  genital  seg- 
ment and  communicate  with  the  receptacula  seminis. 
They  are  difficult  to  see  in  the  adult  female,  but  each 
has  frequently  a  spermatophore  attached  which  indi- 
cates the  position.  The  openings  of  the  oviducts  are 
in  the  same  segment,  but  nearer  the  lateral  margins 
and  just  under  the  fifth  feet.  The  openings  of  the 
vasa  deferentia  are  situated  on  the  postero-lateral 
margins  of  the  genital  segment  of  the  male.  The  anus 
is  in  the  middle  line  at  the  apex  of  the  abdomen.  In 
addition  to  these  more  important  openings,  there  are 
also  apertures  of  pore-canals  and  glands  on  the 
anterior  surface  of  the  basal  joint  of  the  protopodites 
of  the  second  and  third  pairs  of  feet,  and  also  on  the 
dorsal  surface  of  the  cephalo-thorax  and  abdomen. 
The  opening  in  some  cases  is  at  the  apex  of  a  small 
papilla,  and  communicates  with  a  sac  in  the  interior. 
The  function  of  these  glands  is  uncertain,  but  it  is 
possible  that  it  is  connected  with  the  aeration  of  the 
blood.  If  a  little  methylene  blue  solution  be  added 
to  the  sea- water  in  which  the  parasites  are  living,  a 
general  staining  takes  place,  but  the  glands  are  more 
deeply  stained  than  the  rest  of  the  body. 

*  Fig.  1,  PI.  XIII,  shows  the  general  arrangement  of  the  appendages  in 
Lepeophtheirus. 


12  BRITISH  PARASITIC  COPEl'ODA. 

COLOUR. 

The  colour  of  the  living  animals  varies  with  the 
position  in  which  they  live.  On  the  dark  side  of  the 
fish  they  are  of  a  deep  brown,  almost  black,  colour.  On 
the  "white  "  side  and  under  the  fins  they  are  nearly 
colourless,  due  to  the  contraction  of  the  pigment-cells, 
which  appear  as  brown  spots  under  the  microscope. 
The  dark-coloured  specimens  soon  become  colourless 
when  exposed  to  light. 

ALIMENTARY  SYSTEM,  ETC. 

The  body- wall  consists  of  (1)  chitinous  cuticle  or 
exoskeleton,  (2)  cellular  hypodermis,  and  (3)  connective 
tissue  laminae  which  line  the  integument,  traverse  the 
body-cavity,  and  support  the  alimentary  canal  and 
other  organs.  The  only  cavity  left  inside  the  body- 
wall  is  the  system  of  lacunae  in  which  the  colourless 
blood  flows. 

The  mouth,  already  described,  leads  into  a  short 
narrow  oesophagus,  lined  with  a  thin  chitinous  coat 
which  is  continuous  with  the  exoskeleton.  The  oeso- 
phagus passes  through  the  anterior  part  of  the  nervous 
system,  and  in  a  transverse  section  of  that  region 
appears  as  a  minute  pinhole.  The  stomach  lies  along 
the  ventral  surface  and  is  lageniform  in  shape.  At 
the  anterior  end  it  is  produced  into  a  short  caecum, 
\vhich  extends  over  the  posterior  end  of  the  oesophagus 
and  terminates  by  opening  into  the  intestine.  The 
intestine  is  simply  a  direct  continuation  of  the  stomach 
and  terminates  in  a  short  rectum  leading  into  the  anus 
at  the  apex  of  the  abdomen.  There  are  no  convolu- 
tions in  the  alimentary  canal.  The  wall  of  the  whole 
alimentary  canal  is  lined  with  a  thin  layer  of  chitin 


INTRODUCTION.  13 

continuous  with  the  exterior.  The  wall  of  the  stomach 
and  intestines  is  marked  by  a  series  of  transverse  con- 
strictions, giving  it  a  crenate  appearance  which  is 
easily  seen  in  the  living  animal.  When  the  animal  is 
alive  an  intermittent  movement  of  the  alimentary  canal 
is  maintained.  The  action  is  wave-like.  It  begins  at 
one  end  and  passes  slowly  to  the  other.  After  con- 
tinuing in  one  direction  for  a  time,  it  reverses  and 
passes  along  the  opposite  way.  The  fluids  in  the 
alimentary  canal  are  usually  colourless.  Sometimes, 
however,  when  taken  direct  from  the  fish  and  placed 
under  the  microscope,  a  reddish  tint  may  be  observed 
at  the  posterior  end  of  the  ossophagus.  Two  pairs  of 
digestive  glands  are  connected  with  the  alimentary 
canal.  The  first  and  most  important  pair  is  situated 
in  the  anterior  end  of  the  cephalo-thorax.  Each  gland 
consists  of  three  portions,  two  moderately  large  masses 
on  the  lateral  margins  just  behind  the  antennules,  and 
a  median,  smaller  one,  in  front  of  the  base  of  the 
mouth.  The  lateral  masses  are  connected  with  the 
median  one  by  a  duct.  A  duct  is  given  off  by  the 
median  portion  and  passes  posteriorly  along  the  out- 
side of  the  oesophagus.  It  enters  the  caecum  at  the 
anterior  end  of  the  stomach.  When  the  parasite  is 
first  removed  from  the  host  the  glands  are  usually  of 
a  dark  brown  colour,  but  they  soon  become  bleached. 
The  product  of  the  glands  is  a  pale  yellow  fluid.  The 
second  pair  of  glands  is  much  smaller  than  the  first, 
and  is  situated  close  to  the  median  line  between  the 
first  and  second  pairs  of  feet.  The  glands  are  of 
a  brown  colour  and  shaped  like  a  comma.  A  minute 
duct  from  each  gland  passes  downward  and  then 
forward  along  the  stomach,  which  :it  enters  near  the 
posterior  end. 


14  BRITISH    PARASITIC    COPKPODA. 

ClUCULATORY    SYSTKM. 

There  is  no  heart  in  Lepeophtlieirus,  nor  are  there 
any  proper  blood-vessels.  The  circulation  is  wholly 
laounar.  The  blood-streams  simply  pass  through  the 
spaces  left  among  the  internal  organs  and  between 
the  connective-tissue  bands  of  the  body-wall.  The 
streams  appear  to  have  certain  definite  courses,  but 
they  are  not  uniform,  continuous  currents.  The  fluid 
progresses  by  successive  jerks,  due  to  the  peristaltic 
movements  of  the  alimentary  canal.  The  blood  is  a 
clear  fluid  containing  numerous  colourless  corpuscles 
which  vary  in  size  and  shape.  The  corpuscles  are 
able  to  accommodate  themselves  to  the  diameter  of  the 
spaces  through  wThich  they  pass.  There  are  no  inde- 
pendent organs  of  respiration,  unless  the  pore-canals 
and  glands  in  the  basal  joint  of  the  protopodite  of  the 
second  and  third  pairs  of  feet  act  as  such.  Hartog* 
and  others  have  suggested  that  the  blood  is  probably 
aerated  from  the  sea- water  contained  in  the  alimentary 
canal  by  the  method  of  "  anal  respiration."  Further 
precise  observations  are,  however,  required  to  sub- 
stantiate this  hypothesis,  as  the  method  is  so  entirely 
different  from  that  in  the  higher  Crustacea. 

MUSCULAR  SYSTEM. 

The  muscular  system  is  a  very  complex  one,  as 
shown  by  the  illustrations  of  the  dorsal  and  ventral 
surfaces  on  Plate  XIII.  The  members  of  the  Cali- 
goida  as  a  general  rule  are  so  very  transparent, 
however,  that  the  investigation  of  the  musculature 
can  be  carried  out  with  very  little  effort.  An  excel- 
lent description  of  the  muscular  system  is  given  by 

*  "  The  morphology  of  Cyclops  and  the  relations  of  the  Copepoda,"  '  Trans. 
Linn.  Soc.  Lond.'  (2),  vol.  v,  pt.  1,  pp.  1-46,  1888. 


INTRODUCTION.  15 

C.  B.  Wilson  in  his  work  on  "North  American  Parasitic 
Copepods  belonging  to  the  Family  Caligida3,"  Part  1.* 

NERVOUS  SYSTEM. 

The  nervous  system  of  Caligus  and  Lepeoplttlteirus, 
and  probably  also  of  the  other  members  of  the  Cali- 
goida,  appears  to  be  very  similar.  It  is  composed  of 
two  central  ganglia  and  the  paired  nerves  which  arise 
from  them.  One  ganglion,  the  supra-cesophageal,  lies 
above  the  oesophagus,  and  the  other,  the  sub-cesopha- 
geal,  immediately  below  it.  The  ganglia  are  practi- 
cally fused  together  by  the  wide  commissures  which 
join  them.  A  very  narrow  opening  is  left  in  the 
centre  for  the  passage  of  the  oesophagus.  These  are 
the  only  ganglia,  and  they  supply  the  various  parts 
of  the  body  with  nerves.  The  supra-cesophageal 
ganglion  is  about  half  the  size  of  the  sub-cesophageal. 
It  is  produced  on  its  dorsal  surface  into  an  optic  lobe 
from  which  arises  a  distinct  pair  of  optic  nerves. 
Horizontal  sections  of  the  optic  lobe  show  that  the 
roots  of  these  nerves  cross  each  other,  and  each  optic 
nerve,  therefore,  is  supplied  by  fibres  from  both  sides 
of  the  brain.  The  only  other  nerves  that  have  their 
origin  in  the  supra-cesophageal  ganglion  are  those 
which  supply  the  antennules  and  the  antennae.  The 
nerves  of  the  antennules  divide  into  a  number  of 
branches  after  they  enter  these  appendages,  and  every 
seta  on  the  surface  of  the  basal  joint  and  apex  of  the 
second  branch  is  supplied  with  fibres.  It  is  evident 
that  they  are  important  sensory  organs.  The  sub- 
oesophageal  ganglion  is  heart-shaped,  and  fully  twice 
the  size  of  the  supra-cesophageal.  It  supplies  the 
nerves  to  the  remainder  of  the  appendages.  The 

*  '  Proc.  U.  S.  National  Museum,'  vol.  xxviii,  1905. 


16  BRITISH    PARASITIC    COPEPODA. 

frontal  and  lateral  margins  give  off  seven  pairs  of 
nerves.  Three  other  pairs  arise  from  the  posterior 
end  and  form  a  sort  of  spinal  cord.  There  are  thir- 
teen pairs  of  nerves  altogether,  as  shown  in  Plate  XV, 
fig.  9.  Each  nerve,  after  leaving  the  main  trunk, 
sends  out  numerous  branches  which  pass  to  the  various 
muscles  controlling  the  appendages  enervated  by  that 
nerve.  There  is  considerable  difficulty  in  tracing  the 
endings  of  the  branches  when  they  pass  amongst  the 
muscles. 

REPRODUCTION. 

The  reproductive  organs  are  paired,  and  as  already 
stated  the  sexes  are  distinct.  In  the  mature  female 
the  ovaries  appear  as  comparatively  large  kidney- 
shaped  organs  on  each  side  of  the  anterior  end  of  the 
stomach.  An  oviduct  arises  near  the  anterior  end  of 
the  ventral  surface  and  passes  posteriorly  as  a  narrow 
tube  until  it  enters  the  genital  segment.  It  then 
expands  rapidly  and  becomes  convoluted,  finally  pass- 
ing out  to  the  postero-lateral  margins  of  the  segment, 
where  it  opens  to  the  exterior  just  under  the  fifth  feet. 
Communicating  with  the  oviduct  near  its  extremity  is 
a  short  semi-transparent  cement-gland  which  secretes 
the  enclosing  membrane  of  the  ovisac.  The  vulvaB 
are  situated  near  the  middle  line  close  to  the  junction 
of  the  genital  segment  with  the  abdomen.  The  vulva 
appears  to  be  a  simple  opening  leading  into  the  vagina 
which  expands  into  a  receptaculum  seminis.  This  is 
an  elongated  sac  passing  from  the  median  line  to  the 
oviduct,  which  it  enters  alongside  the  duct  of  the 
cement-gland. 

The  sexual  organs  of  the  male  are  very  similar  in 
position  and  arrangement  to  those  of  the  female. 


INTRODUCTION.  17 

They  consist  of  a  pair  of  testes,  a  long  vas  deferens 
leading  posteriorly  from  them,  and  a  pair  of  spermato- 
phore  sacs  in  the  genital  segment.  The  testes  are 
oval  bodies  situated  in  a  corresponding  position  to  the 
ovaries  in  the  female.  The  spermatophore  is  an  oval 
body  of  a  pale  yellow  colour  filled  with  sperms.  It  is 
expelled  from  an  opening  near  the  posterior  end  of  the 
genital  segment.  A  short  cement-gland  is  situated  in 
the  segment  and  is  furnished  with  a  duct  which  is 
connected  with  the  anterior  end  of  the  sac. 

The  female  is  fertilized  early  in  life  by  the  male 
attaching  spermatophores  to  the  vulvae.  The  contents 
of  these  bodies  appear  to  suffice  for  the  fertilization  of 
all  the  eggs  which  the  female  produces  during  its  life. 
The  genital  segment  of  an  unfertilized  female  is  very 
small.  It  is  only  about  one-fifth  the  size  it  attains  in 
the  mature  condition.  The  eggs  are  fertilized  from 
the  store  of  sperms  as  they  leave  the  oviduct,  and  are 
then  enclosed  in  a  thin  chitinous  tube  which  gradually 
lengthens  as  the  eggs  are  expelled.  This  tube  is  the 
ovisac,  and  the  eggs  are  arranged  in  a  single  column 
sometimes  exceeding  the  length  of  the  animal.  The 
whole  of  the  embryos  in  the  tube  practically  hatch  at 
once  when  the  development  is  completed.  The  embryos 
hatch  as  nauplii  about  0*46  mm.  in  length.  The 
nauplii  are  free-swimmers  for  a  time  and  then  settle 
down  as  Cyclops  forms  upon  their  host.  As  soon  as 
the  cyclops  form  settles  it  develops  a  thin  chitinous 
filament  from  a  median  gland  in  the  anterior  end  of 
the  cephalo-thorax.  The  filament  is  inserted  in  the 
tissues  of  the  host  and  the  young  parasite  becomes 
firmly  anchored.  A  median  sucker  which  assists  in  the 
attachment  is  also  developed  at  the  same  time.  The 
genus  Chalimus,  described  by  Burmeister  in  1831,  was 

VOL.  i.  2 


18  BRITISH    PARASITIC    COPEPODA. 

shown  by  Hesse  and  others  to  be  only  the  Cyclops  stage 
of  the  Caligoida.  The  cyclops  form  grows,  and  the 
various  appendages  make  their  appearance  in  regular 
order.  When  the  appendages  are  developed  the 
filament  separates  at  its  junction  with  the  frontal 
margin,  and  the  parasite  is  free  to  move  about  over  its 
host  or  to  seek  a  new  one.  A  notch  is  left  in  the 
frontal  margin  when  the  filament  separates,  and  con- 
tinues all  through  the  adult  life.  The  male,  at  the 
conclusion  of  its  cyclops  stage,  is  practically  fully  de- 
veloped. The  female  remains  in  an  immature  con- 
dition until  it  is  fertilized  and  the  ova  begin  to  pass 
down  the  oviducts.  The  genital  segment  then  in- 
creases in  size  to  its  normal  adult  condition. 

TRIBE  LEKN^OIDA. 

The  typical  member  of  this  tribe  is  Lernasa  bran- 
chialis  Linn.  It  presents  one  of  the  most  marked 
examples  of  retrograde  development  which  is  to  be 
found  in  the  whole  group  of  parasitic  Copepoda.  It 
is  difficult  to  believe  at  a  first  glance  that  the  parasite 
is  a  crustacean  and  that  it  is  related  to  LepeopMheirus. 
There  is  great  excuse  for  the  difficulty  experienced  by 
the  earlier  zoologists  in  deciding  the  true  position  of 
the  members  of  this  family  in  the  animal  kingdom. 
Nothing  was  then  known  about  their  life-history,  and 
it  is  not  surprising  that  Linnseus  included  Lernasa 
amongst  his  Vermes. 

The  adult  female  is  found  on  the  gills  of  various 
Gadoids,  such  as  cod,  haddock,  and  whiting.  (See 
Plate  A.)  Immature  (cyclops  stage)  males,  and 
females  with  adult  males  attached,  are  to  be  found  on 
the  apex  of  the  gill-filaments  of  flounders  and  plaice, 
sometimes  in  large  numbers.  The  adult  female  is 


INTBODUCTIOX.  10 

securely  attached  to  its  host  by  strong  branched  horns 
which  are  buried  in  the  tissues  of  the  gill-arches.  In 
many  cases  the  head  will  be  found  to  have  actually 
penetrated  the  ventral  aorta.  The  specimens  can 
only  be  removed  from  the  host  by  careful  dissection. 
Any  attempt  to  remove  them  by  force  results  in  the 
head  being  left  in  the  tissues.  The  parasite,  when  once 
fixed,  remains  in  the  same  position  throughout  life. 
"When  it  dies  the  softer  parts  decay,  but  the  head 
remains  embedded  in  the  tissues  of  the  host.  The 
heads  of  dead  parasites  are  frequently  met  with  when 
dissecting-out  living  specimens. 

The  adult  female  is  cylindrical  and  is  a  little  over  an 
inch  in  length.  It  is  unsegmented,  but  can  be  roughly 
divided  into  three  parts — a  globular  head  with  anchor- 
like  processes,  a  narrow  neck,  and  a  much  swollen 
posterior  part.  The  globular  head  corresponds  to  the 
anterior  region  of  the  cephalo-thorax  in  Lepeophiheirus. 
It  is  furnished  with  three  more  or  less  branched  horns 
which  are  outgrowths  from  the  cephalo-thorax.  The 
head  is  slightly  curved  downwards  and  terminates  in 
a  conical  apex.  The  anterior  portion  of  the  neck 
represents  the  remainder  of  the  cephalo-thorax  and 
the  fourth  thoracic  segment.  The  remainder  of  the 
neck  and  the  greater  part  of  the  swollen  mass  behind 
correspond  to  the  genital  segment  of  Lepeophtheirus. 
The  abdomen  is  represented  by  the  terminal  portion 
of  the  swollen  part,  which  gradually  tapers  to  a  blunt 
end.  The  whole  of  the  swollen  part  is  bent  into  the 
form  of  the  letter  S.  The  neck  is  marked  by  fine 
transverse  lines. 

The  appendages  are  rudimentary,  the  greater  number 
being  entirely  absent.  The  appendages  present  are  a 
pair  of  maxillipeds  immediately  under  the  mouth  and 


20  BRITISH    PARASITIC    COPEPODA. 

four  pairs  of  feet  at  the  anterior  end  of  the  narrow 
neck.  The  feet  are  exactly  as  they  exist  in  the  fully 
developed  cyclops  stage,  both  in  size  and  structure. 
The  protopodite  is  two-jointed.  The  exopodite  of  the 
whole  four  pairs  is  two-jointed.  The  endopodite  of 
the  first  two  pairs  is  also  two-jointed.  The  third  and 
fourth  pairs  of  feet  have  no  endopodite. 

The  external  openings  are  the  mouth  placed  at  the 
apex  of  the  head,  the  openings  of  the  oviducts  on  the 
ventral  aspect  of  the  S-shaped  region,  and  the  anus  at 
the  blunt  apex  of  the  abdomen. 

The  colour  of  the  living  animal  is  a  dark  red,  due 
to  the  contained  blood.  When  removed  from  the  fish 
and  placed  in  sea-water  the  colour  disappears.  Speci- 
mens of  Lernsea  removed  from  their  host  and  placed 
in  sea- water  do  not  appear  to  live  longer  than  twelve 
hours.  The  parasites  are  simply  inert  sacs  quite  in- 
capable of  movement.  Occasionally  they  are  covered 
with  colonies  of  hydroids  which  may  entirely  obscure 
them.  The  exoskeleton  consists  of  chitinous  cuticle 
moderately  thin  and  soft  in  the  swollen  part,  but  thick 
and  hard  on  the  neck  and  head. 

The  mouth  of  the  adult  opens  directly  into  the 
alimentary  canal.  The  oesophagus  and  true  stomach 
have  entirely  disappeared  during  the  metamorphoses 
of  the  cephalo-thorax.  A  peristaltic  movement  of  the 
intestine  similar  to  that  of  Lepeopktiievnts  can  be  seen 
in  the  living  animal.  There  are  no  indications  of 
digestive  glands,  and  it  is  probable  that  the  digestion 
is  intracellular. 

There  is  no  heart  in  adult  Lernsea  and  no  move- 
ment of  fluids  that  would  indicate  a  blood-circulation. 
The  animal  is  probably  dependent  on  the  blood  sucked 
from  the  host  for  the  oxygen  necessary  to  maintain 


INTRODUCTION.  21 

life.  It  is  possible  that  the  early  death  after  removal 
from  the  host  is  due  to  the  inability  to  take  up  oxygen 
from  the  water. 

The  muscular  system  is  represented  by  a  network  of 
fibres  between  the  integument  and  the  alimentary  canal. 

There  does  not  appear  to  be  any  nervous  system  in 
the  adult. 

The  reproductive  organs  of  Lerridea,  like  those  of 
Lepeophtheirus,  are  bilaterally  symmetrical,  but  during 
the  metamorphoses  of  the  female  the  ovaries  undergo 
a  great  change  of  position.  They  are  displaced  from 
the  cephalo-thorax  and  pass  into  the  genital  segment, 
where  they  occupy  a  narrow  region  at  the  apex  of  the 
deep  indentation.  The  two  ovaries  are  practically 
fused  together.  The  oviducts  arise  from  their  anterior 
ends,  pass  across  the  segment  to  its  ventral  surface, 
and  then  course  along  each  side  of  the  median  line  to 
the  external  openings.  The  cement-glands  are  nearly 
of  the  same  length  and  breadth  as  the  oviducts  and  lie 
underneath  them.  The  posterior  end  communicates 
with  the  oviduct  just  inside  the  opening  to  the 
exterior.  The  ovisacs  consist  of  long  slender  con- 
voluted tubes  which  may  reach  the  length  of  eight 
inches  when  straightened  out.  The  eggs  are  arranged 
in  a  single  column.  The  female  is  fertilized  shortly 
before  the  completion  of  the  cyclops  stage.  It  is 
probable  that  the  sperms  pass  up  the  oviduct  and 
fertilize  the  eggs  very  soon  afterwards,  as  no  trace  of 
a  receptaculum  seminis  can  be  made  out  in  the  adult. 

The  young  Lernsea  hatches  as  a  nauplius  with  three 
pairs  of  appendages  similar  to  those  of  the  Lepeo- 
plitli virus  nauplii.  It  leads  a  short  pelagic  life  and 
then  settles  on  the  gill-filaments  of  the  flounder  and 
plaice  and  occasionally  other  fishes.  It  attaches  itself 


22  BRITISH    PARASITIC    COPEPODA. 

to  the  filament  by  a  thin  broad  chitinous  plate  and  by 
the  claw-like  antennae.  The  young  parasite  assumes 
the  cyclops  form  and  continues  its  progressive  develop- 
ment. The  various  appendages  and  internal  organs 
make  their  appearance..  The  male  reaches  maturity 
without  altering  from  the  cyclops  form,  and  undergoes 
no  further  change.  A  considerable  lengthening  of 
the  female  genital  segment  accompanies  the  develop- 
ment of  the  various  appendages.  Fertilization  takes 
place,  and  the  young  female  severs  its  connection  with 
the  gill-filament.  It  leads  a  pelagic  life  for  a  time, 
and  is  occasionally  found  in  surface-plankton.  The 
males,  unless  accidentally  separated,  remain  on  the 
gill-filaments  after  the  females  have  gone. 

The  cyclops  form  of  Lernsea  appears  to  cause  con- 
siderable damage  to  the  gills  of  its  temporary  host. 
The  whole  of  the  apex  of  the  gill-ray  assumes  a  tumid 
appearance,  and  a  considerable  number  of  the  gill- 
filaments  disappear  from  both  sides.  (See  Plate  A.*) 
When  the  fertilized  female  leaves  the  gills  of  the 
flounder  or  plaice  the  appendages  and  internal  organs 
have  practically  completed  their  development.  A  pair 
of  eyes  similar  in  structure  to  that  of  adult  Lepeo- 
phtheirus  is  present  on  the  anterior  region  of  the 
cephalo-thorax.  The  appendages  are  represented  by 
one  pair  of  four-jointed  antennules,  one  pair  of  claw- 
like  antennae,  one  pair  of  mandibles  which  are  not 
enclosed  in  the  mouth-tube,  one  pair  of  maxillae,  two 
pairs  of  maxillipeds,  and  five  pairs  of  feet.  The  body 
is  divided  into  five  distinct  segments — the  cephalo- 
thorax,  three  thoracic  segments,  and  one  terminal 
segment  which  represents  the  genital  segment  and 
abdomen.  The  whole  of  the  terminal  segment  is 

*  See  also  Plate  XLII,  fig.  8. 


INTRODUCTION.  23 

marked  by  fine  transverse  lines.  The  colour  of  the 
animal  varies  from  dark  violet  to  light  red.  The 
alimentary  canal  is  similar  in  structure  to  that  of 
the  adult  Lepeophtheirus.  A  large  digestive  gland 
occupies  each  side  of  the  cephalo-thorax.  The 
nervous  system  of  the  Lernsean  cyclops  is  practically 
similar  to  that  of  the  adult  Lepeophtheirus.  The 
ovaries  occupy  a  normal  position. 

At  the  conclusion  of  its  pelagic  life  the  Lernsean 
cyclops  fixes  itself  to  the  gills  of  a  fish,  and  the  retro- 
gressive metamorphoses  commence.  The  parasite 
buries  its  head  in  the  tissues  of  the  host  and  then 
develops  three  horns.  The  horns  are  simple  at  first, 
but  by  gradual  division  they  acquire  the  adult  type. 
The  genital  segment  elongates  very  considerably. 
The  eyes,  antennules,  antennae,  mandibles,  maxillae, 
and  one  pair  of  maxillipeds  completely  disappear. 
One  pair  of  maxillipeds  persists  all  through  life,  and 
is  represented  in  the  adult  by  a  pair  of  small  hooks 
placed  under  the  mouth. 

The  next  phase,  represented  on  Plate  XLII,  shows 
that  the  development  of  the  horns,  the  disappearance 
of  the  various  appendages,  and  the  great  lengthening 
of  the  genital  segment  are  followed  by  a  looping  of  the 
posterior  region  at  that  segment.  This  loop  gradually 
expands,  and  finally  takes  on  the  adult  condition. 

THE  FOOD  OF  THE  PARASITES. 

There  appears  to  be  considerable  doubt  regarding 
the  precise  food  of  the  Copepod  Parasites  of  Fishes. 
Some  authors  conclude  that,  because  no  red  colour  can 
be  seen  in  the  alimentary  canal,  such  families  as  the 
Caligoida  feed  entirely  upon  the  mucus  of  the  host's 
body.  It  has  been  suggested,  therefore,  that  Lepeo- 


24  BRITISH    PARASITIC    COPEPODA. 

phtheirus  and  allied  forms  are  not  parasites  in  the  strict 
sense  of  the  term,  and  may  not  be  hurtful  to  their 
hosts.  There  is  little  doubt  about  the  food  of  Lernsea. 
It  is  generally  found  in  a  position  that  is  plentifully 
supplied  with  blood.  Its  mouth  is  buried  out  of  the 
reach  of  mucus,  and  is  often  in  direct  communication 
with  the  main  blood- stream  entering  the  gills  to  be 
purified.  Caligoids  from  the  gill-chamber  and  the 
mouth  seldom  show  any  trace  of  red  colour.  Degene- 
rate forms  such  as  Glavella  and  Chondracanthus, 
although  actually  living  amongst  the  gill-filaments, 
are  usually  of  a  pale  yellow  colour,  with  occasionally  a 
grey  central  streak  indicating  the  alimentary  canal. 
Lernanthropus  Jcroyeri,  which  lives  amongst  the  gill- 
filaments  of  Labrax  lupus,  is  nearly  always  of  a  deep 
brownish-red  colour.  It  is  said  that  mucus  at  the  best 
is  a  poor  food,  but  Lepeophtheirns  can  live  for  upwards 
of  six  weeks  in  filtered  sea- water  without  visible  food 
of  any  kind.  Mucus  may  not  be  a  very  sustaining  form 
of  nourishment,  but  as  the  Caligoids  apparently  do  not 
require  much  food  they  may  be  able  to  obtain  sufficient 
from  the  mucus.  C.  B.  Wilson  says  :  "  There  is  more 
mucus  on  the  scales  than  anywhere  else ;  why  should 
they  choose  the  fins  or  inside  of  the  operculum?  "  The 
fins  and  gill-chamber  afford  a  certain  amount  of  pro- 
tection to  the  parasites,  and  it  is  just  as  likely  that 
they  choose  these  places  for  shelter  as  for  food.  It 
has  to  be  remembered,  however,  that  the  difference 
between  the  Caligoida  and  the  obviously  blood-sucking 
Lernsea  is  very  great.  The  Caligoids  are  provided 
with  large  digestive  glands  which  are  entirely  absent 
in  the  adult  female  Lcrnwu.  When  one  finds  blood  in 
the  alimentary  canal  of  a  parasite  which  has  no  digestive 
glands,  and  none  in  those  which  are  provided  with 


INTKODUCTION.  25 

such  organs,  it  may  reasonably  be  concluded  that  the 
character  of  the  food  will  be  rapidly  altered.  The 
fluid  from  the  glands  meets  the  food  immediately  it 
enters  the  stomach  of  the  Caligoids  and  acts  upon  it  at 
once.  If  blood  be  the  food,  the  red  colour  may  be 
destroyed,  and  give  rise  to  the  impression  that  Cali- 
goids are  not  blood-suckers. 

Nothing  appears  to  be  known  regarding  the  internal 
organs  of  the  Copepod  Parasites  of  Fishes  with  the 
exception  of   the  Caligoida  and  Lernaea.     When   the 
anatomy   of    all    the    families   has    been  investigated 
the  food  question  may  be  settled.     One  or  two  para- 
sites   on  a  fish   may  not   be    hurtful,   but  when   the 
numbers   increase    they  probably  have    an   irritating 
effect,  and  finally,  when  they  remain  in  one  position 
for    some    time,  the    skin  and   tissues    become   badly 
lacerated,  giving  rise  to  tumours.      The  Medesicaste, 
which  lives  on  the  gills  of  various  species  of  gurnards, 
occasionally   has   its   head    buried   in    a    tumour-like 
swelling,    but   we    have    been    unable    to    determine 
whether  the  tumour  existed  previous  to  the  attach- 
ment   of    the   parasite    or   was    entirely    due    to    the 
congestion  of  the  blood-vessels  caused  by  its  attack. 
Gr.  H.  Drew,  in  a  paper  entitled  "  Some  cases  of  new 
growths  in    Fish "    (Journ.   Mar.   Biol.  Assoc.,   N.  s., 
vol.  ix,  No.  3,  June  1912),  describes  this  tumour-like 
swelling  in  the  gurnard  as  a  case  of  ha3mangiomata,  and 
regards  it  as  probable  that  the  parasite  attacked  the 
tumour  after  it  had  developed,  but  we  have  never  come 
across  the  tumour  without  the  parasite,  or  the  remains 
of  it,  being  present.     It  is   quite  as  likely,  therefore, 
that  the  haemangiomata  of  the  gurnard  described  by 
Drew  is  caused  by  the  parasite.    (See  also  our  remarks 
on  Lernsea,  p.  22.) 


SYSTEMATIC    ARRANGEMENT. 

In  this  account  of  the  Copepoda  found  parasitic  on 
British  fishes,  the  arrangement  outlined  by  Professor 
G.  0.  Sars  in  the  introduction  to  vol.  iv  of  his  great 
work  on  the  '  Crustacea  of  Norway  '  has,  so  far  as  it 
concerns  these  parasitic  species,  been  followed  by  us. 

Professor  Sars  arranges  the  Copepoda  into  seven 
divisions  or  tribes,  three  of  which  are  represented 
below — viz.,  the  Cyclopoida,  the  Caligoida,  and  the 
Lernseoida.  The  Cyclopoida  show  considerable  varia- 
tion in  regard  to  their  habits  and  manner  of  life  ;  some 
are  entirely  free-living  (as  Cyclops},  others  are  asso- 
ciated with  different  organisms  either  as  commensals 
or  messmates,  their  commensal! sm  tending  in  some 
cases  in  the  adult  stage  towards  a  more  or  less  true 
parasitic  life.  Several  species  belonging  to  this  tribe 
are  associated  with  fishes. 

The  Caligoida,  which  are  almost  all  parasitic  on 
fishes,  also  exhibit  considerable  differences  in  their 
habits,  but  although  none  of  them  can  be  accurately 
described  as  free-living  in  the  adult  stage,  some  species, 
such  as  Galigus  rapax,  possess  considerable  freedom  of 
movement,  and  have,  in  consequence,  a  tolerably  wide 
distribution.  In  the  majority  of  cases,  however,  the 
Caligoida,  though  not  usually  permanently  fixed  to 
their  host,  are  limited  in  their  movements,  and  do  not 
apparently,  to  any  extent,  migrate  from  one  fish  to 
another ;  and  not  only  are  they  more  or  less  confined  to 
particular  fishes  but  sometimes  also  to  particular  parts 
of  the  fish,  hence  such  names  as  Galigus  zei  and 
LepeopMheirus  pectoralis.  In  the  first  case  the  parasite 
is  usually  found  only  on  the  dory  (Zeus  faber),  while 
in  the  second  it  occurs  chiefly  on  the  pectoral  fins 
of  flat  fishes,  such  as  plaice,  flounders,  and  dabs. 

The  Lernaeoida  differ  from  the  other  two  tribes  or 
divisions  by  the  females  in  the  adult  stage  being  all 


SYSTEMATIC    ARRANGEMENT.  27 

more  or  less  permanently  fixed  to  their  host.  This 
group  of  parasites  was  arranged  by  M.  Edwards  into 
three  families — viz.,  the  Chondracanthiens,  the  Lerneo- 
podiens,  and  the  Lerneoceriens.  The  Chondracan- 
thiens "  are  fixed  by  the  aid  of  stout  foot-jaws  armed 
with  strong  hooks."  The  Lerneopodiens  have  the 
second  maxillipeds  modified,  and  furnished,  at  their 
extremity,  with  a  chitinous  horn-coloured  process, 
which,  penetrating  the  gills,  gill-covers,  or  some  other 
part  of  the  fish,  forms  a  permanent  attachment  to  it, 
while  the  head  of  the  parasite  is  free  and  apparently 
possesses  to  a  small  extent  a  certain  freedom  of  move- 
ment. In  this  family  the  male  is  very  small  and  is  not 
attached  to  the  fish,  but  is  usually  found  adhering  to 
the  body  of  the  female,  two  or  three  males  being  some- 
times found  on  the  same  female.  The  third  family  of 
M.  Edwards,  the  Lerneoceriens,  are  fixed  to  their  host 
by  having  the  head,  sometimes  with  its  appendages, 
buried  in  its  tissues.  This  arrangement  of  Milne 
Edwards,  slightly  modified,  was  adopted  by  Dr.  Baird 
in  his  '  British  Entomostraca,'  and  is  to  some  extent 
still  adhered  to. 

Various  attempts  have  been  made  to  frame  a  classifi- 
cation of  the  Copepoda  which  would  include  the  para- 
sitic and  semi-parasitic  forms,  but,  with  the  exception 
of  that  of  Professor  G.  0.  Sars,  they  have  proved 
more  or  less  unsatisfactory,  and  therefore,  as  already 
stated,  we  have,  as  regards  these  parasitic  species, 
adopted  the  division  proposed  by  Sars.  Referring  to 
the  various  attempts  at  classification,  C.  B.  Wilson, 
in  a  recent  article  on  the  subject,  remarks :  "  It 
requires  about  as  thorough  a  knowledge  of  the  Cope- 
poda to  select  intelligently  from  these  various  schemes, 
backed  as  they  are  by  competent  authority,  as  it 
would  to  construct  an  original  scheme.  Indeed  most 
authors  have  apparently  found  the  latter  the  easier, 
since  each  has  propounded  a  scheme  of  his  own."* 

*  "The   Classification   of  the   Copepods,"   by   C.   B.   Wilson,   in  '  Zool. 
Anzeiger,'  vol.  xxxv,  No.  20,  26th  April,  1910,  p.  611. 


28  BRITISH    PARASITIC    COPEPODA. 

Dr.  Bassett-Smith  in  his  excellent  paper  on  "  Para- 
sitic Copepoda  found  on  Fishes,"  published  in  1899,* 
follows,  with  some  slight  modifications,  the  classifica- 
tion proposed  by  Gerstaecker  in  Bronn's  '  Tierreich,' 
1881,  and  as  Sars'  main  divisions  fit  in  fairly  well  with 
this  arrangement  it  has  been  retained  here. 

The  Cydopoida. 

The  Cyclopoida  are  represented  among  the  Cope- 
poda parasitic  on  British  fishes  by  a  single  family, 
the  ErgasilidaD,  which  comprises  the  three  genera 
Ergasilm,  Bomolochus,  and  Tliersitina. 

The  Caligoida. 

The  Caligoida  are  represented  by  many  genera  and 
species  ;  they  are  arranged  under  three  families — viz., 
the  Caligidae,  the  Dichelestiidae,  and  the  Philichthyidffi. 
The  Caligidae  have  been  divided  into  the  following  sub- 
families :  the  Caliginae,  Trebina3,  Euryphorinae,  Pan- 
darinae,  and  Cecropinae ;  but  with  the  exception  of 
the  Caliginae,  which  comprise  C aligns,  Lepeophtheimx, 
and  one  or  two  other  genera,  these  subdivisions  are 
each  represented  by  only  a  small  number  of  species, 
and  it  has,  therefore,  not  been  considered  necessary  to 
adopt  these  minor  divisions  here. 

The  Lernsdoida. 

The  Lernaeoida  also  comprise  a  considerable  number 
of  genera  and  species,  and  these,  like  the  Caligoida, 
are  arranged  under  three  families — viz.,  the  Lernaeidse, 
the  Chondracanthidae,  and  the  Lernaeopodidae.  These 
represent  three  tolerably  distinct  types,  and  exhibit  in 
the  adult  female  a  more  or  less  retrograde  develop- 
ment, producing  in  many  cases  results,  in  regard  to 

*  "  A  Systematic  Description  of  Parasitic  Copepoda  found  on  Fishes,  with 
an  Enumeration  of  the  Known  Species,"  in  '  Proc.  Zool.  Soc.  London,'  18th 
April,  1899. 


SYSTEMATIC    ARRANGEMENT.  29 

their  form  and  structure,  of  a  remarkable  kind,  as 
indicated  in  the  life-history  of  Lernaea  already  referred 
to.  In  the  family  Lernseidse  the  body  of  the  adult 
female  is  greatly  distorted,  and  the  head  is  buried 
deeply  in  the  tissues  of  the  host;  on  the  other  hand, 
the  mature  male,  which,  as  shown  in  Plate  XLII, 
fig.  5,  closely  resembles  the  young  female  before  it  has 
begun  to  assume  that  abnormal  development  charac- 
teristic of  the  adult  stage,  does  not,  so  far  as  known, 
undergo  any  further  change,  but  continues  during  its 
short  life  to  retain  its  normal  structure  and  form. 
The  Chondracanthidas  differ  from  the  other  two 
families  by  the  manner  of  their  fixation,  and  also  by 
the  peculiar  form  of  the  mandibles,  which  are  unlike 
those  of  any  of  the  other  parasitic  groups  described 
here.  The  Lernseopodidae  are  also  distinguished  by 
their  mode  of  fixation,  as  shown  elsewhere. 

The  Linnasan  species  Lernsza  asellina,  which  was 
ascribed  by  Blainville  and  Baird  to  Lernentoma,  and 
by  Nordmann  and  others  to  Chondracanthnx,  was  re- 
moved to  a  new  genus,  Oralien,\)y  Bassett-Smith,  on 
account  of  some  peculiar  structural  differences.  But 
while  appreciating  this,  and  after  carefully  comparing 
the  characters  of  Oralien  with  those  of  the  older  genus 
Medexicaste  Kroyer,  we  are  inclined  to  think  that  the 
difference  between  them  is  scarcely  of  sufficient  im- 
portance for  the  establishment  of  a  new  genus — a 
conclusion  previously  come  to  by  Brian.*  We  have 
therefore  transferred  this  Linnaean  species  to  Kroyer's 
genus  Medesicaste.  Moreover,  as  Splii/rion  appears  to 
be  a  true  Lernaean  rather  than  a  Chondracanthian 
genus,  with  which  family  it  is  sometimes  associated, 
it  has  been  transferred  by  us  to  the  family  Lernaeidae. 

*  '  Copepodi  parassiti  del  Pesci  d'ltalia,'  p.  94. 


SYSTEMATIC    LIST 
OF   THE  SPECIES  DESCRIBED  IN    THIS  VOLUME. 


Order  COPEPODA. 

Tribe  I.  Cyclopoida  G.  O.  Sars. 

Family  i.  ERGASILID^. 

1.  EEGASILUS  Nordmann.  2.  onosi  T.  Scott. 

1.  nanus  Glaus.  3.  zeugopteri  T.  Scott. 

2.  BOMOLOCHUS  Nordmann.  3.  THERSITINA  Norman. 

1.  solese  Clans.  1.  gasterostei  Pagenstecher. 

Tribe  II.  Caligoida  G.  O.  Sars. 
Family  n.  CALIGID^. 


4.  CALIGUS  O.  F.  Miiller. 

1.  curtus  O.  F.  Miiller. 

2.  minimus  Otto. 

3.  rapax  M.  Edwards. 

4.  centrodonti  Baird. 

5.  gurnardi  Kroyer. 

6.  iabracis  T.  Scott. 

7.  zei  Norman. 

8.  brevicaudatus  A.  Scott. 

9.  pelamydis  Kroyer. 
10.  diaphanus  Nordmann. 

5.  PSEUDOCALIGUS  A.  Scott. 

1.  brevipedes  Bassett-Smith. 

6.  SCI^ENOPHILUS  P.  J.  van 

Beneden. 
1.  tenuis  P.  J.  van  Beneden. 

7.  LEPEOPHTHEIRUS  Nordmann. 

1.  pectoralis  O.  F.  Miiller. 

2.  nordmanni  M.  Edwards. 

3.  hippoglossi  Kroyer. 

4.  thomsoni  Baird. 

[obscurus  Bassett-Smith.] 

5.  salmonis  Kroyer. 

6.  pollachii  Bassett-Smith. 

7.  sturionis  Kroyer. 

8.  LUTKENIA  Glaus. 

1.  asterodermi  Glaus. 


[NOGAUS  Leach. 

1.  ambiguus  T.  Scott.] 

9.  DEMOLEUS  Heller. 
1.  paradoxus  Otto. 

10.  TREBIUS  Kroyer. 

1.  caudatus  Kroyer. 

11.  ELYTROPHORA  Gerstaecker. 
1.  brachyptera  Gerstaecker. 

12.  DINEMOURA  Latreille. 

1.  producta  O.  F.  Miiller. 

13.  ECHTHROGALEUS  Steenstrup 

&  Liitken. 

1.  coleoptratus  Guerin-Men- 

neville. 

2.  lutTteni  Norman. 

14.  PHYLLOTHREUS  Norman. 

1.  cornutus  M.  Edwards. 

15.  PANDARUS  Leach. 

1.  bicolor  Leach. 

16.  CECROPS  Leach. 

1.  latreillii  Leach. 

17.  ORTHAGORISCICOLA  Poche. 
1.  muricata  Kroyer. 

18.  PHILORTHRAGORISCUS  Horst. 
1.  serratus  Kroyer. 


LIST    OF    SPECIES. 


31 


Family  in.   DICHELESTIID.E. 


19.  DICHELESTIUM  Hermann. 

1.  oblongum  Abildgaard. 

20.  ANTHOSOMA  Leach. 

1.  crassum  Abildgaard. 

21.  LERNANTHROPTJS  Blainville. 

1.  kroyeri  P.  J.  van  Beneden. 

22.  HATSCHEKIA  Poche. 

1.  hippoglossi  Kroyer. 

2.  mulli  P.  J.  van  Beneden. 

3.  labracis  P.  J.  van  Beneden. 

4.  cluthK  T.  Scott. 

5.  cornigera  T.  Scott. 

6.  pygmsea  T.  Scott. 


23.  KEOYERIA  P.  J.  van  Beneden. 
1.  lineata  P.  J.  van  Beneden. 

24.  CONGERICOLA  P.  J.  van 

Beneden. 
1.  pallida  P.  J.  van  Beneden. 

25.  EUDACTYLINA  P.  J.  van 

Beneden. 

1.  acuta  P.  J.  van  Beneden. 

2.  acanthii  A.  Scott. 

3.  similis  T.  Scott. 

4.  minuta  T.  Scott. 

5.  insolens  T.  &  A.  Scott. 


Family  iv.  PHILICHTHYID^. 

26.  PHILICHTHYS  Steenstrup. 
1.  xiphiiB  Steenstrup. 

Tribe  III.  Lernseoida  G.  O.  Sars. 
Family  v.    LERNJELTLE. 


27.  LERN^A  Linnaeus. 

1.  branchialis  Linnyeus. 

2.  lusci  Bassett-Smith. 

3.  minuta  T.  Scott. 

4.  lumpi  T.  Scott. 

28.  H.EMOBAPHES  Steenstrup  & 

Liitken. 
1.  cyclopterinus  O.  Fabricius. 

29.  H^MOBAPHOIDES  T.  &  A. 

Scott. 
1.  ambiguus  T.  Scott. 

30.  PENNELLA  Oken. 

1.  orthagorisci  E.  P.  Wright. 


31.  LERN^OCERA  Blainville. 
1.  cyprinacea  Linnaeus. 

32.  LERNJEENICUS  Lesueur. 

1.  sprattse  Sowerby. 

2.  encrasicola  Turton. 

33.  TRYPAPHYLUS  Richiardi. 

1.  musteli  P.  J.  van  Beneden. 

34.  REBELULA  Poche. 

1.  edwardsi  Kolliker. 

35.  SPHYRION  Cuvier. 

1.  lumpi  Kroyer. 


Family  vi.   CHONDRACANTHID^E. 

7.  clavatus  Bassett-Smith. 

8.  nodosus  O.  F.  Miiller. 

9.  zei  De  la  Roche. 

10.  lophii  Johnston. 

11.  merluccii  Holten. 

12.  ornatus  T.  Scott. 
37.  MEDESICASTE  Kroyer. 

1.  asellinum  Linnaeus. 


36.  CHONDRACANTHUS  De  la 

Roche. 

1.  coi'nutus  O.  F.  Miiller. 

2.  annulatus  Olsson. 

3.  solese  Kroyer. 

4.  flurse  Kroyer. 

5.  depressus  T.  Scott. 

6.  limandse  Kroyer. 


32 


mtlTiSH    PABAS1T1C    COPEPODA. 


Family  vn.   LERN^EOPODIDJE. 
38.  THYSANOTE  Kroyer.  3.  insidiosa  Heller. 


1.  impudica  Nordmann. 

39.  CHAROPINUS  Kroyer. 

1.  dalmanni  Betzius. 

2.  dubius  T.  Scott. 

3.  ramosus  Kroyer. 

40.  ACHTHERES  Nordmann. 

1.  percaruni  Nordmann. 

41.  LERN^OPODA  Blainville. 

1.  elongata  Grant. 

2.  galei  Kroyer. 

3.  cluthse  T.  Scott. 

4.  salmonea  Linnaeus. 

5.  bidiscalis  de  Yisme  Kane. 

6.  similis  T.  &  A.  Scott. 

7.  lampri  T.  &  A.  Scott. 

42.  BRACHIELLA  Cuvier. 

1.  thynni  Cuvier. 

2.  rostrata  Kroyer. 


4.  merluccii  Bassett-Smith. 

5.  triglse  Glaus. 

6.  ovalis  Kroyer. 

7.  bispinosa  Nordmann. 

8.  pastinacaP.  J.vanBeneden. 

9.  parkeri  G.  M.  Thomson. 
43.  CLAVELLA  Oken. 

1.  uncinata  O.  F.  Miiller. 

2.  rugosa  Kroyer. 

3.  dubia  T.  &  A.  Scott. 

4.  emarginata  Kroyer. 

5.  scombri  Kurz. 

6.  brevicolis  M.  Edwards. 

7.  stellata  Kroyer. 

8.  paradoxa  P.  J.vanBeneden. 

9.  quadrata  Bassett-Smith. 

10.  canthari  Heller. 

11.  alata  Brian. 

12.  lophii  M.  Edwards. 


CLASS    CRUSTACEA. 

SUB-CLASS    ENTOMOSTRACA. 

Order    COPE  POD  A. 
Tribe  I.  CYCLOPOIDA  G.  0.  Sars. 

Cephalothorax  ovate  and  usually  more  robust  than 
the  abdomen.  Antennules  slender  and  elongated  or 
tolerably  short  and  stout;  those  of  the  male  alike  on 
both  sides,  sometimes  modified  for  grasping. 

Antennae  unbranched,  or  the  outer  branch  rudimen- 
tary ;  usually  feebly  armed,  but  sometimes  stout  or 
elongated  and  provided  with  strong  terminal  claws. 
Maxillipeds  usually  less  developed  than  in  the  Cala- 
noida,  but  the  second  pair  sometimes  strongly  uncinate. 

First  four  pairs  of  swimming  legs  as  in  the  Cala- 
noida ;  fifth  pair  rudimentary,  alike  in  both  sexes, 
usually  one-  but  sometimes  two- jointed,  rarely  with 
more  than  two  joints.  Egg-strings  two. 

The  Cyclopoida  found  on  British  fishes  all  belong  to  the 
one  family  Ergasilidae,  and  to  the  three  genera  Ergasilus, 
Bomolochus,  and  Thersitina.  The  species  comprised  within 
these  three  genera  are  associated  with  fishes  of  various  kinds. 
They  cannot  all  be  accurately  described  as  parasites,  some  of 
them,  such  as  Bomolochiis  soless,  should  rather  be  regarded  as 
commensals  ^>r  messmates ;  they  appear  to  be  able,  within 
certain  limits,  to  move  about  with  considerable  freedom. 
Their  food  appears  for  the  most  part  to  consist  of  the  mucus 
exuded  by  the  fish,  and  it  is  doubtful  if  they  would  long  sur- 
vive it'  removed  from  their  host. 

Family  i.  ERGASILIDAE. 

Body  more  or  less  cyclopoid  in  form.  First  segment 
usually  large,  sometimes  subglobose  in  the  female. 
Antennules  composed  of  five  to  seven  joints.  Antennae 

VOL.  i.  3 


34  BRITISH    PARASITIC    COPEPODA. 

two-  or  three- jointed,  more  or  less  prehensile,  and 
usually  armed  with  terminal  claws.  Mandibles  small. 
Maxillae  rudimentary.  First  maxillipeds  small  and  of 
a  simple  structure.  Second  maxillipeds  well  developed 
and  provided  with  strong  terminal  claws.  First  four 
pairs  of  thoracic  legs  biramose ;  both  rami  of  the  first 
three  pairs  composed  of  three  articulations,  but  in  the 
fourth  pair,  while  the  inner  ramus  is  three-jointed,  as 
in  the  other  three  pairs,  the  outer  may  consist  either 
of  three  joints  or  only  of  two.  Fifth  pair  small,  one- 
branched,  uniarticulate  or  rudimentary.  Egg-strings 
two. 


Genus  1.  ERGASILUS  Xoflmann,  1832. 

Somewhat  like  Cyclops  in  general  appearance. 
Cephalothorax  elongated,  segments  five,  the  first 
segment  large. 

Antennules  composed  of  five  or  six  joints.  Antenna? 
elongated  and  composed  of  three  joints,  terminal  claws 
large,  and  forming  powerful  grasping  organs.  First 
four  pairs  of  thoracic  legs  biramose  ;  both  rami  of  the 
first  three  pairs  three-jointed  ;  fourth  pair  with  the 
inner  ramus  three-  and  the  outer  two-jointed.  Fifth 
pair  small  or  rudimentary.  Egg-strings  two. 

1.  Ergasilus   nanus  P.  J.  van  Beneden. 

(Plate  I,  fig.   1;  Plate  11,  figs.  1-5;  Plate  XLVIII, 

fig.  17.) 

1870.  Eryasilns  nanusP.  J.  van  Beneden.  (16)  Les  Poissons  des  cotes 
de  Belgique,  leurs  parasites  et  leurs  comniensaux,  p.  27,  pi.  i,  fit;-.  <; 
(recorded  and  figured  but  not  described  in  this  work). 

1901.  Ergasilus  tutnus  T.  Scott.     (113)  p.  122,  pi.  vii,  figs.  1-8. 

Female. — Body  somewhat  expanded  anteriorly,  pos- 
terior extremity  attenuated.  Cephalic  segment  large, 
and  if  viewed  from  above,  somewhat  pear-shaped  in  out- 
line ;  the  widest  part,  which  is  near  the  anterior  end  of 
the  segment,  equal  to  fully  half  its  length,  and  a  shallow 


ERGASILUS    NAN  US.  35 

but  obvious  constriction  occurs  near  its  middle.  The 
remaining  thoracic  and  the  abdominal  segments  small. 

Antennules  short,  apparently  only  five- jointed,  and 
sparingly  setiferous ;  the  first  joint  about  twice  the 
length  of  the  second,  the  fourth  rather  smaller  than  any 
of  the  others.  Antennae  tolerably  slender  and  greatly 
elongated,  composed  of  three  joints,  and  furnished  with 
moderately  strong  and  curved  terminal  claws.  Mouth- 
appendages  apparently  more  or  less  rudimentary  or 
obsolete. 

The  first  four  pairs  of  thoracic  legs  all  biramose  and 
well  developed ;  the  first  three  pairs  with  both  the 
inner  and  outer  rami  three-jointed,  but  in  the  fourth 
pair  while  the  inner  ramus  is  three-,  the  outer  is  only 
two-jointed,  the  first  joint  being  about  twice  as  long 
as  the  end  one.  The  fifth  pair  small,  and  consisting 
each  of  a  single  one-jointed  branch  which  is  about 
three  times  longer  than  broad,  with  the  lateral  margins 
subparallel,  and  the  distal  end  truncated  and  bearing 
two  or  three  moderately  long  apical  seta?.  Caudal 
rami  short.  Egg-strings  two,  large,  more  than  half 
the  length  of  the  animal  and  containing  numerous 
ova.  Length,  exclusive  of  egg-strings,  T2  mm. 

Habitat. — Parasitic  on  the  gills  of  the  grey  mullet, 
Mugil  chelo  (Guvier).  Bay  of  Nigg,  Aberdeen,  in  July, 
1900  (T.  Scott).  Swan  Pool,  Falmouth  (A.  M.  Nonnau. 
1884). 

This  appears  to  be  a  rare  species  ;  though  we  have  ex- 
amined several  specimens  of  the  grey  mullet,  we  have  only 
once  observed  it.  Another  species,  E.  sieboldii,  found  parasitic 
on  carp,  pike,  and  some  other  fresh-water  fishes,  appears  to 
have  a  wide  distribution  on  the  Continent  and  may  yet  be 
obtained  in  British  waters. 

We  have  not  seen  the  male  of  Eryasilus  nanns,  nor  have  we 
seen  any  published  record  of  its  occurrence;  the  male  of  E. 
sieboldii,  on  the  other  hand,  appears  to  be  the  form  which 
has  been  most  frequently  met  with.  Though  several  other 
species  of  Er<jasilus  are  recorded,  E.  nanus  is  apparently  the 
only  British  representative  of  the  genus. 


36  BRITISH    PARASITIC    COPEPODA. 


Genus  2.  BOMOLOCHUS  Nordmann,  1832. 

Body  elongated,  subpyriform,  and  not  unlike  a 
Cyclops  in  general  appearance.  Antennules  tolerably 
short  and  composed  of  about  seven  joints.  Antennae 
small,  three-jointed.  Mandibles  small,  simple,  and 
furnished  with  unequal  tooth-like  processes.  Maxillae 
somewhat  rudimentary.  First  maxillipeds  small  and 
two-jointed,  the  end  joint  attenuated,  and  provided 
with  a  few  marginal  denticles  and  also  with  a  mode- 
rately stout  marginal  plumose  seta  which  reaches  to 
about  the  apex  of  the  joint.  Second  maxillipeds  large, 
composed  of  two  joints,  and  armed  with  a  terminal 
claw,  which  is  recurved  in  the  female  but  not  in  the 
male.  Swimming-feet  all  biramose  and  with  both 
rami  three-jointed  ;  the  joints  of  the  first  pair  lamelli- 
form,  and  furnished  with  spathulate  and  densely- 
plumose  seta3.  Fifth  pair  of  feet  small  and  consisting 
of  a  single  biarticulated  branch. 

The  male  does  not  differ  greatly  from  the  female, 
except  in  the  structure  and  armature  of  the  second 
maxillipeds. 

1.  Bomolochus  soleae  Glaus. 
(Plate  I,  fig.  3  ;  Plate  II,  figs.  6-9  ;  Plate  III,  figs.  1-4.) 

1864.  Bomolochus  solex  Glaus.  (33)  Zeitschr.  f.  wise.  Zool.,  vol.  xiv. 
p.  374.  pi.  xxxv. 

1893.  Bomolochus  solete  T.  Scott.  (Ilia)  Eleventh  Annual  Report 
Fishery  Board  for  Scotland,  pt.  iii,  p.  212,  pi.  v. 

1902.  Bomolochus  solex  idem.     (114)  p.  288,  pi.  xiii,  figs.  13-18. 

1906.  Bomolochus  solex  A.  Brian.  (21)  Copepodi  Parassiti  dei  Pesc  i 
d'ltalia,  p.  31. 

1909.  Bomolochus  soleee  May  E.  Bainbridge.  (3)  Trans.  Linn.  Soc.. 
ser.  2  (zoology),  vol.  xi,  pt.  3,  p.  45,  pi.  viii 


Cephalic  segment  short,  considerably  ex- 
panded, widest  in  the  middle,  forehead  flattened,  sides 
rounded,  length  equal  to  rather  more  than  half  t  he- 
width  ;  each  of  the  two  thoracic  segments  which  follow 
are  about  equal  to  the  length  of  the  cephalic  segment. 


BOMOLOCHUS    SOLE.E.  o7 

but  each  segment  is  narrower  than  that  which  precedes 
it ;  the  other  thoracic  segments  small,  and  partly  con- 
cealed in  dorsal  view.  Abdominal  segments  also 
small. 

Antennules  moderately  short  and  stout,  composed  of 
seven  joints,  and  furnished  with   long  plumose  setae ; 
the  joints   subequal  in  length  but  the  fourth  rather 
longer  than  either  the  third  or  the   fifth.     Antennae 
three-jointed,  middle  joint  short,  end  joint  provided 
with  three  pectinated,  setiferous  appendages  and  a  few 
apical  setse.     Mandibles  small,  but  moderately  stout, 
and  armed  with  two  small,  oval,  terminal  plates  serrated 
on  the  edges.     First  maxillipeds   small,  each  with  a 
stout,  setiferous,  terminal  spine,  from  the  side  of  which 
springs    a   minute  accessory  spinule.     Second  maxil- 
lipeds having  the  basal  part  considerably  dilated,  but 
the  distal  portion  slender,  curved,  and  claw-like.     The 
first  four  pairs  of  thoracic  legs  with  both  the  inner 
and  outer  ramus  three-jointed;  in  the  first  pair  both 
rami   broadly  lamelliform,    somewhat    distorted,    and 
furnished  with  densely  plumose  setae,  the  middle  joint 
rather  shorter  than  the  first  or  third.     The  second  and 
third  pairs  with  both  rami  longer  and  much  narrower 
than  those  of  the  first  pair,  and  furnished  with  densely 
plumose  setae  on  the  inner  margins  and  short  stout 
spines    on   the    outer ;    under    the    microscope   these 
spines  are  seen  to  end  in  minute  hooks.     The  inner 
ramus  in  the  fourth  pair  narrower  and  rather  longer 
than  the  outer,  and  bearing  a  single  plumose  seta  on 
the  inner  distal  angles  of  the  first  and  second  joints, 
and   also   three   apical    setae,  the   middle   one   being 
longer  than  the  one  on  either  side.     Fifth  pair  con- 
sisting each  of  a  single  two-jointed  ramus,  the  first 
joint  being  very  short,  the  other  of  moderate  length 
and  bearing  one  marginal  and  three  terminal   setae. 
Caudal  rami  short.     Length  about  1*3  mm. 

Habitat. — Found  parasitic  on  the  back  of  the  common 
sole,  Solea  vulgaris  Quen.,  and  in  the  nasal  fossae 
of  various  fishes,  especially  of  cod-fishes  :  it  has  been 


38  BRITISH    PARASITIC   COPEPODA. 

found  much  more  frequently  in  the  nostrils  of  the  cod 
than  in  those  of  any  other  fish  we  have  examined. 
The  following  is  a  list  of  the  fishes  on  which  we  have 
obtained  this  Bomolochus  : — 

1.  Lumpsucker,     Cyclopterus    linitjmx    L.,    in    the 
nostrils,  rather  rare. 

2.  Cod  fish,  Gadus  callir'nix  L.,  in  the  nostrils,  fre- 
quent. 

3.  Haddock,  Gadus  seglefinus  L.,  in  the  nostrils,  not 
common. 

4.  Whiting,   Gadus   merlamjus  L.,   in    the    nostrils, 
not  common. 

•").  Pollack  or  lythe,  (l<nln*  pollachius  L.,  in  the 
nostrils,  moderately  frequent. 

6.  Ling,  Mol.ua  molva  L.,  in  the  nostrils,  not  com- 
mon. 

7.  Plaice,  Pleuronectes  platessa  L.,  in  the  nostrils, 
not  very  rare. 

8.  Flounder,  Pleuronectes  flesus  L.,  in  the  nostrils, 
rare. 

9.  Common  or  black  sole,  Solea  vnlgaris  Quen.,  on 
the  back  of  the  fish,  not  common. 

Bomolochus  solese  has  been  obtained  at  various  places  round 
the  British  Islands  on  one  or  other  of  the  fishes  mentioned. 
The  specimens  obtained  on  the  ling-fish  are  rather  larger 
than  the  typical  form  from  the  black  sole  or  the  cod-fish,  but 
they  do  not  appear  to  differ  much  otherwise.  As  mam-  as 
twenty-nine  specimens  of  Bomolochus  have  been  obtained  in 
the  nostrils  of  a  single  large  cod-fish  captured  in  the  Moray 
Firth.  Frequently,  not  only  adult  males  and  females  (the 
latter  commonly  with  ovisacs),  but  also  young  ones  in  all 
stages  of  development,  may  be  observed  in  the  nostrils  of  the 
cod-fish,  thus  indicating  clearly  enough  that  their  presence  in 
this  curious  domicile  is  not  accidental,  and  that  they  find  the 
conditions  of  life  fairly  satisfactory  amid  such  surroundings, 
even  though  the  accommodation  is  somewhat  limited.  This 
habit  on  the  part  of  the  Bomolochus  is  the  more  interesting 
when  there  is  apparently  nothing  to  hinder  them  from  leaving 
the  nostrils  of  the  fish.  They  can  move  about  freely  amongst 
the  mucus  with  which  the  nostrils  are  usually  well  supplied, 
and  if  they  be  removed  and  placed  in  a  vesse)  of  clear  sea- 


BOMOLOCHUS    SOI. E.Y..  39 

'water  they  will  be  seen  swimming  or  running  about  with 
nearly  as  much  agility  as  a  "free-swimming"  species.  It  is 
fairly  evident  therefore  that  the  presence  of  these  Copepods 
in  the  nostrils  of  fishes  is  a  matter  of  choice,  and  there  is 
nothing  to  show  that  their  presence  is  the  cause  of  much 
inconvenience  to  the  fish.  Moreover,  in  this  situation  there 
are  two  points  in  favour  of  the  Copepod — it  has  plenty  of  food 
of  a  kind,  and  it  is  well  sheltered  from  its  enemies. 

The  male  does  not  differ  much  from  the  female  except  thar 
the  second  maxillipeds  are  armed  with  more  powerful 
terminal  claws. 

2.  Bomolochus  onosi  T.  Scott. 
(Plate  I,  fig.  4 ;  Plate  III,  figs.  5-7.) 

1902.  Bomolochus  onosi  T.  Scott.     (114)  p.  289,  pi.  xiii,  figs.  19-22. 

Female. — Body  elongated,  subpyriform ;  the  an- 
terior segment  proportionally  larger  than  the  same 
segment  in  Bomoloc/nis  soleae,  being  equal  to  nearly 
half  the  entire  length  of  the  cephalothorax ;  the  next 
three  segments  subequal  in  length,  but  each  narrower 
than  the  one  that  precedes  it.  Abdomen  narrow  and 
moderately  elongated,  genital  segment  twice  the 
length  of  the  next  one,  other  segments  smaller,  but 
the  anal  rather  longer  than  either  of  the  two  preced- 
ing segments.  Caudal  rami  about  as  long  as  the  anal 
segment. 

Antennules  moderately  stout,  but  becoming  some- 
what attenuated  towards  the  distal  extremity ;  the 
first  two  joints  tolerably  large,  the  second  being  about 
one  and  a  half  times  the  length  of  the  next,  the  third 
and  fourth  joints  subequal  and  larger  than  those 
which  follow,  the  penultimate  joint  smaller  than  any 
of  the  others  ;  the  plumose  seta3  with  which  the  anten- 
uules  are  furnished,  though  somewhat  similar  to  those 
on  the  antennules  of  Bomo/nclm*  solese,  are  apparently 
not  quite  so  stout.  Antenna?,  mandibles,  and  maxilla^ 
somewhat  similar  to  the  same  appendages  in  Bunm- 
Ini-li  //x  xolese.  Second  maxillipeds  robust,  and  each  armed 
with  a  tolerably  stoiit  and  strongly  curved  terminal 
claw  :  a  slender  seta  also  springs  from  the  distal  end 


40  BRITISH    PARASITIC    COPEPODA. 

of  the  inner  margin  of  the  first  joint,  and  two  smaller 
setae  from  near  the  middle  of  the  second  joint,  while 
from  the  proximal  half  of  the  terminal  claw  there 
spring  two  slender  bristles  of  unequal  length,  the 
longer  one  extending  considerably  beyond  the  end  of 
the  claw. 

Thoracic  legs  somewhat  similar  in  structure  and 
armature  to  those  of  BomolorJms  soJess.  Length  about 
1-3  mm. 

The  species  is  colourless,  with  the  exception  of  a 
slight  chalky  whiteness  along  the  alimentary  tract. 

Male. — The  male  of  Bomolochus  onosi  differs  little 
from  the  female,  except  that  the  terminal  claw  of  the 
second  maxillipeds  is  more  powerful,  more  evenly 
curved,  and  has  its  inner  edge  minutely  dentated. 

Habitat. — Found  parasitic  on  the  inner  surface  of 
the  gill-covers  of  four-bearded  and  five-bearded  rock- 
lings,  Onos  (Motella)  cimbrius  and  Onos  (Motetta) 
mustelus.  Firth  of  Forth,  Moray  Firth,  and  Bressay 
Shoal,  east  of  Shetland  (T.  Scott). 

The  species  described  above  has  a  close  resemblance  to 
Bomolochus  soleee,  and  miufht  easily  be  mistaken  for  it.  The 
most  obvious  difference  is  perhaps  in  the  form  and  armature 
of  the  posterior  maxillipeds;  this  difference  is  so  marked  that 
it  may  be  detected  even  without  dissection,  when  the  creatun- 
is  viewed  from  the  ventral  aspect  with  the  aid  of  a  hand-lens. 

3.  Bomolochus  zeugopteri  T.  Scott. 
(Plate  I,  fig.  2 ;  Plate  III,  figs.  8,  9.) 

1902.  Bomolochus  zeugopteri  T.  Scott.     (114)  p.  290,  pi.  xiii,  figs.  22-25. 

Female. — Cephalic  segment  equal  to  the  combined 
length  of  the  next  three  segments,  broadly  rounded  in 
front,  rostrum  not  very  prominent ;  the  next  segment 
nearly  as  wide  as  the  preceding  one,  and  about  half  as 
long,  the  remaining  segments  narrower  and  shorter. 
Abdomen  narrow,  the  genital  segment  about  as  long 
as  the  combined  length  of  the  next  three  segments, 
the  last  two  segments  subequal  and  rather  shorter 
than  the  second  one.  Caudal  rami  short. 


BOMOLOCHUS  ZEUGOPTERI.  41 

Antennules  tolerably  stout,  shorter  than  the  cephalo- 
thorax  and  bearing  numerous  and  moderately  stout 
plumose  setae,  first  and  second  joints  large,  and,  to- 
gether, about  as  long  as  the  combined  length  of  the 
next  four,  the  third  and  fourth  joints  subequal,  and 
the  penultimate  joint  shorter  than  any  of  the  others. 
Second  maxillipeds  tolerably  stout,  the  terminal  claw 
only  slightly  curved  at  the  end,  but  at  the  base  bent 
backward  upon  the  preceding  joint.  Thoracic  legs 
somewhat  similar  to  those  of  Bomolochus  onosi.  Length 
about  0'84  mm. 

No  males  of  this  species  have  been  observed. 

Habitat. — Found  adhering  to  the  back  of  a  small 
Miiller's  top-knot,  Zencjopterm  punctatus  (Bl.),  cap- 
tured near  the  mouth  of  the  Clyde  estuary  in  Septem- 
ber, 1897.  About  a  dozen  specimens,  all  females,  and 
most  of  them  carrying  ovisacs,  were  obtained  ;  they 
were  adhering  firmly  on  the  rough  dark-coloured  side 
of  the  fish. 

This  species  is  at  once  distinguished  by  the  marked  differ- 
ence in  the  structure  and  armature  of  the  second  maxillipeds ; 
it  is  also  a  smaller  species  than  the  other  two  described 
above. 

Genus  3.  THERSITINA  Norman,  1905.* 

Syn.  Thersitcs  Pagenstecher  1861,  a  name  preoccupied  by  Pfeiffer 
in  1855  for  a  genus  of  Mollusca,  and  by  Spence  Bate  in  1857  for  a 
genus  of  Amphipoda. 

Ergasilides  having  the  cephalic  segment  in  the  female 
greatly  enlarged  and  subglobular ;  other  thoracic  and 
abdominal  segments  small. 

Antennules  short,  stout,  and  composed  of  five  joints. 
Antennae  also  short,  rather  stout,  and  armed  with  a 
tolerably  strong,  claw-like,  terminal  spine,  from  the 
side  of  which  springs  a  second  and  smaller  one. 
Mandibles,  maxillaa,  and  first  maxillipeds  somewhat 
similar  in  structure  to  the  same  appendages  in  the 
Lichomolgida3.  Second  maxillipeds  small,  two-  or 

*  'Museum  Normanianum,'  III,  Crustacea,  second  edition,  p.  41. 


42  BRITISH    PARASITIC   COPKPODA. 

three- jointed,  and  bearing  a  few  stout  apical  spines. 
Thoracic  legs  nearly  as  in  Erf/asiln*. 

In  the  male  the  cephalic  segment  is  not  so  much 
enlarged,  and  the  body  is  more  elongated. 

1.  Thersitina  gasterostei  (Pagenstecher). 
(Plate  XXV,  figs.  1-6 ;  Plate  LI,  fig.  6.) 

1861.  Thersites  gasterostt  i  Pagenst.   (94)  vol.  xvii,  p.  118,  pi. vi,  figs.  1-9. 

1863.  Ergasilus  gasterostei  Kroyer.     (71)  p.  233,  pi.  xii,  figs.  2,  a — 7t. 

1892.  Thersites  gasterostei  Canu.     (29)  p.  245,  pi.  xxiii,  figs.  13-18. 

1899.  Ei-gasilus  gasterostei  Bassett-Smith.     (8)  p.  444. 

1900.  Thcrsites  gasterostei  T.  Scott.     (112)  p.  146,  pi.  v,  figs.  1-7. 
1905.  Thersitina  gasterostei  A.  M.  Norman.    Museum  Normanianum. 

Ill,  Crustacea,  second  edition,  p.  41. 

Female. — Cephalic  segment  considerably  dilated, 
and,  when  viewed  from  above,  concealing  the  remain- 
ing thoracic  segments  as  well  as  part  of  the  abdomen; 
genital  segment  of  the  abdomen  longer  than  the 
combined  length  of  all  the  other  abdominal  segments. 
Caudal  rami  short. 

Antennules  very  short,  tolerably  stout,  and  com- 
posed of  five  joints,  which  are  sparingly  setiferous. 
The  formula  shows  their  proportional  lengths. 

lumbers  of  the  joints  .         .         .12345 

Proportional  lengths  of  the  joints    16  10  11   7  8 

Antennae  short  and  stout,  and  each  furnished  with 
a  tolerably  strong  terminal  claw.  Mandibles  with  a 
bilobed  biting  part.  First  maxillipeds  short,  simple  in 
structure,  and  provided  with  a  few  small  spines. 
Second  maxillipeds  small,  basal  part  enlarged,  ter- 
minal part  more  slender,  forming  a  curved  arm  which 
is  furnished  with  a  few  apical  spines. 

The  first  three  pairs  of  swimming-legs  with  both 
rami  three- jointed,  but  the  outer  ramus  rather  shorter 
than  the  inner.  In  the  fourth  pair  the  outer  ramus  is 
only  two-jointed,  the  elongated  first  joint  consisting 
probably  of  two  coalescent  joints  ;  the  inner  ramus 
three-jointed  as  in  the  preceding  three  pairs.  Length 
about  0*8  mm.  (-3^  of  an  inch). 

II  a  hit  fit. — Parasitic    on    certain   fresh- water  fishes, 


THERSITINA    GASTEKOSTEI.  43 

usually  on  the  inner  surface  of  the  gill-covers.  On 
three-spined  sticklebacks,  Gasterosteus  aculeatus,  cap- 
tured in  Sinclair  Loch,  Barra,  Outer  Hebrides,  in 
May  1 894.  On  the  same  species  of  fish  captured  in 
the  river  Forth  near  Alloa  in  February  1896  ;  and 
in  brackish  pools  on  Aberdeen  links  in  1 900.  Taken 
also  on  a  fifteen-spined  stickleback,  Gastrsea  spinachia, 
captured  in  Loch  Etive,  West  Coast  of  Scotland,  in 
May  1896. 

This  Copepod,  which  has  been  ascribed  by  some  authors  to 
the  genus  Ergasihis,  does  not  agree  very  well  with  some  of 
the  characters  of  that  genus.  The  typical  female  Ergasilus 
has  the  body  tolerably  elongated,  but  in  Thersitina  it  is 
nearly  globose;  the  structure  and  size  of  the  antennae  are 
also  altogether  different.  On  account  of  these  and  one  or 
two  other  differences,  as,  for  example,  in  the  structure  of  the 
mandibles  and  second  maxillipeds,  we  prefer  to  retain  the 
species  in  the  genus  to  which  it  was  ascribed  by  Pagenstecher. 

Tribe  II.  CALIGOIDA  G.  0.  Sars. 

Head  usually  in  the  form  of  a  buckler  or  shield, 
with  or  without  frontal  plates  :  in  some  cases  the 
frontal  plates  are  provided  with  sucking  disks.  Thorax 
consisting  of  several,  usually  more  or  less  distinct, 
rings  or  segments,  with  their  margins  sometimes  pro- 
duced into  flattened  scales  or  plates.  Abdomen  or 
urosome  composed  of  two  or  three  segments,  the 
genital  segment  being,  in  the  female,  sometimes  con- 
siderably expanded  (ex.  Caligus),  or  elongated  (ex. 
Hatschekia). 

Mouth-apparatus  consisting  usually  of  a  syphon 
provided  with  styliform  mandibles  and  other  accessory 
appendages.  Usually  there  are  also  four  pairs  of 
thoracic  limbs,  but  in  some  genera  one  or  two  pairs 
may  be  wanting.  A  fifth  pair,  more  or  less  rudimen- 
tary, is  also  sometimes  present. 

The  species  comprised  in  this  tribe  are  all,  in  the  adult 
stage,  parasitic  on  fishes.  They  are  not  permanently  fixed 
to  their  host,  but  both  the  female  and  male  possess  a  certain 


-44  BRITISH    PARASITIC    COPEPODA. 

freedom  of  locomotion,  closely  approaching  in  some  cases 
that  of  the  normal  free-swimmers ;  usually  however  their 
movements  appear  to  be  more  or  less  restricted.  They  retain 
their  position  on  the  fish,  at  least  to  a  considerable  extent,  by 
means  of  the  strong  terminal  hooks  with  which  certain  of 
their  appendages  are  furnished,  such  as  the  second  pair  of 
antenna?,  the  maxillipeds,  and  one  or  two  others. 

The  young  leave  the  eggs  as  free-swimming  nauplii. 

The  Caligoida  comprise  the  three  families  Caligida?, 
Dichelestiidee,  and  Philichthyid,se,  the  first  two  of  which  are 
represented  by  a  considerable  number  of  genera  and  species. 

Family  n.     CALIGID^E. 

Carapace  tolerably  broad,  more  or  less  flattened, 
provided  with  anterior  frontal  plates.  Free  thoracic 
segments  uncovered  or  sometimes  more  or  less  con- 
cealed by  paired  dorsal  plates.  Antennules  small,  two- 
or  three-jointed.  Antennas  forming  short,  movable, 
hooked  claws.  Mouth  a  suctorial  beak  formed  by  a 
modification  of  the  upper  and  lower  lips,  and  inclosing 
styliform  mandibles.  Second  maxillipeds  stout,  with 
strong  terminal  claws.  First  four  pairs  of  thoracic 
legs  all  biramose,  or  the  first  and  fourth  pairs  may  be 
uniramose.  Fifth  pair  rudimentary.  Eyes  median, 
contiguous,  sometimes  obsolete.  Egg-strings  two, 
usually  elongated. 

The  male  is  generally  smaller  than  the  female. 

In  some  genera  the  mature  stage  is  preceded  by  that  of  the 
chalimus,  or  young  stage,  which  is  temporarily  fixed  to  the 
host  by  a  more  or  less  elongated  slender  frontal  filament  (cf. 
PL  IV,  figs.  3-5). 

•  Genus  4.    CALIGUS     0.  F.  Miiller,  1785. 

Carapace  large,  flattened,  shield-like.  Frontal  plates 
provided  with  small  but  conspicuous  sucking-disks  or 
lunulee.  Fourth  pair  of  thoracic  legs  uniramose.  Fifth 
pair  rudimentary,  and  very  small.  Genital  segment 
in  the  female  usually  expanded  and  moderately  large. 
Abdomen  short  or  moderately  elongated  and  composed 


CALIGUS.  45 

of  one  or  two  segments  ;    caudal  rami  short.       Dorsal 
plates  wanting. 

1.  Caligus  curtus  0.  F.  Muller. 
(Plate  XXIV,  figs.  1,  2 ;  Plate  XXV,  figs.  7-9.) 

1785.  Caligus  curtus  O.  F.  Mtiller.     (86)  p.  130,  pi.  xxi,  fig.  1. 

1816.  Caligus  mulleri  Leach.     (74)  p.  405,  pi.  xx. 

1832.  Caligus  bicuspidatus  Nordmann.     (89)  p.  28. 

1850.  Caligus  diaphanus  Baird.     (4)  p.  269,  pi.  xxxiii,  fig.  1. 

1863.  Caligus  nsglefini  Kroyer.     (71)  p.  89,  pi.  vii,  fig.  3,  a-/. 

Female. — Carapace  oval  and  fully  half  the  entire 
length  of  the  animal,  rather  longer  than  broad,  widest 
behind  and  becoming  gradually  narrower  towards  the 
front,  lateral  margins  slightly  rounded,  frontal  plates 
tolerably  large  and  furnished  with  conspicuous  lunula?. 
Genital  segment  subquadrangular,  rather  longer  than 
broad,  and  equal  to  about  one-fourth  of  the  entire  length. 
Abdomen  narrow  and  scarcely  equal  to  one-third  the 
length  of  the  genital  segment.  Caudal  rami  very 
short  and  furnished  with  about  four  short  seta?. 

Antennules  short,  the  basal  joint  slightly  expanded 
and  its  margin  densely  setiferous ;  end  joint  narrow. 
The  second  maxillipeds  consisting  of  a  stout  basal  joint, 
and  an  end  joint  which  is  narrow  and  armed  with 
two  small  terminal  claws,  one  being  larger  than  the 
other.  Branches  of  the  sternal  fork  short,  moderately 
stout,  and  slightly  divergent,  also  bluntly  rounded 
at  the  end.  Basal  joint  in  the  first  pair  of  thoracic- 
legs  tolerably  stout,  and  bearing  a  single,  short,  two- 
jointed  branch ;  the  joints  narrow  and  subequal, 
the  first  armed  with  a  short  spiniform  seta  on  it> 
outer  distal  angle ;  the  last  with  two  short  apical 
spines,  and  a  moderately  long  one  which  is  curved  and 
claw-like.  The  fifth  pair  of  legs  very  small  and  situated 
near  the  postero-lateral  angles  of  the  genital  segment. 

Length  about  10  mm.,  width  equal  to  about  half  the 
leno'th.  but  the  size  varies  to  some  extent. 

O         * 

The  species  is  of  a  brownish  or  horn  colour,  which 
is  apparently  uniform,  but  when  viewed  with  a  hand- 


46  BRITISH    PARASITIC    COPEPODA. 

lens,  irregular  stellate  markings  are  seen  scattered 
over  the  surface  of  the  carapace. 

M/ile. — In  the  male,  the  average  dimensions  of 
which,  contrary  to  what  is  usual  among  the  Caligidse, 
distinctly  exceed  those  of  the  opposite  sex,  the  cara- 
pace is  proportionally  larger  and  the  genital  segment 
smaller  than  in  the  female.  The  antennae  and  the 
second  maxillipeds  are  more  robust  and  form  more 
powerful  grasping  organs.  The  form  of  the  carapace 
also  differs  somewhat  in  being  proportionally  wider 
behind,  and  in  tapering  more  towards  the  front.  The 
total  length  of  the  male  is  about  13  mm.  and  the 
width  7'5  mm.,  but,  as  in  the  female,  the  size  varies 
somewhat,  ranging,  according  to  C.  B.  Wilson,  from 
13  to  20  mm.  in  length,  and  from  7'4  to  11 '5  mm.  in 
width  of  carapace. 

HaHtat. — Parasitic  on  various  kinds  of  fishes,  but 
especially  on  Gadoids,  and  it  has  been  obtained  in 
abundance  along  with  some  other  species  on  diseased 
cod-fishes. 

This  species,  first  recorded  by  0.  F.  Miiller  in  1785,  is 
regarded  as  the  type  of  the  genus.  It  is,  unlike  Caligus 
rapax,  rarely  captured  as  a  free-swimmer,  neither  is  it  usual 
to  find  it  on  the  gills  or  within  the  gill-covers  of  fishes,  being 
more  frequently  observed  adhering  to,  or  moving  about  over 
the  external  sui-face  of  the  fish. 

Caligus  curtus  is  a  common  form  around  our  shores,  and 
appears  also  to  be  widely  distributed  in  the  North  Sea  and 
the  North  Atlantic.  It  has  been  recorded  as  abundant  durinyr 
the  autumn  along  the  eastern  sea-board  of  the  New  England 
States  of  North  America.* 

2.  Caligus  minimus  Otto. 
(Plate  IV,  figs.  1,  2 ;  Plate  XXV,  figs.  11-16.) 

1828.  Caligus  minimus  Otto.     (93)  vol.  xiv,  p.  354,  pi.  xxii,  figs.  7,  8. 

1826.  Caligus  minimus  Risso.     (105)  p.  135. 

1840.  Caligus  minutus  M.  Edwards.     (43)  vol.  iii,  p.  450. 

1865.  Caligus  minutus  Heller.     (58)  p.  163,  pi.  xiv,  fig.  1. 

1899.  Caligus  minimus  Bassett-Smith.     (8)  p.  447. 

*  'North  American  parasitic  Copepods,'  by  C.  B.  Wilson  (Caliginae). 
'  Proc.  U.  S.  National  Museum/  vol.  xxviii,  p.  581  (1905). 


CALIGUS    MINIMUS.  47 

1901.  Caiigus  minimus  A.  Scott.     (107)  vol.  xv,  p.  349,  pi.  i,  figs.  1-8. 

1905.  Caligus  minimus  T.  Scott.     (116)  p.  109. 

1906.  Caligus  minimus  Norman  &  T.  Scott.     (88)  p.  205. 
1906.  Caligus  minimus  A.  Brian.     (21)  p.  36. 

Female. — Carapace  suborbicular  and  scarcely  equal 
to  half  the  entire  length ;  frontal  plates  and  lunulse 
large.  Eyes  conspicuous.  Free  thoracic  segment 
narrow.  Genital  segment  rather  less  than  a  third  of 
the  total  length,  and  equal  in  width  to  about  two- 
thirds  that  of  the  carapace  ;  the  postero-lateral  angles 
somewhat  produced  into  narrow  rounded  lobes.  Abdo- 
men uniarticulate  and  narrow,  becoming  slightly 
expanded  anteriorly,  equal  in  length  to  about  two- 
thirds  that  of  the  genital  segment.  Caudal  rami 
about  half  as  long  as  the  abdomen. 

Antennules  short;  end  joint  tolerably  elongated  and 
narrow.  Sternal  fork  small,  the  stem  moderately 
long  with  short  and  somewhat  divergent  branches. 
Fourth  pair  of  thoracic  legs  tolerably  elongated,  basal- 
joint  stout,  ramus  two-jointed,  joints  subequal,  the 
first  with  a  small  spine  on  the  outer  distal  angle,  the 
second  furnished  with  one  moderately  long  and  two 
short  apical  spines  as  shown  in  the  figure  (PL  XXV, 
fig.  15).  The  fifth  pair  consisting  each  of  a  minute 
setiferous  plate  near  the  postero-lateral  corners  of  the 
genital  segment. 

N<de. — The  male  is  larger  than  the  female,  and 
differs  from  it  chiefly  in  the  form  of  the  genital 
segment;  this  segment  is  not  much  wider  than  either 
the  free  thoracic  segment  or  the  abdomen.  The 
appendages  are  somewhat  similar  to  those  of  the 
female,  except  that  the  second  maxillipeds  are  con- 
siderably expanded  distally,  and  are  each  armed  with 
a  strong  claw,  so  that  they  form  powerful  grasping 
organs.  The  branches  of  the  sternal  fork  in  the  male 
are  scarcely  if  at  all  divergent. 

Total  length  of  the  female  about  5  mm.,  and  of  the 
male  about  7  mm. 

Habitat. — Parasitic  on  the  bass,  Lahrti.n  lupus. 
Usually  fonnd  inside  the  gill-covers,  or  in  the  mouth  of 


48  BRITISH    PAKASIT1C    COPEPODA. 

the  fish.  Belfast  (Thompson,  1856).  Plymouth 
(Bassett- Smith).  Barrow  Channel,  Lancashire  (A. 
Scott).  Queensferry,  Firth  of  Forth  (T.  Scott). 

The  species  does  not  appear  to  be  very  rare. 

Distribution.  —  European  Seas.  Mediterranean 
(Brian). 

Caligus  minimus,  judging1  from  the  occurrences  of  this 
parasite  known  to  us,  appears  to  be  restricted  almost  entirely 
to  the  bass.  We  do  not  know  of  its  occurrence  on  any  other 
kind  of  fish. 

3.  Caligus  rapax  M.  Edwards.* 
(Plate  IV,  figs.  3-8;  Plate  VI,  figs.  1,  2.) 

1840.  Caligu*  rapax  M.  Edwards.    (43)  vol.  iii,  p.  453,  pi.  xxxviii,  fig.  9. 
1840.  Caligus  elungatus  idem.     (43)  vol  iii,  p.  454. 
1850.  Caligus  rapax  Baird.     (4)  p.  270.  pi.  xxxii,  figs.  2  and  3. 
1861.  Caligus  rapax  Stp.  and  Lkt.     (127)  p.  359.  pi.  ii,  fig.  4. 
1900.  Caligus  rapax  T.  Scott.     (112)  p.  148,  pi.  v.  figs.  13-19. 
1905.  Caligus  rapax  C.  B.  Wilson.     (145)  p.  594,  pi.  vii,  figs.  79-89. 

Female. — Carapace  ovate,  rather  longer  than  broad ; 
frontal  plates  slightly  rounded  ;  lunulas  large  and  con- 
spicuous ;  thoracic  area  fully  half  the  entire  width  of 
the  carapace ;  its  posterior  margin  broadly  rounded 
and  produced  somewhat  beyond  the  narrowly-rounded 
lateral  lobes.  Free  thoracic  segment  narrow,  very 
short,  and  scarcely  more  than  half  the  width  of  the 
next  one.  Genital  segment  quadri-lateral,  about  as 
long  as  broad  and  equal  to  about  half  the  length  of  the 
carapace.  Abdomen  short,  unsegmented,  and  about 
half  the  width  and  scarcely  two-thirds  the  length  of 
the  genital  segment.  Caudal  rami  short,  and  furnished 
with  moderately  long  plumose  seta3. 

Antennules  tolerably  large.  Antennae  small,  simple, 
and  armed  with  a  small  marginal  tooth.  Mandibles 
elongated  and  narrow,  terminal  portion  incurved  and 
toothed  on  the  inner  edge.  Maxilla?  small.  First 
maxillipeds  slender  and  furnished  with  two  slightly- 
curved  terminal  claws  of  unequal  length ;  second 

*  For  a  more  detailed  synonymy  of  this  common  species  see  'North 
American  parasitic  Copepods,'  by  0.  B.  Wilson  (Caliginse).  'Proc.  U.  S. 
National  Museum/  vol.  xxviii,  p.  568  (1905). 


CALIGUS    KAl'AX.  49 

maxillipeds  moderately  stout.  Sternal  fork  con- 
spicuous, its  rami  narrow,  tolerably  elongated,  slightly 
divergent,  and  with  the  ends  blunt-pointed. 

The  first  three  pairs  of  thoracic  legs  short,  biramose, 
with  both  rami  three-jointed;  fourth  pair  one- 
branched,  basal  joint  elongated,  tolerably  stout,  and 
furnished  with  a  small  seta  on  the  upper  distal  angle  ; 
end  portion  narrow  and  consisting  of  two  subequal 
joints,  the  first  with  the  outer  distal  angle  slightly  pro- 
duced and  bearing  a  short  spiniform  seta,  the  other 
with  a  spiniform  seta  near  the  middle  of  the  outer 
margin  and  four  at  the  apex,  the  second  from  the 
inside  being  elongated,  slightly  curved  and  claw-like. 
The  fifth  pair  rudimentary,  each  consisting  of  a 
minute  plate  bearing  a  few  small  setae,  and  situated 
near  the  postero-lateral  angles  of  the  genital  segment. 

Length  about  5  to  6  mm.  Egg-strings  not  greatly 
elongated. 

Male. — The  male  is  smaller  than  the  female ;  the 
form  of  the  carapace  is  somewhat  similar  in  the  two 
sexes,  but  the  genital  segment  is  narrow  and  scarcely 
wider  than  the  preceding  one.  Abdomen  as  long  as 
the  genital  segment  and  composed  of  two  joints,  the 
end  joint  being  about  twice  as  long  as  the  other. 
Caudal  rami  as  in  the  female. 

The  antennas  and  second  maxillipeds  are  stouter 
than  those  of  the  female,  and  are  provided  with 
stronger  terminal  claws  ;  the  other  mouth-appendages 
and  the  thoracic  legs  are  similar  to  those  of  the 
female.  Length  about  4  to  5  mm. 

Halitat. — Found  parasitic  on  various  fishes,  but 
perhaps  most  frequently  on  Gadoids.  It  is  also  not 
uncommon  in  plankton  collections,  among  Calanoids 
and  other  free-swimming  organisms ;  both  males  and 
females  are  frequently  captured  in  this  way,  and  the 
latter  are  generally  without  egg- strings.  Owing  to  the 
wandering  habits  of  this  Galigus  there  is  scarcely 
a  fish  in  our  seas  on  which  it  may  not  at  one  time  or 
other  be  found. 

VOL.  i.  4 


50  BRITISH    PARASITIC    COPEPODA. 

Caligua  rapax  is  apparently  widely  distributed  in  the  North 
Sea  and  North  Atlantic,  and  is,  according  to  C.  B.  Wilson, 
"  the  most  common  species  of  the  genus  on  the  north-eastern 
coast  of  the  United  States,  having  been  taken  from  more  than 
twenty-five  different  kinds  of  fish  by  many  collectors  working 
in  the  interests  of  the  United  States  Fish  Commission " 
('  Proc.  U.S.  National  Museum/  vol.  xxviii,  p.  571). 

A  certain  amount  of  variation  occurs  in  the  size  of  different 
specimens  of  this  species,  and  also  in  the  proportional  dimen- 
sions of  the  different  parts.  The  colour  is  also  somewhat 
variable ;  it  seems  to  change  to  some  extent  with  the  colour 
of  the  fish. 

4.  Caligus  centrodonti  Baird. 
(Plate  V,  figs.  1-3 ;  Plate  XVIII,  figs.  1-3.) 

1850.  Caligus  centrodonti  Baird.     (4)  p.  272,  pi.  xxxii,  figs.  6,  7. 
1863.  Caligus  abbreviatus  Kroyer.     (71)  p.  61,  pi.  iii,  figs.  3  a-h. 
1905.  Caligus  abbreviatus  T.  Scott.     (116)  p.  109,  pi.  v,  figs.  1-6. 
1905.  Caligus  centrodonti  C.  B.  Wilson.     (145)  p.  652,  pi.  xxvii,  figs. 
333,  344. 

Female. — Length  of  carapace  about  equal  to  the  width, 
and  to  two-thirds  of  the  entire  length  of  the  animal, 
widest  posteriorly,  and  becoming  considerably  narrower 
towards  the  front.  Frontal  plates  large,  lunulae  pro- 
minent. Free  thoracic  segment  very  short.  Genital 
segment  short  and  subquadrangular  in  outline,  the 
width  equal  to  about  one  and  a  half  times  the  length, 
and  fully  half  as  wide  as  the  carapace  ;  greatest  width 
near  the  anterior  end ;  lateral  margins  obliquely 
rounded,  posterior  margin  slightly  concave.  Abdomen 
very  short,  small,  uniarticulate,  and  scarcely  reaching 
beyond  the  lateral  lobes  of  the  genital  segment. 
Caudal  rami  also  very  short,  with  four  or  five  short 
setae  round  their  distal  ends.  Antennules  moderately 
short.  Sternal  fork  stout,  with  tolerably  stout  and 
slightly  divergent  rami.  Maxilla3  and  maxillipeds  and 
also  the  first  three  pairs  of  thoracic  legs  resembling 
those  of  the  species  already  described;  the  fourth 
pair  elongated,  the  basal  joint  moderately  stout  and 
furnished  with  a  lobulate  process  on  its  upper  aspect; 
the  single  two-jointed  ramus  somewhat  slender;  the 


CAL1GUS    CENTRODONTI.  51 

proximal  joint  of  the  ramus  short  and  scarcely  half  the 
length  of  the  other,  and  bearing  a  tolerably  long  straight 
spine  on  its  outer  distal  angle ;  the  end  joint  narrow 
and  provided  with  three  terminal  spines,  the  outer- 
most similar  to  that  on  the  preceding  joint,  the  middle 
one  slender  and  nearly  as  long  as  the  joint,  and  ter- 
minating in  a  curved  claw-like  extremity,  the  inner- 
most spine,  a  small  one,  appearing  to  be  merely  a 
prolongation  of  the  inner  distal  angle  of  the  joint. 
Fifth  pair  nearly  obsolete.  Egg-strings  tolerably  stout 
but  not  very  elongated.  Length  about  4  mm. 

Male. — The  male  is  somewhat  similar  to  the  female 
but  larger.  A  specimen  examined  by  us,  which  was 
found  to  be  a  male — not  a  female  as  stated  in  the 
Fishery  Board's  Report — measured  five  millimetres  in 
total  length.  The  carapace  was  suborbicular  and 
distinctly  larger  in  proportion  to  the  total  length, 
while  the  genital  segment  was  much  smaller  than  in  the 
female,  and  the  posterior  margin  of  this  segment  was 
also  more  deeply  concave,  so  much  so  that  the  postero- 
lateral  angles  reached  beyond,  and  enclosed  the  very 
short  abdomen.  The  caudal  rami  were  also  very  short. 

Antennules  and  frontal  plates  tolerably  large. 
Second  maxillipeds  large,  with  the  end-joint  con- 
siderably expanded  and  provided  with  a  strong,  hinged, 
terminal  claw,  so  as  to  form  powerful  grasping  organs 
as  shown  in  the  drawing  (PL  XVIII,  fig.  2). 

Habitat. — Parasitic  on  the  tail  and  fins  of  the  sea- 
bream,  Pagellus  cent-rod  ontus,  and  of  the  ballan  wrasse, 
Labrus  bergylta.  Dublin,  1837,  on  Pagellus  centro- 
dontus  (Baird).  Plymouth,  on  Pagellus  centrodontn* 
(Bassett- Smith).  Moray  Firth,  on  Labrus  bergi/Jtn 
(T.  Scott). 

There  can  be  no  doubt  that  the  species  described  by 
Kroyer  in  1863  under  the  name  of  Caligus  abbreviate  is 
identical  with  Baird's  C.  centrodonti.  The  peculiar  form  of 
the  genital  segment,  the  very  short  abdomen  and  caudal 
rami,  together  with  the  structure  and  armature  of  the  fourth 
pair  of  thoracic  legs,  establish  the  identity  of  the  two  forms. 


52  BRITISH    PARASITIC    COPE  POD  A. 

In  Charles  Branch  Wilson's  figure  of  the  fourth  pair  of  legs 
all  the  three  spines  with  which  the  end  joint  is  furnished 
spring  from  the  apex,  whereas  in  our  specimen  the  outer 
spine  springs  from  a  notch  on  the  outer  margin  a  short 
distance  from  the  apex. 

A  young  specimen  representing  the  chalimus  stage  of  this 
Caligus  (PI.  V,  fig.  3)  was  obtained  along  with  the  adult. 
The  siphon  is  still  present  showing  a  dilated,  two-jointed 
base ;  the  carapace  is  elongate-ovate  in  outline,  the  free 
thoracic  segment  is  concealed,  and  the  abdomen  is  very  short. 
The  frontal  plates  also  slope  backwards  at  a  considerable 
angle. 

The  distribution  of  Caligus  centrodonti,  so  far  as  known, 
appears  to  be  somewhat  limited.  The  only  record,  other  than 
those  for  the  British  Islands,  is  that  of  Kroyer.  The  speci- 
men recorded  by  him  as  Caligus  abbreviatus  was  obtained  on 
a  Labrus  bergylta  at  Bergen  in  1839.  The  species  is  de- 
scribed in  C.  B.  Wilson's  work  on  'North  American  parasitic 
Copepods/  but  the  specimens,  which  were  taken  in  the  gill- 
cavity  of  Pagellus  centrodontus,  were  sent  from  England  by 
the  Rev.  A.  M.  Norman. 

5.  Caligus  gurnard!  Kroyer. 
(Plate  VIII,  figs.  1,  2.) 

1863.  Caligus  yurnardi  Kroyer.  (71)  ser.  3,  vol.  ii,  p.  150,  pi.  ii,  figs. 
3  a-g. 

1896.  Caligus  gurnardi  Bassett-Smith.     (7)  p.  157. 

Female. — Carapace  equal  to  about  three-fifths  of  the 
total  length,  and  rather  longer  than  broad;  frontal 
plates  only  slightly  arcuate,  lunulse  rather  small. 
Free  thoracic  segment  distinct,  small;  genital  segment 
obcordate,  about  half  as  long  as  the  carapace,  its 
greatest  width  about  equal  to  the  length,  posterior 
margin  subtruncated.  Abdomen  short,  uniarticulate, 
length  scarcely  equal  to  twice  the  width.  Caudal 
rami  short. 

Antennules  of  moderate  size,  the  end  joint  narrow 
and  about  as. long  as  the  proximal  one.  Sternal  fork 
tolerably  large  with  moderately  long  and  somewhat 
divergent  branches.  Fourth  pair  of  thoracic  legs 
elongated  with  the  ramus  biarticulate.  Length  6-7 mm. 


CALIGUS    GUKNAKDI.  53 

MH! >'. — The  male  is  somewhat  similar  to  the  female 
in  general  appearance  but  the  genital  segment  is  much 
smaller,  its  width  being  scarcely  a  third  of  the  width 
of  the  carapace ;  the  segment  is  also  not  much  longer 
than  broad.  The  abdomen  is  composed  of  two  joints, 
and  the  end  joint  is  much  shorter  than  the  proximal 
one.  The  cephalothoracic  appendages  appear  to  be 
similar  to  those  of  the  female  except  that  the  second 
maxillipeds  are  rather  stronger,  and  the  fourth  pair  of 
thoracic  legs  of  proportionally  greater  length. 

Habitat. — Parasitic  on  Trinla  spp.,  usually  lodged  in 
the  gill-cavity.  Found  at  Falmouth  in  1884  (A.  M. 
Norman).  Plymouth  on  Trinla  cuculux  (Bassett- Smith). 
Kroyer  obtained  this  species  on  Trigla  gurnardus. 

We  have  not  seen  this  species,  but  it  appears  to  have  an 
extensive  distribution ;  besides  being  recorded  from  the 
Norwegian  and  British  seas,  C.  B.  Wilson  mentions  its  occur- 
rence on  fishes  captured  on  the  coast  of  California,  viz.  on  a 
king  salmon  taken  at  Monterey  and  on  an  elephant  fish  at 
La  Tolla  * 

6.  Caligus  labracis  T.  Scott. 
(Plate  V,  figs.  4,  5 ;  Plate  XVIII,  figs.  4,  5.) 

1902.  Caligus  labracis  T.  Scatt.     (114)  p.  291,  pi.  xiii,  figs.  26-29. 
1904.  Caligus  labracis  A.  Scott.     (109)  p.  38. 

Female. — Carapace  suborbicular,  length  and  width 
about  equal,  lateral  margins  evenly  rounded,  frontal 
plates  large,  lunulse  prominent.  Free  thoracic  segment 
subquadraiigular,  considerably  shorter  than  the  cara- 
pace, and  a  little  more  than  one  fifth  of  the  total 
length;  the  width  of  the  segment  exceeding  the  length 
by  about  one  fourth.  Abdomen  short,  uniarticulate, 
and  about  one  half  as  long  as  the  genital  segment. 
Caudal  rami  very  short. 

Antennules  short.  Mouth-appendages  somewhat 
similar  to  those  of  Caligus  diuplianus  Nordmann. 
Sternal  fork  stout,  with  tolerably  broad  and  slightly 

*  '  North  American  parasitic  Copepods  :  A  list  of  those  found  upon  the 
fishes  of  the  Pacific  coast,'  etc.  '  Proc.  U.  S.  National  Museum/  vol.  xxxv, 
p.  439  (1908). 


54  BRITISH    PARASITIC   COPEPODA. 

divergent  branches,  which  have  their  ends  obliquely 
truncated.  Fourth  pair  of  thoracic  legs  small,  basal 
joint  tolerably  stout ;  ramus  short,  two-jointed,  and 
armed  with  sabre-like  spines,  the  first  joint  with  one 
on  the  outer  distal  angle,  and  the  second  with  two  at 
the  apex,  the  spines  moderately  elongated,  those  at 
the  apex  being  longer  than  the  joint  from  which  they 
spring,  also  with  a  minute  tooth  on  the  inner  distal 
angle.  The  fifth  pair  consisting  each  of  a  minute 
setiferous  plate  on  the  postero-lateral  angle  of  the 
genital  segment.  Egg-strings  short,  containing  a 
comparatively  small  number  of  tolerably  large  ova. 
Length  about  3*5  mm. 

Male. — The  male  is  smaller  than  the  female,  being 
only  about  2'6  mm.  in  total  length.  It  does  not  differ 
greatly  from  the  female  except  that,  as  usual,  the 
second  maxillipeds  are  larger  and  the  genital  segment 
is  much  smaller.  Colour  reddish-brown,  broken  up 
into  minute  patches  of  a  lighter  and  darker  coloration. 

Habitat. — Parasitic  on  the  gills  of  a  striped  wrasse, 
Labrus  mixtus  L.,  captured  in  the  Firth  of  Clyde  in 
January  1900,  and  sent  to  the  Laboratory  of  the 
Fishery  Board  for  Scotland  at  Aberdeen  by  Mr. 
Robert  Duthie,  the  Fishery  Officer  at  Girvan.  Also 
found  on  the  gills  of  Labrus  mixtus  and  Labrus  macu- 
latus  captured  in  the  Irish  Sea  (A.  Scott}. 

7.  Caligus  zei  Norman  and  T.  Scott. 
(Plate  VII,  fig.  1  ;  Plate  VIII,  figs.  3-9.) 

1906.  Caligus  zei  Norman  &  T.  Scott.     (88)  p.  206,  pi.  xxii,  figs.  1-8. 

1907.  Caligus  zei  A.  Scott.     (Ill)  p.  93,  pi.  i. 

Female. — Carapace  suborbicular,  length  and  breadth 
nearly  equal,  margins  only  slightly  arcuate.  Frontal 
plates  and  lunulge  of  moderate  size.  Free  thoracic 
segment  about  as  long  as  broad,  rather  small.  Genital 
segment  subquadrate  and  equal  to  about  a  third  of 
the  entire  length  of  the  animal ;  length  and  width 
nearly  equal,  and  the  postero-lateral  angles,  which  are 


CALIGUS   ZEI.  55 

rounded,  slightly  produced  so  that  the  posterior  margin 
between  the  rounded  angles  is  more  or  less  incurved. 
Abdomen  short  and  uniarticulate.  Caudal  rami  small. 

Antennules  rather  longer  than  usual,  the  second 
joint  being  about  five  times  longer  than  broad  and 
much  longer  than  the  first  joint.  Antennae  sharply 
hook-formed.  First  maxillipeds  elongated  and  slender, 
the  second  joint  long  and  narrow,  and  furnished  with 
two  tolerably  long  spiniform  and  claw -like  setae,  the 
outer  one  being  rather  longer  than  the  inner.  The 
second  maxillipeds  moderately  large ;  the  basal  joint 
stout  but  the  end  one  short  and  narrow,  and  armed 
with  a  tolerably  stout  terminal  claw.  Sternal  fork 
small,  with  moderately  long  and  slightly  tapering 
branches  which  are  also  somewhat  divergent.  The 
fourth  pair  of  thoracic  legs  moderately  elongated ; 
basal  joint  narrow  and  about  as  long  as  the  two- 
jointed  ramus  ;  the  joints  of  the  ramusof  nearly  equal 
length,  the  proximal  joint  provided  with  a  stout  spine 
on  the  outer  distal  angle,  but  the  end  joint  with  four 
spines,  one  near  the  middle  of  the  outer  margin,  and 
three  at  the  apex,  the  middle  one  rather  longer  than 
the  one  on  either  side.  The  fifth  pair,  which  are  very 
small,  situated  near  the  postero-lateral  corners  of  the 
genital  segment.  Length  about  5*5  mm. 

Male. — The  genital  segment  in  the  male  is  as  usual 
considerably  smaller  than  in  the  female  ;  it  is  narrow 
and  scarcely  twice  the  width  of  the  abdomen.  The 
abdomen,  which  is  longer  than  in  the  female,  is  com- 
posed of  two  segments,  the  first  being  rather  shorter 
than  the  second.  The  thoracic  and  other  appendages 
are  somewhat  similar  to  those  of  the  female  except 
that  the  second  maxillipeds  are  stronger. 

Habitat.  -  -  Taken  forty  years  ago  on  the  dory, 
Zeus  faber,  at  Polperro  by  Laughrin,  and  sent  by 
him  to  A.  M.  Norman.*  Several  specimens  were 
found  attached  to  the  skin  of  a  Zeus  faber  captured  off 

*  '  Crustacea  of  Devon  and  Cornwall,'  by  the  Rev.  A.  M.  Norman  and  T. 
Scott,  p.  207  (1906). 


56  BRITISH    PARASITIC    COPEPODA. 

New  Quay  Head  on  10th  June  1906;  also  on  speci- 
mens of  the  same  fish  captured  off  Puffin  Island  in 
1908  ;  on  /rnx  fnl»'r  taken  in  Luce  Bay,  September 
1911  (A.  Scott}.' 

This  species  m;iy  be  distinguished  from  those  closely  allied 
to  it  by  the  unusual  length  of  the  second  joint  of  the  anten- 
nules,  by  the  form  of  the  sternal  fork,  and  by  the  structure 
and  armature  of  the  fourth  pair  of  thoracic  legs. 

8.  Caligus  brevicaudatus  A.  Scott. 

(Plate  VI,  ficr.  3  ;  Plate  VIII,  figs.  10,  11  ;  Plate 
XLVIII,  fig.  6.) 

1901.  Caligus  brevicaudatus  A.  Scott,     (107)  p.  349,  pi.  ii,  figs.  7-10. 

Female. — Carapace  suborbicular,  rather  wider  pos- 
teriorly than  in  front,  and  equal  to  fully  half  of  the 
entire  length  of  the  animal.  Frontal  plates  large  and 
slightly  arcuate ;  lunulse  prominent.  Free  thoracic 
segment  short  and  narrow.  Genital  segment  oblong  in 
outline,  rather  longer  than  broad,  and  equal  to  about 
half  the  width  of  the  carapace.  Abdomen  very  short 
and  uniarticulate.  Caudal  rami  also  very  short,  and 
furnished  with  a  few  plumose  setae. 

Antennules  moderately  stout,  end  joint  rather  shorter 
than  the  basal  one.  Sternal  fork  moderately  stout, 
and  with  the  rami  also  stout  and  scarcely  divergent, 
and  rounded  at  the  tips.  Second  maxillipeds  tolerably 
elongated,  and  slender,  with  somewhat  feeble  terminal 
claws.  Fourth  pair  of  thoracic  legs  small,  and  com- 
posed of  three  joints ;  basal  joint  tolerably  stout,  ramus 
slender  and  rather  longer  than  the  basal  joint ;  the 
terminal  joint  also  rather  longer  than  the  preceding 
one ;  a  small  spiniform  seta  springing  from  the 
extremity  of  the  basal  joint  on  its  upper  aspect,  and 
the  first  joint  of  the  ramus  provided  with  a  similar 
seta  on  its  outer  distal  angle ;  the  end  joint  with  three 
apical  setas  which  differ  considerably  in  length,  the 
inner  one  being  about  as  long  as  the  joint  from  which 
it  springs,  the  outer  scarcely  half  as  long,  the  middle 


CAL1GUS    BREYICAUDATUS.  57 

one  intermediate  in    length  to    the   others.      Length 
about  5*3  mm. 

Habitat. — Parasitic  on  Tritjla  fjurnordus  and  Trigla 
lucerna.  Found  adhering  to  the  inside  of  the  mouth 

O 

of  a   grey  gurnard  captured  in    the  vicinity  of  Piel, 
Barrow-in-Furness,  in  August  lyOl.     Found  also  on 
the  inside  of   the   gill-covers  of  sapphirine  gurnards 
taken  in  Luce  Bay  in  October  1910  (A.  Scott}. 
No  males  have  been  observed. 

This  species  resembles  Caligus  curtus  in  general  appear- 
ance, but  differs  in  the  form  of  the  genital  segment,  in  the 
very  short  abdomen  and  caudal  rami,  and  in  the  structure 
and  armature  of  the  fourth  pair  of  thoracic  legs. 

9.  Caligus  pelamydis  Kroyer. 

(Plate  VII,  figs.  2,  3  ;  Plate  IX,  figs.  1-5  ;  Plate 
LXXI,  fig.  14.) 

1863.  Caligus  pelamydis  Kroyei*.  (71)  p.  50,  pi.  iv,  fig.  4  a-g. 
1896.  Caligus  scomberi  Bassett-Smith.  (6)  p.  11,  pi.  iii,  fig.  2. 
1901.  Caligus  scomberi  T.  Scott.  (113)  p.  148,  pi.  v,  figs.  9, 10. 

1905.  Caligus  pelamydis  C.  B.  Wilson.      (145)  p.  594,  pi.   xiii.   figs. 
154-161;  pi.  xiv,  fig.  116«. 

1906.  Caligus  scomberi  A.  Scott.     (110)  p.  52,  pi.  vi. 
1906.  Caligus  pelamydis  Norman  &  T.  Scott.     (88)  p.  206. 
1910.  Caligus  pelamydis  T.  R.  R.  Stebbing.     (125)  p.  558. 

Female. — Carapace  suborbicular,  length  and  width 
about  equal  and  rather  more  than  one-third  the  total 
length  of  the  animal,  lateral  margins  slightly  arcuate ; 
frontal  plates  tolerably  large,  lunulae  also  of  moderate 
size  but  not  very  prominent.  Free  thoracic  segment 
short,  narrow,  somewhat  dilated.  Genital  segment 
ovate,  equal  to  fully  two- thirds  the  length  of  the 
carapace,  lateral  margins  nearly  straight  distally,  but 
rounded  and  converging  towards  the  anterior  end, 
posterior  margin  truncated,  postero-lateral  angles 
rounded.  Abdomen  narrow,  about  as  long  as  the 
genital  segment,  indistinctly  biarticulated,  end  joint 
short  and  rather  narrower  than  the  elongated  proximal 
one.  Caudal  rami  short  and  provided  with  several 
short  plumose  setas. 


58  BRITISH    PARASITIC    COPEPODA. 

Antennules  moderately  stout ;  sternal  fork  rather 
small,  narrow,  and  elongated,  rami  not  divergent  or 
but  very  slightly  so.  Fourth  pair  of  thoracic  legs 
stout,  comparatively  short,  basal  joint  about  as  long  as 
the  ramus,  which  is  composed  of  three  short  and 
moderately  stout  joints,  the  first  being  the  largest, 
and  having  the  outer  distal  angle  produced  so  as  to 
reach  to  near  the  end  of  the  second  joint,  the  first  and 
second  joints  each  provided  with  a  moderately  stout 
spiniform  seta  on  the  outer  distal  angle,  the  third  joint 
of  a  triangular  form  and  carrying  three  spiniform 
setae,  the  end  one  being  rather  stouter  than  the  others ; 
the  apex  of  the  joint  is  produced  slightly  beyond 
the  base  of  the  end  spine,  forming  a  blunt-pointed 
knob  fringed  with  minute  setae.  From  the  peculiar 
form  of  the  first  and  third  joints  the  marginal  and 
terminal  setae  are  crowded  together,  and  as  each  seta 
is  slightly  longer  than  the  preceding  one,  they  impart 
a  character  to  this  species  somewhat  different  from 
others,  such  as  Calif/nx  i-«p<ix.  Fifth  pair  very  minute. 
Egg-strings  tolerably  elongated. 

This  species  appears  to  vary  in  length  :  the  speci- 
men figured  here  measured  about  5*5  mm.,  and 
C.  B.  Wilson  gives  the  length  of  his  specimens  as 
3*3  mm. 

Male. — The  male  of  this  Cali(jn**  does  not  appear  to 
have  been  previously  met  with,  and  we  are  inclined  to 
consider  that  it  is  much  rarer  than  the  female.  The 
specimen  of  the  male  figured  on  PI.  LXXI,  fig.  14,  is 
the  first  and  only  one  we  have  yet  secured.  It  repre- 
sents the  result  of  the  examination  of  nearly  fifteen 
hundred  mackerel.  The  specimen  figured  was  found 
on  the  inside  of  the  operculum  of  a  mackerel  caught 
in  the  northern  part  of  the  Irish  Sea  in  July  1912. 
On  that  particular  occasion  two  hundred  fish  were 
examined,  and  although  several  females  \ver<>  found 
only  a  single  male  could  be  detected.  r,///V///x 
•pelamydis  resembles  the  male  of  Caligus  rd/Hiv  in 
general  appearance,  and  without  careful  examination 


CALIGUS  PELAMYDIS.  59 

it  might  be  readily  passed  over  for  that  species.  The 
abdomen  is  two-jointed  and  slightly  shorter  than  the 
genital  segment.  The  first  joint  is  comparatively  short 
and  about  equal  to  half  the  length  of  the  second  joint. 
The  furcal  joints  are  short  and  broad  and  nearly  as 
long  as  the  first  abdominal  segment.  The  specimen 
was  not  dissected,  but  so  far  as  could  be  made  out 
from  the  examination  of  the  entire  animal  the  various 
appendages  are  almost  identical  with  those  of  the 
female.  The  fourth  pair  of  feet  of  the  female,  which 
are  quite  distinct  from  those  of  any  of  the  other 
members  of  the  genus,  form  a  quite  reliable  distin- 
guishing character.  The  fourth  pair  of  feet  of  the 
male  now  illustrated  are  identical  with  those  of  the 
female.  The  living  male  Avas  dark  red  in  colour,  and 
it  was  easily  detected  running  over  the  inner  surface 
of  the  operculum  of  its  host.  Length  2'9  mm. 

Habitat. — Parasitic  on  the  belted  bonito,  Pelamys 
sarda,  and  the  mackerel,  Scomber  scombrus.  Plymouth, 
on  the  inside  of  the  gill-covers  of  mackerel  (Bassett- 
Smith).  Aberdeen  (T.  Scott).  Irish  Sea  (A.  Scott). 
Kroyer's  specimens  were  obtained  on  Pelamys  sarda. 

Distribution. — Caligns  pelamydis  has  apparently  a 
wide  distribution  in  the  seas  of  Europe.  C.  B. 
Wilson  describes  this  species  in  his  work  on  '  North 
American  parasitic  Copepods,'  and  mentions  the  name 
of  its  host,  but  does  not  state  if  the  fish  was  captured 
in  American  waters.* 

We  think  there  can  be  no  reasonable  doubt  that  the  form 
obtained  by  Kroyer  on  Pelamys  sarda,  and  described  by  him 
in  the  work  referred  to  under  the  name  of  Caligus 
pelamydis,  is  identical  with  that  from  the  mackerel;  the 
general  structure  of  the  animal,  the  shape  of  the  sternal  fork 
and  of  the  genital  segment,  and  the  structure  and  armature 
of  the  fourth  pair  of  thoracic  legs,  are  similar  in  both  forms. 

*  See  Part  I  (The  Caliginse),  p.  594. 


60  BRITISH    PARASITIC    COPEPODA. 

10.  Caligus  diaphanus  Nordmann. 

(Plate  XVII,  fig.  1  ;  Plate  XVIII,  figs.  6,  7  ;  Plate 
XL VIII,  fig.  7.) 

1832.  Caligus  diaphanus  Nordmann.  (89)  pt.  2,  p.  26  (non  C.  dia- 
phanus, Baird). 

1863.  Caligtts  diaphanus  Kroyer.      (71)  p.  79,  pi.  vii,  fig.  5  a-c. 

1894.  Caligus  isonyx  T.  Scott.  (Ilia)  12th  Kept.  Fishery  Board  for 
Scotland,  pt.  iii,  p.  194. 

189H.  CaligiiK  diaphanus  Bassett-Smitli.     (6)  p.  156. 

1900.  Caligus  diaplianus  T.  Scott.     (112)  p.  149,  pi.  v,  figs.  20-25. 

1904.  Caligus  dinphanus  A.  Scott.     (109)  p.  38. 

1906.  Caligus  diaphanus  Norman  &  T.  Scott.     (88)  p.  206. 

Fern M 'ilc. — Carapace  suborbicular  and  equal  to  about 
two-fifths  of  the  entire  length  of  the  animal,  and  the 
width  rather  greater  than  the  length.  Frontal  plates 
large,  anterior  margin  slightly  emarginate,-  lunulas 
rather  small,  partly  concealed.  The  free  thoracic 
segment  short  and  narrow ;  genital  segment  sub- 
cordate  and  equal  to  about  two-thirds  of  the  length  of 
the  carapace,  truncated  posteriorly,  and  the  postero- 
lateral  corners  bluntly  rounded.  Abdomen  composed 
of  two  joints,  and  nearly  as  long  as  the  genital 
segment,  the  end  joint  small.  Caudal  rami  small. 

Antennules  of  moderate  size.  Mandibles  slender, 
elongated,  with  the  end  joint  incurved  and  distinctly 
serrated  on  the  inner  margin.  The  fourth  pair  of 
thoracic  legs  short  and  stout,  the  ramus,  which  is 
composed  of  three  short  joints,  has  both  the  first  and 
second  joints  provided  with  a  stout  seta  of  moderate 
size  on  the  outer  distal  angle,  while  the  end  joint  has 
three  similar  apical  setae  ;  all  the  seta3  plumose  and  of 
nearly  equal  size,  except  that  the  inner  one  is  rather 
longer  than  the  others.  Fifth  pair  minute,  and,  as  in 
the  case  of  other  species,  occurring  as  minute  setiferous 
plates  near  the  postero-lateral  corners  of  the  genital 
segment.  Length  about  4' 5  mm. 

Male. — The  carapace  of  the  male  is  rather  wider  in 
proportion  to  its  length ;  the  genital  segment  is  small 
and  scarcely  twice  the  width  of  the  abdomen,  it 
becomes  narrower  towards  the  proximal  end,  and  the 
postero-lateral  corners  are  somewhat  angular.  The 


CALIGUS    DIAPHAXUS.  61 

abdomen  is  composed  of  two  subequal,  angular 
segments,  and  is  only  equal  to  about  one-sixth  of  the 
entire  length. 

Habitat. — Parasitic  on  various  species  of  gurnards 
(Trigla).  Belfast  (IF.  Thompson],  Found  on  the  inner 
surface  of  the  operculum  of  Trivia  him u  do  and  Trigla 
niculus  at  Plymouth  (Bassett- Smith).  On  Trit/li  spp., 
Firths  of  Forth  and  Clyde  (T.  Scott).  Irish  Sea 
(A.  Scott). 

The  species  is  apparently  not  uncommon,  but  we  have 
only  met  with  it  on  gurnards. 

Genus  5.  PSEUDOCALIGUS  A.  Scott,  1901. 

Carapace  large  and  scutiform ;  frontal  plates 
moderately  prominent,  and  provided  with  lunulae. 
Genital  segment  and  abdomen  as  in  Galiyus.  Cephalo- 
thoracic  appendages  also  similar  to  those  of  C aligns, 
except  that  the  fourth  pair  of  thoracic  legs  are  some- 
what rudimentary,  and  consist  each  of  a  single  small 
joint,  furnished  with  a  few  minute  terminal  bristles. 

This  genus  has,  in  its  general  appearance,  a  close 
resemblance  to  C  aligns. 

1.  Pseudocaligus  brevipedes  (Bassett-Smith). 
(Plate  IX,  figs.  6-9;  Plate  X,  figs.  1,  2.) 

1896.  Caligus  brevipedes  Bassett-Smitb.     (6)  p.  11,  pi.  iii,  fig.  1. 

1901.  Pseudocaligus  brevipedes  A.  Scott.     (107)  p.  350,  pi.  ii,  figs.  1-6. 

1902.  Pseudocaligus  brevipedes  T.  Scott.     (114)  p.  291. 

1906.  Pseudocaligus  brevipedes  Norman  &  T.  Scott.     (88)  p.  2u7. 

Female. — Carapace  suborbicular,  about  as  long  as 
broad,  and  equal  to  rather  more  than  half  the  entire 
length  of  the  animal.  Frontal  plates  well  developed, 
lunulae  of  moderate  size.  Free  thoracic  segment  small. 
Genital  segment  subquadrangular,  and  about  half  as 
long  as  the  carapace,  the  length  rather  less  than  the 
width,  and  the  lateral  margins  nearly  straight,  the  pos- 
terior end  also  subtruncated,  and  the  postero-lateral 
corners  bluntly  rounded.  Abdomen  consisting  of  a 


62  BRITISH    PARASITIC    COPEPODA. 

single  joint,  somewhat  longer  than  broad,  and  scarcely 
equal  to  one-third  of  the  length  of  the  genital  segment. 
Caudal  rami  of  moderate  size. 

Antennules  tolerably  stout,  and  composed  of  two 
subequal  joints.  Antenna3  with  the  end  joint  in  the 
form  of  a  strongly-hooked  claw.  Sternal  fork  small 
with  tolerably  short  and  slender  rami  which  are 
moderately  curved  and  somewhat  divergent.  The 
fourth  pair  of  thoracic  legs  consisting  each  of  a  single 
joint,  small  and  rudimentary  and  furnished  with  three 
spiniform  setae,  two  of  them  short  and  subequal,  and 
the  other  tolerably  elongated  and  plumose.  The  fifth 
pair  in  the  form  of  minute  setiferous  plates  near  the 
postero-lateral  corners  of  the  genital  segment.  Length 
about  3*6  mm. 

Male. — The  male  is  rather  smaller  than  the  female, 
and  differs  from  it  chiefly  by  the  small  size  of  the 
genital  segment.  The  carapace  is  also  rather  wider  in 
proportion  to  the  length,  while  the  second  maxillipeds 
are  larger  and  form  more  powerful  grasping  organs. 

Habitat. — Parasitic  on  the  three-bearded  rockling, 
Onos  (Motella)  tricirrata  Brun.,  and  usually  found 
adhering  to  the  inner  surface  of  the  gill-covers. 
Plymouth  (Bassett- Smith).  Irish  Sea,  Barrow  Channel, 
and  at  Port  Erin,  Isle  of  Man  (A.  Scott).  Dunbar,  at 
the  month  of  the  Forth  estuary,  and  near  Aberdeen 
(T.  Scott). 

This  species  is  easily  distinguished  by  the  rudimentary 
character  of  the  fourth  pair  of  thoracic  legs  in  both  sexes. 
From  the  records  of  the  species  published  hitherto  it  seems 
probable  that  the  distribution  of  the  Pseudocaligus  will  he 
coextensive  with  that  of  the  fish  mentioned. 

Genus   6.  SCI^ENOPHILUS  P.  J.  van  Beneden,  1852. 

Carapace  somewhat  similar  to  that  of  Cali<jn*. 
Frontal  plates  distinct  and  provided  with  lunulse. 
Free  thoracic  segment  small.  Genital  segment  narrow 
and  considerably  elongated.  Abdomen  slender  and 
of  great  length.  Caudal  rami  short.  Mouth  append- 


SCLENOPHILUS.  63 

ages  somewhat  as  in  C  (dig  us,  but  the  second  maxilli- 
peds  very  large.  Sternal  fork  absent.  Thoracic  legs 
nearly  as  in 


1.  Scisenophilus  tenuis  P.  J.  van  Beneden. 
(Plate  XI,  figs.  1-6.) 

1852.  Scienophilus  tennis,  P.  J.  van  Beneden.     (13)  p.  46i,  and  plate. 
1861.  Scienophilus  tenuis  idem.     (15)  p.  148,  fig.  21.  • 
1896.  Scixnophilus  tenuis  Bassett-Smith.     (6)  p.  156. 
1906.  Sciienophilus  tenuis  Norman  &  T.  Scott.     (88)  p.  207. 

Female.  —  Carapace  small,  suborbicular,  length  and 
width  about  equal.  Frontal  plates  distinct,  lunulge 
small.  Free  thoracic  segment  small  ;  genital  segment 
elongated  and  narrow,  but  increasing  in  width  gradu- 
ally though  slightly  towards  the  posterior  extremity, 
the  greatest  width  being  equal  to  about  one  fourth  of 
the  length,  and  the  length  equal  to  about  three  times 
the  length  of  the  carapace,  the  distal  end  slightly 
emarginate  and  the  postero-lateral  corners  bluntly 
rounded.  Abdomen  extremely  long  and  slender,  fully 
twice  the  length  of  the  genital  segment  and  about  as 
long  as,  and  not  much  thicker  than,  the  egg-strings. 
Caudal  rami  short,  and  provided  with  four  to  six 
apical  seta3. 

Antennules  small,  two-jointed,  and  similar  to  those 
of  Coliffus  ;  mouth  -appendages  also  similar.  The 
second  maxillipeds  stout  and  elongated,  and  armed 
with  strong  curved  terminal  claws.  The  first  pair  of 
thoracic  legs  slender,  and  bearing  at  their  distal  end 
three  strong  and  curved  setiferous  spines;  only  the 
second  pair  of  legs  distinctly  biramose.  The  fourth 
pair  elongated  and  uniramose,  and  consisting  each  of 
two  tolerably  long  joints,  the  terminal  one  being  fur- 
nished with  a  few  marginal  and  apical  setas.  Total 
length  about  14  mm.  (fully  half  an  inch). 

\\  e  have  not  seen  the  male  of  this  species. 

Habitat.  —  Parasitic  in  the  branchial  chamber  of  the 
maigre,  Scisena  m/nila  (or  Scitena  -umbra),  Plymouth 
(Bassett-  Smith). 


64  BRITISH    PARASITIC   COPEPODA. 

Dr.  Bassett-Smith  obtained  four  specimens  of  this  curious 
parasite  on  the  inside  of  the  operculum  of  a  maigre  captured 
at  Plymouth.  Though  this  is  the  only  British  record  of 
Scifenophilus  we  know  of,  Professor  P.  J.  van  Beneden  states 
that  the  species  is  vei\y  common  on  the  maigre,  and  he  has 
seen  such  a  great  number  of  specimens  ci-owded  together  that 
they  resembled  tufts  of  moss  ("  formant  des  touffes  semblables 
a  une  mousse  ") .  This  fish  is  not  common  in  the  British 
seas,  and,  according  to  Aflalo,  is  taken  only  casually  in  the 
mackerel  nets,  and  this  probably  is  the  reason  why  such  a 
common  parasite  as  this  appears  to  be  has  not  been  more 
frequently  recorded. 

Scisenophilus  tenuis,  so  named  from  its  narrow  and  elon- 
gated form,  has  at  first  sight  a  close  resemblance  to  a  Hat- 
schekia  (Clavella),  but  the  form  and  structure  of  the  carapace 
reveal  at  once  its  near  relationship  with  Caligus. 

Genus  7.  LEPEOPHTHEIRUS  Nordma,nn,  1832. 

Free  thoracic  segment  without  dorsal  plates.  Genital 
segment  simple.  Abdomen  one-  or  two-segmented. 

Mandibles  serrated  only  on  the  inner  edge.  Second 
maxillae  small,  furcate,  the  branches  acuminate,  not 
simple  and  spine-like  as  in  Caligus.  Fourth  pair  of 
thoracic  legs  and  other  thoracic  appendages  as  in 
Caligus. 

Both  the  females  and  the  males  have  a  general 
resemblance  to  those  of  Caligus,  but  the  frontal  plates 
are  without  lunulae. 

1.  Lepeophtheirus  pectoralis  (0.  F.  Midler). 

(Plate  X,  figs.  3-4  ;  Plate  XII,  figs.  2-3;  Plates  XIII, 
XIV,  XV;  and  Plate  XVI,  figs.  1-3.) 

1777.  Lermea  pectoralis  O.  F.  Miiller.  (85)  Zool.  Danica,  p.  41,  pi. 
xxxiii,  fig.  7. 

1838.  Caligus  pectoralis  Kroyer.     (70)  (ii),  p.  8,  pi.  vi,  fig.  4. 

1832.  Lepeophtheirus  pectoralis  Nordmann.     (89)  p.  30. 

1847.  Caligus  pectoralis  Thompson  (129),  p.  21-7. 

1850.  Lepeophtheirus  pectoralis  Baird.     (4)  p.  275,  pi.  xxxii,  fig.  10. 

1900.  Lepeophtheirus  pectoralis  T.  Scott.  (112)  p.  150,  pi.  v,  figs. 
26-31. 

Female. — Carapace  suborbicular,  length  and  width 
nearly  the  same,  and  scarcely  equal  to  half  the  entire 


LEPEOPHTHEIRUS    PECTORALIS.  65 

length  of  the  animal.  Frontal  plates  of  moderate  size, 
lunulae  wanting.  Free  thoracic  segment  small.  Genital 
segment  subquadriform  and  equal  to  about  one-third 
of  the  entire  length  of  the  animal,  with  its  postero- 
lateral  angles  rounded.  Abdomen  short,  with  a  slight 
constriction  near  the  middle  which  in  certain  posi- 
tions gives  it  the  appearance  of  being  obscurely  two- 
segmented.  Caudal  rami  very  short. 

Antennules  of  moderate  size.  Antennae  armed  with 
strong,  terminal,  hooked  claws.  Mandibles  small, 
slender,  and  with  the  inner  edge  of  the  distal  joint 
distinctly  serrated.  Posterior  maxillipeds  strong  and 
provided  with  stout  terminal  claws.  Sternal  fork 
moderately  stout,  with  short  and  scarcely  divergent 
rami,  each  ramus  somewhat  expanded  in  the  middle 
and  thence  tapering  to  the  pointed  extremity.  Fourth 
pair  of  thoracic  legs  short ;  the  basal  joint  tolerably 
stout,  and  the  ramus  consisting  of  two  subequal  joints 
—the  first  with  a  small  spine  on  the  outer  distal  angle, 
and  the  second  with  three  short  terminal  spines,  each 
of  the  two  inner  spines  being  rather  longer  than  the 
one  in  front  of  it.  The  fifth  pair  extremely  small  and 
situated  near  the  postero-lateral  angles  of  the  genital 
segment.  Length  about  5  mm. 

Mule. — The  male  is  little  more  than  half  the  size  of  the 
female,  but  the  carapace  is  proportionally  larger,  being 
equal  to  nearly  two-thirds  of  the  entire  length  of  the 
animal.  Genital  segment  small ;  abdomen  also  small 
and  uniarticulate. 

Habitat. — Found  usually  adhering  to  the  underside 
of  the  pectoral  fins  of  certain  flat  fishes,  as  plaice,  Pleu- 
ronectes  platessa,  dabs,  Pleuronectes  limanda,  and  one 
or  two  others.  Belfast  (W.  Thompson).  Plymouth 
(Bassett-Smitli).  Irish  Sea  (A.  Scott).  Firths  of 
Forth  and  Clyde  (T.  Scott). 

This  is  one  of  the  more  common  and  easily  recognized  of 
the  species  of  Lepeophtheirus,  but  though  widely  dispersed  in 
the  seas  of  Europe  it  does  not  appear  to  have  yet  been 
recorded  from  American  waters. 


66  BRITISH    PARASITIC    COPEPODA. 

2.  Lepeophtheirus  nordmanni  (M.  Edwards). 
(Plate  XII,  fig.  1  ;  Plate  XVI,  figs.  4-11.) 

1840.  Caligus  nordmanni  M.  Edwards.     (43)  p.  455. 

1847.  Caligus  nordmanni  W.  Thompson.     (129)  p.  248. 

1850.  Lepeophtheirus  nordmanni  Baird.     (4)  p.  275,  pi.  xxxiii.  fig.  1. 

1865.  Lepeophtheirus  nordmanni  Heller.     (58)  p.  180,  pi.  xvi.  figs.  1.  -. 

1884.  Lepeophtheirus  nordmanni  Rathbun.  (97a)  Proc.  U.  S.  National 
Mus.,  vol.  vii,  p.  487. 

1900.  Lepeophtheirus  nordmanni  T.  Scott.  (112)  p.  151,  pi.  v,  figs. 
32-37. 

1905.  Lepeophtheirus  nordmanni  C.  B.  Wilson.  (145)  p.  623.  pi.  xix. 
figs.  223-233. 

1909.  Lepeophtheirus  nordmanni  E.  Y.  Elwes.     (45)  p.  19. 

Female. — Carapace   suborbicular,   about  as  long  as 
broad  and  equal  to  about  half  the  entire  length  of  the 
animal.     Frontal  plates  narrow,  without  lunulse.    Free 
thoracic  segment  small,  somewhat  rhomboid  in  shape. 
Genital  segment  obovate,  considerably  narrower  than 
the  carapace,  and  equal  to  fully  one-fourth  of  the  entire 
length  of  the  animal ;  length  and  width  about  equal. 
and  with  the  postero-lateral  corners  forming  rounded 
lobes  so  that  the  space  between  is  deeply  incurvated. 
Abdomen  short,  consisting  of  a  single  segment  with  a 
slight  constriction  near  the  middle.    Caudal  rami  short. 
Antennules    of    moderate   size.      Antennae    armed 
with    tolerably   long   and    strongly-hooked    terminal 
claws.     Mandibles   slender   and  elongated,    end  joint 
comparatively  short  and   finely  serrated  on  the  inner 
margin.      Second   maxillipeds   moderately  stout  and 
elongated,  and  provided  with  strongly-hooked  terminal 
claws.     Sternal  fork  with  the  basal  portion   narrow, 
the  rami  also  comparatively  narrow  and  elongated, 
and   somewhat   divergent.      Fourth    pair  of  thoracic- 
legs  tolerably  elongated,  basal  joint  not  very  stout  and 
rather  shorter  than  the  ramus,  which  consists  of  three 
subequal   joints ;  the  first  and  second  joints  of    the 
ramus  each  provided  with  a  short  spine  on  the  outer 
distal  angle,  the  end  joint  with  three  moderately  long 
apical  spines,  the  outermost  being  scarcely  so  long  as 
the  other  two.     Length  about  12  mm.     Egg-strings 
considerably  elongated. 


LEPEOPHTHEIRDS    XORDMANNI.  67 

Male. — The  male,  which  is  only  about  half  the  size 
of  the  female,  has  the  carapace  proportionally  rather 
longer,  and  the  frontal  plates  are  more  distinct.  The 
free  thoracic  segment  is  also  rather  longer  and  the 
genital  segment  narrower  than  in  the  female,  and  the 
postero-lateral  corners  of  the  genital  segment  have  each 
two  small  angular  processes,  the  one  slightly  anterior 
to  the  other.  Abdomen  short  and  about  one  third  the 
length  of  the  genital  segment,  and  composed  of  two  un- 
equal joints — the  proximal  one  being  small.  Caudal 
rami  short  and  bearing  several  short  setas. 

Habitat. — Parasitic  on  the  short  sun-fish  (Orthagoris- 
cus  mola).  Coast  of  County  Antrim,  Ireland,  1848 
(W.  Thompson}.  Polperro,  Cornwall  (A.  M.  Norman}. 
Plymouth  (Bassett- Smith).  Aberdeen  (T.  Scott}. 
Found  also  on  a  short  sun-fish  captured  off  Berry 
Head  (E.  V.  Elwes). 

L.nordmanni  does  not  appear  to  be  very  commonly  met  with  ; 
the  sunfish  when  captured  is  usually  subjected  to  some  rough 
handling  ere  it  reaches  the  market  and  the  parasites  get 
rubbed  off. 

C.  B.  Wilson  records  this  species  from  both  the  Atlantic 
and  Pacific  Coasts  of  North  America. 

3.  Lepeophtheirus  hippoglossi  (Kroyer). 

(Plate  VI,  figs.  4,  5;  Plate  XVII,  fig.  2 ;  Plate 
XVttl,  figs.  8-10.) 

1838.  Caligus  hippoglossi  Kroyer.     (70)  B.  l.vol.  i,  p.  625,  pi.  vi.  fig.  3. 

1850.  Lepeophtheirus  hippoglossi  Baird.  (4)  p.  276,  pi.  xxxii,  fig. 
12(?). 

1850.  Lepeophtheirus  obscurus  Baird.     (4)  p.  277,  pi.  xxxii,  fig.  11  (<$). 

1863.  Lepeophtheirus  hippoglossi  Kroyer.     (71)  p.  131,  pi.  vi,  fig.  5  a-d. 

1900.  Lepeophtheirus  hippoglossi  T.  Scott.  (112)  p.  151,  pi.  v,  figs. 
38-42;  pi.  vi,  figs.  1,  2. 

1905.  Lepeophtheirus  hippoglossi  C.  B.  Wilson.  (145)  p.  625,  pi.  xx, 
figs.  234-243. 

Female. — Carapace  somewhat  longer  than  broad  and 
equal  to  rather  more  than  half  the  entire  length  of  the 
animal,  lateral  margins  gently  and  evenly  arcuate. 
Frontal  plates  narrow,  without  lunulee.  Free  thoracic 
segment  small.  Genital  segment  fully  half  the  length 


68  BRITISH    PARASITIC   COPEPODA. 

of  the  carapace,  width  about  three  fourths  of  the 
length,  lateral  margins  only  slightly  arcuate.  Abdomen 
short,  composed  of  a  single  segment ;  caudal  rami 
short  and  bearing  a  few  apical  setae. 

Antennules  small.  Antennas  short  and  moderately 
robust,  and  armed  with  a  stout  sinuately-curved 
terminal  hook.  Mandibles  slender  but  scarcely  so 
much  so  as  in  Lepeophtheirus  nordmanni.  Second 
maxillipeds  stout  and  provided  with  short  but  strong 
terminal  claws.  The  sternal  fork  with  the  basal  part 
somewhat  expanded,  the  rami  short,  tolerably  broad 
and  divergent,  each  ramus  truncated  at  the  end  and 
split  into  two  portions  by  a  longitudinal  sinus,  the 
inner  portion  being  much  narrower  than  the  outer. 
Fourth  pair  of  thoracic  legs  tolerably  elongated,  basal 
joint  stout,  ramus  composed  of  three  joints,  the 
middle  one  being  rather  longer  than  the  first  or  third ; 
the  outer  distal  angle  of  the  first  joint  ending  in  a 
bluntly-rounded  knob,  the  second  joint  bearing  a  short 
spine  on  its  outer  distal  angle,  and  the  end  joint  three 
terminal  spines,  the  innermost  of  the  three  spines  being 
longer  than  the  others  and  finely  serrate  along  the 
outer  margin.  The  fifth  pair  very  small  and  rudimen- 
tary. Length  about  half  an  inch  (12*5  mm.),  but 
varying  somewhat  in  different  specimens.  Egg-strings 
slender  and  elongated. 

Male. — Carapace  orbicular,  as  long  as  broad,  and 
equal  to  about  two-thirds  of  the  entire  length  of  the 
animal.  Free  thoracic  segment  very  small,  and 
slightly  produced  on  each  side.  Genital  segment  very 
small,  with  a  pair  of  minute  setiferous  processes  on 
each  side  at  the  postero-lateral  corners.  Length  about 
6'5  mm. 

Habitat. — Parasitic  on  the  backs  of  large  halibut, 
Hippoglossus  vulgaris  Fleming.  Berwick  Bay  (Dr. 
Johnston).  Polperro,  Cornwall  (A.  M.  Norman). 
Aberdeen  (T.  Scott).  Shetland  (C.  B.  Wilson). 

Distribution. — North  Sea;  Greenland,  Iceland, 
Massachusetts  (Cape  Ann),  U.S.A. 


LEPEOPHTHEIRUS  THOMPSOXI.  69 

4.  Lepeophtheirus  thompsoni  Baird. 

(Plate  XVII,  fig.  3  ;    Plate  XXV,  fig.  10  ;  Plate 
XL VIII,  figs.  1-3.) 

1850.  Lepeophtheirus  thompsoni  Baird.     (4)  p.  278,  pi.  xxx,  fig.  2. 

1851.  Caliyus  gracilis  P.  J.  van  Beneden.     (11)  p.  90,  pi.  ii,  figs.  1-7. 
1861.  Caligus    branchialis  Malm,   mscr.  ?       Steenstrup  &    Liitken. 

(127)  p.  362,  pi.  ii,  fig.  3. 

1863.  Lepeophtheirus  rhombi  Kroyer.     (71)  p.  118,  pi.  v,  fig.  5. 

1885.  Lepeophtheirus  grucilis  Carus.  (29a)  Prodr.  Faunae  Mediter- 
raneae,  p.  359. 

1900.  Lepeophtheirus  thompsoni  T.  Scott.  (112)  p.  152,  pi.  v,  figs. 
43-45. 

1900.  Lepeophtheirus  obscurus  idem.     (112)  p.  153,  pi.  vi,  figs.  16-19. 

19()5.  Lepeophtheirus  thompsoni  C.  B.  Wilson.  (145)  p.  619.  pi.  xviii, 
figs.  21-2-219. 

Female. — Carapace  suborbicular  and  equal  in  length 
to  about  two-fifths  of  the  entire  length  of  the  animal. 
Frontal  plates  arcuate,  and  tolerably  prominent.  Free 
thoracic  segment  small.  Genital  segment  large  and 
nearly  as  long  as  the  carapace,  widest  at  the  distal  end, 
which  is  about  three-fourths  the  width  of  the  cara- 
pace, but  the  width  gradually  decreases  anteriorly  to 
where  the  proximal  end  rapidly  contracts  to  form  a 
narrow  neck ;  lateral  margins  slightly  arcuate,  or 
nearly  straight,  postero-lateral  corners  somewhat  pro- 
duced into  broadly-rounded  lobes.  Abdomen  toler- 
ably elongated  and  equal  to  about  two-thirds  the 
length  of  the  genital  segment,  a  slight  constriction 
near  the  posterior  end  giving  it  the  appearance  of  an 
indistinct  joint.  Caudal  rami  short. 

Antennules  about  two-thirds  the  length  of  the  frontal 
plates.  Antennae  rather  slender.  Second  maxillipeds 
tolerably  stout.  Sternal  fork  robust  with  the  rami 
somewhat  expanded,  widest  in  the  middle  and  tapering 
slightly  towards  each  end,  also  moderately  far  apart 
and  scarcely  divergent.  Fourth  pair  of  thoracic  legs 
small,  basal  joint  tolerably  stout,  and  with  the  ramus 
composed  of  three  joints,  the  outer  distal  angle  of  the 
first  joint  forming  a  blunt-pointed  knob,  that  of  the 
second  joint  bearing  a  small  spine,  the  third  armed 
with  one  short  and  two  moderately  long  and  spiniform 
apical  setae.  Fifth  pair  minute.  Length  about  8'5  mm. 


70  BRITISH    PARASITIC    COPEPODA. 

Male. — The  male  is  only  about  half  the  size  of  the 
female.  The  carapace  is  somewhat  elliptical  in  out- 
line, rather  longer  than  broad,  and  equal  to  about  two- 
thirds  of  the  entire  length  of  the  animal ;  lateral 
margins  evenly  rounded.  Genital  segment  suborbicular 
and  equal  to  about  one-third  of  the  length  of  the 
carapace.  Abdomen  about  half  as  long  as  the  genital 
segment.  Total  length  about  4  mm. 

Habitat. — Parasitic  on  the  gills  of  turbot,  Rltombus 
maximus  (L.).  North  of  Ireland  (W.  Thompson). 
Polperro,  Cornwall  (A.  M.  Norman).  Plymouth 
(Bassett-Smith).  Firths  of  Forth  and  Clyde,  Aber- 
deen, &c.  (T.  Scott).  Irish  Sea  (A.  Scott). 

C.  B.  Wilson  records  Lepeophtheirus  thompsoni  from  La 
Jolla,  California,  U.S.A.* 

[Lepeophtheirus  obscurus  Bassett-Smith. 

As  there  is  some  ambiguity  concerning  this  form, 
we  quote  the  following  remarks  by  A.  M.  Norman  and 
T.  Scott,  in  '  Crustacea  of  Devon  and  Cornwall,' 
p.  208  :  "  Mr.  Bassett-Smith  ('  Journ.  Marine  Biol. 
Assoc.,'  vol.  iv,  1896,  p.  157)  records  a  species  from 
the  brill  (Rhombus  Isevis)  taken  at  Plymouth,  and 
refers  it  with  doubt  to  Lepeophtheirus  obscurus  Baird, 
which  was  obtained  from  the  same  species  of  fish. 
Subsequently  Bassett-Smith  figures  what  he  then 
styles  C  aligns  obscurus  Baird  ('Ann.  and  Mag.  Nat. 
Hist.,'  ser.  6,  vol.  xviii,  pi.  iv,  fig.  2),  and  not  only  is 
his  parasite  there  referred  to  the  genus  Calif/us,  but 
the  figures  show  the  presence  of  sucking -disks. 
Whether  the  form  he  found  was  a  Lepeophtheirus  or  a 
CaJigus,  it  was  certainly  not  Lepeophtheirus  obscurus  of 
Baird.  In  Bassett-Smith's  third  paper  ('  Proc.  Zool. 
Soc.,'  1899,  p.  456)  he  referred  it  back  again  to  the 
genus  Lepeophtheirus.  It  is  just  possible,  if  the  species 
he  found  was  a  Lepeophiheirus,  that  it  may  have  been 
the  female  of  L.  appendiculit/is  Kroyer  ('  Naturhist. 
Tidssk.,'  ser.  3,  1863,  p.  207,  pi.  vi,  fig.  4,  a-i),  which 

•  '  Proc.  U.  S.  National  Museum/  vol.  xxxv,  p.  441  (1908). 


LEPEOPHTHEIRUS    OBSCURUS.  71 

has  a  branched  furcula,  but  the  former  was  taken  on 
the  brill,  while  the  latter  was  found  on  Raid  clavata." 
A  LepeophtheiriM  found  on  the  brill  by  T.  Scott,  and 
doubtfully  ascribed  by  him  to  L.  obscuras  Baird,  seems 
to  be  merely  a  form  of  L.  thompsoni,  not  deserving- 
even  varietal  rank.  Bassett-Smith's  L.  obscurus  is 
probably  similar,  for  in  a  copy  of  the  '  Ann.  and  Mag.' 
paper  referred  to  above  kindly  presented  by  the  author, 
the  lunulge  shown  in  figure  2,  Plate  4,  are  deleted  and 
the  words  "  no  lunulas  "  are  added  at  the  side  ;  so  also 
the  bifurcate  appearance  of  the  rami  of  the  sternal 
fork  shown  in  figure  F  on  the  same  plate  may  like- 
wise be  due  to  an  inadvertence.] 

5.  Lepeophtheirus  salmonis  (Kroyer). 
(Plate  XVII,  fig.  4;  Plate  XVIII,  figs.  11,  12.) 

1837-38.  Caligus  salmonis  Kroyer.  (70)  vol.  i.  pi.  vi,  fig.  7  a-c  ;  vol.  ii. 
pp.  13-18. 

1850.  Lepeoplitheirus  stromii  Baird.     (4)  p.  274.  pi.  xxxii,  figs.  8,  9. 

1863.  Lepeophtheirus  salmon  i*  Kroyer.    (71)  p.  211,  pi.  xvii,  figs.  1  a,  I. 

1900.  Lepeophtheirus  stromi  T.  Scott.     (112)  p.  152,  pi.  vi,  figs.  3-8. 

1905.  Lepeophtheirus  salmonis  C.  B.  Wilson.  (145)  p.  640,  pi.  xxiv. 
figs.  294-300. 

Female. — Carapace  rather  longer  than  broad,  and 
equal  to  about  three-sevenths  of  the  entire  length  of 
the  animal,  lateral  margins  slightly  and  evenly  arcuate. 
Frontal  plates  not  very  clearly  defined,  the  margin 
convex,  and  without  lunulae.  Free  thoracic  segment 
very  small.  Genital  segment  tolerably  large  and  of 
an  oblong  form,  rather  longer  than  broad,  its  length 
being  about  a  third  less  than  that  of  the  carapace,  the 
lateral  margins  only  slightly  arcuate  but  the  postero- 
lateral  corners  produced  into  rounded  lobes,  with  the 
space  between  them  deeply  incurved.  Abdomen 
narrow,  elongated  and  un segmented,  and  equal  to 
about  one-fourth  of  the  entire  length  of  the  animal ; 
distal  end  slightly  constricted  so  as  to  have  the  appear- 
ance of  an  indistinct  joint.  Caudal  rami  very  short. 

Antennules  rather  small.  Antennas  tolerably  robust, 
and  furnished  with  a  moderately  strong  terminal  hook. 


72  BRITISH    PARASITIC    COPEPODA. 

Maxillas  short  and  stout,  and  with  the  extremity  dis- 
tinctly bifurcated.  Second  maxillipeds  robust  and 
armed  with  short  and  stout  terminal  claws.  Basal 
portion  of  the  sternal  fork  short,  the  rami  also  short, 
somewhat  expanded  and  bluntly  rounded  at  the  tip ; 
slightly  divergent  and  separated  from  each  other  by  a 
comparatively  wide  semicircular  space.  The  fourth 
pair  of  thoracic  legs  somewhat  like  those  of  Lepeoph- 
theirus  hippoglossi,  but  rather  more  robust,  the  first 
joint  of  the  ramus,  which  is  rather  longer  than  the 
second  or  third,  with  the  outer  distal  angle  in  the  form 
of  a  blunt  knob  covered  with  microscopic  bristles,  the 
second  joint  provided  with  a  short  spine  on  the  outer 
distal  angle,  and  the  third  with  three  spiniform  apical 
setae,  the  inner  one  being  the  longest.  Egg-strings 
very  long  and  slender.  Length  14-16  mm. 

Male. — The  carapace  of  the  male  is  rather  longer 
than  broad  and  more  than  half  the  entire  length  of 
the  animal.  Frontal  plates  narrow.  Free  thoracic 
segment  of  moderate  size,  its  length  rather  less  than  the 
width.  Genital  segment  ovate,  longer  than  broad,  and 
equal  to  about  one-third  of  the  length  of  the  carapace. 
Abdomen  rather  narrower  than  the  genital  segment, 
and  about  a  third  shorter.  Caudal  rami  about  half  as 
long  as  the  abdomen. 

The  thoracic  appendages  are  somewhat  similar  to 
those  of  the  female,  except  that  the  second  maxillipeds 
are  proportionally  stronger.  Length  6-7  mm. 

Habitat. — Parasitic  chiefly  on  salmon,  Salmo  salar, 
L.,  but  it  also  occurs  on  one  or  two  other  species  of 
the  Salmonidas.  Berwick  (Dr.  Johnston).  Ireland 
(W.  Thompson).  Polperro,  Cornwall  (A.  M.  Norman). 
Plymouth  ( Bassett- Smith).  Scottish  coasts  (T.  Scott). 
Irish  Sea  (A.  Scott). 

This  is  one  of  the  more  widely  distributed  of  the  Caligidse. 
It  is  recorded  from  the  coasts  of  Alaska,  Labrador,  and 
from  other  parts  of  the  North  American  sea-board,  as  well  as 
from  the  coasts  of  Europe.  The  parasite  does  not  appear  to 
survive  long  after  the  fish  enters  the  fresh  water.  The  dorsal 
surface  in  this  species  has  a  curious  metallic  lustre  different 


LEPEOPHTHEIRUS    SALMOXIS.  73 

from  most  of  the  others  of  the  same  genus.     Males  appear  to 
be  comparatively  scarce. 

6.  Lepeophtheirus  pollachii  Bassett-Smith. 

(Plate  XVII,  figs.  5,  6;  Plate  XVIII,  figs.  13-15; 
Plate  XL VIII,  figs.  4,  5,) 

1896.  Lepeophtheirus  pollachius  Bassett-Smith.     (6)  p.  12,  pi.  iv,  fig.  1. 

1899.  Lepeophtheirus  pollachii  idem.     (8)  p.  45"). 

1900.  Lepeophtheirus  pollachii  T.  Scott.    (112)  p.  153.  pi.  vi,  figs.  9-13. 
1905.  Lepeophtheirus   inominatus  C.   B.  Wilson.      (145)   p.  656,  pi. 

xxviii,  figs.  345-352. 

Female. — Carapace  oval,  rather  longer  than  broad, 
and  equal  to  rather  more  than  a  third  of  the  entire 
length  of  the  animal,  lateral  margins  slightly  arcuate. 
Frontal  plates  not  very  prominent.  Free  thoracic  seg- 
ment small.  Genital  segment  subquadrangular,  length 
about  a  fourth  less  than  the  width  at  the  proximal 
end,  and  a  third  less  than  the  length  and  width  of  the 
carapace;  widest  posteriorly;  the  lateral  margins 
nearly  straight  and  the  postero-lateral  corner  sub- 
angular.  Abdomen  fully  as  long  as  the  genital  seg- 
ment, and  indistinctly  biarticulated,  the  end  joint  being 
rather  narrower  than  the  other.  Caudal  rami  very  small. 

Antennules  of  moderate  size.  Antenna?  with  toler- 
ably elongated,  strong  and  abruptly  hooked  terminal 
claws.  Second  maxillipeds  moderately  short  and  robust, 
terminal  claw  stout  and  strongly  curved.  Sternal 
fork  small,  rami  divergent,  and  bluntly  rounded  at  the 
tips.  Fourth  pair  of  thoracic  legs  not  reaching  to  the 
end  of  the  genital  segment;  ramus  somewhat  slender 
and  consisting  of  three  subequal  joints ;  the  first  and 
.second  joints  each  provided  with  a  small  spine  on  the 
outer  distal  angle,  but  the  spine  on  the  first  joint 
sometimes  wanting  ;  the  end  joint  furnished  with  three 
spiniform  apical  seta3  of  unequal  length,  the  innermost 
being  the  longest.  The  entire  length  of  the  specimen 
represented  by  the  drawing  on  PI.  XVII,  fig.  5,  is 
8  mm.  Egg-strings  long  and  slender. 

Mule. — The  carapace  of  the  male  is  equal  to  half  the 
entire  length  of  the  animal.  The  genital  segment  is  of 


74  BRITISH    PARASITIC    COPEPODA. 

an  oval  form,  not  much  longer  than,  and  about  twice  the 
width  of,  the  following  segments ;  its  distal  margin  is 
rounded,  with  a  minute  setiferous  plate  on  each  side 
representing  the  fifth  pair  of  legs.  Abdomen  com- 
posed of  two  subequal  but  indistinctly  segmented 
joints.  Length,  about  4'5  mm. 

Habitat. — Found  for  the  most  part  on  lythe,  Gadus 
poHachius,  adhering  to  the  inside  of  the  mouth,  and 
rarely  on  other  fishes.  Plymouth  (Bassett- Smith). 
Falmouth  (A.  M.  Norman).  On  salmon  captured  at 
Polperro,  Cornwall  (LaugJirin  in  'Museum  Normania- 
num').  Girvan,  Firth  of  Clyde,  and  at  Aberdeen  Fish- 
Market  (T.  Scott).  Irish  Sea  (A.  Scott). 

This  species  does  not  appear  to  be  so  common  as  some  of 
the  others. 

7.  Lepeophtheirus  sturionis  (Kroyer). 
(Plate  XVIII,  figs.  16-19  ;  Plate  XXI,  fig.  1.) 

1837.  Caligus  sturionis  Kroyer.     (70)  pi.  vi,  fig.  6. 

1840.  Lepeophtheirus  sturionis  M.  Edwards.     (43)  vol.  iii,  p.  457. 

1863.  Lepeophtheirus  sturionis  Kroyer.     (71)  p.  139,  pi.  xvii.  fig.  4. 

1905.  Lepeophtheirus  sturionis  T.  Scott.     (116)  p.  110,  pi.  v,  figs.  7-14. 

Female. — Carapace  suborbicular  and  equal  to  about 
two-fifths  of  the  entire  length  of  the  animal.  Frontal 
plates  not  very  prominent.  Free  thoracic  segment 
not  very  clearly  defined.  Genital  segment  somewhat 
pyriform,  widest  posteriorly,  becoming  gradually 
narrower  towards  the  front,  then  suddenly  contract- 
ing to  about  the  width  of  the  free  thoracic  segment, 
length  about  equal  to  the  width  at  the  posterior  end, 
and  to  about  two-thirds  of  the  length  of  the  carapace ; 
bluntly  rounded  at  the  postero-lateral  corners.  Ab- 
domen tolerably  elongated  and  narrow,  being  nearly 
three-fourths  as  long  as  the  genital  segment,  slightly 
constricted  near  the  distal  end,  the  constriction  forming 
a  kind  of  false  joint.  Caudal  rami  very  short  and 
somewhat  rudimentary. 

Basal  joint  of  the  antennules  tolerably  expanded. 
Antennae  robust,  and  armed  with  large  and  strong 


LEPEOPHTHEIRUS    STURIOXls.  75 

terminal  claws,  which  have  their  ends  bent  at  nearly 
a  right  angle  to  the  basal  part.  Mandibles  small, 
and  resembling  those  of  Lepeophtheiru*  pectorali*. 
Second  maxillae  stout,  and  dividing  at  the  apex  into 
two  slightly  bent  teeth.  Second  maxillipeds  mode- 
rately stout  and  elongated,  and  armed  with  short  but 
strong  terminal  claws.  Sternal  fork  very  stout,  with 
short  rami  which  are  stout  at  the  base  and  taper  to  a 
tolerably  sharp  point,  the  rami  distinctly  divergent. 
Fourth  pair  of  thoracic  legs  robust,  ramus  moderately 
elongated  and  composed  of  three  joints,  the  middle 
joint  being  rather  longer  than  the  first  or  third ;  the 
outer  distal  angle  of  the  first  joint  terminating  in  a 
minute  tooth,  a  tolerably  stout  spine  springing  from 
the  outer  distal  angle  of  the  second  joint,  the  end  joint 
armed  with  apical  spiniform  seta?  of  unequal  length,  the 
innermost  being  considerably  longer  than  the  other  two, 
and  the  outermost  the  shortest.  Length  about  14  mm. 

We  have  not  seen  the  male  of  this  species. 

Hi  i  bit  at. — Found  as  a  parasite  on  the  sturgeon, 
Acipemer  sturio  Linn.  Obtained  on  a  sturgeon 
captured  about  sixteen  miles  south-east  of  Aberdeen 
and  landed  at  the  Fish-Market  there,  29th  December 
1904.  We  are  indebted  to  Dr.  Alexander  Bowman 
for  this  specimen. 

This  species  does  not  appear  to  be  a  very  common  one. 

Genus  8.  LUTKENIA  Clan*,  186k 

Syn.  Cecropsina  Heller,  1865. 

Carapace  obcordate,  or  nearly  round,  without  frontal 
plates.  Antennules  two-jointed.  Fourth  ring  of  the 
thorax  covered  by  small  dorsal  plates.  Genital  seg- 
ment prolonged  backwards  in  the  form  of  lobes. 
Abdomen  short,  not  jointed,  and  terminating  in  two 
small  caudal  plates. 

The  first  pair  of  thoracic  legs  consisting  of  one  or 
two  branches,  but  the  inner  branch,  when  present,  very 
small.  The  next  three  pairs  two-branched.  Both 


76  BRITISH    PARASITIC    COPEPODA. 

branches  of  the  second  and  third  pairs  two-jointed,  and 
of  the  fourth  pair  one-jointed. 

1.  Liitkenia  asterodermi  Glaus. 
(Plate  XIX,  figs.  1-9  ;    Plate  XXIII,  fig.  4.) 

1864.  Liitkenia  asterodermi  Glaus.     (33)  p.  365-383,  pi.  xxxiv. 

1865.  Cecropsina  glabra  Heller.     (58)  p.  209,  pi.  xix,  figs.  1,  2. 

1906.  Liitkenia  asterodermi  Norman  &  T.  Scott.      (88)  p.  210,  pi.  xx. 
figs.  9,  10;  pi.  xxiv,  figs.  1-8. 

1906.  Liitkenia  asterodermi  A.  Brian.     (21)  p.  48. 

Female. — Carapace  suborbicular  or  obcordate,  with 
the  posterior  margin  deeply  hollowed  out.  Last 
thoracic  segment  produced  into  a  leaf -like  bifurcated 
dorsal  expansion,  the  distal  end  forming  two  rounded 
lobes  which  are  separated  by  a  tolerably  deep  and 
narrow  sinus ;  the  width  of  the  plate  at  the  proximal 
end  equal  to  about  two-thirds  the  width  of  the  cara- 
pace; the  anterior  portion  of  the  outer  margin  sloping 
in  a  slightly  arcuate  line  from  the  middle  towards  the 
front  corners  which  are  distinctly  angular.  Genital 
segment  produced  backwards  into  two  contiguous  lobes 
which  completely  overhang  and  conceal  the  abdomen 
and  caudal  rami,  so  that  they  can  only  be  seen  from 
the  ventral  aspect. 

Abdomen  somewhat  lozenge-shaped,  broader  than 
long,  the  length  being  three-fifths  the  width.  Caudal 
rami  nearly  contiguous,  broadly  lamelliform  and 
scarcely  half  as  long  as  the  abdomen. 

Antennules  very  small,  second  joint  slender  and 
nearly  as  long  as  the  first.  Antennae  armed  with 
strong  hook-like  terminal  claws.  First  maxillipeds 
slender  and  furnished  with  terminal  claws,  two  of 
which  are  small  and  subequal  and  the  others  rather 
longer  and  stouter.  Second  maxillipeds  large,  basal 
joint  stout  with  one  or  two  nodulous  processes  on  the 
inner  aspect,  the  terminal  claw  large,  strong,  and 
sickle-shaped.  First  pair  of  thoracic  legs  small,  bi- 
ramose,  inner  ramus  minute,  simple,  and  not  half  the 
length  of  the  first  joint  of  the  outer  ramus.  The  outer 
ramus  two-jointed,  the  end  joint  very  small,  its  distal 


LUTKENIA   ASTERODERMI.  77 

end  truncated  and  provided  with  three  or  four  minute 
apical  spines.  In  the  second  and  third  pairs  both  rami 
two-jointed ;  the  first  joint  of  the  outer  ramus  consider- 
ably larger  than  the  second ;  in  the  inner  ramus  the 
first  joint  is  the  smaller  one.  In  the  fourth  pair,  also 
biramose,  both  rami  only  one-jointed,  the  inner  ramus 
being  very  minute. 

Habitat. — Parasitic  on  Luvarns  imperialis  Raf. 
Three  specimens  of  this  Lutkenia  were  sent  to  the 
Rev.  A.  M.  Norman  by  Laughrin  about  1863,  which 
had  been  obtained  by  him  from  a  specimen  of  Luvarux 
captured  off  Polperro,  Cornwall.  ('Crustacea  of  Devon 
and  Cornwall,'  by  Norman  and  T.  Scott,  1906,  p.  210.) 

Distribution. — Mediterranean  ;  apparently  very  rare 
in  the  British  Seas. 

Genus  NOGAUS  Leach,  1819.* 
Syn.  Nogagus  M.  Edwards,  1840. 

The  genus  Nogaus  is  now  generally  regarded  as  unsatis- 
factory. It  comprises  males  only,  some  oF  which  have  already 
been  recognized  as  belonging  to  more  than  one  genus,  of  which 
the  females  had  previously  only  been  known ;  and  it  is  con- 
sidered probable  that  as  our  knowledge  of  the  Copepod  para- 
sites of  fishes  increases  and  their  relationships  and  life-history 
are  better  understood,  all  the  males  ascribed  to  Nogaus  will  ere 
long  be  removed  from  it  and  the  genus  itself  become  obsolete. 
There  are  however,  a  few  of  the  Nogaus  males  whose  relation- 
ship is  still  doubtful,  and  it  will  be  better  to  leave  these 
where  they  are  till  they  can  be  disposed  of  satisfactorily. 
Among  these  doubtful  forms  is  the  one  described  below. 

In  Nogaus  the  frontal  plates  are  without  lunulae,  but  other- 
wise the  forms  ascribed  to  this  genus  have  a  general  resem- 
blance to  C aligns.  Steenstrup  and  Lutken  divided  Nogaus  (or 
Nogagus)  into  two  groups,  the  principal  differences  between 
them  being  as  follow.  In  species  belonging  to  the  first 
group  the  four  pairs  of  swimming  legs  are  biramose,  and  the 
rami  are  all  two-jointed  ;  the  abdomen  also  is  two-jointed.  In 
those  belonging  to  the  second  group,  while  the  rami  of  the 

*  The  name  "  Nogaus  "  was  used  by  Dr.  Leach  in  1819  ;  it  was  afterwards 
changed  to  Nogagus  by  M.  Edwards  in  1840,  but  we  find  Dr.  Baird  still  using 
the  original  word  "  Nogaus  "  in  his  '  British  Entomostraca '  at  p.  282  ;  and 
C.  B.  Wilson  in  his  recent  work  on  '  North  American  parasitic  Copepods  of 
Fishes'  also  adopts  this  form  of  the  name. 


78  BRITISH    PARASITIC    COPEPODA. 

first  three  pairs  are  two-jointed,  the  fourth  has  only  one- 
jointed  rami,  and  the  abdomen  consists  of  a  single  segment. 
The  form  described  below  differs  from  both  these  groups,  but 
partakes  to  some  extent  of  the  characters  of  both. 

Nogaus  ambiguus  T.  Scott.     (Provisional  name.) 
(Plate  XX,  figs.  1-8.) 

1907.  Nogagus  ambiguus  T.  Scott.  (117)  Twenty-fifth  Annual  Report  of 
the  Fishery  Board  for  Scotland,  Part  III,  p.  217,  pi.  xv,  figs.  10-17  (  $  ). 

The  cephalic  shield  in  this  form  is  of  an  oval  outline,  the 
front  is  somewhat  narrowly  rounded  but  the  frontal  plau-s 
are  moderately  large.  The  last  two  thoracic  segments  are 
subequal,  their  width  is  about  one-third  of  that  of  the 
cephalic  shield  at  its  widest  part,  and  the  last  segment  is 
truncated  behind.  The  abdomen  consists  of  a  single  small 
subtriangular  segment  blunt-pointed  at  the  apex ;  and  the 
caudal  rami,  which  are  short  but  moderately  wide,  are  fur- 
nished with  tolerably  long  plumose  setae. 

The  antennules,  which  are  of  average  size,  are  provided 
with  long  plumose  hairs.  The  antennae,  mandibles,  and 
maxillae  are  of  the  usual  G aligns  type.  The  first  maxillipeds 
are  elongated,  and  are  each  armed  with  a  long  and  powerful 
terminal  claw  which  has  a  moderately  stout  seta  at  its  base, 
nearly  as  in  Nogaus  lunatus  (Stp.  &  Liitk.),  a  species  which 
the  present  form  resembles  in  some  other  particulars.  The 
second  maxillipeds  are  short  and  very  stout,  and  are  each 
fitted  with  a  stout  claw  which  forms,  with  the  tuberculated 
palm,  a  strong  grasping  organ.  All  the  four  pairs  of  swim- 
ming legs  are  short  and  biramose  ;  in  the  first  three  pairs 
both  the  outer  and  inner  ram  us  are  two-jointed  and  of  nearly 
equal  length,  and  the  end  joints  of  both  rami  bear  tolerably 
long,  densely  plumose  setae  round  the  inner  margin  and  end  ; 
there  are  also  a  few  short  spines  on  the  outer  margin.  The 
fourth  pair  are  rather  small,  the  inner  ramus  is  Inarticulate 
as  in  the  other  three  pairs,  but  the  outer  ramus  is  composed 
of  a  single,  somewhat  club-shaped  joint  with  three  long 
plumose  setas  round  the  distal  end  of  the  inner  margin,  and 
with  four  spines — three  small  ones  and  a  moderately  large 
terminal  spine — on  the  exterior  edge.  Length  about  5'omin. 

Habitat. — Parasitic  on  a  piked  dog-fish,  Squalus  acanthias, 
captured  in  the  North  Sea  in  1902. 

This  form  has  a  somewhat  close  resemblance  to  N.  lwintns 
described  by  Steenstrup  and  Liitken  ('Bidrag  til  Kundskab/ 
p.  389,  pi.  ix,  fig.  17,  1861). 


DEMOLEUS.  79 

Genus  9.  DEMOLEUS   Heller,  1865. 

Syn.  Caligus  Otto  (not  O.  F.  Miiller). 

Carapace  suborbicular,  divided  into  three  parts  by 
two  longitudinal  sutures,  middle  portion  subquadrate, 
lateral  portions  narrow,  produced  backwards  into  pro- 
minent rounded  lobes.  Frontal  plates  distinct,  with- 
out Iunula3.  Eyes  conspicuous,  close  together.  First 
and  second  free  thoracic  segments  small;  the  next  larger 
and  prolonged  backwards  so  as  to  form  small  dorsal 
plates  in  the  female  but  which  are  wanting  in  the 
male.  Genital  segment  elongated  in  the  female,  sub- 
quadrate  in  the  male.  Abdomen  short,  not  jointed, 
covered  dorsally  with  a  foliaceous  lamina.  Caudal 
appendages  large. 

1.  Demoleus  paradoxus  (Otto). 
(Plate  XII,  figs.  4,  5.) 

1828.  Caligus  paradoxus  Otto.     (93)  p.  352,  pi.  xxii,  fig.  5. 
1861.  Nogagus  grandis  Steenstrup    &    Liitken.       (127)  p.  386,  pi.  x, 
fig.  19. 

L865.  Demoleus  paradoxus  Heller.     (58)  p.  199,  pi.  19,  fig.  3. 

Female. — Carapace  suborbicular  and  equal  to  about 
a  third  of  the  entire  length  of  the  animal ;  frontal 
plates  distinct,  lunulse  wanting,  postero-lateral  lobes 
considerably  produced  behind.  First  and  second  free 
thoracic  segments  small,  and  just  filling  the  space 
between  the  produced  lateral  lobes  of  the  carapace; 
the  first  segment  with,  and  the  second  segment  with- 
out, lateral  processes.  The  next  segment  less  than 
half  the  width  of  the  other  two  and  furnished  with 
two  small  dorsal  plates.  Genital  segment  elongated, 
length  eqiial  to  fully  twice  the  width,  and  divided 
posteriorly  by  a  deep  median  sinus  into  two  lobes 
which  are  rounded  at  the  end.  Abdomen  very  small, 
triangular,  not  seen  from  the  dorsal  aspect.  Caudal 
rami  large,  extending  beyond  the  end  of  the  genital 
segment  and  bearing  a  few  minute  spiniform  setae. 

Antennules   two-jointed,    partly  concealed    by  the 


80  BRITISH    PARASITIC    COPEPODA. 

frontal  plates ;  antenna?  small  with  weak  terminal 
claws.  The  terminal  claws  of  the  second  maxillipeds 
of  moderate  size.  The  first  four  pairs  of  thoracic  legs 
all  biramose,  and  the  rami  biarticulated  and  furnished 
with  plumose  setaB,  the  first  and  fourth  pairs  with  very 
small  basal  joints,  those  of  the  second  and  third  con- 
siderably expanded.  Egg-strings  very  long  and  slender, 
and  looped  so  as  to  appear  as  if  they  each  consisted  of 
three  strands. 

Male. — The  male,  which  is  of  the  usual  Noyaus  form, 
is  somewhat  similar  to  the  female,  but  the  suborbicular 
carapace  is  proportionally  larger,  being  equal  to  at 
least  three-sevenths  of  the  total  length.  The  first 
free  thoracic  segment  fills  the  space  between  the  lateral 
prolongations  of  the  carapace,  and  is  slightly  produced 
into  small  rounded  lobes  which  are  contiguous  with 
the  lobes  of  the  carapace.  The  next  segment  is  small, 
while  the  third  (the  fourth  counting  the  carapace)  is 
without  dorsal  plates.  Genital  segment  oblong,  rather 
longer  than  broad,  width  equal  to  fully  one-third  the 
width  of  the  carapace,  and  having  the  postero-lateral 
corners  slightly  produced  and  rounded.  Abdomen 
small,  two-jointed  ;  caudal  rami  large  and  lamelliform, 
longer  than  broad  and  furnished  with  small  spiniform 
seta3  on  their  truncated  distal  extremities.  Cephalic 
appendages  somewhat  like  those  of  the  female,  but  the 
second  maxillipeds  are  short  and  tolerably  stout,  bear- 
ing stout  terminal  claws ;  the  thoracic  legs  are  also 
similar  to  those  of  the  female.  Length  variable, 
about  13  to  16*5  mm. 

Habitat. — Parasitic  on  dog-fishes.  On  a  dog-fish 
captured  off  the  North  of  Ireland.  Belfast  Bay  (IT. 
Thompson,  '  Nat.  Hist,  of  Ireland,'  vol.  iv,  1856). 

We  have  not  seen  this  species.  Our  figure  of  it  is  repro- 
duced from  that  of  Otto  referred  to  above. 

C.  B.  Wilson,  after  a  critical  examination  of  the  characters 
of  Nogagus  grandis  Steenstrup  and  Ltitken,  remarks  it  is 
"  fairly  certain  "  that  this  Nogagus  is  the  male  of  Demoleus 
paradoxus  (Otto). 


TREBIUS.  81 

Genus  10.  TREBIUS  Kri^r,  1838. 

Resembling  Lepeophtheinis  in  its  general  form  and 
in  the  absence  of  lunulse,  and  also  generally  in  the 
structure  of  the  body  and  its  appendages,  except  that 
the  fourth  pair  of  thoracic  legs  are  biramose  in  both 
the  male  and  female.  The  second  maxillas  tolerably 
long  with  the  extremity  pointed  or  slightly  bifurcated. 
The  first  maxillipeds  rather  stronger  than  in  Lepeo- 
phtheiras  or  Caligus,  but  the  second  pair  less  powerful 
than  those  of  the  two  genera  mentioned. 

Several  species  of  Trebius  have  been  described,  but  the  one 
recorded  below  is  the  only  species  represented  in  the  British 
fauna: 

1.  Trebius  caudatus  Kroyer. 
(Plate  XXII,  figs.  1,  2;  Plate  LIV,  figs.  1-11.) 

1838.  Trebius  caudatus  Kroyer.     (70)  p.  30,  pi.  i,  fig.  4. 
1850.  Trebius  caudatus  Baivd.     (4)  p.  280,  pi.  xxxiii.  fig.  3. 
1900.  Trebius  caudatus  T.  Scott,     (11:2)  p.  155.  pi.  vi.  figs.  20-26. 
1907.  Trebius  caudatus  C.  B.  Wilson.     (147)  p.  681.  pi.  xv,  figs.  11-13 ; 
pi.  xvi,  figs.  14-22. 

Female.  —  Carapace  suborbicular,  rather  longer 
than  broad,  and  equal  to  about  a  third  of  the  entire 
length  of  the  animal.  Frontal  plates  narrow,  without 
lunulas.  Eyes  conspicuous  and  close  together.  Free 
thoracic  segment  small.  Genital  segment  oblong, 
rather  longer  than  broad,  its  width  equal  to  about 
three-fourths  of  the  length,  and  to  about  two-thirds 
the  width  of  the  carapace,  the  lateral  margins  nearly 
straight,  its  posterior  end  truncated,  and  the  postero- 
lateral  corners  rounded  and  provided  with  three  small 
but  stout  marginal  spines.  Abdomen  elongated, 
narrow,  and  composed  of  three  segments,  its  length 
about  equal  to  that  of  the  carapace,  the  proximal  joint 
longest,  being  rather  more  elongated  than  the  next 
two  combined ;  the  second  about  twice  the  length  of 
the  third  joint,  the  articulation  between  the  second  and 
third  joints  not  very  clearly  defined.  Caudal  rami 
short  and  furnished  with  a  few  plumose  apical  setae. 
VOL.  i.  6 


82  BRITISH   PARASITIC    COPEPODA. 

Antennules  small.  Antennae  armed  with  strong 
terminal  hooks.  Mandibles  similar  to  those  of 
Lepeophtheirus  but  the  end  joint  somewhat  stouter  and 
more  distinctly  toothed.  Second  maxillae  with  the 
endopodite  slightly  bifurcate.  Second  maxillipeds 
tolerably  elongated,  not  very  robust  and  provided 
with  rather  weak  terminal  claws.  Sternal  fork 
small,  with  the  rami  simple,  short,  and  slightly 
divergent.  The  four  pairs  of  thoracic  legs  all 
biramose ;  the  first  pair  with  both  rami  two -jointed, 
but  the  rami  of  the  other  three  pairs  composed  of 
three  joints ;  the  basal  joint  of  the  fourth  pair  short 
and  tolerably  expanded,  the  rami  also  short  and  of 
nearly  equal  length,  the  inner  being  rather  the  shorter, 
both  rami  with  the  inner  margins  fringed  with 
tolerably  long  plumose  setae.  Fifth  pair  nearly 
obsolete.  Length  about  10  mm. 

Male. — Carapace  orbicular  and  equal  to  about  half 
the  entire  length.  Genital  segment  small,  ovate, 
somewhat  longer  but  not  much  wider  than  the  fret- 
thoracic  segment.  Abdomen  biarticulate,  narrow,  and 
about  as  long  as  the  genital  segment;  proximal  joint 
rather  shorter  than  the  end  one.  Length  about  4*5  mm. 

Habitat. — Parasitic  on  skates,  rays,  dogfishes,  &c. 
Belfast  (W.  Thompson).  Polperro,  Cornwall  (A.  M. 
Norman).  Plymouth  (Bassett-  Smith).  Irish  Sea 
(A.  Scott).  Firths  of  Forth  and  Clyde  and  at  Aber- 
deen (T.  Scott). 

Not  very  rare.  The  distribution  of  Trebius  caudatus 
appears  to  be  somewhat  limited;  it  is  mentioned  by  C.  B. 
Wilson  in  his  'North  American  parasitic  Copepods,'  but  the 
specimens,  he  states,  were  collected  off  the  coast  of  Shetland. 


Genus  11.  ELYTROPHORA  Gerstaecker,  1853. 

Female. — Carapace  rounded,  frontal  plates  distinct 
but  without  lunulaa.  First  three  thoracic  segments 
fused  with  the  head  ;  fourth  segment  with  two  dorsal 
plates.  Genital  segment  lobed  posteriorly.  Abdomen 


ELYTROPHORA.  83 

two-jointed,  joints  subequal,  without  wings.  Caudal 
rami  tolerably  large.  Antennules  two  -  jointed. 
Antenna3  uncinate.  Mouth-organs  somewhat  similar 
to  those  of  Caliyus.  Thoracic  legs,  four  pairs,  all 
biramose.  In  the  first  pair  both  rami  two-jointed ; 
both  rami  of  the  second  and  third  pairs  three-jointed, 
but  in  the  fourth  pair,  while  the  outer  ramus  is  three, 
the  inner  is  only  two-jointed. 

Male. — Somewhat  similar  to  the  female,  but  rather 
smaller. 

1.  Elytrophora  brachyptera  G-erstaecker. 

(Plate  XIX,  fig.  10;    Plate  XXIII,  figs.  1,  2;    Plate 
XXXI,  figs.  1-6.) 

1853.  Elytrophora  brachyptera  Gerst.     (48)  p.  60,  pi.  iii,  figs.  1-14. 

1863.  Arnseus  thynni  Kroyer.     (71)  p.  157,  pi.  viii,  fig.  5  a-g. 

1865.  Elytrophora  brachyptera  Heller.     (58)  p.  189,  pi.  xvii. 

1896.  Elytrophora  brachyptera  Bassett- Smith.     (6)  p.  12,  pi.  iv,  fig.  3. 

Female. — Carapace  orbicular,  scarcely  equal  to  half 
the  entire  length  of  the  animal,  or  as  5  to  11.  Frontal 
plates  distinct,  without  lunulae.  The  fourth  thoracic 
segment  carrying  two  small  dorsal  plates  which  are 
somewhat  widely  apart  in  front,  but  gradually 
approach  each  other  behind ;  their  outer  margins 
incurved,  and  the  posterior  margins,  which  are 
rounded,  slightly  overlapping  the  anterior  edge  of 
the  genital  segment.  Genital  segment  ovate  and 
moderately  tumid,  nearly  half  as  wide  as  the  carapace 
and  about  one  and  a  half  times  longer  than  broad, 
the  lateral  margins  slightly  arcuate,  and  the  postero- 
lateral  corners  produced  into  short  rounded  lobes. 
Abdomen  biarticulate,  narrower  than  the  genital 
segment,  first  joint  with  the  postero-lateral  corners 
somewhat  produced  and  rounded,  anal  segment  sub- 
orbicular  with  a  minute  posterior  lobe  in  the  median 
line  ;  caudal  rami  obovate, expanded  towards  the  distal 
end,  and  bearing  four  or  five  apical  plumose  setae. 

Antennules  small.  Antennas  strongly  uncinate. 
Mandible  and  maxillae  somewhat  like  those  in  Trebius. 


84  BRITISH   PARASITIC  COPEPODA. 

Second  maxillipeds  armed  with  strong  terminal  claws. 
Thoracic  legs  four  pairs,  all  biramose ;  both  rami  of 
the  first  pair  two -jointed,  the  outer  ramus  tolerably 
elongated,  but  the  inner  very  small ;  both  rami  of  the 
second  and  third  pairs  composed  of  three  joints,  but  in 
the  second  the  rami  are  nearly  of  equal  length,  with  the 
end  joints  very  small,  while  in  the  third  the  outer  ramus 
is  distinctly  shorter  than  the  inner.  These  three  pairs 
of  thoracic  legs  all  liberally  supplied  with  densely 
plumose  setae.  In  the  fourth  pair  the  outer  ramus 
stout,  and  composed  of  sub-equal  joints,  both  the  first 
and  second  joints  having  a  strong  and  slightly-curved 
spine  on  their  outer  distal  angle,  while  the  end  joint 
has  three  similar  spines  on  its  outer  margin,  and  three 
or  four  small  ones  on  the  inner  margin;  the  inner 
ramus,  which  is  situated  close  behind  the  outer,  small, 
and  composed  of  two  subequal  joints ;  the  basal  joint 
of  the  fourth  pair  also  tolerably  large,  and  gibbous 
below.  Length  about  11 '5  mm. 

Male. — The  male,  though  somewhat  similar  to  the 
female  in  its  general  appearance,  is  smaller,  and  the 
second  maxillipeds  are  more  powerfully  clawed ;  and 
while  the  genital  segment  is  only  about  half  as  large, 
the  abdomen  is  rather  longer  than  in  the  female.  The 
postero-lateral  corners  of  the  penultimate  segment  of 
the  abdomen  are  angular,  while  the  anal  segment  has 
a  subquadriform  outline.  The  caudal  rami  are  furnished 
with  four  setaB  longer  and  more  densely  plumose  than 
in  the  female.  Length  about  9  mm. 

Habitat. — Parasitic  ,on  the  tunny,  Orcynus  thynnus, 
Plymouth  (Bassett- Smith).  Outer  Hebrides  (Dr.  Alex. 
Bowman].  We  are  indebted  to  Dr.  Bowman  for  speci- 
mens of  this  interesting  species. 

Distribution. — European  seas. 

The  species  is  not  an  uncommon  one  on  the  tunny. 


DINEMOUEA.  85 

Genus  12.  DINEMOURA  Latreille,  1829. 

Syn.  Dinematura  Burraeister,  1833. 

Female. — Carapace  suborbicular,  deeply  excavated 
posteriorly ;  frontal  plates  narrow.  The  first  free 
segment  of  the  thorax  with  small  lateral  lobes ;  the 
next  segment  narrow  with  or  without  rudimentary 
dorsal  plates ;  the  third  segment  with  dorsal  plates  of 
tolerable  size,  separated  by  a  narrow  median  fissure, 
and  overlapping  the  anterior  portion  of  the  genital 
segment.  The  genital  segment  of  an  oblong  form 
and  with  the  postero-lateral  corners  produced  into 
short,  broadly-rounded  lobes.  Abdomen  small  and 
uniarticulate ;  caudal  rami  tolerably  large  and 
foliaceous.  Between  the  genital  segment  and  the 
abdomen  there  is  a  very  small  joint  with  two  dorsal 
plates  and  furnished  below  with  a  pair  of  rudimentary 
legs.* 

Antennae  short  and  moderately  stout,  and  armed 
with  strong  hooked  terminal  claws.  Mandibles  long 
and  very  slender,  and  provided  with  a  few  minute 
teeth  near  the  tip.  Second  maxillae  slender,  three- 
jointed ;  first  maxillipeds  also  slender,  and  furnished, 
each,  with  an  apical  claw  and  two  small  lateral  pro- 
cesses. Second  maxillipeds  moderately  stout.  Swim- 
ming-legs all  biramose ;  first  pair  with  both  rami 
two-jointed ;  those  of  the  second  and  third  pairs 
three-jointed,  while  in  the  fourth  pair  both  rami  con- 
sist of  tolerably  large  one-jointed  foliaceous  plates. 

Male. — Carapace  proportionally  wider  than  in  the 
female.  Second  free  thoracic  segment  without  dorsal 
plates.  The  dorsal  plates  of  the  third  segment  small 
and  overlapping  only  a  small  portion  of  the  genital 
segment.  Genital  segment  cuneiform,  wider  towards 
the  distal  end.  Abdomen  very  narrow,  biarticulate ; 
caudal  rami  large.  Swimming-legs  biramose,  both 

*  C.  B.  Wilson  appears  to  be  the  first  to  give  an  accurate  description  of  this 
part  of  the  animal  which  he  names  the  sixth  segment.  C/.  'North  American 
Parasitic  Copepoda/  '  Proc.  U.  S.  National  Museum/  vol.  xxxiii,  pp.  374,  376 

(1907). 


86  BEITISH   PARASITIC  COPKPODA. 

rami  of  the  first  and  fourth  pairs  composed  of  two 
joints,  and  those  of  the  second  and  third  pairs  of 
three  joints ;  the  rami  of  the  first  three  pairs  are 
furnished  with  tolerably  long  plumose  setae  while  those 
of  the  fourth  pair  are  armed  with  spines. 
The  only  British  species  is  that  described  below. 

1.  Dinemoura  producta  (0.  F.  Miiller). 

(Plate  XXII,  fig.  3 ;    Plate  XXVI,  figs.  1-3  ;    Plate 
XXVII,  figs.  1-8.) 

1785.  Caligus  productus  O.  F.  Miiller.     (86)  p.  132,  pi.  21,  fig.  3. 

1829.  Dinemoura  producta  Latr.   (38)  Cuv.  Regne  Anim.,  vol.  iv,  p.  127. 

1835.  Pandarus  lamnx  Johnston.     (65)  p.  203. 

1850.  Dinemoura  lamnse  Baird.     (4)  p.  286,  pi.  xxxiii.  fig.  7. 

1853.  Nogagus  productus  Gerst.  (48)  Wiegmann's  Archiv  fur  Natur- 
gescli.,  vol.  xix,  p.  63,  pi.  iv,  figs.  1-10. 

1857.  Dinematura  elongata  P.  J.  van  Beneden.  (14a)  Bull.  Acad. 
Roy.  Belg.,  p.  231,  pi.  xxiv. 

1861.  Dinematura  producta  Stp.  &  Liitk.     (127)  p.  34,  pi.  vii,  fig.  13. 

1900.  Dinematura  producta  T.  Scott.     (112)  p.  156,  pi.  vi,  figs.  27-31. 

1907.  Dinematura  producta  C.  B.  Wilson.     (148)  p.  380,  pi.  xxiii. 

Female. — Carapace  suborbicular  and  equal  to  about 
a  third  of  the  entire  length  of  the  animal ;  width 
slightly  exceeding  the  length ;  lateral  margins  boldly 
rounded  ;  frontal  plates  narrow  ;  eyes  small,  but  quite 
distinct,  not  quite  close  together  and  distant  from  the 
front  margin  about  a  tenth  part  of  the  total  length. 
The  first  free  thoracic  segment  furnished  with  small 
lateral  plates  which  inclose  the  next  segment  between 
them,  these  two  segments  together  filling  the  entire 
space  between  the  produced  postero-lateral  lobes  of 
the  carapace.  The  third  segment  of  the  thorax  carry- 
ing a  dorsal  plate  which  is  equal  to  about  one-sixth  of 
the  entire  length  of  the  animal  and  is  as  wide  as  the 
genital  segment  the  anterior  part  of  which  it  overlaps ; 
the  antero-lateral  corners  of  the  plate  subangular, 
and  also  divided  from  behind  forward  into  two  lobes 
by  a  narrow  median  fissure  which  extends  to  near  its 
base,  each  lobe  being  boldly  rounded  at  the  posterior 
end.  Genital  segment  oblong,  considerably  longer 


DINEMOURA    PRODUCTA.  87 

than  the  segment  last  described  and  equal  to  nearly 
two-thirds  of  the  width  of  the  carapace  ;  the  postero- 
lateral  corners  of  the  segment  produced  backwards  into 
moderately  narrow  lobes  with  rounded  ends  and  hav- 
ing a  space  between  them  equal  to  about  the  width  of 
one  of  the  lobes ;  a  shallow  median  groove  also  extend- 
ing along  nearly  the  whole  length  of  the  segments  as 
indicated  in  the  drawing  (PI.  XXII.  fig.  3).  The  space 
between  the  lobes  occupied  by  a  small  plate  provided 
with  two  slightly  divergent  appendages  w^hich  scarcely 
reach  to  the  end  of  the  abdomen.  Abdominal  segment 
small,  subquadr angular,  concealed  in  dorsal  view. 
Caudal  rami  in  the  form  of  broad  foliaceous  plates 
rather  longer  than  broad,  and  having  one  marginal, 
and  three  short,  tolerably  stout,  spiniform  setae.  There 
is  also  a  small  segment,  intermediate  between  the 
genital  segment  and  abdomen,  which  is  provided  with 
lateral  uniarticulate  and  somewhat  rudimentary  appen- 
dages, but  this  segment  is  seen  only  from  the  ventral 
aspect. 

Antennules  small.  Antennas  short  and  stout  and 
armed  with  strongly-hooked  terminal  claws.  Mandi- 
bles elongated  and  extremely  slender,  with  a  few 
minute  marginal  setas  near  the  tip.  First  maxillipeds 
each  furnished  with  a  terminal  and  tolerably  elon- 
gated hook-like  appendage  and  one  or  two  short 
accessory  processes.  Second  maxillipeds  short  and 
stout,  but  somewhat  rudimentary  in  structure.  Swim- 
ming-legs all  biramose  ;  both  rami  in  the  first  pair 
two-jointed,  the  first  joint  of  the  outer  ramus  consider- 
ably expanded,  and  its  outer  distal  angle  reaching 
forward  to  the  middle  of  the  short  end  joint  and 
terminating  in  a  short  stout  spine  ;  the  inner  ramus 
very  small  and  the  joints  subequal.  The  fourth  pair 
large  and  foliaceous,  each  ramus  about  twice  as  long  as 
broad,  and  furnished  with  a  few  minute  spines  round 
the  distal  end.  Length  exclusive  of  egg-strings  about 
20  mm.;  egg-strings  alone  sometimes  reaching  to  80mm. 

We  have  not  seen  the  male  of  this  species. 


88  BRITISH  PARASITIC  COPEPODA. 

Habitat. — Parasitic  usually  on  the  porbeagle  shark. 
Lanma  cornubica.  Berwick  Bay,  1834  (Dr.  Johnston). 
Polperro,  Cornwall  (A.  M.  Norman).  Moray  Firth— 
off  Dunrobin,  and  at  Aberdeen  Fish-Market  (T.  Scott). 
Near  Shetland  (C.  B.  Wilson).  On  a  thrasher  shark, 
Alopios  vnlpes,  at  Buddon,  Firth  of  Tay,  in  1887 
(Prof.  d'Arcy  W.  Thompson).  Recorded  also  from  the 
Greenland  shark,  Scymnus  glacialis. 

Distribution. — European  waters.     Atlantic  coast  of 
North  America. 


Genus  13.   ECHTHROGALEUS  Steenstrup  $  Lutken, 

1861. 

!•''•, ,nil<'. — Carapace,  antenna?,  and  mouth-appen- 
dages nearly  as  in  Phyllorthragoriscus,  but  the  dorsal 
plates  of  the  last  thoracic  segment  larger.  The  genital 
segment,  which  is  also  large,  extending  backwards  so 
as  to  overlap  and  conceal  wholly  or  partially  the 
abdominal  segment  and  caudal  rami ;  the  postero- 
lateral  lobes  of  the  genital  segments  rounded  at  the 
end  and  separated  by  a  tolerably  deep  sinus  which 
may  be  narrow  as  in  E.  coleoptratus  or  moderately 
wide  as  in  E.  dentic.ulatus. 

Thoracic  limbs  as  in  Phyllorthragoriscns  except  that 
the  inner  ramus  of  the  second  and  third  pairs  are 
composed  of  two  instead  of  three  articulations. 

"  Male. — Carapace  like  that  of  the  female  but  pro- 
portionately larger,  frontal  plates  more  prominent. 
Lateral  lobes  of  second  thoracic  segment  corresponding 
to  the  first  pair  of  dorsal  plates  in  the  female;  no 
lobes  on  the  third  segment;  a  rudimentary  pair  on 
the  fourth  segment  which  are  closely  appressed  to  the 
anterior  margin  of  the  genital  segment.  The  latter 
smaller  than  in  the  female,  with  one  pair  of  legs  at  or 
just  in  front  of  the  posterior  corners.  Abdomen 
small  and  two- jointed ;  anal  lamina  large  and  armed 
with  plumose  seta?.  Appendages  as  in  the  female." 
(C.  B.  Wilson.) 


ECHTHEOGALEUS    COLEOPTRATUS.  89 

1.  Echthrogaleus  coleoptratus  (Guerin). 
(Plate  XXII,  fig.  4.) 

1829-1843.  Dinematuracoleoptrata  Guerin.  (55)  pi.  xxxv,  fig.  6.  (1840). 

1835.  Pandarus  alatvs  ("M.Edwards")  Johnston.  (66)  p.  202,  two 
text-figs. 

1850    Dinemoura  alata  Baird.     (4)  p.  285,  pi.  xxxiii,  figs.  8,  9. 

1861.  Echthrogaleus  coleoptratus  Stp.  &  Ltk.  (127)  p.  380,  pi.  viii, 
fig.  15. 

1900.  Echthrogaleus  coleoptratus  T.  Scott.     (112)  p.  156,  pi.  vi.  fig.  52. 

1907.  Echthrogaleus  coleoptratus  C.  B.  Wilson.     (148)  p.  367,  pi.  xix. 

1910.  Echthrogaleus  coleoptratus  T.  B.  R.  Stebbing.     (125)  p.  559. 

Female. — Body  oblong,  fully  twice  as  long  as  broad. 
Carapace  suborbicular  and  equal  to  about  a  third  of 
the  entire  length  of  the  animal ;  frontal  plates  toler- 
ably large  and  distinct.     First  two  thoracic  segments 
short  and  narrower  than  the  carapace  ;  dorsal  expan- 
sion not  greatly  developed.     Dorsal  plates  of  the  third 
segment  much  enlarged,  wider  behind  than  in  front, 
and  covering  rather  less  than  half  the  genital  segment, 
their  posterior  margins  obliquely  and  sinuately  trun- 
cated so  that  the  inner  corners  extend  further  back- 
ward than  the  outer,  and  though  the  inner  margins  of 
the  plates  come  close  together  in  the  middle  line  they 
do  not  overlap,  their  margins  being  even,  not  serrated, 
and   their   surface    smooth    and    ornamented    with    a 
number  of  small  pellucid  impressed  circular  markings 
arranged  in   a  more  or  less  regular  pattern,   which, 
along  with  the  form  of  the  plates,  gives  them  a  fairly 
close  resemblance  to  the  elytra  of  certain  coleopterous 
insects.     Genital    segment  tolerably  large,  extending 
backwards    considerably    beyond    the    dorsal    plates 
described  above,  becoming  somewhat  narrower  pos- 
teriorly and  being  divided  into  two  lobes  by  a  narrow 
and  deep   median  cleft  or  sinus ;  the  inner  edges  of 
the  lobes  closely  appressed  and  not  overlapping,  and 
their  posterior  margins  rounded  and  reaching  to  about 
the  end  of  the  caudal  rami ;  the  abdomen,  which  is 
concealed  in  dorsal  view  by  the  genital  segment,  com- 
paratively small  and   sub-quadriform  in   outline,  the 
width  being  somewhat  greater  than  the  length  ;  caudal 


90  BRITISH  PARASITIC  COPEPODA. 

rami  lamelliform,  broadly  ovate,  the  ends  subtruncate, 
scarcely  extending  beyond  the  genital  segment,  and 
provided  with  a  few  apical  spinules.  Intermediate 
between  the  genital  segment  and  abdomen  is  a  small 
rounded  plate  concealed  in  dorsal  view. 

Antennules  rather  slender,  not  prominent;  antennae 
furnished  with  strong,  hooked,  terminal  claws.  Mouth- 
tube  moderately  short  and  slender.  Second  maxillipeds 
short,  moderately  stout,  and  furnished  with  powerful 
terminal  claws.  Other  mouth-organs  as  in  Dinemonra. 
Swimming-legs  short  and  biramous ;  first  and  second 
pairs  with  both  rami  two-jointed  ;  third  pair  with  the 
outer  ramus  composed  of  three  and  the  inner  of  two 
joints ;  while  in  the  fourth  pair  both  rami  consist  of  a 
single  foliaceous  joint.  The  fifth  pair  of  thoracic  legs 
represented  by  a  small  spine-like  process  on  the  under 
side  and  near  the  posterior  end  of  the  genital  lobes. 

Length  11  to  13  mm.    Egg-strings  long  and  slender. 

Habitat. — Found  parasitic  on  the  porbeagle  shark, 
Larnna  cornubim.  Berwick  Bay  (Dr.  Johnston). 
Aberdeen  Fish-Market  and  near  Fair  Island  between 
Orkney  and  Shetland  (T.  Scott).  From  both  the  por- 
beagle and  the  blue  shark,  Carcharias  ylaucus,  taken 
at  Polperro,  Cornwall  (A.  M.  Norman). 

The  distribution  of  this  Echthrogaleus  is  extensive  and 
includes  the  seas  of  Europe,  the  Atlantic  and  Pacific  coasts 
of  North  America,  and  the  coast  of  South  Africa. 

2.  Echthrogaleus  liitkeni  (Norman). 
(Plate  XXIX,  fig.  1 ;  Plate  XXX,  figs.  1-8.) 

1869.  Nogagus  IntJceni  Norman.  Last  Rept.  on  Dredging  among  the 
Shetland  Isles;  Brit.  Assoc.  Rept,  for  1868.  p.  300.  J 

1906.  Echthrogaleus  liitkeni  Norman  &  T.  Scott.  (88)  p.  213.  pi.  xxii, 
figs.  1-9. 

In  the  "  Last  Report  on  Dredging  among  the 
Shetland  Isles,"  the  Rev.  A.  M.  Xorman  records  and 
describes  a  fish  parasite  under  the  name  of  N< ></</</ H* 
Jiitkp.ni.  The  specimen,  which  was  procured  by  Dr. 
Saxbv,  was  found  on  a  skate.  Two  other  specimens 


ECHTHROGALEUS   LUTKBNI.  91 

were  subsequently  obtained  at  Polperro  in  Cornwall, 
but  the  name  of  the  fish  on  which  they  occurred  has 
not  been  recorded.  All  these  specimens  were  males. 
In  dealing  with  this  group  of  fish  parasites  it  is  some- 
times difficult,  if  males  only  are  available,  to  determine 
the  species  to  which  the  specimens  belong ;  a  careful 
study,  however,  of  the  examples  referred  to,  leaves 
little  doubt  that  they  are  the  males  of  an  Eckthro- 
galeus. 

The  following  is  the  description  of  E.  liitlteni  as 
given  in  '  Crustacea  of  Devon  and  Cornwall '  :— 
"  The  cephalosome  is  much  rounded,  its  breadth 
much  greater  than  the  length ;  the  hinder  corners  of 
the  lateral  area  incurved,  well  rounded,  and  reaching 
backwards  to  the  end  of  the  first  of  the  two  exposed 
segments  of  the  metasome.  First  segments  of  meta- 
some  with  lateral  expansions  broader  and  longer  than 
in  the  following  short  segment.  The  urosome  consists 
of  three  segments ;  the  first,  or  genital  segment,  is  sub- 
quadrate  with  slightly  arched  sides,  longer  than  broad; 
the  second  segment  very  short,  the  terminal  rather 
broader  than  long;  the  uropodal  lamina?  are  as  long  as 
the  two  preceding  joints,  and  of  an  ovate  form. 

"  The  antennules  have  the  first  joint  much  longer 
than  the  second ;  the  second  joint  has  one  spine  on 
the  hinder  margin.  The  antennae  have  the  penulti- 
mate joint  stout,  the  last  long  and  gradually  attenuated, 
only  very  slightly  curved,  bearing  a  single  seta  on  the 
inner  face.  The  first  maxillipeds  have  the  claws 
setose.  The  second  maxillipeds  have  the  terminal 
joint  very  broad  and  stout,  obliquely  truncate  distally, 
with  a  nodule,  and  areolated  disk  at  the  commence- 
ment of  the  palm  ;  the  finger  short  and  stout.  The 
first  feet  have  both  rami  composed  of  two  joints ;  the 
inner  branch  terminates  in  three  seta?,  the  outer  in 
four ;  the  first  joint  of  this  outer  branch  has  one  spine 
on  the  outer  margin,  and  the  second  joint  three.  The 
second,  third,  and  fourth  feet  are  alike  in  general 
character,  though  differing  slightly  in  the  number  of 


92  BRITISH   PARASITIC   COPEPODA. 

setae  and  external  marginal  spines.  The  fifth  feet, 
which  are  situated  under  the  genital  segment,  are 
minute,  one-jointed,  bearing  two  or  three  short  setae. 
"  Polperro,  two  specimens,  but  the  record  of  the  fish 
on  which  they  were  found  was  not  given.  The  type 
specimen  was  taken  on  a  skate  at  Shetland."  (See 
pp.  213-214.) 

Our  figure  of  the  species  is  reproduced  from  that  in  the 
work  referred  to.  We  have  not,  ourselves,  obtained  this 

parasite. 

Genus  14.  PHYLLOTHREUS  Xonnan,  1903. 

Syn.  Phyllopliora  M.  Edw.  (name  preoccupied). 

Body  depressed.  Carapace  broadly  cordate,  without 
frontal  plates.  Thorax  furnished  with  three  pairs  of 
broadly-rounded  overlapping  laminae,  which  extend 
considerably  on  either  side  of  the  carapace.  Abdo- 
minal region  two-segmented ;  genital  segment  tolerably 
short  and  broad  ;  distal  segment  small,  rounded,  and 
provided  with  short  lateral  processes. 

Antennules  small.  Antennas  assuming  the  form  of 
large  hooks  which  project  in  front  of  the  carapace. 
All  the  thoracic  legs  biramose  and  lamelliform.  Egg- 
strings  slender  and  elongated. 

The  name  Phyllophora  employed  by  M.  Edwards  for  this 
genus  was  preoccupied  by  Thunberg  in  1812  (for  a  genus  of 
Orthoptera),  and  by  Gray  in  1838. 

1.  Phyllothreus  cornutus  pi.  Edwards). 
(Plate  XIX,  figs.  11-18;    Plate  XXIII,  fig.  3.) 

1840.  Phyllophora  cornuta  M.  Edw.    (43)  p.  471,  pi.  xxxviii,  figs.  13. 14. 

1899.  Phyllopharus  cornutus  Bassett-Smith.     (8)  p.  465. 

1903.  Phyllothreus  cornutus  Norman.  (87)  Ann.  and  Mag.  Nat.  Hist. 
7),  vol.  xi.  p.  368  (April). 

1906.  Phyllothreus  cornutus  Norman  &  T.  Scott.  (88)  p.  iH'2.  pi.  xxiv. 
figs.  9-1 7. 

Female. — Carapace  subcordate,  wider  posteriorly, 
greatest  width  equal  to  about  one  and  one-third  times 
the  length,  lateral  margins  slightly  arcuate,  converging 


PHYLLOTHREUS    COBXUTUS.  93 

towards  the  front  which  is  truncated  and  without 
frontal  plates ;  posterior  edge  deeply  emarginate,  and 
with  the  lateral  corners  rounded.  Thorax  provided 
with  three  pairs  of  leaf -like  and  suborbicular  over- 
lapping plates,  which  extend  on  each  side  to  consider- 
ably beyond  the  margin  of  the  carapace  and  reach 
backwards  to  a  distance  equal  to  the  length  of  it. 
Abdominal  region  distinctly  narrower  than  the  cara- 
pace and  composed  of  two  segments ;  the  genital 
segment  suborbicular,  its  length  being  rather  less  than 
the  width,  and  bearing,  at  the  corners  of  the  truncated 
hinder  margin,  ovate  processes  which  represent  the 
fifth  pair  of  feet ;  the  last  segment  consisting  of  two 
small  transversely-obovate  plates  from  between  which 
issue  the  two  slender  and  elongated  egg-strings. 

Antennules  small,  two-jointed,  end  joint  narrow, 
much  shorter  than  the  proximal  one,  and  bearing  a 
few  apical  setaB  and  a  minute  spine  near  the  middle  of 
the  lower  margin;  the  antennas  are  represented  by 
large  hooks  which  project  considerably  in  front  of  the 
carapace  and  form  powerful  grasping*  organs.  First 
maxillipeds  with  the  end  joint  narrow  and  provided 
with  three  terminal  spines,  the  middle  one  being  the 
largest,  tips  of  all  three  slightly  hooked ;  second 
maxillipeds  cheliform.  Thoracic  legs  short,  biramous, 
and  more  or  less  lamelliform ;  first  pair  with  outer 
ramus  one- jointed  and  slightly  geniculated,  and  the 
inner  two-jointed ;  second  pair  with  both  rami  tw«  '- 
jointed ;  while  in  the  third  and  fourth  pairs  both 
rami  are  uniarticulate.  All  the  rami  are  devoid  of 
seta?  and  bear  only  a  few  small  spines.  Length  about 
13  mm.  Male  unknown. 

Habitat. — Parasitic  on  the  blue  shark,  Carcharius 
glaucus.  Two  specimens  Avere  collected  by  William 
Laughrin  at  Polperro,  Cornwall,  many  years  ago,  and 
were  sent  by  him  to  the  Rev.  Canon  A.  M.  Norman. 
''  The  only  other  previously  known  habitat  of  the 
species  was,  according  to  Milne  Edwards,  Tongatabu 
in  the  Friendly  Islands,  whence  the  type  specimens 


94  BRITISH    PARASITIC   COPEPODA. 

came ;  this  is  therefore  a  remarkable  instance  of  wide 
distribution  "  (A.  M.  Norman). 

We  are  greatly  indebted  to  Canon  Norinan  for  the  privilege 
of  examining  the  specimens  referred  to,  and  for  permitting  us 
to  reproduce  the  figure  of  it  published  in  (  Crustacea  of  Devon 
and  Cornwall.' 

Genus  15.  PANDARUS  Leach,  1816. 

Female. — Body  moderately  broad  and  elongate. 
Carapace  ovate,  wider  behind  than  in  front ;  frontal 
plates  of  moderate  size ;  posterior  margin  not  very 
deeply  excavated.  Thorax  provided  with  three  pairs 
of  dorsal  plates,  the  first  pair  lateral  and  of  an 
elongate-ovate  form,  the  second  pair  between  them  in 
the  form  of  broadly-rounded  lobes  separated  from 
each  other  by  a  moderately  deep  median  sinus;  the 
third  pair  nearly  as  wide  as  the  carapace  and  prolonged 
backwards  so  as  to  cover  a  considerable  portion  of  the 
genital  segment  ;  the  dorsal  plates  of  the  genital 
segment  with  the  inner  lateral  margins  contiguous  and 
apparently  coalescent,  and  produced  posteriorly  into 
rounded  or  angular  lobes  having  between  them  a 
flattened  suborbicular  median  plate  concealing  the 
abdomen. 

Antennules  biarticulate  and  provided  with  an 
adhesive  disk  at  the  base.  Antennae  armed  with 
terminal  claw-like  hooks,  and  also  furnished  with 
adhesive  disks  or  pads  somewhat  similar  to  those  at 
the  base  of  the  antennules  and  maxillipeds.  Thoracic- 
legs  biramose ;  rami  of  the  first  three  pairs  biarticu- 
late, the  outer  ramus  of  the  first  pair  more  or  less 
abnormal  in  form  and  the  joints  sometimes  coalescent ; 
in  the  fourth  pair  the  rami  consisting  of  a  single  joint. 
Caudal  rami  subtriangular  and  divaricate,  usually  seen 
projecting — one  on  each  side — beyond  the  plate  at  the 
end  of  the  genital  segment. 

Male. — The  male  has  a  close  general  resemblance  to 
the  male  of  Lepeophtheirus,  the  antennules,  which  are 
provided  with  adhesive  disks  as  in  the  female,  differ  in 


PANDARUS.  95 

l)eing  armed  with  terminal  claws  ;  the  maxillipeds  are 
also  furnished  with  small  terminal  but  distinct  claw- 
like  hooks.  The  other  mouth-appendages  are  some- 
what similar  to  those  of  the  female.  All  the  four 
pairs  of  thoracic  legs  are  biramose,  with  bi articulate 
rami,  and  they  differ  from  those  of  the  female  in  being 
provided  with  moderately  long  and  densely  plumose 
setee. 

1.  Pandarus  bicolor  Leach. 

(Plate  XXI,  fig.  2 ;    Plate  XXII,  figs.  5-6;   Plate 
XXVI,  figs.  4-19 ;  Plate  LVIII,  figs.  1-8.) 

1816.  Pandarus  bicolor  and  boscii  Leach.  (74)  pp.  405,  406,  pi.  xx, 
figs.  1  and  2  and  figs.  1-10. 

1840.  Pandarus  Jissifrons  M.  Edwards.     (43)  p.  470. 

1850.  Pandarus  bicolor  and  boscii  Baird.  (4)  pp.  288,  289,  ph  xxxiii. 
fig.  6. 

(?)  1854.  Nogagus  augustulus  Gerst.  (£).  (48)  p.  193,  pi.  vii,  figs.  17 
and  18  (<J). 

1900.  Pandarus  bicolor  T.  Scott  (<$  &  ? ).  (112)  p.  157,  pi.  vi,  figs. 
33-38  (<J  &  ?). 

1907.  Pandarus  bicolor  C.  B.  Wilson.     (148)  p.  400,  pi.  xxvii. 

1907.  Nogagus  latiis  T.  Scott.  (117)  p.  21 1>,  pi.  xv,  figs.  1-9  (<J,  im- 
mature). 

Female. — Body  oblong,  width  equal  to  rather  more 
than  a  third  of  the  entire  length.  Carapace  widest 
posteriorly,  lateral  margins  slightly  arcuate,  converg- 
ing towards  the  front,  anterior  margin  with  a  small 
median  notch,  frontal  plates  tolerably  distinct,  postero- 
lateral  corners  not  greatly  produced.  Thorax  provided 
with  three  pairs  of  dorsal  plates  ;  first  pair  lateral  and 
of  an  ovate  form  and  inclosing  the  second  pair  between 
them  ;  the  second  pair  terminating  in  broadly-rounded 
lobes  which  scarcely  reach  beyond  the  ends  of  the 
first,  the  combined  width  of  the  two  pairs  being 
nearly  equal  to  that  of  the  carapace ;  the  posterior 
margins  of  the  two  pairs  of  plates  are  nearly  in  a 
straight  line  and  have  the  appearance  of  four  subequal 
lobes ;  the  third  pair  about  as  wide  as  the  carapace  and 
prolonged  backward  to  near  the  middle  of  the  genital 
segment,  separated  posteriorly  by  a  moderately  deep 
median  sinus  and  terminating  in  two  broadly-rounded 


96  BRITISH  PARASITIC  COPEPODA. 

lobes.  Dorsal  plates  of  the  genital  segment  consider- 
ably produced,  their  inner  margins  contiguous  and 
coalescent ;  posterior  corners  prolonged  into  rounded 
lobes,  the  space  between  the  lobes  being  filled  by  a 
suborbicular  lamina  which  entirely  conceals  the 
abdomen,  while  the  caudal  rami  are  seen  projecting 
one  on  each  side  of  the  median  plate  in  the  form  of  a 
triangular  process. 

Antennules  small,  partly  concealed  by  the  frontal 
plates ;  antennae  also  small,  terminal  claws  slender 
with  an  accessory  spine  on  the  inner  margin. 
Adhesion-disks  four  pairs.  First  maxillipeds  slender, 
joints  subequal,  terminal  claws  unequal ;  second 
maxillipeds  considerably  dilated.  Thoracic  legs 
biramose  ;  the  inner  ramus  in  the  first  pair  biarticulate, 
the  end  joint  being  longer  than  the  proximal  one,  and 
with  the  apex  broadly  rounded  and  bearing  a  few 
setae  on  the  lower  half  of  the  inner  margin;  outer 
branch  longer  than  the  inner  and  composed  of  two 
partly  or  wholly  coalescent  joints,  the  proximal  part 
being  distinctly  wider  than  the  distal  portion,  which 
is  abruptly  geniculated  and  tapers  towards  the  apex  ; 
second  and  third  pairs  with  both  rami  two-jointed ; 
while  in  the  fourth  pair  each  ramus  is  composed  of  a 
single  joint.  Length  about  10  mm. 

Male. — The  male  has  a  general  resemblance  to  the 
male  of  a  Lepeophtheirus.  The  antennules  are  provided 
with  adhesive  disks  as  in  the  female,  but  differ  in 
being  armed  with  terminal  claws ;  the  second  maxilli- 
peds are  also  furnished  with  distinct  though  small 
claw-like  hooks.  All  the  four  pairs  of  thoracic  legs 
are  biramose  with  biarticulate  rami ;  the  rami  also 
differ  from  those  of  the  female  in  being  provided  with 
moderately  long  and  densely  plumose  setae.  The 
genital  segment  is  subquadriform  and  equal  to  scarcely 
one-fourth  of  the  total  length,  and  the  abdomen  is 
composed  of  two  segments.  Length  about  6  mm. 

Habitat. — Parasitic  on  various  dog-fishes  and  sharks: 
Galeus  canis  (Squalus  galeus Linn.) ;  Carcharias  glaucus ; 


PANDARUS    BICOLOR.  97 

Scyttium  catulus ;  and  Squalus  mustelus.  Falmouth 
1849  (W.  P.  Cocks — see  Baird).  Torcross,  Devon  (Dr. 
Leach).  Plymouth  (A.  M.  Norman  and  Bassett- Smith). 
Firth  of  Clyde,  Aberdeen,  Moray  Firth  (T.  Scott). 
Shetland  (G.  B.  Wilson).  Irish  Sea  (A.  Scott). 

This  appears  to  be  the  only  British  species  of  Pandarus 
recorded  hitherto.  Pandarus  boscii  Leach  is  considered  to 
be  only  a  pale-coloured  variety ;  an  apparently  similar  variety 
— pale-coloured — is  recorded  in  the  26th  '  Annual  Report  of 
the  Fishery  Board  for  Scotland/  Part  III,  p.  74,  pl.iii  (1909). 
It  was  obtained  along  with  specimens  of  the  typical  form  on 
a  number  of  Squalits  acanthias  captured  on  the  West  Coast 
of  Scotland  in  March  1908.  Pandarus  fissicornis  M.  Edw. 
is  regarded  by  Kroyer  as  synonymous  with  the  present  species, 
and  Canon  A.  M.  Norman  considers  that  the  species  described 
by  Gerstaecker  under  the  name  of  Nogagus  angustulus  is  the 
male  of  this  Pandarus.  The  female  of  the  typical  form  is 
ornamented  ou  the  back  with  dark-brownish  or  almost  black 
coloured  patches.  The  carapace  is  usually  coloured,  and  so 
are  the  second  and  third  pairs  of  thoracic  plates. 


Genus  16.  CECROPS  Leach,  1816. 

Female. — Carapace  oval,  robust,  distinctly  notched 
in  front  and  deeply  excavated  posteriorly.  Frontal 
plates  coalescent  with  the  carapace.  Second  thoracic 
segment  with  tolerably  large  rounded  lateral  lobes, 
and  the  last  one  with  a  pair  of  short  dorsal  plates. 
Genital  segment  small  but  provided  with  considerably 
expanded  dorsal  plates,  larger  than  the  carapace,  and 
reaching  backward  so  as  to  conceal  the  short  caudal 
rami.  Abdomen  small,  somewhat  flattened. 

Antennules  small,  two- jointed.  Antennae  moderately 
stout,  each  terminating  in  a  strong  hook.  Mandibles 
and  other  mouth-organs  of  the  usual  caligoid  type. 
All  four  pairs  of  thoracic  legs  biramose.  Both  rami 
of  the  first  three  pairs  composed  of  two  joints,  and 
those  of  the  fourth  pair  of  one  joint. 

Male. — The  male,  which  is  smaller  than  the  female, 
is  similar  to  it,  except  that  the  genital  segment  wants 

VOL.  i.  7 


98  BRITISH  PARASITIC  COPEPODA. 

the  large  dorsal  plates  which  the  female  possesses. 
The  frontal  sinus  is  also  not  so  pronounced. 

1.  Cecrops  latreillii  Leach. 

(Plate  XXI,  figs.  3,  4;  Plate  XXVII,  figs.  9,  10; 
Plate  XXVIII,  figs.  1-7.) 

1816.  Cecrops  latreillii  Leach.     (74)  p.  20,  and  five  figures. 

1850.  Cecrops  latreillii  Baird.     (4)  p.  293,  pi.  xxxiv,  fig.  1. 

1857.  Cecrops  latreillii  Hoeven.  (61a)  Mem.  d'Entoniol.  de  la  Soc. 
Entom.  des  Pays-bas,  vol.  i,  p.  67,  pis.  iii  &  iv. 

1892.  Cecrops  latreillii  A.  Scott.  Trans.  Nat.  Hist.  Soc.  Glasgow, 
vol.  iii,  pt.  3,  p.  266. 

1900.  Cecrops  latreillii  T.  Scott.     (112)  p.  157. 

1907.  Cecrops  latreillii  C.  B.  Wilson.  (148)  p.  468,  pis.  xxxviii  &  xxxix. 

1909.  Cecrops  latreillii  E.  V.  Elwes.     (45)  p.  20. 

1910.  Cecrops  latreillii  T.  R.  R  Stebbing.     (125)  p.  558. 

Female. — Carapace  oval,  stout,  length  and  width 
nearly  equal,  deeply  emarginate  in  front,  and  with  the 
posterior  margin  deeply  excavated.  Second  and  third 
thoracic  segments  apparently  coalescent  and  forming 
one  segment  which  bears  a  dorsal  plate  with  broadly- 
rounded  lateral  lobes.  The  last  thoracic  segment  with 
a  tolerably  large  dorsal  plate,  the  front  margin  of 
which  is  nearly  straight,  but  posteriorly  of  a  semi- 
circular outline  and  reaching  to  near  the  middle  of  the 
genital  segment;  a  narrow  and  moderately  deep  cleft 
or  sinus  dividing  the  plate  in  the  median  line  at  its 
posterior  margin.  The  dorsal  plates  of  the  genital 
segment  nearly  twice  as  long  as  the  carapace  and 
extending  backward  so  as  to  conceal  the  abdomen  and 
caudal  rami ;  their  inner  margins  contiguous  and 
apparently  coalescent,  forming  a  single  plate  which  is 
\vider  than  the  carapace  and  terminates  posteriorly  in 
two  equal  and  broadly -rounded  lobes;  the  genital 
segment  covered  by  these  coalescent  plates  narrow  and 
flattened,  and  the  abdomen  and  caudal  rami  small. 

Antennules  two-jointed,  end  joint  small.  Antennas 
armed  with  strong,  hooked,  terminal  claws.  Second 
maxillipeds  stout,  terminal  claws  strong  and  hook- 
like.  All  the  four  pairs  of  thoracic  legs  biramose  and 


CECROPS    LATREILLII.  99 

both  rami  two-jointed,  except  in  the  fourth  pair,  the 
rami  of  which  are  both  uniarticulate.  The  outer 
ramus  in  the  first  three  pairs  stouter  than  the  inner, 
and  the  first  joint  larger  than  the  end  one,  and 
carrying  on  its  outer  distal  angle  a  short  but  stout 
spine.  The  outer  ramus  in  the  fourth  pair  small, 
but  the  inner  considerably  expanded  and  so  also  is 
the  basal  joint  of  this  pair.  Caudal  rami  short  and  fur- 
nished with  a  few  apical  seta3.  Length  about  25  mm. 

M'«.le. — The  male  differs  from  the  female  in  being 
smaller,  and  it  also  wants  the  large  posterior  dorsal 
plates  of  the  genital  segment.  Some  of  the  thoracic 
legs  are  also  slightly  modified.  Length  about  16  mm. 

Habitat. — Parasitic  on  the  gills  of  the  short  sun-fish, 
Orthagoriscus  molci.  Recorded  from  many  parts  of 
our  coasts.  South  of  Ireland,  Dublin,  Coast  of 
Antrim,  &c.  (G.  J.  Allman—Aug.  1848,  R.  Ball,  W. 
Thompson, — see  Baird,  p.  293).  Polperro  (A.  M. 
Norman).  Plymouth  (Bassett-  Smith}.  Falmouth 
(Cock*).  Solway,  Jan.  1857  (J.  Stewart).  Firth  of 
Forth  (A.  Scott).  Lerwick,  Shetland;  Mallaig,  W. 
coast  of  Scotland  (T.  Scott).  On  a  short  sun-fish 
captured  off  Berry  Head  (Major  E.  V.  Elwes). 

In  the  female  the  egg-strings  are  very  long,  but  instead  of 
projecting  externally  they  are  twisted  upon  each  other  in 
numerous  loops  and  lie  concealed  in  the  hollow  space 
between  the  abdomen  and  the  large  buckler-shaped  last 
segment  of  the  thorax.  The  specimens  we  have  seen  have 
all  been  obtained  from  the  gills  of  the  short  sun-fish,  where 
large  numbers  may  sometimes  be  found  crowded  together. 
The  general  colour  of  the  parasites  is  yellowish,  but  the 
colour  of  the  strong  terminal  hooks  of  the  niaxillipeds  is 
dark  brown,  nearly  black. 

Cecrops  latreillii  appears  to  be  one  of  the  most  widely 
dispersed  species  of  the  Caligidae;  in  addition  to  the 
European  records  of  this  parasite,  it  has  also  been  reported 
from  both  the  Atlantic  and  Pacific  coasts  of  North  America, 
and  G.  M.  Thomson  states  that  several  specimens  were 
obtained  from  the  mouth  of  a  sun-fish  (Orthagoriscus  mola) 
which  was  caught  in  Otago  Harbour  (Otago  Museum).* 
*  'Trans.  N.  Z.  Institute,'  vol.  xxii  (1889),  p.  362. 


100  BRITISH   PARASITIC   COPEPODA. 

Genus  17.  ORTHAGORISCICOLA  Poche,  1902. 

Syn.  Laemargus  Kroyer.    (Name  preoccupied  for  a  genus  of  fishes.) 

Female. — Carapace,  outline  trapezoidal,  consider- 
ably narrower  in  front,  posterior  corners  rounded, 
length  equal  to  about  three-fourths  of  the  width  at 
the  widest  part.  The  first  and  second  thoracic  seg- 
ments very  short  and  fully  half  as  wide  as  the  carapace. 
Third  segment  provided  with  an  expanded  dorsal 
plate,  which  overlaps  a  considerable  portion  of  the 
genital  segment  and  is  divided  posteriorly  by  a  median 
cleft  into  two  broadly-rounded  lobes.  Genital  segment 
enlarged,  dorsal  plates  greatly  expanded,  contiguous, 
slightly  overlapping  each  other  in  the  median  line, 
and,  viewed  from  the  dorsal  aspect,  entirely  concealing 
the  abdomen  and  caudal  rami. 

Antennules  tolerably  elongated  and  composed  of 
three  joints.  Antennas,  mandibles,  and  maxillipeds 
somewhat  similar  to  those  of  Philorthragori-scus.  All 
the  thoracic  legs  biramous ;  the  first  and  second  pairs 
both  somewhat  similar  to  the  normal  type  observed  in 
this  group  of  parasites,  but  in  the  third  and  fourth 
pairs  the  rami  consist  of  broad  one-jointed  laminae 
almost  devoid  of  spines  or  seta3. 

Male. — The  male  resembles  the  female  but  is 
rather  smaller.  The  structure  of  the  appendages 
does  not  greatly  differ  except  that  the  antennae  and 
second  maxillipeds  are  armed  with  stronger  terminal 
claws  ;  the  rami  of  the  third  pair  of  thoracic  legs  are 
also  biarticulate. 

Kroyer  established  this  genus  in  1837  under  the  name  of 
Lsemarguft,  but  it  happened  that  only  a  short  time  before  the 
same  name  had  been  given  to  a  genus  of  fishes  by  Henle 
(1837). 

1.  Orthagoriscicola  muricata  (Kroyer). 
(Plate  XXI,  fig.  5;  Plate  XXVIII,  figs.  8-18.) 

1S37.  Lxmargua  muricatus  Kroyer.    (70)  p.  487,  pi.  v,  figs.  A-E. 
1850.  Lxmargus  muricatus  Baird.     (4)  p.  295,  pi.  xxxiv,  figs.  3  &  4. 
1857.  L&rnargus  muricatus  Hoaven.      (6la)  Op.  cit.  p.  11,  pi.  iv,  figs. 
1-10,  12,  14,  15. 


ORTHAGORISCICOLA    MURICATA.  101 

1861.  Lsemargus  muricatus  P.  J.  van  Beneden.  (15)  p.  129.  pi.  xix, 
figs.  1-4. 

1892.  Lsemargus  muricatus  A.  Scott.  Trans.  Xat.  Hist.  Soc.  Glasgow, 
vol.  iii,  pt.  3,  p.  266. 

1900.  L&margus  muricatus  T.  Scott.     (112)  p.  158,  pi.  vi,  figs.  39-42. 

1902.  Orthagoriscicola  muricata  Poche.     (97)  p.  14. 

1907.  Orthagoriscicola  muricata  C.  B.  Wilson.  (148)  p.  473,  pis.  xl  &  xli. 

1909.  Orthagoriscicola  muricata  E.  V.  Elwes.     (45)  p.  20. 

1910.  Orihagoriscicola  muricata  T.  B.  B.  Stebbing.     (125)  p.  559. 

Female. — Carapace  trapezoidal  in  outline,  much 
wider  behind  than  in  front,  postero-lateral  corners 
broadly  rounded,  lateral  margins  minutely  serrated, 
posterior  margin  slightly  incurved,  a  number  of 
minute  spines  scattered  over  the  dorsal  surface  of  the 
carapace,  and  the  frontal  plates  apparently  fused  with 
it.  First  and  second  thoracic  segments  short  and  about 
half  as  wide  as  the  carapace,  attenuated  at  the  sides 
and  without  accessory  dorsal  plates.  The  next  seg- 
ment provided  with  a  broad  dorsal  plate  which  overlaps 
a  considerable  portion  of  the  genital  segment  and  is 
divided  by  a  median  cleft  into  two  broadly-rounded 
lobes  the  margins  of  which  are  minutely  serrated.  The 
genital  segment  furnished  with  t\vo  large  broadly- 
expanded  plates  the  inner  margins  of  which  somewhat 
overlap  each  other ;  the  plates  suborbicular  in  outline 
and  together  fully  one  and  a  half  times  the  width  of 
the  carapace,  also  entirely  concealing  the  abdomen  and 
caudal  rami ;  their  posterior  margins  broadly  rounded 
and  conspicuously  serrated. 

Antennules  of  moderate  length  and  composed  of 
three  joints,  the  first  as  long  as  the  other  two  com- 
bined. Antennae  short,  armed  with  stout  and  strongly- 
hooked  terminal  claws.  Mandibles  long,  stylet-shaped, 
and  minutely  serrate  at  the  distal  end.  First  maxilli- 
peds  small,  provided  with  short  but  moderately  broad 
terminal  claws  serrated  on  the  margins.  Second 
maxillipeds  strong ;  end  joint  with  one  or  two  marginal 
processes  on  its  inner  aspect  and  provided  with  a 
strong  curved  terminal  claw  considerably  shorter  than 
the  joint  to  which  it  is  articulated.  The  thoracic 
legs  all  biramose,  the  rami  of  the  first  and  second  pairs 


102  BRITISH  PARASITIC   COPEPODA. 

two-jointed,  but  those  of  the  third  and  fourth  pairs 
uniarticulate,  tolerably  large,  and  lamelliform.  Length 
about  20  mm. 

Mule. — The  male  does  not  differ  greatly  from  the 
female,  but  it  is  only  about  half  or  three-quarters  the 
size,  and  the  dorsal  plates  of  the  thorax  and  genital 
segment  are  proportionately  smaller ;  the  dorsal  plates 
of  the  genital  segment  have  also  their  inner  margins 
apparently  coalescent  except  at  the  posterior  end, 
where  they  are  separated  by  a  moderately  deep  sinus; 
they  scarcely  extend  so  far  back  as  in  the  female,  so 
that  the  caudal  rami  are  exposed. 

The  antennas  and  the  second  maxillipeds  are  also 
stronger  and  form  more  powerful  grasping  organs  than 
those  of  the  female ;  the  rami  of  the  third  pair  of 
thoracic  legs  are  not  foliaceous,  but,  like  the  first  and 
second,  are  biarticulate ;  they  differ  however  in  the 
inner  ramus  being  small  and  somewhat  rudimentary. 
The  fourth  pair  are  similar  to  the  fourth  pair  in  the 
female.  Length  from  10  to  15  mm. 

In  both  sexes  the  colour  is  dull  yellow. 

Habitat. — Parasitic  on  the  short  sun-fish,  Ortlm- 
goriftcus  mola.  "  Specimens  taken  off  Plymouth  were 
given  to  A.  M.  Norman  a  great  many  years  ago  by  the 
late  Mr.  C.  Spence  Bate."*  Moray  Firth  (T.  Edward). 
Firth  of  Forth,  October  1890  (A.  Scott).  Dr.  Baird 
records  this  parasite  on  the  authority  of  W.  Yarrell, 
but  does  not  mention  the  locality.  On  a  short  sun-fish 
captured  off  Berry  Head,  1898  (Major  E.  I".  Wives, 
Babbacombe). 

Distribution.  -  -  European  Seas.  South  Africa 
(T.  R.  R.  StMing).  New  Zealand  (6?.  M.  Thomson). 
The  Atlantic  and  Pacific  coasts  of  North  America 
(C.  B.  Wilson). 

*  'The  Crustacea  of  Dovon  and  Cornwall,'  1906,  p.  211. 


PHILOKTHRAGORISCUS.  103 

Genus  18.  PHILORTHRAGORISCUS  Horst,  1897. 

Syn.  Dinematura  Kroyer,  in  part. 

Female. — Carapace  suborbicular,  width  somewhat 
exceeding  the  length.  First  thoracic  segment  fused 
with  the  head;  second  and  third  united  together, 
forming  one  segment,  provided  with  small  lateral  ex- 
pansions. Fourth  segment  furnished  with  a  large 
dorsal  plate,  overlapping  fully  the  half  of  the  genital 
segment,  about  as  wide  as  the  carapace  and  divided 
into  two  suborbicular  lobes  by  a  median  fissure  which 
extends  nearly  to  the  base  of  the  plate.  The  genital 
segment  also  furnished  with  a  bilobed  dorsal  plate, 
nearly  as  wTide  as  that  of  the  fourth  segment,  and, 
viewed  from  above,  almost  concealing  the  com- 
paratively small  abdomen.  Caudal  rami  short  and 
tolerably  broad. 

Antennules  two- join  ted  and  tolerably  elongated. 
Antennae  stout  and  armed  with  large  hook-like  terminal 
claws.  Mandibles  long  and  slender.  First  maxilli- 
peds  composed  of  two  joints  and  provided  with  three 
terminal  spines,  two  of  them  being  of  moderate  length 
and  claw-like.  Second  maxillipeds  stout  and  bearing 
strong  terminal  claws.  First  four  pairs  of  swimming- 
legs  biramose ;  both  rami  of  the  first  three  pairs  bi- 
articulate.  Caudal  rami  short. 

Wale. — The  carapace  of  the  male  is  much  larger 
than  the  rest  of  the  body;  width  greater  than  the 
length,  dorsal  surface  grooved  as  in  Pandurus.  Second 
and  third  thoracic  segments  coalescent,  and  furnished 
with  a  pair  of  small  lateral  plates.  Fourth  segment 
with  very  small  dorsal  plates,  which  are  coalescent 
along  the  middle  line,  while  the  posterior  margin  with 
its  intermediate  sinus  is  similar  to  that  of  the  genital 
segment  in  the  female  of  Perissojms.  Abdomen  as  in 
the  female  but  more  exposed  behind  the  genital  seg- 
ment. Caudal  rami  rather  smaller  than  in  the  female. 

Antennules  proportionately  longer ;  the  antennae 
also  enlarged,  their  terminal  claws  projecting  well  in 


104  BRITISH  PAEASITIC  COPEPODA. 

front  of  the  carapace.     Other  appendages  somewhat 
similar  to  those  of  the  female. 

We  are  indebted  to  Major  E.  V.  Ehves,  Bahbacombe,  for  the 
privilege  of  examining  and  describing  the  male,  he  having 
kindly  sent  it  to  us  for  that  purpose  along  with  specimens 
of  the  female. 

Philorthragoriscus  serratus  (Kroyer). 
(Plate  XXIV,  figs.  3,  4;  Plate  XXVII,  figs.  11-24.) 

1863.  Dinematura  serrata  Kroyer.     (71)  p.  176,  pi.  viii,  fig.  4  a-i. 
1897.  Philorthragoriscus  serratus  Horst.  (63a)  Notes  Leyden  Museum, 
vol.  19  N.  £,  Note  xiv,  p.  137,  pi.  vii. 

1901.  Dinematura  serrata  T.  Scott.     (113)  p.  125. 

1906.  Philorthragoriscus  serratus  A.  Brian.     (21)  p.  53. 

1907.  Philorthragoriscus  serratus  C.  B.  Wilson.      (147)  p.  479,  pis. 
xlii  &  xliii. 

1909.  Philorthragoriscus  serratus  E.  V.  Elwes.     (45)  p.  20. 

Female. — Carapace,  which  is  generally  described  in 
the  generic  definition,  with  the  lateral  margin  denticu- 
late. The  antero -lateral  corners  of  the  dorsal  plates  of 
the  fourth  segment  produced  outward  into  sharp  teeth, 
and  both  lobes  with  their  posterior  margins  also  denti- 
culate. The  outer  ramus  in  the  first  four  pairs  of 
thoracic  legs  considerably  larger  than  the  inner,  the 
first  joint  being  longer  than  the  entire  inner  ramus,  and 
having  a  small  tooth  on  its  outer  distal  angle  ;  the  end 
joint  small  and  bearing  a  few  small  spines  and  setas  on 
its  rounded  apex ;  the  joints  of  the  inner  ramus  sub- 
equal,  and  the  end  joint  somewhat  expanded  and 
furnished  with  three  apical  setae.  Basiopodites  of 
the  second  and  third  pairs  dilated,  rami  small.  The 
basiopodite  of  the  fourth  pair  also  considerably  en- 
larged, and  both  rami  small,  uniarticulate,  and  some- 
what rudimentary,  but  the  inner  much  smaller  than  the 
outer  ramus.  Egg-strings  long  and  slender.  Colour 
yellowish.  Length  about  7  mm. 

Male. — See  under  generic  definition.    Length  5  mm. 

Habitat. — Taken  on  a  short  sun-fish,  Orthafjoriscus 
mola  (L.),  at  Banff  in  1862  by  the  late  Thomas 
Edward.  On  a  short  sun-fish  captured  off  Berry 
Head,  1898  (E.  V.  Ehves). 


PHILORTHRAGORISCUS    SEKRATUS.  ]  05 

Distribution. — European  seas.  Atlantic  coast  of 
North  America  (C.  B.  Wilson). 

The  species  will  be  found  recorded  under  the  Eev.  A.  M. 
Norman's  MS.  name  Honima  jimbriat.o.  in  the  appendix  to 
Smiles'  '  Life  of  'J'homas  Edward '  (p.  437,  1876),  as  one  of 
the  many  creatures  that  keen-sighted  naturalist  added  to  the 
fauna  of  Scotland.  The  same  species  was  also  found  on  a 
short  sun-fish  captured  by  Mr.  C.  Beadle,  off  Berry  Head,  in 
August  1908,  and  presented  by  him  to  the  Torquay  Natural 
History  Society.  On  this  sun-fish  Major  E.  V.  Elwes  obtained, 
among  other  interesting  parasites,  four  female  and  one  male 
Philorthragoriscus  serratn*  which  he  very  kindly  permitted  us 
to  examine. 

Family  HI.    DICHELESTIID.E. 

Body  generally  elongated,  head  moderately  small. 
Free  thoracic  segments  usually  simple,  but  sometimes 
provided  with  dorsal  plates.  Abdomen  usually  small 
or  rudimentary. 

Antennules  slender,  moderately  elongated,  and  com- 
posed of  several  joints,  rarely  short  with  two  or  three 
joints.  Antennae  armed  with  terminal  claws  and 
generally  projecting  more  or  less  beyond  the  edge  of 
the  cephalothorax.  Mouth  parts  somewhat  similar  to 
those  of  the  CaKgidae.  Thoracic  legs  usually  four 
pairs,  frequently  short,  stump-like  or  suppressed,  or 
\vith  the  posterior  limbs  transformed  into  lamelliform 
plates.  Eye  single,  median,  or  absent.  Genital  organs 
as  in  the  Caligidae.  Sexual  differences  not  very 
marked,  but  the  male  usually  smaller  than  the  female, 
and  both  for  the  most  part  capable  of  a  certain  amount 
of  locomotion. 

Genus  19.  DICHELESTIUM  Hermann,  1804. 

Head  obtuse,  body  elongated,  consisting  of  four 
distinctly-articulated  segments  without  dorsal  plates. 
Genital  segment  tolerably  elongated.  Abdomen  small. 
Caudal  rami  not  very  prominent. 

Antennules  slender  and  composed  of  eight  joints. 


106  BRITISH   PARASITIC   COPEPODA. 

Antennas  large,  as  long  as  the  antennules,  and  chele- 
form  or  uncinate  at  the  end,  usually  projecting 
forward  beyond  the  front  of  the  head.  The  first  and 
second  pairs  of  thoracic  legs  small  and  biramose,  but 
the  fourth  pair  each  composed  of  a  single  one-jointed 
lamelliform  plate. 

The  male  is  somewhat  similar  to  the  female,  but 
smaller. 

1.  Dichelestium  oblongum  ( Abildgaard) . 
(Plate  XXXI,  figs.  7-18;  Plate  XLV,  figs.  4,  5.) 

1794.  Caligus  oblongus  Abildgaard.     (1)  vol.  iii,  p.  52,  pi.  v.  figs.  4-11. 
1804.  Dichelestium  sturionis  Hermann.     (61)  p.  125,  pi.  v,  figs.  7  &  8. 
1838.  Dichelestium  sturionis  Kroyer.    (70)  vol.  i,  p.  299,  pi.  ii,  fig.  5,  5o. 
1836.  Dichelestium    sturionis    Rathke.      (99a)   Act.   Akad.    Leopold 
Carol,  vol.  xix,  p.  127,  pi.  xvii,  figs.  1-17. 

1840.  Dichelestium  sturionis  M.  Edw.     (43)  p.  485,  pi.  xxxix,  fig.  4. 

1905.  Dichelestium  sturionis  T.  Scott.     (116)  p.  Ill,  pi.  v,  figs.  17-24 ; 
pi.  vi,  figs.  1-6. 

1906.  Dichelestium  oblongum  Norinan  &  T.  Scott.     (88)  p.  215. 

Female. — Body  elongated,  narrow  ;  carapace  nearly 
as  broad  as  long  and  somewhat  rhomboid  in  outline, 
widest  behind  the  middle,  and  with  the  sides  bluntly 
angulated ;  it  is  also  obscurely  lobed  in  front  and 
narrowed  and  truncated  behind.  Thoracic  segments 
four,  the  first  and  second  short  and  subequal,  but 
the  first  produced  laterally  into  short  rounded  lobes 
directed  backwards,  the  second  having  the  sides  also 
lobate  but  produced  slightly  outwards.  The  third 
segment,  which  is  rather  longer  than  the  preceding 
one,  widest  behind,  and  with  a  slight  constriction  in 
the  middle.  The  fourth  segment  similarly  constricted, 
and  somewhat  longer  than  the  third.  The  genital 
segment  about  one  and  a  half  times  the  length  of  the 
preceding  segment  and  tapering  slightly  towards  the 
posterior  end.  Abdomen  short.  Caudal  rami  small ; 
egg-strings  long  and  narrow. 

Antennules  moderately  short  and  slender  and  com- 
posed of  eight  subequal  joints.  Antenna?  stout,  and 
extending  prominently  in  front  of  the  carapace ;  indis- 
tinctly three-  or  four-jointed,  the  end  joint  slightly 


DICHELESTIUM    OBLONGUM.  107 

reflexed  and  furnished  with  a  small  apical  claw  which 
can  be  folded  inwards  so  as  to  impinge  against  a 
rounded  knob  and  thus  form  a  tolerably  powerful 
grasping-organ.  Mandibles  somewhat  like  those 
of  Caligus  except  that  the  basal  part  is  rather 
stouter.  Maxillas  small,  biramose,  primary  branch 
stout,  tapering  towards  the  distal  end,  and  bearing 
two  slender  apical  setaa  ;  secondary  branch  very  small. 
The  first  maxillipeds  with  the  first  and  second  joints 
of  nearly  equal  length,  but  the  first  is  more  robust ;  end 
joint  very  small  and  bearing  a  few  short  spines  and 
seta3.  Second  maxillipeds  short,  robust,  and  furnished 
with  stout  terminal  claws.  Thoracic  legs  short  and 
stout,  and  the  first  and  second  pairs  biramose.  Both 
rami  of  the  first  pair  indistinctly  two- jointed,  the 
proximal  joint  of  the  outer  ramus  having  a  small  spine 
on  its  outer  distal  angle  while  the  end  joint  has  five 
spines :  all  moderately  stout,  on  its  rounded  apex ; 
the  inner  ramus,  which  is  shorter  than  the  outer, 
carrying  two  terminal  spines.  The  second  pair 
similar  to  the  first  but  the  outer  branch  rather  stouter 
and  the  spines  shorter ;  the  inner  branch  also  propor- 
tionally rather  shorter.  The  fourth  pair  one-branched 
and  each  branch  consisting  of  a  single  uniarticulate, 
lamelliform  plate,  rather  longer  than  broad,  with  a  few 
minute  prickles  round  the  distal  end.  Length  17  to 
18  mm.,  but  varying  somewhat. 

Male. — The  male  bears  a  close  resemblance  to  the 
female,  but  is  considerably  smaller,  and  the  genital 
segment  is  proportionally  shorter.  In  the  second 
pair  of  thoracic  legs  the  inner  branch  is  very  short 
and  broad,  and  bears  on  its  outer  aspect  a  small  flat- 
tened plate.  The  fourth  pair  are  also  proportionally 
shorter  and  broader.  Length  about  13  mm. 

Habitat. — Parasitic  on  the  gills  of  the  sturgeon, 
Adpemter  xtn,-io.  On  a  sturgeon  captured  atPolperro, 
Cornwall,  in  1867  (A.  M.  Norman).  On  a  sturgeon 
captured  about  sixteen  miles  S.E.  by  E.  of  Aberdeen 
in  December  1904  (Dr.  Alex  Bowman).  On  a  sturgeon 


108  BRITISH  PARASITIC  COPEPODA. 

captured    near    Barrow-in-Furness,    Lancashire     (A. 

Scott). 

The  structure  of  the  mouth-organs  of  Dichelestium,  and 
especially  of  the  mandibles,  shows  a  somewhat  close  relation- 
ship with  the  Caligidae.  The  parasite  seems  to  be  peculiar 
to  the  sturgeon,  and  to  have  a  distribution  coextensive  with 
that  of  the  fish. 


Genus  20.  ANTHOSOMA  Lwch,  1816. 

Cephalothorax  of  considerable  size,  in  the  form  of  a 
narrow  ovoid  buckler  having  attached  to  it  near  the 
mouth  a  pair  of  large  foot-jaws  armed  with  strong 
hooks.  Genital  segment  furnished  with  elytraform 
appendages.  Thoracic  feet,  three  pairs,  all  folia- 
ceous. 

The  two  sexes  are  somewhat  similar  except  that, 
in  the  female,  the  genital  segment  and  abdomen  are 
almost  entirely  concealed  by  the  elytraform  append- 
ages, but  are  more  or  less  exposed  in  the  male. 

Anthosoma  crassum  ( Abildgaard) . 
(Plate  XXIII,  figs.  5,  6.) 

1794.  Caligus  crassus  Abildg.     (1)  vol.  iii,  p.  54,  pi.  v,  figs.  1-3. 
1816.  Caligus  imbricatus  Risso.      Hist.  nat.  Crust,  des  Environs  de 
Nice,  p.  162,  pi.  iii,  fig.  13. 

1816.  Anthosoma  smithii  Leach.     (74)  p.  406,  pi.  xx,  fig.  1. 

1838.  Anthoaoma  smithii  Kroyer.    (70)  vol.  i,  p.  295,  pi.  ii,  figs.  2  &2a. 

1850.  Anthosoma  smithii  Bah'd.     (4)  p.  296,  pi.  xxxiii,  fig.  9. 

1861.  Anthosoma  crassum  Stp.  &  Ltk.  (<$).    (127)  p.  397,  pi.  xxii,  fig.  24. 

1905.  Anthosoma  crassum  T.  Scott.     (116)  p.  112,  pi.  v,  figs.  15  &  16. 

1906.  Anthosoma  crassum  Norman  &  T.  Scott.     (88)  p.  214. 

Female. — Tolerably  elongated,  and,  Avhen  seen  from 
above,  ovate  in  general  outline  but  narrowed  in  front. 
The  head  and  a  considerable  portion  of  the  thorax 
covered  by  a  brownish-coloured  horny  shield  ^4iich 
gradually  expands  towards  the  posterior  end,  and  the 
junction  of  the  thorax  with  the  head  marked  by  an 
obscure  constriction.  The  remaining  portion  of  the 
thorax,  and  also  the  abdomen  and  caudal  rami,  covered 


ANTHOSOMA   CRASSUM.  109 

entirely  by  two  large  foliaceous  elytraform  circular 
plates,  the  inner  margins  of  which  partly  overlap  each 
other  on  the  dorsal  aspect,  these  plates  being  orna- 
mented with  numerous  minute  scattered  punctures  or 
depressions. 

Antennules  moderately  short,  and  composed  of 
six  sparingly-setiferous  joints;  the  antennas  stout, 
three-jointed,  longer  than  the  antennules,  and  armed 
with  strong  terminal  hook-like  claws.  First  maxilli- 
peds  slender  and  feebly  armed,  apparently  consisting 
of  three  joints,  the  end  one  being  small  and  of  a 
peculiar  shape ;  second  maxillipeds  short,  very  stout, 
and  furnished  with  strong  terminal  claws.  Thoracic 
legs  in  the  form  of  thin  and  broadly-foliaceous  plates 
each  with  a  distinct  notch  on  the  inner  margin,  con- 
cealing the  genital  segment  as  well  as  part  of  the 
abdomen.  Caudal  rami  narrow  and  moderately  elon- 
gated. Length  about  15  mm.  Egg-strings  long  and 
slender,  reaching  in  length  from  40  to  about  50  mm. 

The  shield  is  of  a  chitinous  texture,  the  colour  on 
the  sides  is  yellowish  but  merging  into  blackish-brown 
along  the  middle  and  towards  the  front ;  the  elytra- 
form  plates  and  thoracic  feet,  which  also  appear  to  be 
slightly  chitinous,  are  whitish  with  a  slight  tinge  of 
yellow. 

Male. — The  male  has  a  close  resemblance  to  the 
female,  except  that  the  large  dorsal  plates  which  cover 
the  posterior  portion  of  the  female  are  wanting. 

This  interesting  species  was  found  on  what  was  supposed 
to  be  a  porbeagle  shark  (Lamna  cornubicu)  captured  off  the 
coast  of  Scotland  in  October  1904,  by  one  of  the  trawling 
steamers  which  make  only  short  runs  from  Aberdeen  and 
which  are  locally  known  as  "  short  trippers."  Two  specimens 
of  the  Anthosoma  were  obtained — the  one  described  here  and 
a  smaller  one,  probably  a  male.  We  are  indebted  to  the 
kindness  of  Mr.  Irvine,  Aberdeen,  for  the  specimen  here  de- 
scribed. Dr.  Baird  states  (op.  cit.,  p.  299)  that  a  specimen 
was  "  discovered  sticking  to  a  shark  (the  Lamna  cornubica) 
thrown  ashore  at  Exmouth,  Devonshire,  by  T.  Smith,  Esq., 
of  the  Temple,  who  sent  it  to  Dr.  Leach,  British  Museum." 


110  BRITISH  PARASITIC   COPEPODA. 

Anthosoma  crassum  has  apparently  a  wide  distribution  in 
both  the  north  and  south  hemispheres.  Mr.  G.  M.  Thomson 
of  New  Zealand,  after  describing  the  species,  states  that 
"numerous  specimens  were  taken  from  the  upper  jaw  of  a 
porbeagle  shark,  Lamna  cornubica  (Otago  Museum).  Also  a 
number  from  the  same  kind  of  shark  taken  at  Napier  by  A. 
Hamilton " ;  and  he  adds  that  "  according  to  Gould  this 
species  has  been  taken  on  the  mackerel-shark,  Lamna  punc- 
tata,  on  the  coast  of  Massachusetts,  U.S. A."* 


Genus  21.  LERNANTHROPUS  Blainville,  1823. 

Body  broadly  ovate,  depressed.  Cephalon  oblong 
or  pyriform,  with  the  sides  incurved.  Neck  distinct ; 
the  posterior  part  in  the  female  covered  by  a  lauge 
dorsal  shield  sometimes  divided  into  two  portions  by 
a  transverse  constriction,  and  prolonged  backwards  so 
as  to  conceal  more  or  less  completely  both  the  genital 
segment  and  the  abdomen ;  in  the  male  the  dorsal 
shield  not  being  so  large  as  to  conceal  the  abdomen. 

Antennules  slender,  composed  of  five  or  more — 
usually  seven — articulations,  and  sometimes  furnished 
with  supplementary  appendages.  Antennae  robust 
"and  armed  with  strong  terminal  hooks.  Other  mouth- 
organs  somewhat  similar  to  those  of  the  Caligidse. 
Thoracic  legs  biramose  ;  the  first  and  second  pairs 
very  small  and  rudimentary;  the  third  and  fourth 
tolerably  large ;  rarni  lamelliform,  those  of  the  last 
pair  usually,  and  sometimes  those  also  of  the  others, 
forming  elongated  appendages  with  their  distal  ends 
more  or  less  attenuated. 

Lernanthropus  krbyeri  P.  J.  van  Beneden. 
(Plate  XXIX,  figs.  2-5;  Plate  XXX,  figs.  9-17.) 

1851.  Lernanthropus  kroyeri  P.  J.  van  Ben.   (11)  p.  102,  pi.  iii,  figs.  7-9. 
1858.  Lernanthropus  kroyeri  Clans.     (30)  p.  18,  pi.  ii,  figs.  15-19. 
1864.  Lernanthropus  kroyeri  Nordmann.    (90)  p.  508,  pi.  vii,  figs.  5-8. 
1879.  Lernanthropus  kroyeri  Heider.      (56)  vol.  ii,  p.  90,  pi.  v,  figs. 
72-73. 

1896.  Lernanthropus  kroyeri  Bassett-Smitb.     (7)  p.  159. 
1904.  Lernanthropus  kroyeri  A.  Scott.     (109)  p.  43. 

*  'Trans.  N.  Z.  Institute,'  vol  xxii  (1889),  p.  366. 


LERNANTHROPUS    EROYEUI.  Ill 

Female. — The  body,  which  is  oblong  in  shape,  some- 
what flattened  and  rather  wider  towards  the  posterior 
end,  and  divided  into  three  unequal,  but  moderately 
distinct,  portions ;  the  head,  which  is  the  shortest, 
equal  to  about  one-fourth  of  the  entire  length  of  the 
animal,  exclusive  of  the  posterior  appendages,  widest 
behind  and  tapering  slightly  on  each  side  forwards  to 
the  flatly-rounded  forehead ;  the  next  two  segments 
larger  and  subquadriform,  but  the  last  segment  about 
a  third  longer  than  the  middle  one.  The  genital 
segment  and  abdomen,  which  are  small,  entirely  con- 
cealed in  dorsal  view ;  caudal  rami  moderately  stout 
and  elongated. 

Antennules  moderately  short  and  composed  of  seven 
joints,  basal  joint  robust,  the  others  small ;  a  slender 
two-  or  three-jointed  appendage  springing  from  near, 
but  a  little  behind,  the  base  of  each  of  the  antennules, 
and  reaching  to  fully  beyond  their  apex.  Antennas 
short,  robust,  and  furnished  with  short  but  strong 
terminal  claws ;  mandibles  and  maxillas  slender ; 
maxillipeds  short,  stout,  and  strongly  uncinate. 
Thoracic  legs  biramose  ;  first  and  second  pairs  very 
small  and  rudimentary,  the  inner  ramus  uniarticulate 
and  rather  more  robust  than  the  outer,  which  consists 
of  one  or  two  small  joints. 

Other  appendages  occur  on  the  ventral  aspect  which 
are  referred  to  by  Steenstrup  and  Liitken  and  others 
as  the  third  and  fourth  pairs  of  legs.  The  third  pair 
consist  each  of  a  one-jointed  linguliform  appendage 
which  reaches  to  near  the  base  of  the  next  pair ;  the 
fourth  pair  have  each  two  branches;  they  form  elon- 
gated one-jointed  appendages  which  reach  backwards 
considerably  beyond  the  posterior  end  of  the  body; 
they  are  nearly  of  equal  length,  and  taper  towards  the 
blunt-pointed  extremity. 

Colour  dark  red.     Length  about  21  mm. 

Male. — The  male,  which  is  only  about  half  the  size 
of  the  female,  has  a  general  resemblance  to  it,  but  the 
head  is  proportionally  larger,  the  dorsal  shield  is 


112  BRITISH   PARASITIC   COPEPODA. 

smaller,  and  the  urosome  and  caudal  rami  are  not 
covered.  The  third  and  fourth  pairs  of  ventral 
appendages  are  also  more  prominent. 

Habitat. — Parasitic  on  the  gills  of  the  bass  or 
sea-perch,  Labrax  lupus.  Plymouth  (Bassett- Smith). 
Barrow  Channel,  Lancashire  (A.  Scott). 

Genus  22.  HATSCHEKIA  Poche,  1902. 

Syn.  Clavella  Kroyer  (1838)  and  others  but  not  Oken,  1815. 

Body  elongated  and  narrow.  Cephalon  distinct, 
small,  usually  rounded.  Thorax  short,  obscurely 
biarticulated,  without  dorsal  plates.  Genital  segment 
much  elongated,  narrow,  and  subcylindrical,  five  or 
six  times  the  length  of  the  cephalothorax.  Abdo- 
men and  caudal  rami  very  short  or  obsolete. 

Antennules  small  and  composed  usually  of  not  more 
than  six  articulations.  Antennas  short  and  stout, 
with  strong  terminal  hooks,  sometimes  and  perhaps 
generally  with  a  slender  spiniform  or  other  appendage 
at  the  base  of  each  antenna.  Mandibles  and  maxillas 
small.  First  maxillipeds  apparently  obsolete.  Second 
maxillipeds  slender  and  uncinate.  Thoracic  legs  two 
pairs,  very  short,  and  two-branched. 

Professor  van  Beneden  remarks  that  this  ^renus  is  perfectly 
characterized  and  easy  to  distinguish  by  the  length  of  the 
body;  by  the  three  pairs  of  appendages  that  follow  tin- 
antennas  ;  and  by  the  two  pairs  of  short  biramose  feet. 

1.  Hatschekia  hippoglossi  (Kroyer). 
(Plate  XXXIII,  figs.  3,  4 ;  Plate  XXXIV,  figs.  8-11.) 

'1838.  Clavella  hippoglossi  Kroyer.     (70)  p.  196.  pi.  ii.  fig.  3. 

1829-1843.  Clavella  hippoglossi  Guerin.  (55)  Icon,  du  Regne  Anim., 
Crustacea,  pi.  x,  fig.  7. 

1840.  Clavella  hippoglossi  M.  Edwards.     (43)  vol.  iii,  p.  494. 

1851.  Clavella  hippoglossi  P.  J.  van  Beneden.  (11)  p.  100,  pi.  iii, 
figs.  5  &  6. 

1900.  Clavella  hippoglossi  T.  Scott.     (112)  p.  159,  pi.  vii,  figs.  1-6. 

Female. — Body  slender,  elongated,  and  subcylin- 
drical. Cephalon  small,  of  an  oval  form,  width  greater 


HATSCHEKIA    HIPPOGLOSSI.  113 

than  the  length,  sides  rounded.  Between  the  cephalon 
and  the  genital  segment  is  a  short  neck,  narrow  and 
indistinctly  segmented,  and  provided  with  rounded 
lobes  on  each  side.  Genital  segment  considerably 
elongated  and  rather  narrow,  its  width  scarcely  equal 
to  one-fourth  of  the  length,  and  with  the  postero- 
lateral  corners  produced  into  rounded  lobes  about 
equal  in  size  to  the  small  abdomen  that  is  intermediate 
between  them  and  which  is  also  rounded ;  the  pos- 
terior end  has  thus  a  trilobed  appearance.  Caudal 
rami  extremely  small. 

Antennules  short,  rather  stout,  and  composed  of 
five  small  joints  which  are  sparingly  setiferous. 
Antennae  tolerably  large  and  armed  with  strong 
terminal  hooks  and  with  a  small  appendage  at  the 
base.  Mandibles  small,  elongated,  tapering  distally, 
and  provided  with  a  few  small  teeth  at  the  distal 
end  of  the  inner  margin.  Maxilla?  very  small  but 
comparatively  stout,  and  furnished  with  two  or  three 
tooth-like  processes.  Maxillipeds  elongated  and 
slender.  Thoracic  legs  two  pairs,  short  and  biramose, 
both  rami  appearing  to  be  composed  of  two  somewhat 
indistinct  joints.  Length  about  9  mm. ;  length  of  head 
and  neck  combined  1*5  mm.  Egg-strings  long  and 
slender.  Colour  resembling  that  of  the  gills  to  which 
the  parasite  was  adhering. 

Male. — The  male  is  much  smaller  than  the  female 
but  has  a  general  resemblance  to  it.  The  cephalon  is 
proportionally  rather  larger  and  the  thoracic  ring  is 
distinctly  segmented.  The  genital  segment  is  also 
proportionally  much  shorter  than  in  the  female,  being 
only  about  twice  as  long  as  broad. 

Antennules  short,  composed  of  five  joints.  Antennas 
provided  with  large  and  strong  hooks,  projecting  well 
in  front  of  the  cephalon.  Caudal  rami  narrow  and 
more  prominent  than  in  the  female.  Length  1*5  mm. 

Habitat. — Parasitic  on  the  gills  of  halibut,  Hi}>j><>- 
glossus  vulgaru ;  not  uncommon.  The  reddish 
coloured,  thread-like  egg-strings  may  sometimes  be 

VOL.  I.  8 


114  BRITISH  PARASITIC  COPEPODA. 

observed  projecting  beyond  the  edges  of  the  gill- 
filaments.  Frequently  observed  on  halibut  brought 
to  the  Fish-Market  at  Aberdeen. 

The  males  are  apparently  very  rare.  Though  many  speci- 
mens of  halibut  have  been  examined,  only  one  male  specimen 
of  this  species  has  been  met  with. 

2.  Hatschekia  mulli  (P.  J.  van  Beneden). 
(Plate  XXXII,  figs.  1-11.) 

1851.  Clavella  mulli  P.  J.  van  Beneden.     (11)  p.  99,  pi.  iii,  figs.  3  &  4. 
1896.  Clavella  mulli  Bassett-Smith.     (7)  p.  159. 
1906.  Clavella  mulli  Norman  &  T.  Scott.     (88)  p.  215. 

Female. — Body  narrow,  elongated,  and  sub-cylin- 
drical ;  head  small,  subglobose,  but  the  width  rather 
greater  than  the  length  ;  front  somewhat  lobate  and 
without  any  horn-like  processes.  Neck  very  short, 
the  thorax,  which  is  indistinctly  segmented,  merging 
almost  imperceptibly  into  the  genital  segment ;  on  the 
dorsal  aspect  of  the  thorax,  and  on  each  side  of  the 
median  line,  a  small  rounded  protuberance,  seen  best 
in  lateral  view  (PL  XXXII,  fig.  2).  Genital  segment 
elongated  and  narrow,  slightly  expanded  in  the  middle 
and  tapering  gradually  towards  both  ends,  greatest 
width  equal  to  about  one-fourth  of  the  entire  length 
of  the  animal;  posterior  end  trilobed,  lateral  lobes 
small  and  distinct,  and  produced  slightly  outwards, 
the  middle  one  broad  and  not  very  prominent. 

The  cephalothoracic  appendages  comprise  the 
antennules,  which  are  moderately  small  and  composed 
of  three  spinulose  joints,  the  last  one  with  also  a  few 
apical  spines  ;  the  antenna?,  composed  each  of  a  single 
large  and  moderately  long  basal  part,  and  furnished 
with  a  stout  terminal  hook-like  claw ;  there  is  also  at 
the  base  of  each  antenna  a  small  secondary  appen- 
dage— probably  a  sense-organ  (PL  XXXIII,  fig.  5). 
Mandibles  small  with  the  extremity  slightly  curved 
and  hook-like.  Maxillee  small,  with  both  the  internal 
and  external  rami  considerably  attenuated.  Second 
maxillipeds  moderately  slender  and  somewhat  similar 


HATSCHEKIA    MULLI.  115 

to  those  of  Hatschekia  hippoglossi.  Thoracic  legs  two 
pairs,  each  composed  of  a  stout  two-jointed  basal  part, 
which  is  furnished  with  two  short  two-jointed  ranii. 
Egg-strings  long  and  slender.  Length  of  adult  female 
exclusive  of  egg-strings  3 '4  mm.,  and  including  egg- 
strings  about  10  mm. 

No  males  have  been  observed. 

Habitat. — Parasitic  on  the  gills  of  red  mullet,  Mullus 
barbatus.  Recorded  from  Plymouth  by  Dr.  Bassett- 
Smith.  Observed  also  on  the  gills  of  four  specimens 
of  red  mullet  sent  to  us  from  Looe,  Cornwall,  by 
Mr.  N.  M.  Richards  of  that  town,  and  on  one  from 
Plymouth  sent  by  Dr.  E.  J.  Allen,  Director  of  the 
Plymouth  Laboratory.  It  was  also  on  Mullus  barbatus 
that  Professor  van  Beneden  obtained  his  specimens  of 
HatscheJda  mulli. 

A  feature  which  appears  to  be  peculiar  to  this  species,  and 
which  was  also  noticed  by  van  Beneden,  is  the  secondary 
process  at  the  base  of  each  antenna :  this  process  diifers  from 
that  of  any  of  the  other  species  known  to  us. 

H.  mulli  is  readily  distinguished  from  other  members  of 
the  genus  recorded  here  by  the  dorsal  humps  on  the  thoracic 
region,  and  the  small  lateral  lobes  at  the  posterior  end.  A 
young  female  is  represented  in  dorsal  view  at  fig.  3,  and  it 
also  shows  traces  of  the  characters  by  which  the  species  is 
distinguished. 

3.  Hatschekia  labracis  (P.  J.  van  Beneden). 
(Plate  XXXIII,  fig.  2  ;  Plate  XXXIV,  figs.  6,  7.) 

1870.  Clavella  labracis  P.  J.  van  Beneden.     (16)  pp.  45  &  46,  pi.  i,  fig.  4. 

1901.  Clavella  labracis  T.  Scott.     (113)  p.  127. 

1902.  Clavella  labracis  T.  Scott.     (114)  p.  292,  pi.  xiii,  figs.  10-12. 
1904.  Clavella  labracis  A.  Scott.     (109)  p.  40. 

Female. — Cephalothoracic,  segment,  seen  from  the 
dorsal  aspect,  rhomboid  or  diamond-shaped,  the  lateral 
margins  produced  so  as  to  form  distinct  angular  pro- 
jections ;  the  width  of  the  segment  across  the  lateral 
angles  rather  greater  than  the  length  and  equal  to 
about  a  fifth  of  the  entire  length  of  the  animal.  Genital 
segment  elongate-ovate,  about  three  times  as  long  as 
the  cephalothorax,  widest  in  the  middle  and  with  the 


116  BRITISH   PARASITIC   COPEPODA. 

lateral  margins  slightly  convex.     Abdomen  and  caudal 
rami  very  small. 

Antennules  short,  moderately  stout,  and  consisting 
of  about  five  joints,  the  first  large  and  equal  to  nearly 
all  the  other  joints  combined,  and  its  lower  distal  angle 
produced  downwards  in  the  form  of  a  strong  hook ; 
the  three  end  joints  subequal  and  shorter  than  the 
preceding  one ;  several  short,  dagger-like  spines 
springing  from  the  upper  margin  of  the  various 
joints.  Antennae  about  as  long  as  the  antennules, 
two-jointed  and  armed  with  stout  terminal  claws;  a 
small  process  in  the  form  of  a  knob  occurs  at  the  base 
•  of  each  antenna.  Mandibles  and  maxillse  small  and 
simple  in  structure.  Maxillipecls  moderately  slender, 
composed  of  two  (or  three)  joints,  and  with  the 
extremities  uncinate.  Thoracic  legs  two  pairs,  both 
biramose  and  somewhat  similar  in  structure ;  the  basio- 
podite  consisting  of  two  moderately  stout  joints  and 
both  rami  also  two-jointed,  the  inner  ramus  in  both 
pairs  being  rather  more  robust  than  the  outer  one;  the 
proximal  joint  of  the  outer  ramus  the  largest  and 
bearing  a  small  spine  on  its  outer  distal  angle,  the 
joints  of  the  inner  ramus  also  unequal  but  the  proximal 
one  the  smaller.  Caudal  rami  short.  Length  about 
1  mm.  Egg-strings  fully  as  long  as  the  animal,  and 
with  proportionately  few  but  rather  large  ova.  Colour 
similar  to  that  of  the  gills  of  the  host. 

The  male  of  this  species  has  not  yet  been  observed. 
Habitat. — Parasitic  on  the  gills  of  the  striped  Avrasse, 
Labrus  mixtus  Linn.,  and  the  ballan  wrasse,  Labr/i* 
bergylta  Ascan.  (Labrus  maculatus  Bloch).  Firth  of 
Clyde  ( T.  Scott).  Irish  Sea  (A.  Scott).  Professor  P.  J. 
van  Beneden  states  that  Hatschekia  labracis  is  abundant 
on  both  of  the  species  of  fish  mentioned  above. 

This  Hatschekia,  though  distinct  enough,  is  very  small  ami 
easily  overlooked,  but  as  the  egg-strings  are  of  a  somewhat 
lighter  colour  than  the  gills  of  the  fish,  and  tolerably 
elongated,  they  help  to  reveal  the  presence  of  the  parasite. 


HATSCHEKIA   CLUTHJI.  117 

4.  Hatschekia  cluthae  (T.  Scott). 
(Plate  XXXIII,  fig.  1 ;  Plate  XXXIV,  figs.  1-5.) 

1902.  Clavella  cluthse  T.  Scott.     (114)  p.  292,  pi.  xii,  figs.  26-31. 

Female. — With  a  general  resemblance  to  the  female 
of  H.  labracis  (van  Beneden)  recorded  above,  but 
much  larger,  and  the  lateral  margins  of  the  cephalic 
segment  evenly  rounded  instead  of  being  angular  as 
in  that  species.  The  genital  segment,  the  form  of 
which  is  also  somewhat  different  from  that  of  H. 
l< /brads,  becoming  gradually  wider  posteriorly,  so  that 
the  widest  part  near  the  hinder  end  is  about  twice  as 
wide  as  it  is  immediately  posterior  to  the  cephalon  ;  the 
segment  narrowing  convexly  and  somewhat  rapidly 
behind  the  widest  part  to  the  obscurely-angulated  ex- 
tremity. Abdomen  and  caudal  rami  very  small. 

Antennules  apparently  only  four-jointed,  moderately 
stout  and  furnished  with  a  few  minute  spines,  the  basal 
joint  about  as  long  as  the  next  three  taken  together, 
but  the  end  joint  very  small.  Antennas  fully  as  long 
as  the  antennules,  and  composed  of  two  joints,  each 
provided  with  a  short  but  strong  terminal  hook-like 
claw.  Maxilla3  very  small  and  simple  in  structure, 
consisting  each  of  a  minute  papilliform  basal  joint, 
bearing  three^small  spines.  Maxillipeds  small,  two-  or 
three-jointed,  and  furnished  with  small  terminal  claws. 
Both  pairs  of  thoracic  legs  biramose  and  somewhat 
similar  in  structure ;  the  basiopodite  tolerably  stout 
and  composed  of  two  joints;  the  rami  also  two- 
jointed,  and  armed  with  small  terminal  spines ;  the 
first  joint  of  the  outer  ramus  larger  than  the  second  and 
carrying  a  small  spine  at  its  outer  distal  angle,  while 
on  the  other  hand  the  end  joint  of  the  inner  ramus  is 
the  larger  one ;  the  second  basal  joint  also  with  a 
small  spine  on  its  inner  distal  angle. 

Caudal  rami  very  short ;  the  egg-strings  also  toler- 
ably short  and  slender.  Colour  somewhat  similar  to 
that  of  the  gills  of  the  fish.  Length  about  1'5  mm. 
exclusive  of  the  egg-strings. 


118  BRITISH  PARASITIC  COPEPODA. 

Habitat. — Parasitic  on  the  gills  of  Jago's  goldsinny, 
Ctenolabms  rupestris  Linn.,  East  Loch  Tarbert  (a 
branch  of  Loch  Fyne)  (T.  Scott). 

The  male  has  not  yet  been  observed. 

The  more  obvious  characters  by  which  this  species  may  be 
distinguished  from  H.  labracis  appear  to  be  its  larger  size,  the 
different  form  of  the  cephalon  and  genital  segment,  and  the 
structure  and  armature  of  the  antennules. 

5.  Hatschekia  cornigera  T.  Scott. 
(Plate  XXXV,  figs.  1,  2 ;   Plate  XXXVI,  figs.  1-5.) 

1909.  Hatschekia  cornigera  T.  Scott.     (118)  p.  74,  pi.  iii,  figs.  1-7. 

Female. — Body  narrow  and  greatly  elongated.  Head 
proportionally  very  small  and  expanding  laterally  into 
broadly-rounded  lobes,  also  produced  backward,  on 
the  median  dorsal  aspect,  into  a  blunt-pointed  spur- 
like  process ;  this  segment  being  distinctly  limited, 
by  a  constriction,  from  the  thorax,  which  is  narrow 
where  it  joins  the  head. 

No  distinct  separation  between  the  thorax  and  the 
genital  segment,  the  one  merging  gradually  into  the 
other.  Genital  segment  very  long  and  narrow,  and  of 
about  the  same  width  throughout — the  width  being 
only  equal  to  about  one  -  sixth  of  the  length ;  the 
segment  near  its  posterior  end  tapering  to  the  narrow 
and  obscurely  bilobed  extremity ;  abdomen  very  small 
and  not  clearly  defined. 

Antennules  short,  moderately  stout,  and  composed 
of  five  articulations  which  are  sparingly  setiferous. 
Antenna?  large  and  armed  with  strong  and  hook-like 
terminal  claws.  Mandibles  and  maxilla?  somewhat 
similar  to  those  of  H.  cluthae.  Maxillipeds  tolerably 
elongated  and  slender,  with  a  short  spine  arising  from 
the  inner  aspect  and  near  the  proximal  end  of  the 
second  joint,  the  end  joint  terminating  in  a  pair  of  not 
very  strong  and  slightly-curved  spines.  Both  pairs 
of  thoracic  legs  biramose;  the  basiopodite  consider- 
ably enlarged  and  composed  of  two  articulations  ;  the 


HATSCHEKIA   CORN1GKKA.  1  1 '-> 

outer  and  inner  rami  also  two-jointed  and  provided 
with  a  few  apical  spines.  Caudal  rami  inconspicuous 
or  obsolete.  Length  about  2'5  mm.  Egg-strings 
scarcely  as  long  as  the  genital  segment.  Colour 
similar  to  that  of  the  gills  of  the  fish. 

No' males  have  been  observed. 

Habitat. — Parasitic  on  the  gills  of  sea  bream, 
Pagelliw  centrodontns  De  la  Roche,  captured  in  the 
North  Sea  and  landed  at  the  Fish-Market  at  Aberdeen 
during  the  early  months  of  1908  (T.  Scott). 

This  species  is  very  slender  in  proportion  to  its  length,  and 
in  this  respect  it  has  a  resemblance  to  Kroyeria  ;  the  head  is 
also  proportionally  very  small.  When  in  situ  on  the  gills  of 
the  fish,  the  parasite  is  not  very  conspicuous  and  may  be 
easily  overlooked.  The  horn-like  process  on  the  dorsal  aspect 
of  the  cephalon,  best  seen  in  lateral  view,  is  perhaps  one  of 
the  more  distinctive  features  of  the  species. 

6.  Hatschekia  pygmaea  T.  Scott. 
(Plate  XXXV,  figs.  3-7 ;  Plate  XXXVI,  figs.  6-9.) 

1907.  Clavella  labracis  (?)  P.  J.  van  Beneden,  A.  Scott,  (lll)p.  95,pl.  iv. 

Female.  —  Antennules  comparatively  short,  stout, 
and  composed  of  five  articulations,  the  first  being 
robust  and  equal  to  about  two-fifths  of  the  entire 
length  of  the  antennule,  the  next  about  half  the  size 
of  the  first,  but  the  remaining  three  considerably 
smaller  and  subeqnal ;  the  first  and  second  joints 
furnished  with  a  number  of  short  spatulate  hairs  on 
their  upper  aspect ;  the  first  joint  also  with  a  short 
and  stout  spiniform  seta  on  the  lower  distal  angle,  a 
minute  seta  springing  from  the  lower  margin  of  the 
third  joint,  while  the  end  one  has  several  similar  seta3 
on  its  lower  margin  and  apex  and  two  small  hooks  on 
the  upper  distal  angle  as  shown  in  the  drawing 
(PL  XXXV,  fig.  4).  Antennae  tolerably  elongated 
and  slender,  and  terminating  in  strongly-curved  apical 
hooks.  Mandibles  and  maxillae  rudimentary,  the 
former  having  apparently  no  serrated  apex.  Both 
pairs  of  thoracic  legs  biramose,  small  and  more  or  less 


120  BRITISH  PABASITIC  COPEPODA. 

rudimentary ;  in  the  first  pair  both  rami  two-jointed, 
the  outer  ramus  of  the  second  pair  also  consisting  of 
two  joints  but  the  inner  one  three-jointed.  Caudal 
rami  very  small  and  inconspicuous.  Length  about 
1  mm.  Colour  similar  to  that  of  the  gills  of  the  fish. 
Egg-strings  tolerably  short  and  containing  compara- 
tively few  but  moderately  large  ova. 

No  males  have  been  observed. 

Habitat. — Found  adhering  to  the  gills  of  Crenihibi-H* 
in  el  ops  (Linn.),  the  connor  or  goldsinny,  captured  in 
Luce  Bay,  Solway  Firth  (A.  Scott). 

This  species,  which  was  described  in  1907,  was  at  first 
doubtfully  assigned  to  Clarella  (or  Hatschekia)  labracis  van 
Beneden;  the  examination,  however,  of  additional  specimens, 
obtained  subsequently,  showed  that  certain  differences  which 
had  been  recognized  in  the  first  specimens  were  fairly  constant, 
and  were  moreover  sufficiently  important  to  make  it  necessary 
to  regard  it  as  distinct  from  others  that  have  been  described. 

In  its  general  appearance  this  species  has  a  resemblance  to 
the  Hatschekia  labracis  of  van  Beneden.  It  differs  from  that 
species  in  the  head  being  rounded  at  the  sides — not  angular 
as  in  that  species — in  the  armature  of  the  antennules,  and  in 
the  terminal  claws  of  the  antenna?  being  much  less  strongly 
hooked,  as  well  as  in  one  or  two  other  anatomical  details.  At 
the  base  of  each  antenna  there  is  a  small  knob-like  process 
similar  to  that  on  the  antenna  of  Hatschekia  lahracis.  This 
fish  is  not  the  same  as  Jago's  goldsinny,  but  belongs  to  a 
different  species  of  the  Wrasse  family. 

Genus  23.  KROYERIA  P.  J.  von  Beneden,  1853. 

Syn.  Lonchidium  Gerstaecker,  1854. 

Cephalic  segment  moderately  broad  and  plate-like, 
and  furnished  at  the  posterior  end  with  movable  styli- 
form  processes,  projecting  backwards.  Three  distinct, 
free  thoracic  segments,  without  lobes  or  dorsal  plates. 
Genital  segment  long  and  narrowly  cylindrical.  Ab- 
domen short,  unsegmented  in  the  female,  and  termi- 
nating in  two  lanceolate  setose  furca.  Antennules 
composed  of  seven  distinct  joints.  Antenna  very 
stout  and  cheliform.  Mandibles  and  maxilla?  rudimen- 


KEOYEKIA.  121 

tary  and  resembling  those  of  Eudactylina.  Second 
pair  of  maxillipeds  large  and  furnished  with  powerful 
claws.  Thoracic  legs,  four  pairs,  well  developed  and 
biramose;  each  ramus  three-jointed,  and  furnished 
on  the  inner  margin  with  long  plumose  setae. 

The  male  has  a  general  resemblance  to  the  female 
but  is  considerably  smaller.  The  thoracic  and  ab- 
dominal segments  are  also  narrower  than  in  the  female, 
and  the  abdomen  is  distinctly  three-jointed. 

1.  Kroyeria  lineata  P.  J.  van  Beneden. 
(Plate  LXX,  figs.  1-13.) 

1853.  Kroyeria  lineata  P.  J.  van  Beneden.  (13c)  Bull.  Acad.  Roy. 
Belg.,  vol.  xx,  p.  94. 

1861.  Kroyeria  lineata  idem.  (15)  Rec.  sur  les  Crust.  Belg.,  p.  149, 
pi.  xxii. 

1858.  Kroyeria  lineata  Glaus.    (30)  Beitrag  Parasit.  Crust.,  p.  24,  pi.  ii. 

1880.  Kroyeria  lineata  Valle.  (141a)  Boll.  Soc.  Adriat.  Sc.  Nat.  vol.  vi, 
p.  65. 

1885.  Kroyeria  lineata  Carus.  (29a)  Podrom.  Faunae  Mediterranean, 
p.  364. 

1899.  Lonchidium  lineatum  Bassett-Smitli.  (8)  Proc.  Zool.  Soc. 
Lond.  1899,  p.  473. 

1906.  Kroyeria  lineata  A.  Brian.  (21)  Copepodi  Parassiti  dei  Pesci 
d'ltalia,  p.  67,  pi.  v,  fig.  3. 

Female. — Length,  exclusive  of  the  furcal  setae, 
4'5  mm.  Cephalic  segment  moderately  broad  and 
flattened  and  having  the  antero-lateral  margins  con- 
cave, giving  rise  to  a  broadly-rounded  forehead. 
Posterior  margin  furnished  on  each  side  with  a  strong 
movable  spine,  the  apex  of  which  is  somewhat  cheli- 
form,  and  reaches  to  the  end  of  the  first  free  segment 
of  the  thorax.  The  eyes,  two  in  number,  situated  in 
the  front  portion  of  the  segment,  a  V-shaped  band  of 
chitin  with  a  pointed  end  traversing  the  segment  from 
front  to  rear  (PI.  LXX,  fig.  1).  The  three  thoracic  seg- 
ments short  and  quadrangular  in  outline,  the  second 
being  distinctly  shorter  than  the  other  two.  The  third 
segment  considerably  longer  than  the  first  and  nearly 
twice  the  length  of  the  second,  with  its  lateral  margins 
slightly  inflated  posteriorly.  All  three  segments  pro- 
vided with  dorsal  and  lateral  bars  of  chitin.  Genital 


122  BRITISH   PARASITIC  COPEPODA. 

segment  very  long  and  narrowly  cylindrical.  Its 
distal  end,  in  dorsal  view,  distinctly  truncated,  and  in 
lateral  view  broadly  rounded  and  somewhat  gibbous 
(PL  LXX,  fig.  10).  Abdomen  short  and  narrow,  joining 
the  ventral  surface  of  the  distal  end  of  the  genital 
segment ;  uniarticulated,  but  in  some  specimens  two 
slight  constrictions  appear  which  may  correspond  to 
the  distinct  segments  seen  in  the  male.  Furcal  joints 
moderately  long  and  narrow,  and  about  four  times 
longer  than  broad.  Egg-strings  short  and  cylindrical, 
containing  only  a  single  row  of  eggs. 

Antennules  short  and  seven-jointed;  moderately 
setif  erous.  Basal  joint  nearly  as  long  as  the  combined 
lengths  of  the  next  five,  and  its  distal  end  crossed  by 
three  indistinct  lines  as  shown  in  the  drawing  (fig.  2). 
Distal  end  of  the  last  joint  provided  with  a  short,  but 
stout,  sensory  filament.  Antennas  short  and  stout, 
and  armed  with  powerful  chelae  which  are  used  for 
securing  the  parasite  to  its  host,  and  are  easily  visible 
in  the  entire  animal,  even  without  dissection  and  by 
using  an  ordinary  hand  magnifier. 

Mandibles  stylet-shaped,  with  the  distal  end  of  the 
inner  margin  serrate  as  in  Eudactylina.  Maxilla; 
bilobed,  very  small  and  somewhat  rudimentary.  The 
distal  end  of  each  lobe  furnished  with  two  setae. 

First  maxillipeds  small  and  cheliform,  the  claw -like 
end  joint  moderately  broad  and  spoon-shaped ;  the 
distal  end  of  the  upper  margin  of  the  joint  over  which 
the  claw  folds  slightly  serrate  and  ciliated  (fig.  6). 
Second  maxillipeds  large,  and  forming  powerful  pre- 
hensile organs,  their  terminal  claw  strongly  curved 
and  nearly  as  long  as  the  joint  from  which  it  springs. 

The  four  pairs  of  thoracic  legs  all  somewhat  similar 
in  structure.  They  are  biramose,  and  the  rami  ;nv 
three-jointed  as  shown  by  figs.  8  and  9  on  PI.  LXX. 
Basal  plate  of  the  first  pair  produced  at  its  distal 
angles  into  minute  tubercles,  but  in  that  of  the  second, 
third,  and  fourth  pairs  the  angles  are  produced  into 
moderately  long  and  stout  spines  which  are  quite  pro- 


KKOYERTA    LINEATA.  123 

minent  in  the  entire  animal.  Xo  trace  of  a  fifth  pair 
of  feet. 

Male. — Length  exclusive  of  the  furcal  setaa  2' 7  mm. 
The  cephalic  segment  is  similar  to  that  of  the 
female  in  every  respect  except  in  the  shape  and  length 
of  the  movable  spines  at  its  distal  end.  The  spines 
are  evenly  curved  to  the  apex,  and  do  not  reach  the 
end  of  the  first  thoracic  segment.  The  first  two 
segments  of  the  thorax  are  nearly  of  equal  size.  The 
third  segment  is  almost  twice  as  long  as  the  second, 
and  its  proximal  lateral  margins  are  slightly  expanded. 
The  genital  segment  is  narrow  and  cylindrical,  and 
distinctly  longer  than  the  combined  lengths  of  the 
three  thoracic  segments.  The  abdomen  is  composed  of 
three  clearly-defined  segments.  The  first  segment  is 
about  half  the  length  of  the  genital  segment.  The 
second  and  third  are  of  nearly  equal  length,  and  are 
each  about  equal  to  two-thirds  of  the  length  of  the 
genital  segment.  The  furcal  joints  are  almost  similar 
to  those  of  the  female. 

The  various  thoracic  and  other  appendages  are 
similar  to  those  of  the  female,  and  therefore  need  not 
be  described.  A  rudimentary  fifth  pair  of  feet  repre- 
sented by  three  minute  setas  can  be  detected  by  care- 
fully examining  the  lateral  margins  of  the  genital 
segment. 

Habitat. — In  the  hollows  between  the  gill-rays  of 
male  specimens  of  Galeorhinus  galeus  or  tope,  captured 
in  the  Irish  Sea  in  the  vicinity  of  King  William  Bank, 
off  the  north  end  of  the  Isle  of  Man,  April  1912.  We 
have  not  yet  met  with  this  parasite  on  the  gills  of 
female  specimens  of  the  tope,  although  a  considerable 
number  of  them  have  been  examined.  Much  care  is 
required  to  detect  the  parasite,  as  it  is  usually  entirely 
hidden  in  the  hollows  between  the  gill-rays.  The 
presence  of  the  parasites  is  occasionally  revealed  by 
the  egg-strings  projecting  beyond  the  ends  of  the 
gills.  Several  specimens  of  both  sexes  may  sometimes 
be  found  on  the  gills  of  a  single  fish. 


124  BRITISH   PARASITIC  COPEPODA. 

The  genus  and  species  were  both  described  by  P.  J.  van 
Beneden  in  1853.  In  the  following  year  Gerstaecker 
described  a  closely  allied  parasite  under  the  name  Lenchidium 
aculeatum.  Bassett-Smith  in  his  work  'A  Systematic  De- 
scription of  Parasitic  Copepoda  found  on  Fishes/  sets  aside 
the  generic  name  given  by  van  Beneden  and  adopts  Ger- 
staecker's  Lonchidium.  Brian  restores  van  Beneden's  name 
in  his  work  '  Copepodi  Parassiti  dei  Pesci  d'ltalia/  and  as  we 
have  been  unable  to  find  any  satisfactory  reason  to  support 
Bassett-Smith  in  changing  the  generic  name,  we  have  fol- 
lowed Brian  in  adhering  to  van  Beneden's  name  Kroyeria. 
Spence  Bate  used  the  name  Kroyera  to  distinguish  a  genus  of 
Amphipoda  in  1857,  but  Sars  points  out  in  his  '  Crustacea  of 
Norway/  vol.  i,  that  the  name  had  already  been  appropriated 
in  zoology.  Brian  apparently  regards  Gerstaecker's  Lon- 
chidium  aculeatum  to  be  nearly  identical  with  Kroyeria 
lineata.  We  kept  a  number  of  specimens  of  both  sexes  alive 
in  sea-water  for  a  time,  but  were  unable  to  detect  them  making 
any  attempt  to  swim. 

Genus  24.  CONGERICOLA  P.  J.  van  Beneden,  1854. 

Syn.  Cycnus  M.  Edwards  (1840),  preoccupied  by  Hiibner  for  a  genus 
of  Lepidoptera. 

Head  rounded,  small ;  free  thoracic  segments  two, 
without  lobes  or  dorsal  plates :  genital  segment  elon- 
gated, narrow,  and  subcylindrical ;  abdomen  short ; 
caudal  rami  setiferous.  Antennules  composed  of  about 
six  articulations ;  antenna?  two-jointed  and  armed  with 
terminal  claws.  Second  maxillipeds  slender.  Thoracic 
legs  four  pairs,  all  biramose. 

The  only  British  species  known  to  us  is  that  described 
below. 

1.  Congericola  pallida  P.  J.  van  Beneden. 
(Plate  XLI,  fig.  1.) 

1854.  Congericola  pallida  P.  J.  van  Beneden.    (14)  vol.  xxi.pt.  2,  p.  583. 
1861.  Congericola  pallida  idem.     (15)  p.  148,  pi.  xxiii. 
1896.  Cycnus  pallidus  Bassett-Smith.     (7)  p.  159. 

1900.  Cycnus  pallidus  T.  Scott.     (112)  p.  160. 

1901.  Cycnus  pallidus  A.  Scott.     (107)  p.  350. 

1906.  Congericola  pallida  Norman  &  T.  Scott.     (88)  p.  215. 

Female. — Cephalic  segment  small  and  suborbicular. 


CONGEEICOLA  PALLID  A.  125X 

Free  thoracic  segments  two,  very  short,  and  without 
lobes  or  dorsal  plates.  Genital  segment  elongated, 
narrow,  and  subcylindrical.  Abdomen  short ;  caudal 
segments  small  and  setiferous. 

Antennules  short  and  composed  of  about  six  joints, 
but  one  or  two  of  the  articulations  are  not  very 
distinct;  antennae  two-jointed,  and  provided  with 
strong  terminal  hooked  claws.  Mouth-appendages 
somewhat  similar  to  those  in  Hatschekia.  Thoracic 
legs  four  pairs,  biramose,  and  somewhat  rudimentary. 
Colour  pale  reddish,  scarcely  so  deep-coloured  as  the 
gills  of  the  fish.  Length,  exclusive  of  egg-strings, 
about  4  mm. ;  egg-strings  slender  and  elongated,  about 
twice  as  long  as  the  animal. 

This  species,  in  its  general  appearance,  has  a  some- 
what close  resemblance  to  Hatecbelcia. 

The  male  has  not  been  observed. 

Habitat.  -  -  Parasitic  on  the  gills  of  conger  eels, 
Conger  vulgaris  Cuv.  (Conger  niger,  Risso).  Plymouth 
(Bassett- Smith).  Firth  of  Clyde  and  at  Aberdeen  (T. 
Scott}.  Lancashire  coast  (A.  Scott). 

This  parasite  is  not  uncommon  on  the  gills  of  large  speci- 
mens of  the  conger,  and  sometimes  occurs  in  considerable 
numbers.  Thirty  individuals  have  been  taken  from  the  gills 
of  a  single  fish.  The  species  has  been  recorded  from  the 
Adriatic  (Dr.  Graeffe)  as  well  as  from  the  coast  of  Belgium 
(P.  J.  van  Beneden). 


Genus  25.  EUDACTYLINA  P.  J.  can  Beneden,  1853. 

Female. — Cephalothorax  composed  of  five  segments ; 
cephalic  segment  obtuse,  wider  behind  than  in  front ; 
thoracic  segments  without  dorsal  plates  or  lateral 
processes.  Abdomen,  including  the  genital  segment, 
considerably  shorter  than  the  cephalothorax  and  com- 
posed of  three  segments.  Antennules  short,  stout, 
and  usually  five-jointed,  basal  joint  usually  provided 
with  strong  hooked  spines ;  antenna  three-jointed  and 
armed  with  stout  terminal  claws.  Mandibles  and 


126  BRITISH   PARASITIC   COPE  POD  A. 

maxillae  small,  somewhat  similar  in  structure  to  those 
of  Hatschekia.  First  maxillipeds  small,  composed  of 
three  joints,  and  provided  with  a  small  terminal  claw ; 
second  maxillipeds  of  moderate  size,  armed  with 
terminal  claws,  strong  and  cheliform.  First  four 
pairs  of  thoracic  legs  short,  biramose ;  rami  of  the 
first  pair  two-  or  three-jointed ;  those  of  the  third  and 
fourth  pairs  are  usually  both  composed  of  three  joints; 
but  though  in  the  second  pair  the  inner  ramus  is  some- 
what similar  in  structure  to  that  of  the  next  pair,  the 
outer  one  is  more  or  less  modified.  Fifth  pair  con- 
sisting each  of  a  small  uniarticulate  lamina ;  caudal 
rami  short. 

Male. — The  male  somewhat  resembles  the  female, 
but  differs  in  being  smaller  and  in  the  antennules  being 
armed  with  one  or  two  moderately  strong  terminal 
hooks.  The  second  maxillipeds  are  not  cheliform  but 
resemble  in  structure  those  in  Hatschekia ;  the  outer 
ramus  of  the  second  pair  of  thoracic  legs  is  not  modi- 
fied, and  there  is  also  a  difference  in  the  form  of  the 
caudal  rami.  Moreover  the  abdomen,  including  the 
genital  segment,  is  in  the  male  nearly  as  long  as  the 
cephalothorax. 

1.  Eudactylina  acuta  P.  J.  van  Beneden. 
(Plate  XXXVII,  fig.  1 ;  Plate  XXXVIII,  figs.  1-5.) 

1853.  Eudactylina  acuta  P.  J.  van  Beneden.     (13b)  Bull.  Acad.  Roy. 
Belgique.  vol.  xx,  pt.  i,  p.  235. 

1861.  Eudactylina  acuta  idem.     (15)  p.  150,  pi.  xxv. 

1892.  Eudactylina  acuta  Canu.     (29)  p.  52,  pis.  2  &  3. 

1902.  Eudactylina  acuta  T.  Scott.     (114)  p.  293,  pi.  xii,  figs.  20-25. 

1904.  Eudactylina  acuta  A.  Scott.     (109)  p.  40. 

Female. — Body  slender  and  elongated ;  the  cephalo- 
thorax consisting  of  five  distinct  segments,  and  the 
abdomen  of  three,  including  the  genital  segment. 
Cephalic  segment  about  equal  in  length  to  the  next 
two  segments  combined ;  the  first  of  these  two  seg- 
ments smaller  than  the  second,  the  fourth  and  fifth 
subequal.  Abdomen  small  and  only  a  little  more  than 


EUDACTYLINA   ACUTA.  127 

one-fourth  the  length  of  the  cephalothorax ;  caudal 
rami  short  and  broadly  ovate.  Antennules  short, 
stout,  and  composed  of  about  five  joints,  and  armed 
with  several  strong  spines;  a  large  strongly-curved 
spine  springing  from  the  upper  distal  angle  of  the 
second  joint  and  reaching  to  near  the  end  of  the  next 
joint ;  a  stout  but  shorter  spine  on  the  lateral  aspect 
of  the  same  joint  and  also  one  or  two  spiniform  setae ; 
a  tolerably  stout,  elongated,  and  nearly  straight  spine 
springing  from  the  upper  distal  end  of  the  following 
joint,  and  immediately  below,  another,  also  moderately 
stout,  but  only  half  the  length  of  the  first ;  the  pen- 
ultimate joint  also  provided  with  a  short  spine,  and  a 
few  spiniform  setae  at  its  distal  end  ;  the  terminal  joint 
very  small.  Antennae  small,  but  armed  with  stout 
terminal  claw-like  spines ;  also  one  or  two  stout  spines 
on  the  inner  aspect  of  the  first  and  second  joints. 
Mandibles  slender,  elongated;  first  maxillipeds  small, 
three-jointed,  and  furnished  with  a  minute  terminal 
claw.  Second  maxillipeds  of  moderate  size,  each 
armed  with  a  tolerably  powerful,  terminal  chela  which 
forms  an  effective  grasping-organ,  having  a  somewhat 
close  resemblance  to  similar  appendages  in  Pseudotanais 
—a  genus  belonging  to  Isopoda-Chelifera. 

The  first  four  pairs  of  thoracic  legs  all  biramose  ;  in 
the  first,  third,  and  fourth  pairs  both  the  inner  and 
outer  ramus  distinctly  three-jointed ;  in  the  second 
pair  the  inner  ramus  composed  of  three  subequal 
joints,  but  the  outer  somewhat  abnormal  in  structure, 
the  first  joint  comparatively  large  and  fully  as  long  as 
the  entire  inner  ramus,  while  the  distal  extremity 
appears  to  consist  of  two  minute  coalescent  joints; 
the  basiopodite  in  all  the  four  pairs  composed  of  two 
unequal  joints,  the  second  being  the  smaller;  the 
inner  margin  of  the  second  basal  joint  in  the  first  pail- 
fringed  with  about  five  very  short  but  stout  spinules  ; 
the  first  and  second  joints  of  the  outer  ramus  each 
with  a  small  dagger-shaped  spine  on  the  outer  distal 
angle,  and  the  third  joint  with  two  similar  spines  and 


128  BRITISH   PARASITIC  COPEPODA. 

a  moderately  elongated  seta  at  the  apex ;  the  inner 
ramus  also  provided  with  two  spiniform  apical  setae, 
and  both  rami  furnished  with  marginal  spinules  as 
shown  in  the  drawings ;  the  armature  of  the  rami  of 
the  third  and  fourth  pairs  somewhat  similar  to  that 
described  above,  but  in  the  second  pair,  while  the 
armature  of  the  inner  ramus  does  not  differ  materially 
from  that  of  the  others,  the  outer  ramus  is  devoid  of 
either  spines  or  setae.  Fifth  pair  small,  uniarticulate, 
lamelliform,  and  broadly  ovate,  situated  on  the  lateral 
aspect  and  near  the  distal  end  of  the  last  thoracic 
segment,  each  furnished  with  about  three  apical 
setae  and  their  outer  margins  fringed  with  minute 
spines.  Caudal  rami  short,  nearly  twice  as  long  as 
broad,  with  two  short  stout  spines  at  the  apex,  a 
small  seta  on  the  lower  half  of  the  outer  margin, 
and  a  fringe  of  minute  prickles  on  the  lower  inner 
margin.  Length  about  2*5  mm.  Egg-strings  toler- 
ably slender  aud  elongated.  Colour  similar  to  that  of 
the  gills,  but  the  egg-strings  are  not  so  dark  red. 

No  males  have  been  observed. 

Habitat. — Parasitic  on  the  gills  of  the  angel-fish, 
RJiina  squatina  (Linn.).  Moray  Firth  and  Firth  of 
Clyde  (T.  Scott).  Irish  Sea  (A.  Scott).  Not  rare. 

2.  Eudactylina  acanthi!  A.  Scott. 

(Plate  XXXVII,  figs.  2,  3  ;   Plate  XXXVIII, 

figs.  6-12.) 

1901.  Eudactylina  acanthii  A.  Scott.     (108)  p.  14. 

1902.  Eudactylina  acanthii  T.  Scott.     (114)  p.  296,  pi.  xiii,  figs.  1-9. 
1904.  Eudactylina  acanthii  A.  Scott.     (109)  p.  41. 

Female. — Body  moderately  stout,  cephalothorax 
equal  to  five  times  the  length  of  the  abdomen,  in- 
cluding the  genital  segment ;  the  first  cephalothoracic 
segment  about  one  and  a  half  times  the  length  of  the 
next,  the  second  and  third  subequal,  the  fourth  rather 
larger  than  the  third  or  the  following  segment.  Ab- 
domen very  short,  consisting  of  three  segments,  the 


EUDACTTLINA   ACANTHII.  129 

genital  segment  being  fully  as  large  as  the  other  two 
combined. 

Antennules  short,  tolerably  stout,  and  tapering 
to \vards  the  distal  end ;  first  two  joints  large  and 
together  equal  to  more  than  half  the  entire  length  of  the 
antennule ;  the  curved  spine  at  the  distal  end  of  the 
second  joint  much  smaller  than  the  spine  similar  to  it 
on  the  antennules  of  Eudactylina  acuta,  and  the  strong, 
elongate,  nearly  straight  spine  at  the  distal  end  of  the 
third  joint  in  that  species  wanting  here.  Antennae 
somewhat  similar  to  those  of  Eudactylina  acuta,  but 
the  stout  spines  on  the  first  and  second  joints  wanting. 
Second  maxillipeds  cheliform,  other  mouth-appendages 
similar  to  those  of  the  species  mentioned  above. 

The  inner  ramus  two-jointed  in  all  the  four  pairs  of 
thoracic  legs ;  the  outer  ramus  of  the  first  pair  con- 
sisting apparently  of  only  one  joint,  or  of  two  subequal 
and  coalescent  joints,  those  of  the  next  three  pairs 
appearing  to  be  composed  of  three  joints,  but  the 
articulation  between  the  second  and  third  joints  not 
so  distinct  as  that  between  the  first  and  second ;  in  the 
first  pair  the  inner  ramus  is  provided  with  a  number 
of  short  but  stout  spines  chiefly  on  the  exterior  aspect, 
and  the  outer  fringed  with  minute  setae ;  a  small  spine 
also  springing  from  a  notch  near  the  middle  of  the 
outer  margin  and  two  or  three  small  setae  from  the 
distal  end.  The  inner  ramus  in  the  second  pair  some- 
what similar  to,  but  rather  stouter  than,  the  inner 
ramus  of  the  first  pair  ;  the  outer  ramus  three-jointed, 
but  the  second  and  third  joints  appearing  to  be  co- 
alescent ;  both  rami  fringed  on  the  exterior  edge  with 
small  prickles,  the  outer  margin  of  the  first  basal  joint, 
which  is  somewhat  expanded,  forming  a  rounded 
gibbose  projection,  also  fringed  with  similar  prickles, 
which  are  scattered  sparingly  over  portions  of  all  the 
joints.  The  remaining  two  pairs  somewhat  similar  in 
structure  to  the  second  but  rather  more  robust  and 
less  spiniferous.  The  fifth  pair  resembling  those  of 
Eudactylina  acuta,  but  differing  slightly  in  their  form 

VOL.  i.  9 


130  BRITISH    PARASITIC    COPEPODA. 

and  armature.  Caudal  rami  moderately  stout,  fully  as 
long  as  the  last  abdominal  segment ;  two  short  spines 
springing  from  the  outer  margin  of  each  ramus  and 
three  from  the  apex,  the  middle  seta  being  the  longest. 
Length  about  2  mm.  Colour  similar  to  that  of  the 
gills  of  the  fish. 

No  males  have  been  met  with. 

Habitat. — Parasitic  on  the  gills  of  the  piked  dog- 
fish or  spur-dog,  Squalus  acanthias  Linn.(  =  Acanthias 
vulgaris  Risso).  Beaumaris  Bay,  Anglesey,  Septem- 
ber 1901,  and  other  parts  of  the  Irish  Sea  (A.  Scott). 

This  Eudactylina  is  frequent  on  the  gills  of  Squalus  acan- 
thias captured  in  the  Irish  Sea,  and  it  may  probably  also  occur 
on  Scottish  specimens  of  the  same  fish.  Eudactylina  acuta 
has  been  recorded  from  both  the  angel-fish  and  the  piked 
dog-fish  by  van  Beneden  and  Dr.  Canu,  but  though  the 
EudactylinsB  obtained  by  these  authors  from  the  two  fishes 
mentioned  may  belong  to  the  one  species,  those  found  para- 
sitic on  the  dog-fishes  taken  in  Beaumaris  Bay,  &c.,  certainly 
differed  from  the  specimens  obtained  on  angel-fishes  captured 
on  the  English  and  Scottish  coasts  and  examined  by  us. 

3.  Eudactylina  similis  T.  Scott. 
(Plate  XXXVII,  figs.  4,  5;  Plate  XXXIX,  figs.  1-17.) 

1902.  Eudactylina  similis  T.  Scott.     (114)  p.  295,  pi.  xii,  figs.  1-19. 

Female. — First  cephalothoracic  segment  about  one 
and  a  half  times  as  long  as  the  next,  but  the  length  of 
that  segment,  and  of  the  two  that  follow,  nearly  the 
same ;  the  last  segment  rather  smaller  than  any  of  the 
others.  Abdomen,  including  the  genital  segment, 
short,  being  only  about  one-third  as  long  as  the 
cephalothorax. 

Antennules  stout,  and  somewhat  similar  in  structure 
and  armature  to  those  of  Eudactylina-  acuta,  but  the  two 
principal  spines  have  each  a  fringe  of  minute  prickles 
along  the  upper  edge,  and  the  penultimate  joint  is 
proportionally  shorter  ;  antenna3  tolerably  stout,  elon- 
gated, and  composed  of  four  articulations,  the  first 
and  second  joints  each  provided  with  a  stout  but 


EUDAC1YLIXA.    S1MILIS.  131 

moderately  short  spine  on  the  inner  aspect,  while  the 
end  joint  bears  two  curved  spines  which  are  stout  and 
claw-like ;  the  second  joint  rather  shorter  than  the 
first  or  third,  and  the  terminal  one  very  small. 
Mandibles  slender  and  moderately  elongated,  with  the 
distal  half  of  the  end  joint  serrated  on  the  inner  edge. 
Maxillae  small,  bilobed,  principal  lobe  stout,  rather 
longer  than  broad,  and  provided  with  apical  setae  of 
unequal  length,  one  being  nearly  twice  as  long  as 
the  others;  secondary  lobe  elongated,  narrow,  and 
bearing  a  moderately  long  apical  seta.  First  maxilli- 
peds  small,  three-jointed,  and  furnished  with  a  short 
but  rather  stout  terminal  claw.  Second  maxillipeds 
tolerably  large  and  strongly  chelate ;  the  end  joint 
considerably  expanded  and  its  postero-lateral  corners 
more  or  less  produced,  one  of  them  extending  into  a 
spoon-like  process,  while  to  the  other  is  articulated 
a  strongly-curved  claw,  the  apex  of  which  impinges 
against  the  spoon-like  process  of  the  opposite  angle, 
thus  forming  an  effective  grasping  organ. 

First  pair  of  thoracic  legs  somewhat  similar  to  those  of 
Eudactylina  acuta  except  in  the  following  particulars : 
the  second  basal  joint  is  furnished  with  two  small  but 
stout  spines  on  the  inner  distal  angle  instead  of  a 
fringe  of  stout  marginal  spinules ;  the  first  joint  of 
the  outer  ramus  is  proportionally  considerably  larger 
than  either  the  second  or  third  joints,  the  inner 
ramus  is  more  slender,  and  the  articulations  are  more 
unequal.  The  second  pair  are  similar  in  structure  to 
the  same  pair  in  Eudactylina  acuta,  but  the  outer  ramus 
is  proportionally  and  distinctly  larger.  The  third  and 
fourth  pairs  are  somewhat  similar  in  the  two  species ; 
the  fifth,  however,  are  larger  and  proportionally  broader 
than  those  of  the  species  named,  the  length  does  not 
greatly  exceed  the  width,  and  there  is  also  a  corre- 
sponding difference  in  their  outline.  Caudal  rami 
about  twice  as  long  as  the  anal  segment  of  the 
abdomen,  and  moderately  wide  but  becoming  narrower 
towards  the  apex,  each  bearing  three  small  spiniform 


132  BRITISH    PARASITIC    COPEPODA. 

seise — one  at  the  apex  and  two  on  the  lower  half  of 
the  outer  margin.  Length  about  3  mm. 

Male. — The  male  is  smaller  than  the  female,  the 
body  is  more  slender,  and  the  abdomen  is  about  as  long 
as  the  cephalothorax.  Antennules  tolerably  stout  and 
composed  of  about  seven  articulations;  the  first  and 
second  joints  are  short  but  considerably  dilated,  the 
second  is  provided  with  a  stout  and  strongly  curved 
spine  which  springs  from  the  upper  distal  angle ;  the 
remaining  joints  are  all  nearly  of  equal  width  and 
much  narrower  than  the  basal  joints,  the  third  joint  is 
about  as  long  as  broad,  the  fourth  and  fifth  are  very 
short,  the  sixth  is  rather  longer  than  the  fourth  and 
fifth  combined,  while  the  end  joint  is  nearly  three 
times  the  length  of  the  sixth ;  the  third  and  fifth 
joints  are  each  furnished  with  a  stout  and  moderately 
long  straight  spine,  and  a  shorter  spine  also  occurs  on 
the  distal  end  of  the  sixth  joint,  while  the  last  joint 
is  armed  with  a  strong  terminal  hook  and  a  slender 
sensory  filament.  Antenna?  and  mouth-appendages 
like  those  of  the  female  except  that  the  second  maxilli- 
peds  are  not  chelate  but  provided  with  a  simple 
terminal  claw.  The  first  four  pairs  of  thoracic  legs 
have  both  rami  three-jointed,  but  the  articulation 
between  the  second  and  third  joints  of  the  outer  ramus 
of  the  first  pair  is  not  clearly  defined ;  the  inner  ramus 
of  the  second  pair  is  provided  with  a  tolerably 
elongated  and  slightly  curved  spine  which  springs 
from  the  inner  distal  angle  of  the  first  joint ;  the  outer 
ramus  of  the  second  pair  is  normal  in  structure.  Both 
rami  of  the  third  pair  are  moderately  slender  and 
setiferous.  Fifth  pair  somewhat  similar  to  those 
of  the  female.  Caudal  rami  narrow,  each  with  two 
apical  and  one  marginal  spiniform  seta?.  Length  about 
2  mm.  Colour  similar  to  that  of  the  gills  of  the  fish. 
Egg-strings  moderately  slender  and  elongated. 

Habitat. — Parasitic  on  the  gills  of  the  starry  ray, 
Raia  radifitn  Don.  The  fishes  on  which  this  parasite 
was  obtained  were  captured  east  of  the  Shetland 


EUDACTYLLXA    SIMILIS.  133 

Islands  in  May  and  off  Aberdeen  in  November  1901 
(T.  Scott). 

This  species  lias  a  general  likeness  to  Eudactylina 
't<-iita  van  Beneden,  tbut  differs  from  it  in  several 
respects. 

4.  Eudactylina  minuta  T.  Scott. 
(Plate  XXXVII,  figs.  6,  7 ;    Plate  XL,  figs.  1-9.) 

1904.  Eudactylina  minuta  T.  Scott.     (115)  p.  275,  pi.  xvii,  figs.  1-11. 

Female. — Body  slender ;  the  cephalothorax  about 
four  times  as  long  as  the  abdomen ;  the  first  cephalo- 
thoracic  segment  scarcely  equal  in  length  to  the  next 
two  segments  combined ;  the  last  two  segments  of  the 
thorax  rather  more  dilated  than  the  others ;  all  the 
segments  rough  with  minute  scattered  hairs,  especi- 
ally along  the  dorsal  aspect. 

Antennules  short,  stout,  and  apparently  consist- 
ing of  five  joints ;  the  first  three  joints  large  and 
subequal,  the  fourth  narrow  and  only  about  a  third  of 
the  length  of  the  preceding  joint,  end  joint  very  small ; 
the  second  joint  furnished  with  a  stout  and  strongly- 
curved  spine  on  the  upper  distal  angle,  two  smaller 
spines  springing  from  the  distal  half  of  the  upper 
margin  of  the  third  joint ;  no  terminal  claw,  but  only 
a  few  apical  seta3.  Antenna?  moderately  elongate, 
three-jointed,  and  having  a  general  resemblance  to 
those  of  Eudacti/lina  acuta ;  the  second  joint,  which  is 
about  equal  to  the  third  one,  having  the  lower  distal 
angle  produced  downwards  in  the  form  of  a  short 
stout  spine,  while  the  end  joint  terminates  in  a  strong 
curved  claw.  Mandibles  and  maxillae  somewhat 
similar  to  those  of  Eudactylina  acuta.  First  max- 
illipeds  moderately  stout  and  armed  with  a  stout 
and  nearly  straight  terminal  claw,  while  the  end 
joint  has  a  row  of  minute  coarse  denticles  along  its 
inner  edge.  Second  maxillipeds  large  and  strong  and 
somewhat  similar  in  structure  to  those  of  Eudactylina 
similis,  but  the  extremity  of  the  claw  which  impinges 


134  BRITISH   PARASITIC    COPEPODA. 

against  the  lower  spoon-like  process  forms  a  rounded 
apical  expansion.  Both  rami  in  the  first  pair  of 
thoracic  legs  distinctly  two-jointed  and  moderately 
stont,  the  inner  ramus,  which  is  larger  than  the  outer, 
sparingly  fringed  with  minute  seta?  and  provided  with 
two  apical  spines  of  unequal  length  ;  the  outer  and 
shorter  ramus  with  a  fringe  of  minute  setae  on  the 
outer  margin  of  the  first  joint,  the  end  joint  bearing 
several  spines  round  its  outer  margin  and  apex,  the 
inner  spine  of  moderate  length  but  the  others  small. 
The  second  pair  with  a  general  resemblance  to  those 
of  both  En<l<t<-ti/lii/<i  acuta  and  En.  similis ;  the  inner 
ramus,  which  is  distinctly  three-jointed,  considerably 
smaller  than  the  outer  one,  and  the  first  joint  having 
a  longitudinal  row  of  small  spines  extending  obliquely 
upwards  from  near  the  distal  end  of  the  outer  margin, 
while  the  end  joint  bears  two  small  apical  spines  of 
unequal  length ;  the  outer  ramus  stout,  tolerably 
elongated  and  indistinctly  three-jointed,  end  joint 
small,  about  as  broad  as  long,  and  bearing  a  spiniform 
seta  on  its  margin  and  two  minute  prickles  on  the 
rounded  apex  ;  two  short  spines,  each  with  a  thickened 
base,  springing  from  near  the  distal  end  of  the  outer 
margin  of  the  first  joint,  this  joint  being  elongated 
and  slightly  arcuate ;  a  pseudo-articulation  may  be 
noticed  between  the  two  short  spines  and  extending 
partly  across  the  joint.  The  third  and  fourth  pairs 
nearly  alike  and  resembling  those  of  Eiidactylina 
similis  except  that  the  inner  rami  have  a  number  of 
scattered  spinules  on  their  outer  aspect ;  the  outer 
rami  each  rounded  at  the  extremity  and  carrying  a 
single  elongated  terminal  seta ;  they  are  also  provided 
with  a  few  small  spines  on  the  outer  margin  of  the 
second  and  third  joints,  while  a  fringe  of  minute  prickles 
extends  along  the  margin  of  the  first  joint.  The  fifth 
pair,  which  are  broadly  foliaceous,  ornamented  with 
several  transverse  rows  of  minute  spines  and  also 
furnished  with  three  apical  seta1.  Caudal  rami  short, 
about  as  long  as  the  last  abdominal  segment,  and  bear- 


EUDACTYLINA   MINUTA.  135 

ing  short,  moderately  stout  apical  spines,  with  two 
setae  on  the  outer  margin.  Length  a  little  over  1  mm. 
Egg-strings  short,  bearing  a  small  number  of  mode- 
rately large  ova.  Colour  reddish,  resembling  the  colour 
of  the  gills  of  the  fish. 

No  males  observed. 

Habitat.  —  Parasitic  on  the  gills  of  a  sting  ray, 
Trygon  pastinaca  Linn.,  captured  in  the  Dornoch 
Firth  in  October  1903  (T.  Scott).  The  fish  was  sent  to 
Dr.  Fulton,  Scientific  Superintendent,  Fishery  Board 
for  Scotland,  who  kindly  placed  it  at  our  disposal. 

5.  Eudactylina  insolens  T.  and  A.  Scott. 
(Plate  LXXI,  figs.  1-12.) 

Female. — Length  exclusive  of  the  furcal  seta3  1'8 
mm.  Body  moderately  robust  and  cylindrical,  and 
having  no  appearance  of  segmentation  between  the 
third  and  fourth  free  thoracic  segments  as  is  usual  in 
the  members  of  the  genus.  The  cephalic  segment, 
seen  from  above,  comparatively  large  and  somewhat 
quadrangular  in  outline.  Frontal  margin  broadly 
rounded  and  terminating  on  each  side  in  a  distinct 
knob-like  projection.  Lateral  margins  for  some  dis- 
tance behind  the  knob  nearly  straight.  First  thoracic 
segment  deeply  constricted  a  little  behind  the  middle. 
Second  segment  decidedly  larger  than  the  first,  and  its 
lateral  margins  somewhat  inflated.  Third  segment 
large  and  cylindrical,  tapering  slightly  towards  the 
posterior  end.  Abdomen  very  short  and  three-jointed, 
rather  less  than  one-seventh  of  the  length  of  the  entire 
animal.  Genital  segment  comparatively  large  and 
swollen,  and  equal  to  the  combined  length  of  the 
second  and  third  segments  together  with  the  furcal 
joints.  Second  and  third  segments  short  and  of  nearly 
equal  length.  Furcal  joints  short  and  about  as  long  as 
the  last  abdominal  segment,  their  length  equal  to  twice 
the  width.  Each  furcal  joint  furnished  with  one 
marginal  and  four  apical  setae,  which  are  very  small. 


136  BRITISH    PARASITIC    COPEPODA. 

The  frontal  end  of  the  cephalic  segment  and  the  second 
and  third  abdominal  segments  as  well  as  the  furcal  joints 
have  the  dorsal  surface  covered  with  fine  spinnles. 

Antennules  short,  stout,  and  six-jointed,  resembling 
those  of  Eudactylina  acanthii.  The  fourth  joint  very 
distinctly  shorter  than  any  of  the  others.  The  second 
joint  furnished  with  a  single  stout  curved  spine. 

Antennae  also  similar  to  those  of  Eudactylina  acanthii, 
except  that  the  inner  margin  of  the  second  joint  is 
produced  into  two  short  teeth,  and  the  terminal  claw 
is  much  stouter. 

Mandibles  and  maxillae  somewhat  rudimentary  in 
structure  and  very  similar  to  those  of  Eudaetylin 
aacu ta. 

The  first  pair  of  maxillipeds  resembling  those  of  the 
other  members  of  the  genus  in  general  appearance,  but 
the  end  joint  is  narrowly  ovate  in  shape  and  its  inner 
margin  is  furnished  with  a  row  of  fine  teeth.  Terminal 
claw  slender.  The  second  pair  of  maxillipeds  large  and 
strong,  and  forming  powerful  chelae.  They  are  nearly 
similar  in  structure  to  those  of  Eudactylina  minuta. 

The  first  pair  of  feet  biramose.  Both  branches 
short,  stout,  and  two-jointed.  The  second  joint  of 
each  branch  much  shorter  than  the  first.  The  armature 
of  the  joints  similar  to  that  of  the  first  pair  of  Eudacty- 
lina minuta.  The  second  pair  of  feet  decidedly  different 
from  the  second  pair  of  the  other  members  of  the 
genus  known  to  us.  Inner  branch  very  short  and  three- 
jointed.  Outer  branch  also  three-jointed  but  having  a 
distinctly  uncinate  appearance  and  being  about  three 
times  the  length  of  the  inner  branch.  The  first  joint  of 
the  outer  branch  large  and  swollen ;  equal  to  four  times 
the  combined  length  of  the  second  and  third  joints. 
The  second  joint  short  and  wide.  The  outer  margin 
produced  into  a  bluntly-rounded  point.  The  third 
joint  very  short  and  narrow,  and  appearing  to  be 
loosely  articulated  to  the  second  joint.  It  requires 
some  care  to  detect  it,  as  it  appears  to  be  easily  folded 
over  the  surface  of  the  second  joint.  The  outer  margin 


EUDACTYLINA    INSOLENS.  137 

of  the  first  joint  strongly  chitinized.  The  third  pair 
of  feet  with  the  branches  of  nearly  equal  length  and 
both  branches  three-jointed.  The  fourth  pair  of  feet 
with  a  three-jointed  outer  branch  and  a  two-jointed 
inner  branch.  The  first  joint  of  the  outer  branch  large 
and  swollen.  The  second  and  third  joints  short  and  of 
nearly  equal  length.  The  inner  branch  about  half  the 
length  of  the  outer  one  and  its  two  joints  of  nearly 
equal  length.  The  fifth  pair  large  and  foliaceous  and 
similar  to  those  of  Eudactijlina  minuta,  except  that 
there  are  no  spinules  on  the  surface. 

Habitat. — Four  specimens,  all  females,  were  found 
on  the  gill  filaments  of  a  male  tope,  Galeorhinus 
galeus,  captured  in  the  vicinity  of  King  William  Bank, 
off  the  north  of  the  Isle  of  Man,  Irish  Sea,  April 
1912.  The  topes  from  which  Eudactylina  insolens  and 
Kroyeria  cineata  were  obtained,  were  caught  in  the 
trawl  of  the  Lancashire  and  Western  Sea  Fisheries 
steamer,  and  landed  at  Piel,  Barrow-in-Furness,  along 
with  other  material,  by  Captain  Wignall. 

We  Avere  inclined  at  first  to  regard  this  Eudactylina  as  a 
form  of  Eudactijlina  acanihii,  but  a  close  examination  showed 
that  there  were  decided  differences.  The  strong  uncinate 
appearance  of  the  long  outer  branch  of  the  second  pair  of 
feet  can  be  easily  seen  by  examining  the  entire  animal  when 
lying  on  its  side.  That  character,  along  with  the  differences  in 
the  structure  of  the  first,  third,  and  fourth  pairs  of  feet,  readily 
separate  Eudactylina  insolens  from  Eudactylina  acanthii  or 
any  of  the  other  members  of  the  genus.  The  incomplete 
segmentation  of  the  thorax,  which  gives  the  species  only  three 
free  segments  instead  of  four,  may  be  abnormal  and  due  to 
uncompleted  development,  but  as  the  whole  of  the  appendages 
appear  quite  normal  we  prefer  in  the  meantime,  in  the 
absence  of  further  material,  to  regard  the  form  as  distinct. 


Family  iv.  PHILICHTHYID^:. 

Female. — Body  elongated,  more  or  less  segmented 
but  without  articulated  locomotive  appendages.  Fre- 
quently furnished  with  lateral  processes,  which  may 


138  BRITISH   PARASITIC   COPEPODA. 

be  slender  and  flexuose,  or  in  the  form  of  spines. 
Antennae  and  mouth-organs  more  or  less  rudimentary. 

M<il>>. — Body  slender,  distinctly  segmented,  and 
furnished  with  several  cephalothoracic  appendages, 
including  antennules  and  antennas ;  first  and  second 
maxillipeds  and  two  pairs  of  thoracic  legs  all  bira- 
mose;  the  first  abdominal  segment  also  sometimes 
provided  with  a  pair  of  limbs.  The  first  maxillipeds 
with  strong  terminal  hooks  forming  powerful  grasping 
organs.  Abdomen  usually  composed  of  about  eight 
segments. 

Holitat. — The  species  belonging  to  this  Family 
occur  free  in  the  mucus  canals  and  sinuses  of  various 
fishes. 

Genus  PHILICHTHYS  Steenstrup,  1861. 

Female. — Head  small,  rounded.  Body  elongated 
and  distinctly  segmented ;  no  dorsal  plates,  but  the 
body,  including  the  head,  furnished  with  a  number  of 
lateral  and  ventral  processes,  moderately  slender,  and 
more  or  less  curved  inwards  upon  the  ventral  aspect. 
The  egg-strings,  which  are  of  moderate  length  and 
thickness,  extending  alongside  the  body,  and  are  partly 
enclosed  and  supported  by  the  curved  lateral  and 
ventral  processes. 

There  is  in  the  female  a  single  median  eye-spot. 

Mule. — The  male  is  much  smaller  than  the  female. 
The  body  is  slender  and  distinctly  segmented.  The 
anterior  part  of  the  body  consists  of  three  segments, 
the  first  moderately  large  and  bluntly  rounded  in  front, 
the  other  smaller.  The  posterior  portion  is  also 
segmented,  very  narrow,  and  considerably  longer  than 
the  front  part. 

Antennules  slender,  composed  of  six  articulations ; 
antenna?  two-jointed  and  provided  with  two  hook-like 
setse.  The  first  maxillipeds  moderately  large,  the 
second  feeble. 

Only  one  species  is  known. 


PHIL1CHTHYS    XIPHI^. 

1.  Philichthys  xiphiaB  Steenstrup. 
(Plate  XLV,  figs.  2,  3.) 

1862.  PhilicJithys  xi^hiie  Steenstrup.     (126)  p.  295.  pi.  ii. 

1664.  Philiclitliys  xiplnee  Bergsoe.     (17)  p.  87.  pi.  13. 

1877.  Philichthys  xiLiliix  C.  Yogt,     (142)  p.  29.  pi.  ii,  figs.  13-15. 

Female. — Body  elongated  and  somewhat  tumid,  and 
having  a  rugged  or  coarse  appearance  ;  consisting  of 
numerous  segments  and  furnished  with  many  append- 
ages which  vary  in  shape  and  size.  Anterior  portion 
of  the  cephalothorax  consisting  of  three  small  seg- 
ments, the  one  in  front  being  extremely  minute ;  a 
minute  median  eye-spot  present  on  the  dorsum  of  the 
second  segment  and  a  mouth-aperture  beneath ;  the 
body  immediately  posterior  to  this  front  portion  of  the 
cephalothorax  becoming  more  tumid  and  expanding 
equally  on  each  side  so  as  to  form  a  nearly  circular 
disc,  the  width  of  which  is  fully  more  than  a  third  of 
the  entire  length  ;  the  remaining  portion  of  the  body 
for  the  most  part  subcylindrical  and  composed  of 
numerous  annulations,  the  penultimate  segment  small 
and  only  about  half  the  width  of  the  preceding  one  ;  the 
anal  segment  broadly  subtriangular  and  with  two 
small  knobs  on  the  dorsal  aspect,  one  on  each  side 
of  the  median  line,  and  a  blunt-pointed,  finger-like 
process  extending  backwards  from  the  middle  of  the 
posterior  margin.  Genital  segment  the  sixth  from  the 
posterior  end. 

Body  furnished  with  about  fifteen  appendages  on  each 
side,  a  few  ventral  but  most  of  them  lateral  and  all  soft 
and  uniarticulate,  those  on  the  posterior  half  of  the 
body  more  or  less  incurved  and  hook-like.  Egg-strings 
tolerably  elongated  and  thick,  attached  to  the  genital 
orifices  by  the  middle,  extending  forward  as  well  as 
backward  along  the  ventral  aspect,  and  enclosed  and 
supported  by  the  curved  lateral  and  ventral  processes  ; 
the  egg-strings  not  extending  beyond  the  posterior  end 
of  the  body.  Colour  pale  purple,  consisting  of  numerous 
minute  purple  spots  on  a  white  ground.  Length 
varying  from  C  to  36  mm. — (Beryso<j.) 


140  BRITISH    PARASITIC    COPEPODA. 

Male. — Slender,  elongated,  becoming  gradually  at- 
tenuated posteriorly.  Body  distinctly  segmented,  rings 
free  and  mobile.  First  segment  of  the  cephalothorax 
scutiform,  about  as  broad  as  long  and  equal  in  length 
to  the  next  two  segments  taken  together ;  third  seg- 
ment larger  than  the  second  and  armed  with  a  strong, 
slightly  curved  spine  on  each  postero-lateral  angle. 
Abdomen  slender ;  anal  segment  longer  and  narrower 
than  any  of  the  preceding  segments.  Caudal  ranii 
very  slender,  elongate,  rather  shorter  than  the  anal 
segment,  and  provided  with  two  apical  setaa. 

Antennules  very  slender  and  consisting  of  six  indis- 
tinct joints.  Antennas  moderately  stout,  two- jointed, 
and  furnished  with  two  terminal,  slightly  hooked  setse. 
In  the  first  maxillipeds  the  basal  part  is  greatly 
enlarged  and  bears  strong  claw-like  terminal  spines ; 
the  second  pair  are  small  and  feeble.  Locomotary  legs 
two  pairs,  short  and  biramose ;  both  pairs  have  the 
outer  ramus  two-  and  the  inner  one-jointed ;  the  rami 
are  subequal  in  length  but  the  outer  ramus  is  rather 
more  robust,  and  the  proximal  joint  is  very  short; 
both  pairs  are  liberally  supplied  with  spines  and  setae. 
Length  about  4  mm. 

Habitat. — Living  freely  in  the  mucous  canals  in 
the  head  of  the  sword-fish  (Xiphias  gladiiis).  On  a 
sword-fish  captured  off  Lowestoftin  1892  ('Cambridge 
Natural  History,'  vol.  iv,  p.  73,  footnote). 

Distribution. — Mediterranean.  New  Zealand  (G.  M. 
Thorn  soil). 

Dr.  S.  F.  Harmer,  who  examined  the  sword-fish  and  ob- 
tained the  specimens  of  Philichthys  described  above,  has  sent 
us  the  following  note,  which  he  kind!}-  permits  us  to  use : — 

"  Some  years  ago  (1892),  when  examining  a  specimen  of 
sword-fish  which  had  been  taken  off  Lowestofr,  it  occurred  to 
me  to  look  for  Philichthys  xiphite,  which  1  readily  found  in  the 
place  in  which  it  has  been  described  as  occurring-,  namely, 
in  the  frontal  bones.  ...  I  speak  from  memory,  but  I 
think  I  am  right  in  saying  that  one  of  the  parasites  was  found 
iri  each  frontal  bone." — (S.  F.  Harmer.) 


LKRN^OIDA.  141 

Tribe  III.  LERN^EOIDA. 

Mouth  usually  suctorial.  Thorax  not  articulated, 
or  only  obscurely  so.  Thoracic  legs,  when  present,  of 
a  more  or  less  rudimentary  structure.  Body  some- 
times, as  stated  by  Baird,  "  very  outre  in  appearance."* 
Egg-strings  two,  stout  and  of  moderate  length,  or  some- 
times slender  and  greatly  elongated  and  straight  or 
more  or  less  twisted.  Male  usually  very  small. 

The  species  belonging  to  this  tribe  are  all  more  or  less 
permanently  fixed  upon  their  hosts  ;  but,  as  stated  by  Baird, 
it  is  in  general  "  only  the  adult  female  of  the  Lernaeida9  that  we 
are  in  the  habit  of  observing,  and  in  an  animal  whose  organs 
of  motion  and  perception  for  the  most  part  are  merely  rudimen- 
tary, and  whose  existence  is  strictly  stationary,  the  manner  of 
life  must  be  very  simple/'t  They  are  usually  arranged  under 
the  three  families  Lerna3idae,  Chondracanthidas,  and  Lernseo- 
podse,  which  differ,  and,  for  the  most  part,  are  characterized 
by  the  manner  in  which  the  parasites  fasten  themselves  to  the 
fish  on  which  they  live,  which  also  presupposes  corresponding 
differences  in  at  least  some  of  the  other  appendages,  as  well 
as  in  the  relation  of  the  sexes.  (See  remarks  on  Lernsea  in 
the  Introduction.) 

The  young  Lernsea  leaves  the  egg  as  a  free-swimming 
nauplius,  which,  in  general  appearance,  is  very  similar  to  the 
lai'va  of  Cyclops. 


Family  v. 

Body  of  the  mature  and  fixed  ovigerous  female  more 
or  less  cylindrical,  and  unsegmented  but  roughly 
divided  into  three  parts  —  a  globular  head  with  anchor- 
like  processes  either  simple  or  branched  ;  a  narrow, 
cylindrical,  and  sometimes  more  or  less  flexuous 
neck  connecting  the  head  with  the  posterior  part  of 
the  body  or  genital  segment  ;  the  genital  segment 
usually  more  or  less  swollen,  and  straight  or  sig- 
moid.  Egg-strings  two,  slender,  elongated,  sometimes 
twisted  into  two  involved  masses,  or  forming  more  or 
less  regular  spirals. 

*  '  British  Entomostraca/  p.  307.  t  Op.  cit.,  p.  318. 


142  BRITISH    PARASITIC    COPEPODA. 

In  the  young  but  sexually  mature  stage  the  Lernteidae  do 
not  differ  greatly  from  the  preceding  families.  The  sexually 
mature  young  are  furnished  with  two  pairs,  of  antennas;  the 
posterior  pair  usually  end  in  strong  hooks  which  project 
beyond  the  forehead ;  the  maxillipeds  are  small  and  feeble, 
and  the  four  pairs  of  thoracic  legs  are  tolerably  developed. 
The  abdomen  is  usually  rudimentary,  and  a  median  eye- spot 
is  present.  In  the  larval  stages  the  young  approximate  more 
closely  to  Cyclops  and  are  more  or  less  free-swimming. 

Genus  27.  LERN^EA  Linnxus,  1767. 

Head  globular,  slightly  recurved,  with  the  apex 
rounded  or  conical,  and  provided  usually  with  three 
chitinous,  more  or  less  branched  and  horn-like  append- 
ages, two  of  them  lateral  and  one  median  and  dorsal. 
Thorax  in  the  form  of  a  moderately  long,  slender,  and 
fiexuous  neck,  which  gradually  becomes  merged  into 
the  genital  segment.  Genital  segment  moderately 
enlarged,  elongated  and  subcylindrical,  and  usually 
more  or  less  abruptly  bent  upon  itself,  somewhat  like 
the  letter  S.  Egg-strings  elongated  and  slender,  and 
twisted  into  involved  roundish  masses  under  the  pos- 
terior portion  of  the  genital  segment.  Several  of  the 
cephalothoracic  appendages  becoming,  in  the  fixed  stage 
of  the  female,  degenerate  and  rudimentary  or  obsolete ; 
the  first  maxillipeds  however  retain  their  form,  and 
are  furnished  with  terminal  hooks ;  the  four  pairs  of 
thoracic  legs  are  also  persistent,  and  may  be  seen  on 
the  ventral  aspect  behind  the  subglobular  head  with  the 
aid  of  a  low-power  objective. 

The  various  species  of  Lern?ea  are  securely  anchored  to  the 
host  by  the  cephalic  horns. 

1.  Lernaea  branchialis  Linnaeus. 
(Plates  XLII  &  XLIII.) 

1767.  Lernasa  branchialis  Linn.     (78)  vol.  i,  pt.  2,  p.  1092. 
1850.  Lernsea  branchialis  Baii'd.     (4)  p.  344,  pi.  xxxv,  fig.  12. 

1900.  Lernsea  branchialis  T.  Scott.     (112)  p.  161,  pi.  vii,  figs.  11,  12. 

1901.  Lernaea  branchialis  A.  Scott.     (108)  p.  33,  pis.  iv  and  v. 

Female. — Head  apiculated  or  conical,  slightly  re- 
curved and  provided  with  strong,  branching,  horn-like 


LERN^A    BRANCHIALIS.  143 

appendages ;  neck  narrow,  of  moderate  length,  and 
somewhat  flexuose ;  genital  segment  usually  tolerably 
elongated,  somewhat  swollen  and  tapering  slightly  to 
the  bluntly-pointed  distal  extremity ;  also  abruptly 
folded  upon  itself  in  the  form  of  the  letter  S.  Egg- 
strings  long,  slender,  and  twisted  into  roundish 
masses  under  the  posterior  portion  of  the  genital 
segment. 

Cephalothoracic  appendages  rudimentary  or  obso- 
lete, except  the  first  pair  of  maxillipeds,  which  are 
situated  near  the  apex  of  the  head  immediately  behind 
the  mouth ;  the  four  pairs  of  thoracic  legs  situated  at 
the  proximal  end  of  the  neck,  and  being  exactly  as  they 
exist  in  the  cyclops  stage,  both  in  size  and  structure. 
The  first  and  second  pairs  biramose  and  both  rami 
biarticulate,  but  the  inner  ramus  wanting  in  the  third 
and  fourth  pairs  while  the  outer  is  composed  of  two 
joints.  The  whole  animal  when  stretched  out,  and 
exclusive  of  the  cephalic  horns  and  the  egg-strings, 
measuring  about  40  mm.,  but  the  size  varies  to  some 
extent.  Colour  dark  red,  due  to  the  contained 
blood. 

Cephalic  horns  usually  fixed  in  the  gill-arches  of 
the  fish,  the  tissue  of  which  they  simply  penetrate 
when  the  animal  settles  on  the  host,  and  then  become 
branched,  thus  securing  a  firm  anchorage.  The 
branches  in  this  species  assume  a  more  or  less  dicho- 
tomous  arrangement,  and  in  this  respect  differ  from 
the  other  species  to  be  described. 

3f«le. — The  male  is  very  small,  and  resembles  the 
young  female  in  general  appearance.  Having  reached 
the  cyclopoid  stage  it  undergoes  no  further  change,  and 
is  then  sexually  mature. 

Habitat. — The  female  in  the  adult  fixed  stage  is 
usually  parasitic  on  the  gills  of  various  Gadoids,  as  cod- 
fishes, haddocks,  and  whitings,  and  is  not  uncommon ; 
while  young  females  with  males  attached  to  them  may 
be  found  on  the  gill-filaments  of  flat-fishes  such  as  the 
flounder,  Pleuronectes  flesus.  The  following  are  some 


144  BRITISH    PARASITIC    COPEPODA. 

of  the  localities  where  this  Lernsea  has  been  obtained  : 
Dublin  and  Belfast  Bays  (W.  Thorn  J>*<>H).  Polperro 
and  Falmouth  (A.  M.  Norman).  Plymouth  (Bassett- 
Smith).  Various  parts  of  the  Scottish  and  Lancashire 
coasts  (nob.).  Coasts  of  Northumberland  and  Durham 
(Jiratli/  Ly  X or  mail}.  Four  adult  female  Lernsea  branchi- 
alis  were  obtained  from  the  gill-arches  of  twenty -four 
Callionymus  li/ra  and  one  on  the  gill-arches  of  a  Centro- 
notns  gunnellus  which  were  captured  in  the  Irish  Sea 
in  1910  (A.  Scott). 

2.  Lernaea  lusci  Bassett-Smith. 
(Plate  XLIV,  figs.  1,  2.) 

1896.  Lerniea  lusci  Bassett-Smith.     (6)  p.  13.  pi.  iv,  fig.  6. 
1904.  Lernsea  lusci  T.  Scott.     (115)  p.  277.  pi.  xvii,  figs.  12,  13. 

Female. — Horns  of  the  cephalon  unequally  developed, 
stout,  and  not  so  branching  as  in  Lernsea  branchiaMs ; 
very  short,  except  the  one  which  springs  from  the  dorsal 
aspect  of  the  cephalon,  this  branch,  which  is  tolerably 
elongated,  extends  outwards  at  nearly  right  angles 
to  the  neck,  and  is  narrow  and  linguliform  with  the 
margins  irregularly  lobed  and  reflex ed ;  the  other  horns 
very  short  and  terminating  in  one  or  two  rudimentary 
branches.  Neck  moderately  short  and  thick,  merging 
posteriorly  and  directly  into  the  genital  segment ;  this 
segment  being  proportionally  considerably  swollen  and 
at  first  abruptly  reflexed  and  bent  upon  itself,  except 
at  the  distal  end,  where,  in  marked  contrast  to  Lernsea 
bi-iiiirl/ialis,  it  is  only  slightly  curved.  The  twisted  egg- 
strings  are  also  proportionally  less  slender  than  those 
of  that  species. 

The  antennae  and  other  cephalothoracic  organs 
appear  to  be  somewhat  similar  to  those  of  Lernsea 
branchialis.  Length  of  the  female  represented  by  the 
drawing  (PL  XLIV,  fig.  1)  only  a  little  over  half  an 
inch  (or  about  15  mm.),  measuring  from  the  head  to 
the  end  of  the  genital  segment.  Colour  dark  red. 

Habitat. — Parasitic    usually    on    the    gill-arches    of 


LERN^A    LUSCI.  145 

brassies  or  whiting-pouts,  Gadusluscus  (Linn.).  Found 
on  the  gills  of  this  species  of  fish  at  Plymouth 
(Bassett-Smith).  Found  on  the  gills  of  a  brassie  cap- 
tured 10  miles  off  Aberdeen  in  January  1901  (T.  Scott). 
Frequent  on  the  gill-arches  of  brassies,  Irish  Sea  (A. 
Scott). 

A  Gadus  lusc.us  sent  from  the  Fish-Market  at  Aberdeen 
had  one  of  these  parasites  adhering  to  it;  in  this  example 
the  head  of  the  parasite  was  buried  in  the  tissues  in  the 
abdominal  region,  behind  and  a  little  below  the  base  of  the 
pectoral  fin — a  somewhat  unusual  position  for  a  Lernsea. 

3.  Lernaea  minuta  T.  Scott. 
(Plate  XLIV,  fig.  3.) 

1900.  Lernsea  minuta  T.  Scott.     (112)  p.  161,  pi.  vii,  fig.  13. 
1904.  Lernsea  minuta,  A.  Scott.     (109)  p.  42. 

Female. — Head  moderately  enlarged,  not  very  clearly 
defined,  and  merging  into  the  rather  short  and  stout 
terminal  appendage  which  is  somewhat  distorted  and 
furnished  with  small  marginal  papillae ;  two  very  short 
lateral  appendages  also  present,  with  their  ends  ob- 
scurely bifurcate.  Neck  very  short,  narrow,  and  some- 
what abruptly  joined  to  the  genital  segment ;  this 
segment,  which  is  sigmoid,  having  the  proximal  half 
considerably  swollen,  but  tapering  somewhat  towards 
the  bluntly-rounded  and  slightly-recurved  extremity. 
Egg-strings  as  in  Lernaea  branchialis  but  rather  stouter. 
Antennae  and  other  cephalic  organs  rudimentary  or 
obsolete  ;  thoracic  legs  four  pairs,  small,  but  quite  dis- 
tinct and  situated  immediately  behind  the  lateral 
cephalic  horns.  Length  of  the  specimen  represented 
by  the  drawing  (PL  XLIV,  fig.  3)  a  little  over  7  mm. 
Colour  dark  red. 

Habitat. — Parasitic  on  the  gill-arches  of  speckled, 
gobies,  Gobius  minutus  Gmel.  On  Gobius  minutes 
from  the  Sol  way  in  November  1899  (T.  Scott)  ;  and 
on  specimens  of  the  same  kind  of  fish  captured  in  the 
Irish  Sea  (A.  Scott). 

10 


146  BRITISH    PARASITIC    COPEPODA. 

4.  Lernaea  lumpi  T.  Scott. 
(Plate  XLIV,  fig.  4.) 

1901.  Lernsea  lumpi  T.  Scott.     (113)  p.  128,  pi.  vii,  fig.  12. 

Female. — Head  globular,  furnished  with  three  very 
short,  simple,  spine-like  horns,  two  of  them  lateral  and 
one  dorsal.  Mouth  seen  as  a  small  papilliform  promi- 
nence on  the  ventral  aspect.  Head  separated  from 
the  neck  by  a  shallow  constriction  which  is  not  an 
articulation.  Neck  long,  moderately  slender^  slightly 
flexuose,  and  somewhat  wrinkled.  Genital  segment, 
though  rather  stouter  than  the  neck,  proportionally 
less  swollen  than  in  Lernsea  branchialis,  neither  is  it 
sigmoid  as  in  that  species  but  doubled  round  in  the 
form  of  a  hook;  a  distinct  constriction  also  present 
between  that  part  where  the  egg- strings  are  attached 
and  the  caudal  portion  of  the  body.  Clusters  of  egg- 
strings  small  and  more  or  less  twisted,  as  is  usual  in 
Lernsea.  Antennas  and  mouth-appendages  appearing  to 
be  somewhat  similar  to  those  of  other  species  of  Lernsea. 
Length  about  two  inches  (50  mm.).  Colour  dark  red. 
Habitat. — Parasitic  on  the  gill-arches  of  lumpsuckers, 
Cyclopterus  lumpus.  Found  on  a  lumpsucker  cap- 
tured in  the  salmon  nets  at  the  Bay  of  Nigg  near 
Aberdeen,  29th  March  1900. 

Only  a  single  specimen  of  this  somewhat  curious  parasite 
was  obtained,  though  dozens  of  lumpsuckers  have  been  exa- 
mined ;  the  head  and  a  portion  of  the  neck  measuring  about 
three-quarters  of  an  inch  penetrated  the  tissues  of  the  fish. 

The  structure  of  this  species  seems  in  some  respects  to 
approach  more  nearly  to  that  of  Pennella  than  is  the  case  with 
the  adult  Lernsea  branchialis,  the  body  is  recurved  to  a  much 
smaller  extent,  and  the  cephalic  horns  are  greatly  reduced  in 
size  ;  its  hold  on  the  fish  might  therefore  be  correspondingly 
weakened,  but  its  fixation  is  rendered  secure  by  having  a 
larger  proportion  of  the  neck  enclosed  in  the  tissues  of  the 
fish. 

It  sometimes  happens  that  the  Lernaea  dies  while  still 
attached  to  the  living  fish,  and  in  that  case,  though  the 
genito-abdominal  part  of  the  parasite's  body  disappears,  the 
fish  seems  to  be  unable  to  get  quit  of  the  tougher  and  more 


LERN^A   LUMPI.  147 

chitinous  neck  and  head  which  may  remain  fixed  to  the 
fish  for  a  considerable  time.  It  is  interesting  to  note  the 
difference  in  the  form  of  the  body  of  the  two  closely  allied 
genera  Pennella  and  Lernasa  :  in  the  one  the  body  is  elongated, 
cylindrical,  and  straight  or  nearly  so ;  in  the  other  it  is  bent 
back  upon  itself,  forming  one  or  two  more  or  less  abrupt  loops. 

Genus  28.    HJEMOBAPHES   Steenstntp  $  Liiiktn, 

1861. 

Parasites  having  a  general  resemblance  to  Lernsea. 

Head  rectangular,  flattened,  longer  than  broad  and 
without  lateral  horn-like  appendages.  Two  short, 
more  or  less  distinct  thoracic  segments  immediately 
posterior  to  the  head,  each  bearing  a  pair  of  rudimen- 
tary bilobed  appendages,  followed  by  two  pairs  of  legs, 
biramose  and  biarticulate.  Xeck  elongated,  the 
anterior  end  abruptly  reflexed  so  that  the  head 
becomes  pendulous,  and  near  the  flexure  are  two  short, 
lateral,  bluntly-pointed  horns.  Genital  segment  sig- 
moid,  proximal  half  swollen,  distal  half  narrower  and 
with  the  apex  bluntly  pointed,  a  pair  of  short  lateral 
processes  occurring  on  either  side  over  the  origin  of 
the  egg-strings.  Egg-strings  very  long  and  slender, 
but  twisted  up  into  regular  convoluted  spires. 

1.  Haemobaphes  cyclopterina  (0.  Fabr.). 
(Plate  XLIV,  figs.  5-7.) 

1780.  Lermea  cyclopterina  O.  Fabr.     Fauna  Grcenlandica,  p.  337. 

1822.  Lernseocera  cyclopterina  Blainv.     (24)  vol.  95,  p.  376. 

1837.  Lern&a  cyclopterina  Kroyer.     (70)  p.  502,  pi.  v.  fig.  4. 

1840.  Lerntea  cyclopterina  M.  Edwards.     (43)  vol.  iii,  p.  529. 

1861.  Hsemobaphes  cyclopterina  Steenstrup  &  Liitken.      (127)  p.  405, 

pi.  xiii,  fig.  30. 

1900.  Hiemobaphes  cyclopterimis  T.  Scott.     (112)  p.  162,  pi.  vii,  fig.  14. 

Female. — Head  small,  rectangular,  without  horn-like 
projections ;  two  short,  more  or  less  distinct  thoracic 
segments  crowded  behind  the  head,  each  furnished 
with  a  pair  of  rudimentary  bilobed  appendages.  Two 
pairs  of  biramose  legs  with  two-jointed  rami  also 
present,  the  rami  being  more  or  less  setiferous.  Neck 
long  and  slender,  and  bearing  midway  between  the  head 


148  BRITISH    PARASITIC    COPEPODA. 

and  genital  segment  two  short  lateral  horns  or  pro- 
cesses ;  at  about  this  point  a  more  or  less  abrupt 
flexure  occurring,  so  that  the  head  becomes  pendulous. 
The  proximal  half  of  the  genital  segment  somewhat 
swollen,  the  terminal  part  narrow  and  ending  in  a 
bluntly-pointed  apex.  A  pair  of  short  processes  on 
each  side  of  the  genital  segment  over  the  origin  of  the 
egg-strings.  Egg-strings,  which  form  regular  con- 
voluted spires,  situated  at  the  termination  of  the 
swollen  portion  of  the  genital  segment.  Length  about 
12  mm.  Colour  dark  red,  similar  to  that  of  Lernaea. 

Habitat. — Parasitic  on  the  gill-arches  of  various 
fishes.  On  the  gills  of  a  pogge,  Agonus  cataphractux, 
obtained  by  Mr.  Peter  Jamieson  in  the  stomach  of  a 
large  codfish  landed  at  Dunbar,  Haddingtonshire,  in 
April  1891.  Firth  of  Forth,  on  the  gills  of  a  pogge 
in  February  1892,  and  on  the  gills  of  a  butter-fish, 
Centronotus  gunnellus,  captured  in  1901  (T.  Scott). 
Irish  Sea  (A.  Scott). 

The  following  other  fishes  are  mentioned  by  Steen- 
strup  and  Liitken  as  hosts  for  this  parasite :  Cyclop- 
terns  spinosus,  Cottus  scorpius,  C.  bubalis,  and  C.  grcen- 
landicus,  Sebastes  norvegicus,  Centronotus  fasciatus,  and 
Gadus  merlangus.* 

Genus  29.  HJEMOBAPHOIDES  T.  $  A.  Scott, 

Syn.  H&mobaphes  T.  Scott  (not  Stp.  &  Liitk.). 

Resembling  Hasmobaphee  Stp.  &  Liitk.,  but  the  head 
furnished  with  branched  chitinic  horns ;  neck  very 
short,  the  posterior  portion  of  the  genital  segment 
more  produced,  compressed,  and  expanded  at  the  end. 

1.  Haemobaphoides  ambiguus  (T.  Scott). 
(Plate  XLIV,  fig.  8.) 

1900.  Hsemobaphes  ambiguus  T.  Scott.     (112)  p.  162,  pi.  vii,  fig.  15. 

Female. — Head  not  very  clearly  defined,  and  pro- 
vided with  branched  cartilaginous  horns,  which  are 

*  '  Parasitiske  Copepoder,'  p.  65  (1861). 


HJIMOBAPHOIDES    AMB1GUTJS.  149 

short  and  stout.  Neck  very  short  or  nearly  obsolete, 
genital  segment  flexuous  ;  the  anterior  portion  swollen 
as  in  Haemobapkes,  but  the  distal  portion  narrow,  and 
prolonged  so  that  it  at  least  equals  in  length  the 
proximal  part;  this  narrow  elongated  part  also  flat- 
tened, and,  at  the  extremity,  abruptly  expanded,  the 
margins  somewhat  irregular  in  outline  and  inflexed, 
and  the  lateral  lobes  at  its  proximal  end  moderately 
prominent.  A  distinct  though  quite  shallow  median 
groove  extending  along  the  dorsum  of  the  swollen  half 
of  the  genital  segment.  Egg-strings  forming  regular 
convoluted  spires  as  in  Hsemobaphes.  Colour  reddish- 
brown.  Length  about  11*5  mm. 

Habitat. — Parasitic  on  the  gills  of  spotted  dragonets, 
Callionymus  maculatus  Bonap.  On  spotted  dragonets 
captured  in  the  Solway  Firth  and  in  the  Firth  of  Clyde. 

In  a  sample  of  fifty-five  Callionymus  maculatus  captured 
in  the  Firth  of  Clyde  in  October  1901,  fifteen  specimens  of 
Hsemobaphoides  ambigimsavd  eight  of  Chondracanthus  ornatus 
were  obtained.  In  most  instances  the  specimens  of  the  two 
species  occurred  singly  and  on  different  fishes,  but  in  several 
cases  two  specimens  of  the  same  species  or  a  specimen  of  each 
occurred  on  the  gills  of  a  single  fish.  For  example,  a  spotted 
dragonet  73  mm.  in  length  had  a  Chondracanthus  on  one  side 
and  a  Hsemobaphoides  on  the  other ;  another  dragonet  had  a 
Chondracanthus  and  a  Hsemobaphoides  on  the  same  side;  a 
third  had  two  Chondracanthus  on  the  same  side,  while  the 
other  side  was  free  of  parasites;  and  a  fourth  had  a  Hsemo- 
baphoides on  each  side  but  no  Chondracanthus.  It  was  also 
noticed  that  when  only  one  parasite  occurred  on  a  fish  it  was 
frequently  on  the  right  side — the  fish  resting  on  its  ventral 
surface  and  with  its  head  toward  the  observer.  It  was  further 
noticed  that  though  seventeen  specimens  of  the  common 
dragonet  (Callionymus  lyra)  captured  at  the  same  time  and 
place  were  examined,  no  parasites  were  observed  on  them. 


Genus  30.  PENNELLA  Okeu,  1815. 

Female. — Body  greatly  elongated  and  slender. 
Head  tolerably  large,  globose  or  nearly  so,  studded 
with  minute  tubercles  and  usually  provided  with  horn- 


150  BRITISH    PARASITIC    COPEPODA. 

like  appendages  Avhich  extend  obliquely  backwards 
or  at  nearly  right  angles  to  the  median  line  of  the 
body.  Thoracic  region  forming  a  more  or  less  elon- 
gated and  slender  neck.  Anterior  portion  of  the 
genito-abdominal  region  elongated  and  moderately 
stout,  and  bearing  near  its  distal  end  two  tolerably  long 
egg-strings.  The  terminal  or  caudal  portion  of  the 
region  more  or  less  distinctly  annulated  and  carrying 
along  its  ventral  surface  numerous  fascicles  of  bristle- 
like  and  more  or  less  branching  appendages. 

Antennules  short,  small,  setiferous.  Antennae  small, 
uncinate.  Mouth-aperture  near  the  anterior  end  on 
the  ventral  aspect.  Thoracic  legs  four  pairs,  situated 
close  behind  the  head  and  with  only  a  small  interval 
between  each  pair.  The  first  and  second  pairs  bi- 
ramose,  but  the  others  one-branched ;  the  rami  all 
two-jointed,  and  all  the  thoracic  limbs  small. 

In  the  immature  Pennella  the  head  is  narrow  and 
subcylindrical,  and  the  horns  are  usually  wanting. 
Both  pairs  of  antennas  though  small  are  quite  distinct, 
the  second  pair  are  provided  with  strong  terminal 
claws  and  form  effective  grasping  organs ;  the  second 
maxillipeds  are  also  stout  and  strongly  clawed;  a 
considerable  space  intervenes  between  these  append- 
ages and  the  thoracic  legs. 

"Male  minute  and  not  elongated  "  (Bassett- Smith}. 

M.  Edwards  remarks  that  the  male  is  very  small,  nearly 
spherical,  and  possesses  anteriorly  a  conical  sucker,  furnished 
with  a  few  styliform  appendages  ;  and  that  on  the  inferior 
aspect  there  are  two  pairs  of  very  large  subcheliform  claws 
by  means  of  which  it  is  enabled  to  hang  on  to  the  female.* 
We  have  not  seen  the  male. 

1.  Pennella  orthagorisci  E.  P.  Wright. 
(Plate  LI,  fig.  2.) 

1829-1843.  Pennella  filosa  Gnerin-Meneville.     (55)  p.  11,  pi.  ix,  fig.  3. 
1861.  Pennella  filom  Steenstrup  &  Liitken.     (127)  pi.  xiv.  fig.  31. 
1870.  Pennella  orthagorisci  E.  P.  Wright.      (1-">U)  p.  42.  pi.  i,  figs.  1-6. 

*  '  Hist.  Nat.  Crust.,'  vol.  iii,  p.  522.     See  also  G.  M.  Thomson,  '  Trans. 
New  Zealand  Institute/  vol.  xxii,  1889,  p.  368. 


PENNELLA   OBTHAGOEISCI.  151 

1889.  Pennella  orthagorisci  Giard.     (50)  p.  82. 

1899.  Pennela  filosa  Bassett-Smitb.  (part).     (8)  p.  483. 

1905.  Pennella  filosa  T.  Scott.     (116)  p.  113. 

1905.  Pennella  arthag&risci  T.  R.  R.  Stebbing.     (124)  p.  119. 

1906.  Pennella  filosa  Norman  &  T.  Scott.     (88)  p.  216. 

1908.  Pennella  filosa  Cuvier?  A.  Brian.     (21  A)  p.  8,  text -figs.  2  &  3. 
1910.  Pennella  orthagorisci  T.  R.  R.  Stebbing.     (125)  p.  256. 

Female. — Body  elongated  and  slender ;  head  mode- 
rately large,  globose  or  nearly  so,  and  provided  with 
three  horn-like  appendages  on  the  ventral  aspect; 
the  middle  horn  very  small  and  rudimentary  but  the 
others  of  moderate  size  and  projecting  obliquely  back- 
wards. Neck  elongate,  slender,  smooth,  and  equal  to 
about  one  third  of  the  entire  length  of  the  animal. 
Genital  segment  moderately  stout  and  about  as  long 
as  the  neck ;  obscurely  annulated  and  bearing  at  the 
distal  end  two  long  and  very  slender  egg-strings.  The 
terminal  segment,  or  post-abdomen,  which  is  fully  half 
as  long  as  the  genital  segment,  bearing  along  the 
ventral  side  fascicles  of  branching  cartilaginous  ap- 
pendages, each  fascicle  dividing  into  two  or  three 
principal  branches,  which  are  again  subdivided  irregu- 
larly and  in  a  bifurcate  manner  into  long  slender 
filaments,  but  including  also  a  few  which  are  short  or 
undeveloped.  Colour  of  the  animal  blood-red.  Length 
90  to  100  mm.  (3-J  to  4  inches). 

Habitat. — Parasitic  usually  on  the  short  sun-fish, 
Orthagoriscus  mola. 

The  Rev.  A.  M.  Norman,  whose  kindness  we  have? 
experienced  on  numerous  occasions,  has  permitted  us  to 
examine  and  figure  a  Pennella  sent  to  him  many  years  ago 
(about  1862)  by  Thomas  Edward  of  Banff.  The  specimen 
was  found  on  a  short  sun- fish  captured  in  the  Moray  Firth, 
and  is  referred  to  in  Smiles'  Life  of  Edward  among  the 
numerous  other  natural  history  records  at  the  end  of  that 
work,  under  the  name  of  Pennella  jibrosa,  that  name  being 
no  doubt  a  misprint  for  "filosa  "  ;  unfortunately  this  speci- 
men wanted  the  head.  Some  years  previous  to  the  publica- 
tion of  Smiles'  Life  of  Edward,  Dr.  E.  P.  Wright  described 
under  the  name  of  Pennella  orthagorisci  specimens  found  on 
short  sun-fish  captured  in  Cork  Harbour  in  1869*  ;  he  also  in 

*  '  Ann.  &  Mag.  Nat.  Hist./  ser.  4,  vol.  v,  p.  42,  pi.  i,  figs.  1-6  (1870). 


152  BRITISH    PARASITIC    COPEPODA. 

the  same  paper  states  that  Dr.  Baird  informed  him  that  he  bad 
"  examined  a  specimen  of  Pennella  from  a  sun-fish  captured 
at  Megavissy,  Cornwall,  which  he  (Dr.  Baird)  refers  to 
P.  filosa  Linn/'  We  have  little  doubt  that  the  specimens 
obtained  at  the  places  mentioned  were  all  referable  to  the 
same  species. 

The  name  Pennella  filosa  sometimes  applied  to  the  sun-fish 
parasite  appears  to  have  been  given  to  it  under  the  supposi- 
tion that  it  and  the  swordfish  Pennella  were  identical ;  thus 
far,  however,  there  is  no  satisfactory  evidence  to  show  that 
they  are  so,  and,  till  such  evidence  is  forthcoming,  the  name 
Pennella  filosa  (Linn.),  as  pointed  out  by  Steeiistrup  and 
Liitken,  should  be  retained  for  the  form  found  on  the  sword- 
fish.  Percival  Wright's  Pennella  orthagorisci  should  also  for 
similar  reasons  be  accepted  for  the  Pennella  of  the  sun-fish. 
The  Rev.  T.  R.  R.  Stebbing,  in  Part  III  of  his  work  on 
"South  African  Crustacea"  (1905),  in  a  short  discussion  on 
Pennella}  remarks  that  "the  description  given  by  Linnaeus 
can  scarcely  be  said  to  have  any  specific  value  apart  from 
the  name  of  the  host,  so  that  no  injury  is  done  him  by  leav- 
ing his  specific  name  in  abeyance  until  a  Pennella  infesting  a 
Xiphias  has  been  again  observed.  For  the  parasite  of  the 
sun-fish  an  appropriate  name  is  available,  which  appears  to 
have  escaped  recent  attention."* 

In  January  1908,  M.  Alexandre  Brian  published  an  in- 
teresting paper  entitled  "  Note  preliminaire  sur  les  Cope- 
podes  parasites  des  poissons  provenant  des  campagnes 
scientifiques  de  S.A.S.  le  Prince  Albert  ler  de  Monaco  ou 
deposes  dans  les  collections  du  Musee  Oceanographique." 
This  Note  forms  Bull.  No.  110  of  the  Oceanographical  Insti- 
tute. The  author  describes  with  illustrative  figures  an  adult, 
and  several  immature,  female  Pennellse  under  the  name  of 
"  Pennella  filosa  Cuvier  "  which  were  obtained  on  a  sun-fish 
captured  in  lat.  39°  56'  10"  N.,  long.  34°  W.,  19th  July 
1887,  and  which  seem  to  be  identical  with  Wright's  P. 
orthagorisci.  He  also  describes  a  "  Pennella  sp.?"  A  single 
adult  obtained  "  dans  la  peau  du  ventre  d'un  Xiplias  yladius  " 
captured  at  Saint- Jean-sur-Mer,  llth  March  1905.  May 
this  Pennella  not  be  referable  to  the  species  described  by 
Linnaeus  ?  It  is  more  than  twice  the  size  of  the  adult  female 
recorded  from  the  sun-fish  ;  the  shape  of  the  head  and  the 
form  and  size  of  its  two  horn-like  appendages  are  also  very 
different.  The  length  of  this  specimen  is  described  as  212 

*  '  Marine  Investigations  in  South  Africa,'  "  South  African  Crustacea," 
pt.  iii,  p.  118. 


PEXNELLA   ORTHAGORISCI.  153 

millimetres  (=  about  8£  inches),  whereas  the  adult  female 
from  the  sun-fish  is  only  93  millimetres  (about  3J-  inches).  The 
head  of  the  young  female  of  the  sun-fish  Pennella,  as  shown 
by  Brian,  is  narrow  and  subcylindrical,  fully  three  times 
longer  than  broad,  and  the  horn-like  processes  are  wanting; 
the  abdominal  appendages  are  also  more  or  less  rudimentary, 
and  the  posterior  annulations  appear  to  be  more  distinct. 

The  free-swimming  larvae  of  Pennella  have  a  close  resem- 
blance to  those  of  Lernsea  branchialis  and  exhibit  the  near 
relationship  between  these  genera.  Dr.  Al.  Mrazek,  in  a 
paper  "  Ueber  Baccuhis  Lubb.  und  Hessella  Br.  Ein  Beitrag 
zur  Anatomie  der  Lernaaiden,"  *  gives  a  detailed  description 
of  the  anatomy  of  these  larval  forms. 

Pennella  baleenopterse  Koren  &  Danielssen. 

Specimens  of  a  giant  species  of  Pennella  found  attached  to 
a  finner  whale  (Baltenoptera  musculns  (Linn.))  were  presented 
to  Sir  William  Turner,  F.R.S.,  Edinburgh,  by  Mr.  Chr. 
Castberg,  the  manager  of  a  Norwegian  Whaling  Company 
which  has  a  fishing-station  at  Ronasvoe,  in  the  north  of 
Shetland.  A  full  and  interesting  description  of  the  species, 
illustrated  with  four  plates,  is  published  by  Sir  William 
Turner  in  the  '  Transactions  of  the  Royal  Society  of  Edin- 
burgh/ vol.  xli,  Part  2  (Xo.  18),  1905. 

This  somewhat  remarkable  species  does  not  come  within 
the  scope  of  a  Monograph  devoted  to  the  parasites  of  fishes, 
but  we  nevertheless  refer  to  it  here  on  account  of  the  author's 
interesting  remarks  on  the  history  of  the  peculiar  genns  to 
which  the  species  belongs,  and  because  the  description  given 
of  the  species  is  also  generally  applicable  to  the  one  found  on 
the  sun-fish. 

The  largest  specimen  obtained  by  Sir  William  Turner 
measured  294  mm.  (nearly  Hi  inches)  in  length,  but,  as 
the  author  remarks,  even  larger  specimens  have  been  recorded 
by  Koren  and  Dauielssen ;  one  of  these  is  said  to  have 
measured  320  mm.  (12^  inches)  in  length.  In  this  species  the 
head  is  provided  with  three  slender  chitinous  horns  of  unequal 
length  which  extend  horizontally  outwards  at  nearly  right 
angles  to  the  body,  the  dorsal  horn  being  usually  the  shortest ; 
and  in  this  and  a  few  other  respects  Pennella  balfenopterse 
differs  from  the  sun -fish  parasite.  It  seems  however  to  be 
still  a  moot-point  whether  all  these  different  Pfuncllpc  are  to 
be  regarded  as  valid  species. 

*  '  Sitzungsberichte  d.  konigl.  bohm.  Gesellsch.  d.  Wiss./  Math.-nat. 
Classe  (1895),  xliv,  pp.  1-17,  2  plates. 


154  BRITISH   PARASITIC    COPEPODA. 

Another  Cetacean  Pennella,  P.  crassicornis  Steenstrup 
&  Ltitken,  was  found  attached  to  a  bottle-nose  whale 
(Hyperoodon  rostratus  (Mull.))  captured  south  of  the  Faroes 
in  1855.*  In  this  form  the  horn-like  appendages  of  the 
cephalon  are  short  and  rather  stout,  and  the  whole  animal  is 
much  smaller. 


Genus  31.  LERNJEOCERA  Blainville,  1822. 

Body  long  and  slender;  head  not  distinctly  de- 
fined, provided  with  horn-shaped  appendages  which 
are  simple  and  more  or  less  symmetrical  in  form. 
Mouth  situated  at  the  apex  of  a  small  conical  lobe  in 
the  median  line  and  projecting  slightly  forward  of  the 
base  of  the  lateral  horn-like  appendages.  Genital 
segment  much  elongated,  becoming  more  or  less 
thickened  posteriorly,  and  somewhat  curved  at  the 
distal  extremity.  Abdomen  very  small  or  obsolete. 
Egg-strings  straight  and  of  moderate  length. 

1.  Lernseocera  cyprinacea  (Linn.). 
(Plate  L,  figs.  1-5.) 

1761.  Leniifa  cyprinacea  Linn.     (77)  vol.  ii,  No.  2100,  pi.  xi,  fig.  2. 
1 783.  Lern&a  cyprinacea  Barbut.     (5)  vol.  i,  p.  3,  pi.  vii,  fig.  3. 
1783.  Lerniea  (/)  esocina  Hermann.     (61)  vol.  xix,  p.  44,  pi.  ii,  fig.  6. 
1822.  Lernseocera  cyprinacea  Blainv.     (24)  vol.  xcv.  p.  377. 
1832.  Lernfeocera  (?)  cyprinacea  Nordm.     (89)  p.  123.  pi.  vi,  figs.  1-8. 
1840.  Lem&ocera  (?)eo8cina  M.  Edwards.     (43)  vol.  iii,  p.  527,  pi.  xl, 
figs.  13-15. 

1840.  Lernseocera  cyprinacea  idem.     (43)  vol.  iii,  p.  527,  pi.  xl,  fig.  16. 
1850.  Lei-neocera  cyprinacea  Baird.     (4)  p.  343,  pi.  xxxv,  fig.  13. 
1868.  Lern&ocera  (?)  esocina  Glaus.     (34)  vol.  xxxi,  p.  530. 

Female. — "  Head  furnished  with  four  horn-shaped 
appendages,  which  are  somewhat  long  and  slender. 
The  two  outer  or  posterior  are  bifurcated ;  the  anterior 
simple. 

"  The  thorax  is  very  slender  anteriorly,  forming  a 
long  neck,  but  becomes  much  broader  posteriorly,  and 
when  it  terminates  in  the  small  abdomen,  appears 
obliquely  truncate.  The  ovigerous  tubes  are  cylin- 

*  '  Bidrag.  til  Kundskab  om  detaabne  Havs  Synltekrebs  og  Lernaeer/ 
p.  76  (separate  copy),  1861. 


LERNSEOCERA   CYPEINACEA.  155 

drical  and   rather   long.     The   length    of  the    whole 
animal  is  about  eight  lines." 

"  Hob. — Found  on  the  sides  of  the  carp,  bream, 
and  roach  in  many  of  our  ponds  and  rivers  in  great 
abundance  "  (Barbni).  "  I  have  not  seen  any  specimens 
of  this  species  "  (Baird,  '  Entomostraca,'  pp.  343,  344). 

As  we  have  not  been  able  to  obtain  specimens  of  this 
Lernseocera,  Dr.  Baird's  description  and  remarks  are  here 
reproduced.  Fig.  5  on  PL  L  is  also  reproduced  from  his 
work. 

Dr.  Baird  does  not  include  Hermann's  Lernsea  esocina  in 
his  list  of  synonyms,  but  seems  to  regard  it  as  a  different 
species.  He  says :  "  Linnaeus  was  the  first  who  noticed  any 
of  the  animals  belonging  to  this  genus.  In  his  '  Fauna 
Suecica/  1746,  he  describes  a  species  found  in  Sweden  on  a 
carp;  a  species  which  Barbut,  in  1783,  ascertained  to  be 
British.  Hermann  also,  in  1783,  describes  and  figures  another 
species,  and  several  have  since  that  time  been  added  to  the 
list.  .  .  .  The  genus,  as  established  by  Blainville,  con- 
tains two  species,  which  have  been  separated  from  it  by 
Kroyer  and  M.  Edwards ;  but  still  it  has  been  retained  in  a 
restricted  sense  by  all  succeeding  authors."  M.  Edwards 
apparently  recognizes  the  two  species,  Lerneocera  cyprinacea 
and  L.  esocina  ;*  Kroyer  (1863)  on  the  other  hand  does  not 
mention  either,  but  records  Lernseocera  phoxinacea  Kollar, 
and  describes  two  n.  spp.  from  American  waters. 

Linneeus,  after  giving  a  brief  description  of  his  Lernsen 
cyprinacea,  adds,  "  Habitat  in  Piscinns  frequens  supra  corpus 
Cyprini  carassii"t;  and  Pennant,  in  speaking  of  Cyprinus 
carassius,  which  he  also  calls  the  "  Crucian  Carp,"  says  "  it  is 
common  in  many  of  the  fish-ponds  about  London  and  other 
parts  of  the  south  of  England  but  I  believe  is  not  a  native  fish."+ 

From  the  remarks  of  Dr.  Baird  it  is  evident  that  the 
Lernasa  recorded  by  Barbut  is  the  species  described  by 
LinnsenSj  and  that  it  also  was  found  parasitic  on  fishes 
belonging  to  the  Cyprinida?  ;  probably  on  the  "  Karauschen  " 
or  crucian  carps,  which  were  according  to  Pennant  common 
at  that  time  in  many  fish-ponds  about  London. 

Nordmann  in  1832  records  a  Lernseocera  cyprinacea,  five 
specimens  of  which  were  found  "in  der  unteren  Kinnlade  des 
Hechtes,"  or  fresh-water  pike,  Esox  hicius,  a  kind  of  fish  very 

*  '  Hist.  nat.  Crust.,'  vol.  iii  (1840),  p.  527. 

t  '  Systema  Naturae,'  ed.  xii,  vol.  i,  pars  ii,  p.  1093  (1767). 

I  'British  Zoology,'  vol.  iii,  p.  364  (1776). 


1-1)6  BRITISH    PARASITIC    COPEPODA. 

different  from  the  Carp  family ;  and  his  figures  of  the  para- 
sites of  this  fish,  while  in  general  agreement  with  that  of 
Dr.  Baird,  represent  what  appears  to  us  to  be  a  different 
species  from  the  one  figured  by  the  English  author.  Nord- 
mann's  figures  show  a  more  robust  animal,  with  shorter  and 
thicker  cephalic  horns,  the  distal  extremity  is  also  more 
decidedly  deflexed,  and  the  ovisacs  are  short  and  saccate.* 
Probably  this  is  the  Lernseocera  esocina  of  Hermann  and  not 
L.  cyprinacea  (Linn.).  We  prefer  therefore  to  retain  mean- 
while Linne's  species  name,  cyprinacea,  for  the  Lernseocera 
recorded  by  Dr.  Baird. 

Genus  32,  LERNJEENICUS  Lesueur,  1824. 

Body  elongated,  slender,  obscurely  or  non-seg- 
mented. Head  somewhat  expanded,  sometimes  pro- 
duced into  a  cone-like  process  in  front,  and  usually 
provided  with  two  or  three  stiff  cartilaginous  horns, 
projecting  outwards  or  more  or  less  obliquely  back- 
wards. Thorax  very  narrow,  forming  a  kind  of  neck, 
and  merging  posteriorly  into  the  somewhat  stouter 
abdomen.  Abdomen  without  penniform  appendages. 
Antennules  small,  obscurely  Inarticulate,  and  more  or 
less  setiferous.  Antennae  small  but  strongly  chelate, 
and  similar  to  those  of  I'l'inu'lla.  Thoracic  legs  very 
small,  and  situated  immediately  behind  the  head,  each 
pair  slightly  apart  from  the  other ;  the  first  and 
second  pairs  biramous  and  the  others  uuiramous,  and 
all  the  rami  two-jointed.  Egg-strings  long  and  slender. 

1.  Lernaeenicus  sprattae  (Sowerby). 
(Plate  XL VI,  figs.  1-5.) 

1806.  Lerntfa  spratta  Sowerby.  Brit.  Miscellany,  vol.  ii,  p.  17, 
pi.  Ixviii. 

1840.  Lertwonema  monilaris  M.  Edwards.     (43)  p.  525,  pi.  xli,  fig.  5. 

1850.  Lerneonema  spratta  Baird.     (4)  p.  341,  pi.  xxxv,  fig.  10. 

1850.  Lernwonema  bairdi  Salter.  (106)  (ser.  2),  vol.  vi,  p.  86,  pi.  vii, 
fip.  1. 

1865.  Lernu'onema  monilaris  Heller.     (58)  p.  248,  pi.  xxv,  fig.  4. 

1868.  Lermeenicus  stpratta  Olsson.     (92)  p.  46. 

"  This  figure  of  Nordmann's  is  reproduced  on  PI.  L,  fig.  1.  If  com- 
pared with  Dr.  Baird's  figures  of  L.  cyprinacea  on  the  same  plate  (fig.  4), 
the  difference  referred  to  will  be  readily  observed.  See  also  Selago's  figure, 
which  resembles  Haird's  and  is  also  reprodiiced  on  this  plate  (fig.  5). 


LERN^EENICUS   SPRATT^E.  157 

1900.  Lermeenicm  spratte  T.  Scott.     (112)  p.  161,  pi.  vii,  figs.  7-10. 
1907.  Lern&enicus  sprattn1  A.  Scott.     (Ill)  p.  94,  pi.  ii,  figs.  1-5. 

Female. — Body  elongated,  slender  ;  head  somewhat 
enlarged,  and  provided  with  two  stiff  horn-like  pro- 
cesses, one  on  each  side  and  extending  obliquely  back- 
wards. Thorax,  between  the  head  and  the  genital 
segment,  slender  and  neck -like,  with  a  number  of 
minute  constrictions,  giving  to  this  part  of  the  body  a 
moniliform  appearance ;  genital  segment  moderately 
elongated  and  increasing  somewhat  in  thickness  pos- 
teriorly. Abdomen  rudimentary  and  not  very  clearly 
defined,  apparently  destitute  of  appendages. 

Antennules  short,  distinct,  setiferous,  indistinctly 
two-jointed,  the  end  joint  being  shorter  than  the 
other ;  antennas  very  short,  stout,  strongly  chelate 
as  in  Pennella ;  other  mouth-organs  somewhat  rudi- 
mentary. Thoracic  legs  small,  situated  immediately 
posterior  to  the  head  ;  first  and  second  pairs  biramose, 
rami  two-jointed;  the  next  two  pairs  uniramose,  the 
rami  being  also  two-jointed.  In  fresh  or  living  speci- 
mens the  colour  of  the  genito-abdominal  segment  is 
greenish.  Egg-strings  long  and  slender,  usually 
exceeding  the  length  of  the  body,  which,  exclusive  of 
the  egg-strings,  measures  about  18  mm. 

Habitat. — Usually  found  parasitic  on  the  eyes  of 
sprats,  Clupea  spratta,  and  sometimes  also  on  other 
parts  of  the  body.  Occasionally  more  than  one  para- 
site will  be  found  adhering  to  the  same  eye.  London 
Market  1848  (W.  Winy,  see  Baird).  Youghal,  Ireland 
(W.  Thompson  1852).  Observed  on  a  sprat  in  Leith 
Docks  1890  (J.  Scott}.  Not  uncommon  on  sprats 
captured  along  the  Lancashire  coast  (A.  Scott).  One 
perfect  specimen  taken  at  Plymouth  (Bassett-Smith). 

A  sample  of  six  hundred  sprats  captured  with  the  shrimp 
trawl  off  Blackpool  in  1910  yielded  fourteen  Lernseenicus 
sprattse.  The  eye  of  one  of  the  sprats  examined  had  three 
specimens  of  Lernseenicus  fixed  to  it.  The  head  of  the 
parasite  is  entirely  buried  in  the  tissues  of  the  host,  and  can- 
not be  removed  except  by  dissection.  The  parasite  when 
fixed  to  the  eye  appears  to  cause  partial  or  total  blindness. 


158  BRITISH    PARASITIC    COPEPODA. 

2.  Lernseenicus  encrasicola  (Turton). 
(Plate  XLVI,  figs.  6-9.) 

1807.  Lernxa  encrasicola  Turton.     (141)  vol.  i,  p.  137,  No.  108. 

1850.  Lemeonema  encrasicola  Baird.     (4)  p.  341.  pi.  xxxv,  fig.  11.- 

1868.  Lermeenicus  encrasicola  Olsson.     (92)  p.  46. 

1877.  Lermeenicus  encrasicola  Richiardi.     (102)  vol.  iii.  fasc.  i. 

1907.  Lermeenicus  encrasicola  A.  Scott.     (Ill)  p.  93,  pi.  ii,  figs.  6-9. 


Female.  —  Closely  resembling  Lernssenicits 
and  may  be  easily  mistaken  for  it.  Among  the  more 
obvious  points  of  difference  are  the  following  :  —  (1) 
The  horn-shaped  appendages  of  the  cephalon,  instead 
of  pointing  obliquely  backwards,  stand  out  at  nearly 
right  angles  with  the  median  line  of  the  body.  (2) 
"  The  neck  is  long  and  slender,  quite  smooth  and 
destitute  of  the  constrictions  which  mark  so  decidedly 
the  preceding  species"  (Baird).  (3)  It  is  usually 
found  attached  to  the  body  of  its  host,  the  head  some- 
times penetrating  into  the  abdominal  cavity. 

The.  appendages  of  the  cephalon  and  thorax  do  not 
appear  to  differ  greatly  from  those  of  Lernseenicus 
sprattse.  Length  about  27  mm. 

No  males  of  either  species  have  been  observed. 

Habitat.  —  Parasitic  on  the  anchovy,  Engraulis 
encrasicholus,  and  sprat,  Glupea  spratta.  On  a  sprat 
captured  at  Youghal  (R.  Ball,  W.  Thompson).  "  Found 
attached  to  the  bodies  of  Glupea  encrasicholns  and 
sprattus  frequently,  in  Swansea  Bay"  (W.  Turton). 
Attached  to  the  body  of  a  sprat  (/.  Doubleday, 
British  Museum).*  A  broken  specimen,  probably 
belonging  to  this  species,  was  taken  from  a  Clupea 
alosa  at  Plymouth  (Bassett-  Smith).  On  the  eye  of  a 
young  pollack  at  Falmouth  (Cocks;  cf.  'Crust,  of  Devon 
and  Cornwall'  by  Norman  and  Scott,  p.  216,  1906). 

"A  large  catch  of  sprats  was  taken  off  Blackpool  on  19th 
February  1906  by  the  Lancashire  Fisheries  Steamer,  and 
a  few  hundreds  of  them  were  landed  at  Piel.  A  careful 
examination  of  these  was  made,  and  one  sprat  with  two  of 
the  above  mentioned  parasites  attached  to  it  and  another 
with  one  were  found.  The  parasites  were  embedded  in  the 
*  These  records  are  from  '  British  Entomostraca/  p.  342  (1850). 


LERN.EEN1CUS    ENCRASICOLA.  159 

tissues  at  the  anterior  end  of  the  dorsal  fin.  On  dissecting 
one  of  the  specimens  out,  it  was  found  that  the  head  of  it  had 
penetrated  into  the  visceral  cavity"  (A.  Scott).* 

M.  Marcel  Baudoin,  in  his  article  on  the  parasites  of  the 
sardine,  t  describes  under  the  name  of  Lernseenicus  sardinee 
a  form  which  he  has  found  adhering  to  this  Clupeoid.  There 
is,  as  stated  by  Aflalo,  a  British  Pilchard-fishery  on  the  south- 
west coast,J  and  the  same  fish  has  occasionally  been  captured 
in  Scottish  waters,  §  but  no  British  specimen  of  this  Lernseenicus 
has  yet  been  observed.  Though,  however,  many  pilchards 
are  captured  each  season,  this  Lernasenicus  if  present  may  be 
easily  missed,  or  mistaken  for  the  more  common  L.  xprattse. 
One  of  the  more  obvious  characters  of  the  species  being  the 
shape  of  the  head,  as  this  is  buried  in  the  tissues  of  the 
host,  sometimes  at  the  side  of  the  eye  as  in  Lernasenicus 
yprattse  and  sometimes  near  the  dorsal  fin,  it  is  only  by  careful 
dissection  that  it  can  be  obtained  for  examination.  The  neck 
next  the  head  is  extremely  slender,  and  therefore  the  external 
portion  of  the  parasite  is  easily  broken  off,  while  the  head 
remains  entirely  concealed. 


Genus  33.  TRIPAPHYLUS  RiMinli,  1878 

Syn.  Lerneonema,  P.  J.  van  Beneden  (in  part). 

Female.  —  Body  greatly  elongated,  slender,  non- 
segmented.  Head  rounded  and  provided  with  stiff 
cartilaginous  horns.  Thorax  very  slender,  forming 
an  elongated  neck.  Genito-abdominal  segment  narrow 
at  the  proximal  end  but  becoming  enlarged  posteriorly 
and  furnished  with  two  long  and  slender  distal  pro- 
cesses. Antennules  and  other  cephalic  appendages 
somewhat  similar  to  those  of  Lerndsenicus. 

Male.  —  Body  divided  into  two  nearly  equal  portions  ; 
the  anterior  portion  large  and  carrying  three  pairs  of 
appendages  ;  the  cephalon  rather  obscurely  denned, 
and  the  abdomen  not  so  robust  as  the  cephalo-thoracic 
portion.  The  cephalothoracic  appendages  also  some- 
what rudimentary. 

*  '  Report  for  1906  on  the  Lancashire  Sea-  Fisheries  Laboratory  at  the 
University  of  Liverpool,  and  the  Sea-fish  Hatchery  at  Piel,'  No.  xv,  p.  94. 

t  "  Les  parasites  de  la  Sardine,"  'Revue  scientifique,'  5  ser.,  vol.  iii,  No. 
2:5,  p.  715,  with  text-figures  (1905). 

|  'Natural  History  (Vertebrates)  of  the  British  Isles,'  p.  398  (1898). 

§  '  Fishes  of  the  Firth  of  Forth,'  by  Dr.  Parnell,  pp.  320-322  (1838). 


160  BRITISH    PARASITIC    COPEPODA. 

1.  Tripaphylus  musteli  (P.  J.  van  Beneden). 

(Plate  XLV,  fig.  6  ;    Plate   LI,  fig.  1  ;    Plate  XLIX, 

figs  1-7.) 

1851.  Lerneonema  musteli  P.  J.  van  Ben.  (12)  vol.  xviii,  p.  287,  pi. 
No.  8,  figs.  1-7,  (J  &  ?  . 

1851.  Lerneonema  musteli  idem.     (11)  vol.  xvi,  p.  125,  pi.  6,  figs.  11-14. 

1877.  Lerneonema  musteli  Vogt.     (142)  p.  69,  pi.  iii,  fig.  11. 

1878.  Tripaphylus  musteli  Richiardi.     (103)  p.  xx. 

1885.  Tripaphylus  musteli  Cams.    (29a)  Pi%odr.  faunae  Mediterr.,  p.  372. 

1899.  Lermeenicus  musteli  Bassett-Smith.     (8)  p.  485. 

1904.  Lernwenicus  musteli  A.  Scott.     (109)  p.  41. 

L  1906.  Tripaphylus  musteli  A.  Brian.     (21)  p.  87. 

Female. — Body  greatly  elongated  and  slender,  non- 
segmented  and  with  the  surface  quite  smooth.  Head 
rounded  and  furnished  with  cartilaginous  horns. 
Thorax  very  slender,  rather  weak  and  somewhat 
flexuous.  Genito-abdominal  portion  narrow  at  the 
proximal  end  where  it  joins  the  neck,  but  becoming 
gradually  enlarged  from  the  front  backwards,  and 
assuming  nearly  the  form  of  a  spindle.  Body  pro- 
vided posteriorly  with  two  long  slender  appendages 
nearly  equal  in  length  to  the  genital  segment ;  these 
appendages,  though  in  communication  with  the  body- 
cavity,  have  no  connection  with  the  egg-strings,  which 
have  their  origin  immediately  behind  the  base  of  the 
prolongations  referred  to  and  are  nearly  twice  their 
length. 

Head  with  a  considerable  portion  of  the  neck 
buried  in  the  tissues  of  the  gill-arch  of  the  fish. 
Colour  of  the  parasite  deep  red.  Length  as  given 
by  van  Beneden  :  Body  exclusive  of  the  abdominal 
appendages  45  mm. ;  abdominal  appendages  15  mm. 
in  length  and  the  egg-strings  23  mm.  The  body  in 
its  greatest  width  measures  3  mm. — this  specimen 
wanted  the  head.  The  specimen  figured  here  (PI.  LI, 
fig.  1),  which  is  also  minus  the  head,  measures  28  mm. 
exclusive  of  egg-strings. 

Male. — The  male  of  this  species  has  the  body 
divided  into  two  unequal  portions :  the  anterior  por- 
tion is  large,  and  carries  three  pairs  of  appendages— 


TRIPAPHYLUS    MUSTELI.  161 

viz.  one  pair  of  antennae  and  two  pairs  of  feet ;  the 
posterior  is  much  more  narrow,  and  rounded,  and 
carries  at  the  end  two  rounded  tubercles  which  pro- 
bably represent  the  fifth  pair  of  feet ;  the  body  may 
also  be  divided  into  head,  thorax,  and  abdomen.  On 
the  sides  of  the  cephalic  portion  we  distinguish  a 
pair  of  setiferous  antennas  showing  feeble  indications 
of  articulation ;  the  mouth  is  terminal  and  fringed 
with  minute  setas.  The  mandibles  and  maxillas  are 
somewhat  rudimentary.  The  two  pairs  of  maxillipeds 
are  comparatively  well  developed,  and  form  prehen- 
sile appendages  similar  to  what  is  found  in  the  males 
of  many  of  the  sedentary  female  fish-parasites. 

The  thorax  is  dilated  (or  bulging),  smooth  and 
even  on  the  surface;  it  carries  two  pairs  of  feet 
singularly  formed,  and  nearly  as  dilated  and  elongate 
as  the  abdomen.  The  feet  of  both  pairs  are  con- 
solidated in  all  their  length  as  the  organs  of  adhesion 
in  the  females  of  the  Lerneopodians  ;  it  is  only  at  the 
end  that  they  are  divided.  The  anterior  pair  is 
biramose ;  the  outer  ramus  is  two- jointed,  and  is  ter- 
minated by  a  double  hook  for  clinging.  The  other 
pair  is  longer;  the  outer  ramus  shows  three  articu- 
lations terminated  by  two  hooks,  as  in  the  outer  ramus 
of  the  preceding  pair,  but  on  the  base  of  the  hooks  is 
a  small  additional  tooth  which  renders  these  organs  of 
adhesion  more  effective. 

It  will  be  seen  from  the  above  description  and  the 
drawing  PI.  XLV,  fig.  6)  that  there  are  some  of 
the  Lernaean  males  considerably  removed  from  the 
ordinary  type. 

Habitat. — Parasitic  on  the  gills  of  the  smooth  hound, 
Mustelus  vulgaris  (Sqnalus  musielus).  Irish  Sea  (A. 
Scott). 


VOL.   I.  11 


162  BRITISH    PARASITIC    COPEPODA. 

Genus  34.  REBELULA  Poche,  1902. 

Syn.  Lophura  Kolliker  (name  pi-eoccupied  for  a  genus  of  birds). 

Head  subcylindrical,  narrow,  in  the  same  straight 
line  as  the  neck  and  furnished  with  two  bilobed  or 
slightly  branched  processes  at  its  base.*  Neck  usually 
slender  and  elongated.  Genital  segment  large,  inflated, 
somewhat  flattened  dorsally,  and  having  small,  slightly 
obscure  circular  depressions  on  the  dorsal  and  ventral 
aspects,  and  provided  posteriorly  with  two  bundles  of 
filiform  appendages,  one  on  each  side  of  the  abdomen. 
Abdomen  small  and  obscurely  lobate.  Egg-strings 
tolerably  elongated,  and  containing  numerous  small 
ova. 

1.  Rebelula  edwardsi  (Kolliker). 
(Plate  XLV,  fig.  1 ;    Plate  LI,  fig.  5.) 

1853.  Lophura  edwardsi  Kolliker.  (68a)  Zeitschr.  f.  wiss.  Zoo!.,  vol. 
iv,  p.  359. 

1860.  Lophoura  edwardsi  Clans.  (30a)  Wiirzburgernaturwiss.  Zeitschr., 
vol.  i,  p.  20. 

1865.  Lophura  edwardsii  Cornalia.  (36a)  Atti  della  Soc.  Ital.  d.  Sci. 
Nat.,  vol.  ix,  p.  1,  pi.  i. 

1902.  Eelelula  edwardsii  Poche.     (97)  p.  20. 

1906.  Rebelula  edwardsii  Brian.    (21)  p.  90,  pi.  xix,  fig.  1 ;  pi.  xxi,  fig.  5. 

1908.  Rebelula  edwardsi  Brian.     (21a)  p.  15,  text-fig.  6,  a,  b. 

Female. — Head  subcylindrical,  narrow,  moderately 
short,  and,  with  part  of  the  neck,  buried  in  the 
tissue  of  the  host  in  the  neighbourhood  of  the  dorsal 
fin.  Neck  tolerably  long  and  narrow.  Genital  seg- 
ment stout,  suborbicular,  or  pyriform,  somewhat  flat- 
tened dorsally,  and  provided  posteriorly  with  two 
bundles  of  slender  digitiform  filaments,  one  on  each 
side  of  the  abdomen.  Abdomen  small,  obscurely  tri- 
lobed.  Egg-strings  tolerably  elongated,  containing 
numerous  small  ova,  and  springing  from  the  base 
of  the  abdomen,  inside  the  digitiform  appendages. 

The  specimens  examined  by  us  were  of  a  reddish 

*  The  description  of  the  head  of  Rebelula  given  in  the  definition  of  the 
genus  is  taken  from  complete  specimens  found  on  macrurid  fishes  captured 
in  the  Bay  of  Bengal  and  in  the  Malay  Archipelago,  and  representing  two 
apparently  distinct  species  of  this  curious  genus  of  parasites. 


KDWAUDSI.  163 

colour,  but  they  had  been  for  some  time  in  a  preserva- 
tive fluid.  The  smaller  of  two  specimens  measured 
from  the  posterior  end  of  the  neck  to  the  extremity  of 
the  digitiform  processes  about  12  mm.,  the  other  was 
about  twice  that  size. 

Habitat. — Parasitic  on  species  of  Macruridse.  One 
on  a  Macrurns  (Lepldoleprus)  caelorhynchus  Bisso,  cap- 
captured  off  the  south-west  of  Ireland  by  H.M.S. 
*  Research  '  at  Station  I,  depth  200  fathoms,  10th  July 
1899  (A.  M.  Norman).*  One  in  a  gathering  collected 
by  means  of  a  small  trawl,  at  a  depth  of  1448  metres 
in  lat.  58°  43'  X.,  long.  9°  6'  W.,  23rd  August  1910 
(Fishery  Steamer'  Grold seeker').  Host  doubtful:  this 
specimen  appears,  in  some  way,  to  have  become 
detached  from  its  host.  In  both  specimens  the  head 
was  wanting. 

The  following  measurements  are  from  the  specimen 
from  the  west  of  Scotland  :— 

Length  of  neck       .         .         .          .12  mm. 

Length  of  genital  segment      .  15     ,, 

Width  of  genital  segment  at  widest 

part  .          .          .          .         .  5     ,, 

Length  of  posterior  appendages     .       9     „ 

Length  of  egg-strings    .          .    about  52     ,, 
In  this  specimen  the  genital  segment  is  somewhat 
different  in  shape,  and  rather  more  elongated  than  the 
other,  but  otherwise  they  are  similar,  and  appear  to 
belong  to  the  same  species. 

Brian  has  recorded  a  female  Rebehda^  which  was  found 
adhering  to  a  Macrurus  about  14  inches  in  length  captured 
lat.  45°  13'  N.,  long.  3°  06'  W.,  at  a  depth  of  358  metres,  in 
July  1903.  This  parasite,  which  he,  with  some  doubt, 
ascribes  to  R.  edwardxii,  is  not  unlike  the  specimen  from  the 
south-west  of  Ireland  described  by  us.  He  gives  a  figure  of 
the  specimen  but  was  unable  to  show  the  head,  as  the  anterior 
part  was  buried  in  the  tissues  of  the  fish ;  the  visible  portion 
measured  about  12  mm. 

The   author  remarks:    "  J'ai  era   devoir  determiner  cette 

*  Canon  Norman,  with  his  usual  kindness,  permitted  us  to  make  a  draw- 
ing of  this  specimen  (see  PI.  LI,  fig.  5). 

t  '  Bull,  de  1'Institut  Oceanographique,'  No.  110,  p.  15  (1908). 


104  BRITISH    PARASITIC    COPEPOPA. 

espece  avec  quelque  doute,  n'ayantpu  examiner  tout  le  corps, 
qui  dans  sa  portion  anterieure  est  cache  et  enfonce  dans  les 
muscles  du  Hacrurus.  Les  parties  visibles  du  copepode 
comme  F  abdomen  et  ses  prolongements  di^itiformes  montrent, 
cependant,  des  caracteres  specifiques  qu'on  peut  considerer 
comme  probablement  identiques  a  cenx  de  Pespece  bien 
connue  :  R.  EdwardsiKol].,  qui  n'est  indiquee  jusqu'a  present 
que  pour  la  Mediterranee."  As  we  have  indicated,  there  is 
apparently  more  than  one  species  of  Rebelula,  but  identifica- 
tion is  difficult  if  the  specimen  is  incomplete. 


Genus  35.   SPHYRION  Cuvier,  1830. 

Syn.  Lestes  and  Lesteira  Kroyer. 

Head  more  or  less  expanded  transversely,  small  and 
bulb-like  but  sometimes  of  considerable  dimensions, 
and  separated  from  the  genital  segment  by  a  smooth 
and  slender  neck,  cylindrical  and  moderately  elon- 
gated. Genital  segment  of  moderate  size,  smooth, 
ovate,  subglobose,  or  bulbiform,  and  furnished  pos- 
teriorly with  two  tolerably  large  bunches  of  vesicles 
resembling  clusters  of  grapes,  one  cluster  being  on 
each  side  of  the  abdominal  lobe.  Anteunules  rudi- 
mentary. Thoracic  limbs  apparently  suppressed. 
Egg-strings  straight,  tolerably  elongated.  Colour 
pale  red.  Male  unknown. 

The  original  definition  of  the  genus  by  Cuvier  is  sufficiently 
correct,  with  the  exception  of  his  description  of  the  posterior 
appendages  which  he  calls  faiscean  de  polls.  The  Rev. 
T.  R.  R.  Stebbing  remarks  that  these  grape-like  clusters 
"  are  appended  to  the  genital  segment  probably  with  a 
branchial  function."  * 

1.  Sphyrion  lumpi  (Kroyer). 
(Plate  LI,  figs.  3,  4.) 

1845.  Lestes  lumpi  Kroyer.     Danrnarks  Fisk,  vol.  ii.  p.  217. 

1863.  Lesteira  lumpi  Kroyer.     (71)  p.  325,  pi.  xviii,  fig.  5,  a-g. 

1869.  Lesteira  lumpi  Steenstrup.     (126a)  p.  182.  pi.  ii,  fig.  5. 

1899.  Sphyrion  lumpi  Bassett-Smith.     (8)  p.  489. 

1901.  Sphyrion  lumpi  T.  Scott.     (113)  p.  128,  pi.  vii,  fig.  13. 

Female. — Cephalothorax  rather  small  and  scarcely 

*  '  Marine  Investigations  of  South  Africa/  Crustacea,  pt.  1,  p.  60. 


SPHYEION    LUMPI.  165 

equal  to  a  quarter  of  the  entire  length  of  the  animal, 
somewhat  cordiform  or  crescent-shaped,  and  consisting 
of  two  lateral  projections  directed  slightly  forward 
and  expanded  into  rounded  wing-like  processes — one 
on  each  side  of  the  small  cephalon  or  head.  A  neck, 
tolerably  elongated,  slender  and  cylindrical,  joining 
the  genital  segment  to  the  anterior  end  of  the  body. 
Genital  segment  of  moderate  size,  broadly  ovate  or 
obscurely  heart-shaped  and  slightly  flattened ;  the 
width,  which  is  nearly  the  same  as,  or  which  slightly 
exceeds,  the  length,  equal  to  fully  one  and  a  half  times 
the  width  of  the  cephalothorax ;  its  lateral  margins 
boldly  rounded  and  the  posterior  margin  nearly 
straight;  a  small  median  lobe  on  the  posterior  margin 
representing  the  terminal  part  of  the  abdomen,  and 
on  either  side  of  it  a  tolerably  large  cluster  of  vesicles 
resembling  a  bunch  of  grapes,  each  cluster  fully  half 
the  size  of  the  genital  segment.  Egg-strings  straight 
and  moderately  elongated.  Length  of  the  animal  ex- 
clusive of  the  egg-strings  about  40  mm. 

The  following  measurements  are  taken  from  a 
fairly  perfect  specimen  : — Length  of  head,  6  mm. ; 
of  neck,  15'5  mm. ;  of  genital  segment,  about  12  mm. ; 
appendages  of  genital  segment,  7'5  mm. 

Antennules  small  and  feeble.  Thoracic  limbs  appa- 
rently obsolete,  mouth-organs  rudimentary. 

The  male  has  not  been  observed. 

Habitat. — An  imperfect  specimen  was  taken  from  a 
lumpsucker  (Cyclopterus  lumpus)  captured  in  the  nets 
of  the  salmon  fishers  at  the  Bay  of  Nigg  near  Aberdeen 
in  April,  1900;  and  a  fine,  nearly  perfect  specimen 
was  presented  to  one  of  the  authors  by  Mr.  Irvine  of 
Aberdeen  who  obtained  it  on  one  of  a  number  of  cat- 
fishes  (Anarrhichas  lupus)  landed  at  the  Aberdeen  Fish- 
Market  but  captured  in  the  North  Sea,  probably  out- 
side the  Scottish  area,  by  a  Norwegian  Trawler.  It 
is  from  this  specimen  that  the  description  given  above 
was  prepared.  The  Bay  of  Nigg  specimen  was  minus  the 
head,  probably  owing  to  the  fish  having  been  roughly 


166  BRITISH    PARASITIC   COPEPODA. 

handled;  it  also  appeared  to  be  somewhat  immature, 
as  the  appendages  of  the  genital  segment  were  not 
fully  developed;  they  resembled  those  of  a  young 
female  represented  by  figure  5c  on  plate  xviii  of 
Kroyer's  work,  'Bidrag  til  Kundskab  om  Snyltekreb- 
sene '  (1863).  Kroyer's  specimens  of  Sphyrion  lumpi 
were  found  fixed  on  the  tail  of  a  Ci/cloj>f<'i-nx  linn-pus 
from  Iceland. 

A  species  from  the  southern  hemisphere,  Sphyrion  Ifevi- 
gatum  Guerin-Meneville.  described  by  G.  M.  Thomson,  New 
Zealand,  and  also  recorded  from  South  African  waters 
by  the  Rev.  T.  R.  R.  Stebbing,  exhibits  a  remarkable 
difference  in  the  form  and  dimensions  of  the  cephalothorax, 
which,  unlike  that  of  Kroyer's  species,  is  distinctly  larger 
than  the  genital  segment,  while  its  shape,  instead  of  being 
regular,  is  more  or  less  distorted. 

The  cephalothorax  of  Sphyrion,  like  that  of  Lern&a, 
Hsemobaphefi,  and  other  members  of  the  family  Lernasidse, 
penetrates,  and  is  wholly  enveloped  by,  the  tissues  of  the 
host. 

The  nauplius  of  Sphyrion,  as  shown  by  Kroyer,  is  a  free- 
swimming  organism  somewhat  similar  to  that  of  Lerniea 
branchialis. 

Dr.  Bassett- Smith  records,  but  somewhat  doubtfully,  the 
occurrence  of  Sphyrion  lumpi  at  Dungeness.  (Cf.  'A  syste- 
matic Description  of  Parasitic  Cope  pods  found  on  Fishes/ 
p.  488.) 


Family  vi.  CHONDKACIANTHIDJE. 

Female. — Body  usually  more  or  less  incompletely 
segmented,  sometimes  furnished  with  outgrowths  in 
the  form  of  lobes  or  prolongations,  and  frequently 
with  the  head  wholly  or  partially  immersed  in  the 
tissues  of  the  host.  Antennules  short,  two-  or  three- 
jointed,  or  rudimentary.  Antennae  small  and  armed 
with  simple  but  sometimes  powerful  terminal  hooks. 
Mandibles  falciform,  expanded  at  the  base,  and  taper- 
ing to  the  distal  end,  which  is  usually  more  or  less 
attenuated  and  incurved  ;  furnished  with  two  rows  of 
minute  prickles,  usually  marginal,  which  extend  from 


CHOXDEACANTHID^E.  167 

the  base  to  near  the  apex.  Thoracic  legs  rudimentary 
and  usually  in  the  form  of  unsegmented  lobes.  Egg- 
strings  two,  usually  short,  and  containing  numerous 
ova,  but  sometimes  elongated  arid  more  or  less 
twisted. 

Mule. — Very  small  and  adherent  on  the  female  by 
means  of  hooked  appendages.  Cephalothorax  dis- 
tinct ;  limbs  more  or  less  articulated.  Abdomen 
segmented. 

In  the  Chondracanthidas  the  type  of  mandible  is  distinctly 
different  from  that  of  the  Caligida?  or  the  Lernasopodidas;  the 
biting  part  is  composed  of  a  single  moderately  elongated 
piece,  and  is  falciform  in  shape,  broad  at  the  base  and 
tapering  to  the  pointed  and  often  attenuated  distal  extremity  ; 
these  biting  parts  are  articulated  to  a  moderately  stout  base, 
and  curved  towards  each  other  at  an  abrupt  or  almost  a 
right  angle,  and  both  margins  are  fringed  from  the  base 
almost  to  the  apex  with  minute  serratures.  This  type  of 
mandible  is  rarely  met  with  in  species  belonging  to  any  of 
the  other  families  described  here. 


Genus  36.  CHONDRACANTHUS  De  la  Roche,  1811. 

Syn.  Chondracanthus  and  Lemenioma  Baird. 

Female. — Head  usually  small,  not  articulated  to  the 
thorax,  separated  by  a  constriction  which  may  be 
distinct  or  not  clearly  denned.  Thorax  short,  mode- 
rately narrow,  and  indistinctly  bisegmented.  Genital 
segment  proportionally  large,  slightly  flattened,  and 
divided  usually  into  two  portions  by  a  transverse  con- 
striction, more  or  less  distinct,  but  sometimes  indis- 
tinct, and  with  the  postero-lateral  corners  prolonged 
into  narrow  processes  which  may  be  short  or  mode- 
rately elongated.  Abdomen  very  small,  situated 
between  the  lateral  processes  and  composed  of  one 
or  two  segments. 

Antennules  moderately  large,  more  or  less  con- 
spicuous in  front  and  somewhat  rudimentary  in 
structure.  Antennae  very  short  and  armed  with 
strong  terminal  hooks.  Mandibles  falciform,  broad 


168  BRITISH    PARASITIC   COPEPODA. 

at  the  proximal  end,  but  tapering  to  the  more  or 
attenuated  distal  extremity ;  both  margins  fringed 
with  minute  prickles  or  teeth.  First  maxillipeds 
small  and  provided  with  a  straight  terminal  spine 
which  is  sometimes  serrated.  Thoracic  limbs  two  pairs, 
biramose;  rami  rudimentary.  Caudal  rami  obsolete. 

Male. — Very  small.  Cephalothorax  considerably 
dilated.  Abdomen  small,  more  or  less  segmented. 
Maxillipeds  fairly  well  developed,  and  fitted  for 
grasping;  other  appendages  somewhat  rudimentary. 

1.  Chondracanthus  cornutus  (0.  F.  Miiller). 

(Plate  XL VII,  figs.  1,2;  Plate  LII,  fig.  5 ;  Plate  LIII, 

figs.  1-9.)       . 

1777.  Lernsea  cornuta  O.  F.  Miiller.     (85)  p.  124,  pi.  xxxiii,  fig.  1. 

1815.  Anops  coniuta  Oken.     (91)  t.  iii. 

1816.  Entomoda  cornuta  Lamarck.     (72)  vol.  iii,  p.  233. 
1822.  Lernentoma  cornuta  Blainville.     (24)  p.  441. 

1832.  Chondracanthus  cornutus  Nordmann.     (89)  p.  111.  pi.  ix,  figs. 
5-10. 

1850.  Lernentoma  cornuta  Baird.     (4)  p.  328,  pi.  xxxv,  fig.  2. 

1851.  Chondracanthus  cornutus  P.  J.  van  Beneden.    (11)  p.  108,  pi.  iv. 
figs.  1-^. 

1863.  Chondracanthus  cornutus  Kroyer.     (71)  p.  249,  pi.  xiii,  figs.  7  a-8. 

1877.  Chondracanthus  cornutus  C.  Vogt.      (142)  p.  78,  pi.  vi,  figs.  4-8. 

1900.  Chondracanthus  cornutus  T.  Scott.     (112)  p.  164,  pi.  vii,  figs.  19- 
31. 

1906.  Chondracanthus  cornutus  Norman  &  T.  Scott.     (88)  p.  217. 

Female. — Head  ovate,  somewhat  longer  than  broad  ; 
thorax  narrower ;  genital  segment  rather  wider  than 
the  head,  moderately  elongated,  flattened,  and  usually 
with  a  constriction — sometimes  indistinct — dividing  it 
into  two  subequal  portions ;  the  postero-lateral  corners 
of  the  segment  produced  backwards  into  straight  and 
narrow  prolongations,  their  length  being  rather  less 
than  the  width  of  the  segment.  Abdomen  very  small, 
bisegmented  and  rather  shorter  than  the  lateral  pro- 
longations of  the  genital  segment. 

Antennules  robust  and  tolerably  large  but  showing 
scarcely  any  structure.  Antenna3  short  and  armed 
with  strong  terminal  hooks.  Mandibles  stout,  falci- 
form, attenuated  towards  the  distal  extremity,  and 


CHONDRACAXTHUS  CORNUTUS.  169 

fringed  along  both  sides  with  minute  bristles.  First 
maxillipeds  with  the  basal  part  moderately  stout,  but 
the  end  joint  rather  slender,  and  its  inner  edge 
serrated.  Thoracic  legs  short  and  very  rudimentary. 
Length  about  6  mm. 

Male. — The  cephalothorax  in  the  male  is  consider- 
ably enlarged,  and  apparently  unsegmented  ;  dorsum 
boldly  rounded  ;  abdomen  composed  of  three  or  four 
segments.  Caudal  rami  small.  Antennules  conspicuous 
but  showing  little  structure.  Second  maxillipeds 
armed  with  small  but  effective  and  claw-like  terminal 
hooks.  Length  scarcely  0*5  mm.  (-5^j  of  an  inch). 

Habitat. — Parasitic,  usually  inside  the  gill-covers  of 
plaice  (Pleuronectes  platessa).  The  species  is  tolerably 
frequent,  and  has  been  recorded  from  various  parts  of 
the  British  coasts.  In  the  drawing  (PI.  XLVII, 
fig.  2),  a  male  "  m  "  is  seen  clinging  to  the  female. 

Some  variation  has  been  observed  in  specimens  belonging 
to  this  species  as  shown  by  figs.  1  and  2  in  PL  XLVII,  some 
being  longer  and  narrower  than  others  and  with  the  thoracic 
legs  less  developed,  hut  these  seemed  to  be  the  only  differ- 
ences between  them. 

2.  Chondracanthus  annulatus  Olsson. 

(Plate  XX,  fig.  9 ;    Plate  XLVII,   fig.  3 ;  Plate  LVI, 

figs.   8-10.) 

1868.  Chondracanthus  mm  n/ntus  Olsson.     (92)  p.  30.  pi.  ii,  figs.  13-15. 

1880.  Chondracanthus  lievirajse  Delia  Valle.  (141a)  Boll.  Soc.  Adriat. 
Sc.  Nat.,  vol.  vi,  p.  73. 

1900.  Chondraccfiithus  annulatus  T.  Scott.  (112)  p.  164,  pi.  vii,  figs. 
46-51. 

1909.  Chondracanthus  inflatu*  Bainbridge.     (3)  p.  47,  pi.  ix,  figs.  9-15. 

1910.  Chondracanthus  annulatus  Norman  &  Brady.     (8~A)  p.  156. 

Female. — Body  elongated,  moderately  narrow  and 
cylindrical,  about  four  times  longer  than  broad,  and 
only  slightly  flattened.  Head  small  but  well  defined ; 
the  thorax  also  fairly  well  marked  and  the  head  and 
thorax  combined  equal  to  about  one-third  of  the  entire 
length  of  the  animal.  Genital  segment,  which  con- 
stitutes the  other  two-thirds,  showing  a  slight  constric- 


170  BRITISH    PARASITIC    COPEPODA. 

tion  near  the  middle,  with  the  postero-lateral  corners 
produced  into  short  bluntly-rounded  lobes ;  a  small 
median  projection  on  the  dorsal  aspect  which  conceals 
the  proximal  part  of  the  abdomen.  Abdomen,  which 
is  bisegmented,  reaching  to  about  the  end  of  the 
lateral  lobes,  and  imparting  a  trilobed  appearance  to 
the  posterior  end  of  the  genital  segment. 

Antennules  considerably  enlarged  but  showing  very 
little  structure,  and  bearing  a  few  small  apical  spines. 
Antennaa  short,  stout,  and  armed  with  bluntly -pointed 
claws.  Mandibles  similar  to  those  of  Chondracanthus 
cornntus;  maxillipeds  also  somewhat  similar  to  those 
of  the  same  species.  Both  pairs  of  thoracic  legs  short 
and  rudimentary.  Length  about  14  mm.  Colour  pale 
red.  Egg-strings  tolerably  elongated. 

Male. — The  male  of  this  species  is  proportionately 
larger  than  that  of  the  one  previously  described ;  the 
cephalothorax  also  greatly  enlarged.  Antennules 
short,  not  very  robust,  uniarticulate  and  furnished 
Avith  a  few  short  marginal  spines  and  a  fascicle  of 
tolerably  long  apical  seta?.  Antennse  short,  stout,  and 
armed  with  short  but  strong  terminal  hooks.  Second 
raaxillipeds  strong,  biarticulated,  and  provided  with 
terminal  claws.  Other  thoracic  appendages  rudi- 
mentary. Abdomen  composed  of  three  or  four  seg- 
ments, but  one  or  two  are  not  very  clearly  defined. 
Length  about  3  mm. 

Habitat. — Parasitic  on  the  gills  of  large  blue  (or 
grey)  skates  (Raia  latis),  captured  in  the  North  Sea 
and  landed  at  the  Aberdeen  Fish-Market  (T.  Scott). 
North  Shields  (Miss  M.  Lelour).* 

3.  Chondracanthus  soleae  Kroyer. 
(Plate  XLVII,  fig.  4;  Plate  LIU,  figs.  12-15.) 

1838.  Chondracanthus  solefe  Kroyer.     (70)  vol.  ii,  p.  139,  pi.  iii,  fig.  4. 
1863.  Chondracanthus  sola?  idem.     (71)  p.  256. 

1900.  Chondracanthus  sole*  T.  Scott,     (112)  p.  165,  pi.  vii,  figs.  41-45. 
1906.  Chondracanthus  sole*  Norman  &  T.  Scott.     (83)  p.  217. 

*  See  Norman  &  Brady's  'Crustacea  of  Northumberland  and  Durham/ 
p.  156  (1909). 


CHONDKACANTHUS    SOLEJE.  171 

. — Body  tolerably  robust;  head  subtrian- 
gular,  narrow  in  front,  widest  behind,  its  length 
scarcely  equal  to  the  width.  Thorax  short,  composed 
of  two  fairly-distinct  segments ;  the  head  and  thorax 
combined,  equal  to  rather  more  than  half  the  length  of 
the  genital  segment ;  this  segment  robust,  somewhat 
flattened  and  divided  by  a  distinct  transverse  constric- 
tion into  two  nearly  equal  portions ;  the  postero- 
lateral  corners  of  the  distal  portion  produced  back- 
Avards  into  straight  and  narrow  prolongations  the 
length  of  Avhich  is  more  than  half  the  width  of  the 
segment.  Abdomen  very  small,  biarticulated,  and 
considerably  shorter  than  the  lateral  prolongations  of 
the  genital  segment. 

Antennules  uniarticulate,  conspicuous,  but  not  very 
robust,  and  furnished  with  a  few  minute  subapical 
setae.  Antenna?  short,  stout,  and  ending  in  short 
claAv-like  spines.  Mandibles  and  other  mouth-appen- 
dages someAvhat  similar  to  those  of  Chondracanthus 
cornutns.  Both  pairs  of  thoracic  legs  tolerably  elon- 
gated, but  rudimentary  in  structure.  Length  about 
8  mm.  Egg-strings  about  the  same  length. 

Male. — The  male  of  this  species  is  very  small  and 
similar  to  that  of  Ohondracanthu*  cornutux  ;  the  appen- 
dages are  also  similar  except  that  the  antennules  have 
the  basal  joint  considerably  enlarged  and  subtrian- 
gular,  AA'hile  the  end  joint  is  very  small  and  bears  a 
few  minute  seta3. 

Habitat. — Parasitic  on  the  gills  of  the  black  sole 
(Solea  vulgaris),  and  only  occasionally  on  other  flat 
fishes.  Starcross,  Devon,  on  a  dab  (C.  Parker  in  Mus. 
Normanianum).  On  Solea  irulgaria,  Plymouth  (Itawtt- 
Rmitlt).  Firth  of  Clyde  (T.  Scott).  Irish  Sea  (A.  Scott}. 

4.  Chondracanthus  flurae  Kroyer. 
(Plate  XL VII,  fig.  5;  Plate  LIII,  figs.  10,  11.) 

1863.  Chondracanthus  flurie  Kroyer.     (71)  p.  249,  pi.  xiii,  figs.  7  a-d. 
1900.  Chondracanthus  fane  T.  Scott.     (112)  p.  166,  pi.  vii,  figs.  :12-:51. 

l-''-in<ili'. — The  head  and  thoracic  segments  narroAv 


172  BRITISH    PABASIT1C    COPEPODA. 

and  not  so  clearly  defined  as  in  Qhoudr acanthus  solese, 
and  together  scarcely  equal  to  a  third  of  the  entire 
length  of  the  animal.  Genital  segment  robust,  some- 
what flattened,  and  about  twice  as  wide  as  the  thorax ; 
a  distinct  transverse  constriction  dividing  it  into  two 
subequal  portions  ;  the  general  outline  of  the  segment 
broadly  oval,  its  extreme  length  being  about  one 
and  a  half  times  greater  than  the  width  ;  the  postero- 
lateral  corners  of  the  distal  portion  produced  into 
moderately  short,  narrow,  arcuate,  and  slightly  con- 
vergent lobes,  enclosing  between  them  the  small 
biarticulated  abdomen. 

Antennules  moderately  robust  and  indistinctly  bi- 
articulated, with  one  or  two  subapical  setae.  Antennae 
short,  and  armed  with  small  but  stout  terminal  claws. 
Mandibles  and  other  mouth-appendages  somewhat 
similar  to  those  of  Chondr acanthus  cornutu*.  Thoracic 
legs  rather  small  and  rudimentary.  Length  about 
5  mm.  Egg-strings  about  the  same  length. 

Male. — Very  small,  and  somewhat  similar  in  size 
and  structure  to  the  male  of  Chondmcanthus  cornutus. 

Habitat. — Parasitic  on  the  gills  and  inside  the  gill- 
covers  of  long  rough  dabs  (Drepanopsetta  platessoides 
Fabr.  =  Platessa  lim.au  doides  (Bl.)).  Firth  of  Clyde 
(T.  Scott).  Irish  Sea  (A.  Scott). 

This  species  of  Chondracunthus  lias  not  been  observed  on 
any  other  kind  of  fish.  It  was  also  from  long  rough  dabs 
that  Kroyer  obtained  his  specimens  of  this  parasite. 

5.  Chondracanthus  depressus  T.  Scott. 
(Plate  XLI,  figs.  2-4;    Plate  LVI,  figs.  1-7.) 

1905.  Chondracanthus  depressus  T.  Scott.    (116)  p.  114,  pi.  vi,  figs.  7-13. 

I' I- m uli'.— Head  subquadrangular,  nearly  as  long 
as  broad.  The  first  and  second  thoracic  segments 
subequal,  very  short,  and  somewhat  narrower  than 
the  cephalic  segment,  and  that  segment  combined  with 
the  thorax  not  more  than  about  a  third  of  the  entire 
length  of  the  animal,  the  other  two-thirds  comprising 


CHONDEACANTHnS    DEPRESSUS.  173 

the  genital  segment.  This  segment  fully  one  and  a 
half  times  as  wide  as  the  cephalon  and  its  length  only 
about  a  fourth  greater  than  the  width,  a  distinct 
transverse  constriction  dividing  the  segment  into  two 
nearly  equal  parts  which  are  considerably  flattened ; 
the  postero-lateral  prolongations  moderately  short  and 
stout,  and  blunt  at  the  apex,  also  distinctly  con- 
vergent so  that  the  apices  are  usually  contiguous,  and 
sometimes  overlap  each  other.  Abdomen  very  short. 

Antennules  short  and  tolerably  robust;  simple  in 
structure  ;  the  distal  extremity,  which  appears  to  be 
obscurely  jointed,  bearing  scattered  apical  spinules. 
Antenna  somewhat  similar  to  those  of  Chondr acanthus 
cornutus ;  the  mandibles  and  maxillipeds  also  re- 
sembling those  of  the  same  species.  Thoracic  legs 
short,  stout,  biramose,  both  rami  rudimentary,  their 
surface  covered  with  numerous  very  minute  prickles. 
Length  about  5  mm. 

Egg-strings  short  and  stout  and  containing  numerous 
ova. 

This  species  has  a  general  resemblance  to  Cliondra- 
cantkus  flurae  from  the  long  rough  dab,  but  is  rather 
more  flattened. 

No  males  have  been  observed. 

Habitat. — Parasitic  on  the  gills  of  the  flounder 
(Pleuronectes  flestis).  Firth  of  Forth  and  St. 
Andrews  Bay  (T.  Scott).  Irish  Sea  (A.  Scott). 

This  Chondracanthus  differs  from  the  other  described 
species  by  the  very  short  thoracic  segment,  by  the  genital 
segment  being  considerably  flattened  and  of  a  broadly 
quadriform  outline,  and  by  the  structure  of  the  thoracic 
legs. 

An  apparent  variety  of  the  species  here  described,  which 
has  been  observed  parasitic  on  the  same  kind  of  fish,  differs 
in  being  more  elongated  and  rather  less  flattened ;  the 
thoracic  legs  are  larger  and  more  rudimentary,  and  the 
postero-lateral  prolongations  of  the  genital  segment  are 
scarcely  convergent.  This  form,  which,  has  been  recorded 
as  varietv  oblonyiis,  appears  to  be  rare  (see  PL  XLI,  fig.  4 ; 
and  PI.  L7I,  figs.  5-7). 


174  I'.UITISH    PARASITIC    COPKPODA. 

6.  Cho a dr acanthus  limandae  Kroyer. 
(Plate  XLVII,  fig.  6;  Plate  LVI,  figs.  11,  12.) 

1863.  Chondr acanthus  limandie  Kroyer.     (71)  p.  248,  pi.  xiv,  fig.  2,  a-b 
1900.  Chondracanthus  limandx  T.  Scott.     (112)  p.  167,  pi.  vii,  figs. 
38-40. 

Female. — Body  tolerably  robust ;  head  large,  length 
equal  to  about  two-thirds  of  the  width ;  first  thoracic 
segment  very  short,  considerably  narrower  than  the 
head,  second  much  larger,  nearly  as  wide  as  the 
genital  segment,  and  having  on  each  side  on  the  dorsal 
aspect  a  slightly-elevated  rounded  knob  the  diameter 
of  which  is  equal  to  a  third  of  the  width  of  the  seg- 
ment.* Genital  segment  broad,  not  greatly  elongated, 
and  divided  by  a  distinct  transverse  constriction 
into  two  nearly  equal  portions ;  the  postero-lateral 
corners  of  the  distal  portion  are  produced  into  mode- 
rately short  stout  lobes  with  bluntly-rounded  ends. 
Abdomen  short,  biarticulate,  and  nearly  filling  the 
space  between  the  lateral  lobes. 

Antennules  well  developed,  basal  joint  large,  end 
one  small  but  fairly  well  defined,  and  bearing  a  few 
small  apical  spines.  Mandibles  tolerably  large ;  other 
mouth-appendages  as  in  Chondracanthus  corimhix. 
Thoracic  legs  stout  but  not  greatly  elongated.  Len^t  h 
about  5  mm.  Length  of  egg-strings  about  the  same. 
Colour  opaque-white  tinged  with  red. 

Male. — The  male  of  this  species  does  not  differ 
greatly  in  size  or  structure  from  that  of  Chondra- 
canthus  c.ornutm.  The  cephalothorax  is  greatly  en- 
larged, but  the  abdomen  is  small  and  composed  of 
about  three  segments.  Antennae  and  maxillipeds 
provided  with  stout  terminal  claws  fitted  for  Li-rasping. 
Length  about  O65  mm. 

Habitat. — Parasitic  on  the  gills  of  the  dab  (Pl<'Hi-<>- 
ni'i-tes  limanda  Linn.).  This  parasite  does  not  appear 
to  be  very  common,  and  has  only  been  met  with  ou 
the  dab.  Kroyer  obtained  his  specimens  also  on  the 

*  Kroyer  says, — "  Annulo  secundo  duobus  tuberculis  humeralibus  prsedito 
inagnis."  '  Bidrag  til  Kundskab  om  Snyltekrebsene/  p.  256  (1863;. 


CHONDRACAXTHUS    LISIANDjE.  175 

same  kind  of  fish.      Firth  of  Clyde  and  Moray  Firth 
(T.  Scott).     Irish  Sea  (,-1.  Scott). 

7.  Chondracanthus  clavatus  B asset t- Smith. 
(Plate  XL VII,  fig.  7 ;  Plate  LVI,  figs.  14,  15.) 

1896.  Clio n  dr -acanthus   clavatus   Bass«tt-Smith.      (6)  Ann.  and  Mag. 
Nat.  Hist.  (6),  vol.  18,  p.  13,  pi.  v,  fig.  6. 

1900.  Chondracanthus  clavatus  T.  Scott.      (112)  p.  165,  pi.  vii,  figs. 
35-37. 

1901.  Chondracanthus  clavatus  A.  Scott.     (107)  p.  351. 

Female. — Body  claviform,  somewhat  flattened, 
anterior  end  narrow,  expanded  posteriorly.  Head 
oval  or  subcylindrical,  rather  longer  than  broad ;  a 
median  dorsal  line,  quite  distinct  in  some  specimens, 
extending  backwards  for  some  distance  from  the  front 
margin.  Thorax  about  as  long  as  the  head,  but  rather 
narrower  and  not  very  clearly  defined ;  the  head  and 
thorax  together  equal  to  about  two-fifths  of  the  entire 
length  of  the  animal.  Genital  segment  clavate,  some- 
what flattened,  and  gradually  becoming  broader  towards 
the  posterior  end ;  postero-lateral  prolongations  narrow 
and  tolerably  elongated,  about  equal  in  length  to  half 
the  width  of  the  segment,  and  having  a  comparatively 
wide  space  betAveen  them.  Abdomen  very  small,  indis- 
tinctly biarticulate. 

Antennules  short,  moderately  stout,  end  joint  not 
clearly  defined,  provided'  with  a  few  minute  apical 
spines.  Mandibles  and  other  mouth  -  appendages 
somewhat  similar  to  those  of  Chondr  acanthus  cornutu*. 
Thoracic  legs  small  and  rudimentary.  Egg-strings 
moderately  elongated.  Length  6' 5  mm. 

Mile. — Very  small;  the  cephalothorax  is  propor- 
tionally greatly  enlarged,  and  the  abdomen  short  and 
segmented.  The  antennas  are  armed  with  short,  stout, 
terminal  hooks,  and  the  maxillipeds  are  also  similarly 
armed. 

Habitat. — Parasitic  on  the  gills  of  lemon-soles 
(Plenronectes  mierocephalus).  Plymouth  (Baxsett- 
Smith).  Firths  of  Forth  and  Clyde  (T.  Scott).  Irish 
Sea  (A.  Scott). 


176  BRITISH    PARASITIC    COPEPODA. 

8.  Chondracanthus  nodosus   (0.  F.  Miiller). 
(Plate  LII,  figs.  1-3  ;    Plate  XLVIII,  figs.  13-16.) 

1777.  Lemma  nodosa  O.  F.  Miiller.     (85)  p.  40,  pi.  xxxiii,  fig.  5. 
1816.  Lern&a  nodosa  Lamai'ck.     (72)  p.  231. 
1822.  Lernentoma  nodosa  Blainville.     (24)  p.  125. 
1838.  Chondracanthus  nodosus  Krdyer.     (70)  p.  133,  pi.  iii,  fig.  2. 
1840.  Chondracanthus  nodosw  M.  Edwards.     (43)  p.  503. 
1863.  Chondracanthus  nodosus  Kroyer.     (71)  p.  258. 
1909.  Chondracanthus  williamsoui  T.  Scott.     (118)  p.  76,  pi.  iii.  figs. 
8-17. 

Female. — Body  flattened,  and  of  an  ovate  form  when 
seen  from  above  ;  cephalon  subquadrangular  but  with 
a  shallow  rounded  projection  on  each  side.  A  slight 
constriction  separating  the  cephalon  from  the  thorax. 
The  genital  segment,  which  is  coalescent  with  the 
thorax,  broadly  ovate  and  flattened,  and  having  the 
lateral  margins  coarsely  crenulated  or  lobate,  with  six 
rounded  but  somewhat  irregular  projections  on  each 
side,  the  second  and  the  last  three  being  more  promi- 
nent than  the  others ;  the  posterior  end  terminating  in 
a  narrow  median  lobe.  Abdomen  much  reduced  in 
size,  and  of  a  rounded  form. 

Antennules  small,  uniarticulate,  and  rather  rudi- 
mentary in  structure.  Antennae  short  and  armed  with 
strongly-hooked  terminal  claws.  Mandibles  similar 
to  those  of  Ghondr acanthus  cornutus ;  both  pairs  of 
maxillipeds  small ;  the  first  pair  very  similar  to  those 
of  the  species  named,  being  composed  of  a  stout  basal 
part  and  a  straight  spine-like  claw  finely  serrated  on 
the  inner  edge ;  the  second  pair  more  elongated  and 
narrow,  and  each  armed  with  a  short,  stout,  terminal 
claw  and  a  small  rounded  process.  Both  pairs  of 
thoracic  legs  rudimentary  and  nearly  similar  in 
structure ;  each  limb  consisting  of  a  short  and  broad 
basal  part,  gibbous  on  both  sides,  which  bears  a  small 
oblong  distal  process  separated  from  the  basal  part  by 
a  narrow  constriction.  Egg-strings  tolerably  elongate 
and  stout,  and  containing  many  ova.  Length  about 
7' 5  mm.  Colour  opaque  white  with  a  tinge  of  red. 

Plate    LII,    fig.    2,    represents    a    young    female 


CHONDRACANTHUS    NODOSUS.  177 

which,  though  resembling  the  adult  in  having  the 
lateral  margins  coarsely  crenulated,  differs  in  being 
proportionally  narrower  and  in  the  more  quad- 
rangular form  of  the  cephalon. 

Male. — The  male  is  very  small,  the  length  being 
rather  more  than  half  a  millimetre.  The  cephalo- 
thorax  is  considerably  enlarged,  and  the  abdomen 
short  and  indistinctly  segmented.  In  size  and  struc- 
ture the  male  closely  resembles  the  male  of  Chondra- 
canthus  cornutus  except  that  the  structure  of  the 
thoracic  part  is  slightly  different. 

Habitat. — Parasitic  on  Sebastes  norvegicus  ;  usually 
found  fixed  in  the  angles  formed  by  the  junction  of  the 
gill-covers  with  the  gill-arches.  On  specimens  of 
Sebastes  captured  in  the  North  Sea  and  landed  at  the 
Fish-Market,  Aberdeen,  in  February  1908  (T.  Scott). 

9.  Chondracanthus  zei  De  la  Roche. 
(Plate  XLI,  fig.  5;  Plate  LVI,  fig.  13.) 

1811.  Chondracanthus  zei  De  la  Roche.     (41)  p.  270,  pi.  ii,  fig.  2. 
1822.  Chondracanthus  delarochiana  Blainv.     (24)  p.  422,  pi.  xxvi,  fig. 
13. 

1829-1843.  Chondracanthus  zei  Guerin-Meneville.     (55)  t.  9,  fig.  9. 

1831.  Chondracanthus  zei  Burmeister.     (26)  p.  325. 

1832.  Chondracanthus  tuberculatus  Nordmann.     (89)  p.  118. 

1850.  Chondracanthus  zei  Baird.     (4)  p.  327,  pi.  xxxv,  fig.  1. 

1851.  Chondracanthus  zei  P.  J.  van  Beneden.    (11)  p.  110,  pi.  iv,  figs.  5-7. 
1892.  Chondracanthus  zei  T.  Scott.     10th  Ann.  Report  Fishery  Board 

for  Scotland,  pt.  iii,  p.  262. 

1896.  Chondracanthus  zei  Bassett-Smith.     (7)  p.  162. 

1900.  Chondracanthus  zeus  T.  Scott.     (112)  p.  167,  pi.  viii,  fig.  1. 

1906.  Chondracanthus  zei  Norman  &  T.  Scott.     (88)  p.  217. 

Female. — Body  short,  moderately  stout,  and  of  a 
somewhat  ovate  form.  Head  small,  orbicular  ;  thorax 
very  short,  narrowed  behind  the  head  where  it  forms 
a  kind  of  neck.  The  genital  segment,  with  which  the 
thorax  appears  to  be  more  or  less  coalescent,  flattened 
and  becoming  gradually  and  considerably  wider  pos- 
teriorly. Abdomen  small  and  rudimentary.  A  short 
horn-like  process  extends  outwards  from  both  sides  of 
the  thoracic  segment  and  there  is  a  trifid  process  on 

VOL.  i.  12 


178 


BRITISH    PARASITIC    COPEPODA. 


its  dorsal  aspect.  Genital  segment  furnished  with  two 
pairs  of  tridigitate  appendages  on  the  under  side  and 
with  three  pairs  of  somewhat  similar  digitiform  pro- 
longations on  the  lateral  aspect,  the  posterior  prolon- 
gations being  the  larger;  these  latter  appendages 
surround  and  nearly  conceal  the  short,  stout,  and 
flattened  ovisacs ;  several  median  processes  also  occur 
on  the  dorsal  aspect  of  the  genital  segment. 

Antennules  short  and  moderately  expanded.  An- 
tennse  prehensile  and  provided  with  stout  terminal 
hooks.  Mandibles  and  other  mouth -appendages 


a  b 

One  of  the  ovisacs  of  Chondracanthus  zei. 

similar  to  those  of  Chondracanthus  cornutus.  Thoracic 
legs  indistinctly  biramose,  and  their  structure  some- 
what rudimentary.  Ovisacs,  which  are  short  and  con- 
tain numerous  small  ova,  compressed  laterally  so  as  to 
have  a  broadly  and  somewhat  obliquely  ovate  outline ; 
not  extending  beyond  the  ends  of  the  prolongations 
described  above.  Colour  white  tinged  with  red. 
Length  about  12  mm.,  but  the  size  somewhat  variable. 

Male. — The  male  of  this  species  does  not  appear  to 
differ  greatly  from  that  of  Chondracanthus  cornutus  in 
size  and  structure. 

Habitat. — Parasitic  on  the  gills  and  gill-arches  of 
the  dory  (Zeus  faber).  Polperro,  Cornwall  (A.  M. 
Normaii).  Plymouth  (Baxsett- Smith).  Firths  of  Forth 


CHONDRACANTHUS   ZEI.  179 

and  Clyde  (T.  Scott).  Irish  Sea  (A.  Scott).  This 
parasite  is  of  frequent  occurrence  on  the  dory,  and 
Dr.  Bassett- Smith  describes  it  as  very  common  on  the 
gills  of  Zeus  fab er  at  Plymouth. 

The  ovisacs  of  Chondracanthus  zei  differ  so  remarkably 
from  those  common  to  most  of  the  species  known  to  us  that 
we  give  here  a  figure  showing  a  side  and  an  end  view, 
enlarged,  of  one  of  them.  When  the  parasite  is  viewed  from 
the  ventral  aspect  the  ovisacs  appear  as  in  figure  b,  but  the 
side  view  a  can  best  be  seen  whem  the  ovisacs  are  removed. 
x  shows  the  point  of  attachment  of  the  ovisac  to  the  genital 
segment. 

10.  Chondracanthus  lophii  Johnston. 
(Plate  LII,  fig.  4;    Plate  LVI,  figs.  16-18.) 

1836.  Chondracanthus  lophii  Johnston.     (67)  p.  81,  fig.  16. 
1837-1838.  Chondracanthus  gibbosus  Kroyer.      (70)  (1)  p.  252,  pi.  ii, 
fig.  4. 

1843.  Chondracanthus  lophii  Rathke.     (100)  p.  116,  pi.  v,  figs.  16-18. 
1847.  Chondracanthus  gibbosus  Thompson.     (129)  p.  248. 

1850.  Lernentoma  lophii  Baird.     (4)  p.  330,  pi.  xxxv,  fig.  3. 

1851.  Chondracanthus  qibbosus  P.  J.van  Beneden.     (11)  p.  104,  pi.  iii, 
figs.  10-15. 

1862.  Chondracanthus  lophii  Turner  &  "Wilson.     (140)  p.  67,  pi.  iii. 
1877.  Chondracanthus  yibbosus  Vogt.     (142)  p.  76,  pi.  v,  figs.  1-4  ;  pi. 
vi,  figs.  1-3. 

1896.  Chondracanthus  lophii  Bassett-Sinith.     (7)  p.  162. 
1900.  Chondrucanthus  lophii  T.  Scott.     (112)  p.  167. 

Female. — Body  tolerably  elongated,  narrow  in  front, 
posterior  end  moderately  broad  and  flattened.  Head 
small,  having  on  each  side  a  horn-shaped  appendage 
directed  obliquely  backwards.  Thorax  narrow  and 
furnished  with  one  or  two  short,  paired,  marginal 
processes  directed  outwards,  and  a  pair  of  bifurcated 
moderately  long  ventral  appendages.  Genital  seg- 
ment flattened,  and  about  twice  as  long  as  broad, 
constricted  in  the  middle  so  as  to  form  two  subequal 
portions,  the  postero-lateral  corners  of  both  of  which 
form  short  prolongations ;  this  segment  also  furnished 
with  a  row  of  median  digitiform  processes  alternately 
larger  and  smaller,  and  directed  obliquely  backwards. 
Abdomen  very  short.  Egg-strings  greatly  elongated 
and  more  or  less  twisted  into  loops. 


180  BRITISH    PARASITIC    COPEPODA. 

Antennules  short,  conspicuous  in  front,  their  basal 
part  considerably  expanded,  but  the  distal  end  narrow, 
and  minutely  setiferous.  Antennae  short  and  stout, 
and  armed  with  strong  terminal  hook-like  claws. 
Mandibles  and  other  mouth-organs  somewhat  similar  to 
those  of  Cfiondracanthus  cornutus.  Thoracic  legs  in- 
distinctly biramose,  and  more  or  less  rudimentary  in 
structure.  Length  about  12  mm. 

Male. — The  male  of  this  species,  like  that  of  the 
last,  has  a  close  resemblance  to  the  male  of  Chondra- 
cantlms  cornutus  as  indicated  by  Dr.  Baird.  It  is  of  a 
pyriform  shape,  considerably  swollen  in  front  but 
tapering  towards  the  distal  .end,  and  furnished  with 
strongly  uncinate  foot-ja\vs.  It  is  usually  found 
clinging  to  the  female,  but  from  its  minute  size  may 
easily  be  missed. 

Habitat. — Parasitic  usually  on  inner  surface  of  the 
gill-pouches  of  angler-fishes  (Lophius  piscatorius  Linn.). 
It  is  a  moderately  common  species  on  the  angler-fish 
and  has  been  recorded  from  various  parts  of  the 
British  coast.  Dublin,  1839;  Belfast,  1841  (W: 
Thompson}.  Coasts  of  Devon  and  Cornwall  (G.  Parker, 
A.  M.  Norman,  and  others).  Irish  Sea,  and  various 
parts  of  the  Scottish  coasts  (T.  §  A.  Scott).  For  a 
detailed  account  of  the  anatomical  structure  of  this 
curious  species  see  Turner  and  Wilson's  memoir  referred 
to  above.  The  colour  of  this  Chondracanihits  is  usually 
opaque  white.  The  egg-strings  are  of  great  length, 
usually  in  screw-form,  very  slender,  and  contain 
numerous  small  ova.  Specimens  may  often  be  found 
in  considerable  numbers  in  the  gill-pouches  of  both 
large  and  small  anglers. 

11.  Chondracanthus  merluccii  (Holt en). 

(Plate  XX,  fig.  10;  Plate  XLVII,  fig.  8;  Plate  LIII, 
figs.  16-19.) 

1802.  Lernxa  merluccii  Holten.     (63)  vol.  v.  pi.  iii.  fig.  2. 

1837.  Choiidracanthus  merluccii  Kroyer.     (70)  p.  278,  pi.  iii,  fig.  9. 

1840.  Chondracanthus  merluccii  M.  Edwards.     (43)  vol.  iii,  p.  503. 


CHONDBACANTHUS    MEBLUCC1I.  181 

1892.  Chondracanthus  merluccii  T.  Scott.     10th  Ann.  Rept.  Fishery 
Board  for  Scotland,  p.  262. 

1896.  Chondracanthus  merluccii  Bassett-Smith.     (7)  p.  161. 
1900.  Chondracanthus  merluccii  T.  Scott.     (112)  p.  166. 
1906.  Chondracanthus  merlucii  Brian.     (21)  p.  97,  pi.  vii,  fig.  4. 
1906.  Chondracanthus  merluccii  Norman  &  T.  Scott.     (88)  p.  217. 

Female. — Body  oblong  and  flattened.  Head  some- 
what wedge-shaped,  wider  behind  than  in  front,  the 
front  margin  rounded,  and  a  more  or  less  distinct 
median  line  extending  from  it  backwards ;  the  head 
seen  in  profile  sloping  upward  and  backward,  and 
becoming  distinctly  gibbous  behind ;  provided  with 
small,  lateral  horns — one  on  each  side  near  the  postero- 
lateral  corners — which  extend  obliquely  backwards 
like  the  barbs  on  a  fishing  hook.  Thorax  short, 
indistinctly  bisegmented ;  a  constriction  separating 
the  head  from  the  thorax  and  another  separating 
the  thorax  from  the  genital  segment ;  the  second  seg- 
ment of  the  thorax  wider  than  the  first  and  nearly  as 
wide  as  the  genital  segment;  its  anterior  lateral 
corners  produced  forwards  into  small  round  knobs. 
Genital  segment  moderately  thick,  and  flattened 
dorsally,  a  slight  constriction  dividing  it  into  two 
nearly  equal  portions ;  a  pair  of  tolerably  stout  and 
elongated  processes  springing  from  the  ventral  aspect 
of  the  segment  just  in  front  of  the  constriction,  and 
extending  obliquely  backwards  so  as  to  reach  beyond 
its  posterior  end;  the  postero-lateral  corners  of  the 
genital  segment  also  produced  backward  into  elongated 
and  moderately  stout  horn-like  prolongations.  Abdo- 
men very  small. 

The  two  pairs  of  antennae  and  the  mouth-appendages 
similar  to  those  of  Gliondr  acanthus  cornutus;  so  are  also 
the  thoracic  legs,  except  that  the  second  pair  are  con- 
siderably larger  than  the  first.  Length  to  the  end  of  the 
posterior  processes  about  12  mm.  These  processes 
about  three  millimetres  in  length,  being  rather  shorter 
than  the  ventral  prolongations,  which  measure  about 
four  millimetres.  Egg-strings  about  ten  millimetres  in 
length,  moderately  thick,  and  containing  numerous  ova. 


182  BRITISH    PAKASIT1C    COPEPODA. 

Male.  —  The  male  of  this  species  is  very  small,  being 
scarcely  more  than  half  a  millimetre  in  length  ;  the 
cephalothorax,  as  in  the  male  of  Chondr  acanthus 
c.ornutus,  is  proportionally  large  ;  the  abdomen  is  small 
and  composed  of  two  or  three  segments.  Sometimes 
more  than  one  male  may  be  found  adhering  to  a  female. 

Habitat.  —  Parasitic  on  the  hake  (Merluccius  vulgarin 
Cuv.).  Usually  found  clinging  to  the  roof  and  sides, 
sometimes  on  the  under  side  of  the  tongue  and  on  the 
inside  of  the  gill-covers.  Frequently  the  head  is  either 
buried  in  the  tissues  of  the  fish  or  enveloped  in  mucus. 
This  is  a  tolerably  common  parasite  of  the  hake,  and  a 
considerable  number  of  specimens  may  sometimes  be 
obtained  from  a  single  fish.  Coasts  of  Devon  and 
Cornwall  ((?.  Parker,  Laughrin,  -Bassett-Smith).  Irish 
Sea  (A.  Scott).  Firths  of  Forth  and  Clyde,  Aberdeen, 
&c.  (T.  Scott). 

12.  Chondracanthus  ornatus  T.  Scott. 
(Plate  XLI,  fig.  6  ;  Plate  XLY,  fig.  7.) 

1900.  Chondracanthus  ornatus  T.  Scott.      (112)    p.    168   (description 
only). 

1901.  Chondracanthus  ornatus  idem.     (113)  p.  129,  pi.  vii,  fig.  14  (  ?  ). 

1902.  Chondrucanthus  ornatus  idem.     (114)  p.  298,  pi.  xiii,  fig. 


Female.  —  When  viewed  from  above  with  a  general 
outline  closely  similar  to  that  of  an  equilateral  triangle, 
the  bluntly-rounded  head  forming  the  apex,  and  the 
truncated  posterior  end  the  base  ;  the  front  of  the 
head  indistinctly  trilobed,  one  bluntly-rounded  lobe 
being  in  the  centre,  and  projecting  slightly  in  front  of 
the  two  lateral  lobes  which  are  also  bluntly  rounded. 
The  neck  connecting  the  head  with  the  thorax  very 
short.  Three  or  four,  more  or  less  distinct,  tubercles 
along  each  side  of  the  thorax  (forming  the  sides  of  the 
triangle),  a  series  of  three  similar  tubercles  extending 
along  the  middle  of  the  dorsum  ;  the  posterior  tubercle 
of  the  middle  series  standing  well  up,  but  each  of  the 
other  two  standing  at  a  slightly  lower  elevation  than 
the  one  immediately  behind. 


CHONDRACANTHUS    ORNATUS.  183 

position  of  these  lateral  tubercles  seems  to  vary 
slightly  in  different  specimens.  Abdomen  exceedingly 
small  and  inconspicuous.  Egg-strings  of  moderate 
length  and  stoutness,  like  those  of  Chondracanthus 
Umandde. 

The  size  of  the  more  typical  of  the  female  specimens 
observed  is  as  follows : — from  the  forehead  to  the 
posterior  end  of  the  body  5  mm.,  from  the  forehead 
to  the  end  of  the  egg-strings  11 '5  mm.,  the  width  of  the 
genito-thoracic  segment  at  the  posterior  end  about 
equal  to  the  length,  so  that,  as  already  stated,  the 
body  of  the  animal  has  a  general  outline  closely 
similar  to  that  of  an  equilateral  triangle. 

Male. — The  male  is  very  small,  measuring  scarcely 
half  a  millimetre  in  length ;  it  is  of  a  robust  form 
and  does  not  differ  very  much  from  the  male  of 
Chondr acanthus  cornutus. 

Habitat. — Parasitic  on  the  gills  of  spotted  dragonets 
(OalUonymus  maculatus  Bonap.).  Firth  of  Clyde,  1899 
and  1901 ;  Moray  Firth,  1900. 

Though  Chondracanthus  ornatus  is  of  a  tolerably  large  size, 
it  is  so  well  concealed  that  it  easily  escapes  notice,  and  it  is 
only  by  turning  back  the  gill-covers  that  the  observer  can 
be  sure  whether  the  parasite  is  present  or  not.  Hitherto 
this  Chondracanthus  has  only  been  obtained  on  the  spotted 
dragonet,  and  frequently  it  has  been  found  associated  with 
another  species — the  Haemobaphoides  ambiguus  (T.  Scott),  pre- 
viously described.  As  pointed  out  in  the  description  of  Hsemo- 
baphoides,  the  two  species  sometimes  occurred  on  the  same 
fish,  on  opposite  sides  or  on  the  same  side ;  occasionally  also 
a  Cliondr acanthus  would  be  found  on  one  side  and  a  Hsemo- 
baphoides  on  the  other.  The  Chondracanthus  was  usually  of 
a  purplish  colour  tinged  with  brown.  About  14  per  cent,  of 
the  fishes  examined  were  found  to  harbour  the  Chondra- 
canthus. 

Genus  37.  MEDESICASTE  Kroner,  1863. 

Sjn.  Chondracanthus  Auct. ;  Lernentoma  Baird ;  Oralien  Bassett-Smith. 

This  genus  was  established  for  the  reception  of  a 
Chondr  acanthus  which,  though  agreeing  in  some 


184  BRITISH    PARASITIC    COPEPODA. 

respects  with  that  genus,  yet  differed  because  of  the 
remarkable  arrangement  of  the  cephalic  appendages. 
In  typical  Choiidr acanthus  these  appendages  are 
situated  in  more  or  less  proximity  to  each  other,  but 
in  Medesicaste  the  anterior  portion  of  the  cephalo- 
thorax,  which  has  a  bulb-like  form,  and  is  provided 
with  two  pairs  of  antenna?,  is  separated  from  the 
thorax  and  the  thoracic  appendages  by  a  moderately 
long  and  narrow  neck  :  by  this  arrangement  a  con- 
siderable distance  intervenes  between  the  two  pairs  of 
antennae  and  the  mouth  and  other  thoracic  organs. 
The  posterior  part  of  the  body  is  tolerably  large  and 
robust,  its  lateral  margins  are  deeply  incised,  dividing 
it  into  two  portions :  the  thoracic,  which  carries  on 
the  ventral  aspect  two  pairs  of  bilobed  blunt-pointed 
processes  and  other  appendages;  and  the  genital, 
which  is  rounded  and  rather  larger  than  the  other,  and 
has  its  postero-lateral  corners  produced  into  more  or 
less  angular  lobes.  Abdomen  small,  biarticulated,  and 
more  or  less  inclosed  between  the  lateral  lobes  of  the 
genital  segment.  Egg-strings  elongated,  claviform. 

Male  very  small,  similar  to  the  male  of  Chondra- 
raiithus. 

"We  are  unable  to  find  any  valid  difference  between  Medesi- 
caste Kroyer  and  Or  alien  Bassett- Smith. 

The  only  British  species  of  Medesicaste  is  that  described 
below. 

1.  Medesicaste  asellinum  (Linn.). 

(Plate  LII,  fig.  6;    Plate  LVII,  figs.  18,  19.) 

1761.  Lern&a  asellina  Linn.  Fauna  Suec.,  2101 ;  Syst.  Nat.,  Edit.  12. 
vol.  i,  pt.  ii,  p.  1093  (1767). 

1829-1843.  Chondracanthus  triglse  Guerin-Meneville.  (55)  Incono- 
graph.,  pi.  ix,  fig.  8. 

1822.  Lernentoma  triglse  Blainv.     (24)  p.  441,  pi.  Ixii,  fig.  12. 

1832.  Chondrocanthus  triglse  Nordmann.     (89)  p.  116,  pi.  ix,  figs.  1-4. 

1838.  Chondracanthus  triglse  Kroyer.     (70)  p.  135.  pi.  iii,  fig.  3. 

1850.  Lernentoma  asellina  Baird.     (4)  p.  329,  pi.  xxxv,  fig.  4. 

1863.  Medesicaste  triglarum  Kroyer.     (71)  p.  312,  pi.  xviii,  fig.  1,  a-b. 

1869.  Chondracanthus  triglse  Steenstmp.     (126a)  pi.  ii,  fig.  3. 

1896.  Chondracanthus  triglae  Bassett-Smith.     (6)  p.  13,  pi.  iv,  fig.  4. 

1899.  Oralien  asellinus  idem.     (8)  p.  490. 


MEDESICASTE    ASELLINUM. 

1900.  Oralien  aseWnus  T.  Scott.     (112)  p.  163,  pi.  vii,  figs.  16-18. 
1906.  Medesicaste  triglurum  Brian.     (21)  p.  94. 

Female. — Head  small,  subglobose,  situated  at  the 
end  of  a  tolerably  long  and  slender  neck,  rounded  in 
front,  and  with  each  side  expanded  into  rounded  lobes, 
the  whole  forming  a  bulb-like  extremity  usually  in- 
closed in  the  tissues  of  the  host ;  this  anterior  part 
furnished  with  two  pairs  of  antennas,  which  are 
small  and  have  hook-like  extremities.  The  neck, 
where  it  joins  the  posterior  portion  of  the  body, 
slightly  enlarged.  This  posterior  portion  of  the  body 
tolerably  large  and  robust  and  divided  by  a  deep 
transverse  constriction  into  two  subequal  parts  ;  the 
front  part  appearing  to  constitute  the  thorax  Avith  its 
appendages,  and  the  lower  the  genital  segment,  the 
antero-lateral  corners  of  which  extend  outwards  into 
angular  projections ;  the  lateral  margins  of  this  lower 
segment  slightly  arcuate,  converging  clistally,  and 
forming  two  small  postero-lateral  lobes,  separated  from 
each  other  by  a  small  median  sinus,  best  seen  from 
the  ventral  aspect.  Abdomen  very  small,  occupying 
the  space  between  the  postero-lateral  lobes. 

Both  pairs  of  antenna?  small,  and  situated  on  the 
subglobose  cephalic  segment  as  described  above. 
Mandibles  stout,  falcate,  and  with  their  margins 
fringed  with  numerous  small  teeth  as  in  Ckondra- 
(•nnthus;  maxillae  and  other  mouth-appendages  also 
somewhat  similar  to  those  in  Chondracnnthus.  Thoracic 
legs  two  pairs,  very  rudimentary.  Colour  pale  red. 
Egg-strings  nearly  as  long  as  the  body  and  containing 
many  ova.  Length  exclusive  of  egg-strings  about  7  mm. 

Male. — Extremely  small  and  similar  in  structure  to 
the  male  of  Clwndracanthus. 

Habitat. — Parasitic  on  the  gills  of  Trinla  spp., 
Gadus  spp. ;  also  on  the  plaice  (Pleuronectes  platessa) 
and  other  fishes,  captured  in  British  waters,  frequent. 

A  somewhat  variable  species,  and  apparently  widely 
distributed. 


180  BRITISH    PARASITIC    COPEPODA. 

Family  vn.  LERN^OPODID.I:. 

Female. — Body  in  the  adult  female  usually  non- 
segmented  or  indistinctly  or  incompletely  so.  Head 
small,  thorax  not  clearly  denned,  Harrow  and  more  or 
less  elongated,  but  sometimes  short  as  in  Lern&opoda 
chdlise.  Abdomen  usually  separated  from  the  thorax 
by  a  constriction  tolerably  distinct  but  seldom  if  ever 
forming  a  complete  articulation ;  the  genital  segment 
of  the  abdomen  usually  enlarged  and  sometimes  pro- 
vided with  posterior  processes ;  the  remaining  ab- 
dominal segments  usually  obsolete  or  rudimentary. 
Appendages  of  the  cephalon  and  thorax  comprising 
antennules  and  antenna,  mandibles,  maxillae,  and  first 
and  second  maxillipeds,  but  the  thoracic  usually  obso- 
lete or  entirely  wanting.  The  second  maxillipeds  arm- 
like  appendages  elongated  or  short,  and  modified  to 
form  organs  of  attachment,  the  arms  entirely  separated 
except  at  the  tip  or  partly  or  completely  coalescent ; 
united  at  the  distal  extremity  to  a  chitinous  process 
which  penetrates  the  tissues  of  the  host,  and  the 
character  of  which  may  vary  in  the  different  species. 
Egg-strings  generally  only  moderately  elongated  and 
the  ova  small  and  arranged  in  a  multiseriate  manner. 

Male. — Very  small  and  furnished  with  several  ap- 
pendages the  structure  of  which  is  more  or  less  rudi- 
mentary. Its  form  varies  in  the  different  genera, 
and  it  is  usually  found  adhering  to  some  part  of  the 
female — i.e.,  the  rudimentary  abdominal  segment  or 
the  cephalothorax. 

Milne  Edwards  included  Anchorella  (Clavella)  in  his  Family 
Lerneopodiens,  but  Dr.  Baird  removed  this  genus  and  estab- 
lished the  Family  Anchorellidse  for  its  reception.  The  dif- 
ference between  Lern&opnda  and  Anchorella  is  obvious  in  two 
particulars  —  in  the  structure  and  modification  of  the  second 
maxillijK'ds  and  in  the  form  of  the  pygmy  male.  The  first 
provided  Baird  with  the  principal  character  by  which  the 
two  Families  could  be  distinguished,  and  might  have  been 
considered  valid  except  for  the  occurrence  of  genera  inter- 
mediate in  structure,  which  made  it  more  convenient  to  include 
them  all  under  the  one  Family  Lerna3Opodidae. 


THYSANOTE.  187 

Genus  38.  THYSANOTE  Kroyer,  1863. 

Syn.  Brachiella  Nordmann  (in  pai't). 

Cephalothorax  short,  robust;  genital  segment  short, 
dilated,  and  somewhat  flattened,  the  postero-lateral 
corners  each  provided  with  two  moderately  short  pro- 
cesses of  about  equal  length  ;  another  pair  of  rather 
longer  submedian  appendages  springing  from  the 
ventral  aspect  and  a  little  in  front  of  the  posterior 
margin.  Abdomen  obsolete  or  nearly  so. 

Both  pairs  of  antennae  small  and  rudimentary. 
Mandibles  moderately  elongated,  and  having  the  inner 
margin  near  the  distal  end  coarsely  and  irregularly 
serrate.  Maxillae  and  first  maxillipeds  somewhat 
similar  to  those  of  Brac.hiella.  Second  maxillipeds 
free,  each  with  the  extremity  expanded  and  obscurely 
trilobed,  the  tip  of  the  inner  lobe  of  each  maxilliped 
being  apparently  united  together. 

Thysanote  has  a  close  general  resemblance  to  Brachiella, 
both  in  the  form  of  the  body  and  in  the  free  second 
maxillipeds ;  the  structure  however  of  these  maxillipeds 
differs,  and  the  genital  segment  also  differs  in,  being  fur- 
nished with  two  pairs  of  posterior  appendages. 

1.  Thysanote  impudica  (Nordmann). 
(Plate  XXXIII,  fig.  5;  Plate  XLIX,  figs.  8-11.) 

1832.  Brachiella  impudica  Nordmann.     (89)  vol.  ii,  p.  92,  pi.  viii,  fig.  1. 
1840.  Brachiella  impudica  M.  Edwards.     (43)  p.  513. 
1877.  Brachiella  impudica  "Vogt.     (142)  vol.  xvi,  p.  436. 

1899.  Thysanote  impudica  Bassett-Smith.     (8)  p.  162. 

1900.  Thysanote  impudica  T.  Scott.     (112)  p.  169,  pi.  viii,  figs.  2-5. 

Female. —  Cephalothorax  short,  robust,  strongly 
arcuate,  and  about  as  long  as  the  genital  segment. 
Genital  segment  short,  about  as  broad  as  long, 
flattened  and  subquadriform,  posterior  truncated  and 
furnished  with  three  pairs  of  short  appendages,  one 
pair  on  each  side  and  one  pair  submedian. 

Both  pairs  of  antenna?  somewhat  rudimentary.  Man- 
dibles moderately  stout  at  the  distal  end,  and  having 
the  inner  margin  coarsely  and  irregularly  serrate, 


188  BRITISH    PARASITIC   COPEPODA. 

some  of  the  teeth  being  alternately  larger  and  smaller. 
Maxillffi  moderately  stout,  furnished  with  two  mode- 
rately long,  narrow,  and  spiniferous  apical  processes, 
two  small  spinules  also  springing  from  a  subapical 
rudimentary  lobe.  The  first  maxillipeds  very  short, 
stout,  and  strongly  uncinate.  The  second  maxillipeds 
very  short,  with  the  distal  end  expanded  and  united 
at  the  top.  Length  from  the  forehead  to  the  end  of 
the  longer  posterior  appendages  about  6'5  mm. 

Male. — We  have  not  ourselves  seen  the  male  of 
Thysanote  impudica ;  Nordmann  gives  a  figure  of  it 
and  describes  it  as  very  minute  (about  0*6  mm.).  It 
somewhat  resembles  the  male  of  Brachiella,  and  its 
appendages  also  appear  to  be  somewhat  similar  to 
those  of  that  genus. 

Habitat. — Parasitic  on  the  gills  of  Trinla  sp.  and 
Gadus  sp.  On  tjie  gills  of  sapphirine  gurnard  (Trigla 
hirundo)  captured  at  Polperro  and  Starcross  (A.  M. 
Norman').  Plymouth  (Bassett-SmitJi).  Irish  Sea  (A. 
Scott).  Moray  Firth  (T.  Scotf).  Dr.  Bassett-Smith 
records  this  species  also  from  Trigla  cucnlus  and  cjur- 
nardus  ;  and  M.  Nordmann  from  Ga.dux  eeglcjimtx  (the 
haddock). 

Genus  39.  CHAROPINUS  Kroner,  1863. 

Syn.  Lerniea  Retzius  (in  part) ;  Lemeopoda  Nordmann  (in  part). 

Female. — Cephalothorax  of  moderate  size,  ovate  or 
sub-conical,  indistinctly  segmented,  with  obscure  trans- 
verse constrictions  behind  the  cephalon ;  neck  short 
or  none.  Genital  segment  pyriform  or  elongate- 
ovate  ;  abdomen  very  small  or  obsolete.  Posterior 
appendages  two,  slender,  short,  one  on  each  side 
of  the  abdomen.  Antennas  short,  stout,  uncinate. 
Mandibles  and  first  maxillipeds  nearly  as  in  Thijxanotc. 
Second  maxillipeds  greatly  elongated,  slender,  or 
moderately  stout,  contiguous  or  coalescent  at  the 
apex.  Apex  enlarged  or  biramose,  and  clasping  a 
cross  bar  of  chiton,  or  greatly  attenuated  and  fixed  at 


CHAROPINUS.  189 

the  tip  to  a  large  horizontal  chitinic  appendage.  Egg- 
strings  tolerably  thick  and  elongate,  and  containing 
numerous  ova. 

Male. — Very  small,  somewhat  similar  in  structure 
to  the  male  of  Lernteopoda  clutliss. 

1.  Charopinus  dalmanni  (Retzius). 
(Plate  LV,  figs.  1-4;  Plate  LIV,  figs.  12-17.) 

1829.  Lemma  dalmanni  Retzius.    (lOla)  p.  109,:  vol.  xxix,  p.  6,  figs.  5-9, 
(1830). 

1832.  Lerneopoda  dalmani  Nordmann.     (89)  p.  138. 
1837.  Lernseopoda  dalmanni  Kroyer.     (70)  vol.  i,  p.  264. 

1862.  Lerneopoda  dalmunni  Turner  &  Wilson.     (140)  p.  77,  pi.  iv. 

1863.  Charopinus  dalmanni  Kroyer.     (71)  p.  280,  pi.  xiv,  figs.  6,  a-g. 
1879.  Stylophorus  hypocephalus  Hesse.     (59)  (6)  vol.  viii,  art.  15,  p.  31. 
1891.  Charopinus  dalmanni  T.  Scott.     9th  Ann.  Report  Fishery  Board 

for  Scotland,  p.  310. 

1900.  Charopinus  dalmanni  idem.      (112)  p.  169,  pi.  viii,  figs.  6-10. 
1904.  Charopinus  dalmanni  A.  Scott.     (109)  p.  43. 

Female. — Cephalothorax  short,  somewhat  trian- 
gular in  outline,  and  usually  bent  abruptly  downwards 
so  as  to  form  a  more  or  less  distinct  angle  with  the 
posterior  part  of  the  body.  There  springs  from  each 
side  of  the  angle  thus  formed  a  long,  moderately 
slender,  and  indistinctly  annulated  appendage  which  at 
the  apex  becomes  dilated  and  lunuliform.  The  lunuli- 
form  apices  of  these  elongated  appendages,  otherwise 
described  as  the  second  maxillipeds,  though  not 
actually  coalescent,  fit  closely  together,  and  clasp  a 
cartilaginous  or  chitinous  bar  which  extends  some 
distance  on  each  side  of  the  conjoined  apices;  this 
complex  structure,  buried  in  the  tissues  of  the  fish, 
forms  a  secure  anchorage  for  the  parasite.  Imme- 
diately in  front  of  the  base  of  each  of  the  second 
maxillipeds  there  is  on  each  side  of  the  thorax  a  small 
rounded  protuberance  termed  by  Retzius  and  Kroyer 
"  eye-like  spots,"  but  they  are  not  supposed  to  be 
eyes,  and  their  true  character  seems  to  be  obscure. 
The  posterior  and  genital  portion  of  the  body  becomes 
gradually  and  considerably  enlarged  toward  the  distal 
end,  and  the  postero-lateral  corners  form  bluntly- 


190  BRITISH    PARASITIC    COPEPODA. 

rounded  knobs.  Two  moderately  long  and  slender 
appendages  spring  from  the  ventral  aspect  just  in 
front  of  the  base  of  the  egg-strings  and  extend  back- 
wards some  distance  beyond  the  end  of  the  genital 
segment.  Abdomen  and  caudal  rami  obsolete.  Anten- 
nules  stout,  short,  and  apparently  three-jointed ; 
antennae  short  with  a  gibbous  basal  part,  and  the 
small  end  joint  provided  with  a  minute  terminal  cla\v. 
Mandibles  slender,  moderately  elongated,  and  with  a 
portion  of  the  inner  margin  of  the  end  joint  coarsely 
serrate ;  maxillae  simple  and  furnished  with  a  few 
apical  setae.  No  thoracic  legs  observed.  Length 
from  the  apex  of  the  second  maxillipeds  to  the  end  of 
the  posterior  appendages  about  47  mm.  Colour 
opaque  white  tinged  with  red. 

Male. — Very  small,  scarcely  reaching  beyond  two 
millimetres  in  length.  Somewhat  like  Lernseopoda 
cluthas  in  general  appearance  but  larger.  Thorax  and 
abdomen  segmented.  Maxillipeds  short  and  stout  and 
furnished  with  strong  terminal  claws. 

Habitat. — Parasitic  in  the  nasal  fossae  or  spiracles  of 
gray  (or  blue)  skates  (Raia  batis).  Firth  of  Forth; 
frequent  on  large  Raia  batis  brought  to  the  Fish- 
Market  at  Aberdeen  (T.  Scott).  Firth  of  Forth,  1862 
(Dr.  Wilson}.  Polperro,  Cornwall  (A.  M.  Norman). 
Irish  Sea  (A.  Scott).  Usually  only  one  specimen  is 
present  in  a  spiracle,  but  two  and  sometimes  three 
have  been  observed  almost  blocking  up  the  spiracle. 

2.  Charopinus  dubius  T.  Scott. 
(Plate  LV,  fig.  5.) 

1900.  Charopinus  dubius  T.  Scott.     (112)  p.  130,  pi.  vii,  fig.  15. 

Female. — Somewhat  resembling  Charopinus  dalmanni 
Retzius  in  general  appearance  and  also  in  some  of  its 
appendages,  but  considerably  smaller,  being  little  more 
than  half  the  size. 

The  principal  structural  characters  by  which  it  is 
distinguished  from  that  species  are  those  of  the 


CHAROPINUS    DUBIUS.  191 

complex  form  of  the  anchoring  arrangement  of  the 
second  maxillipeds,  which  are  more  slender  in  propor- 
tion to  their  length ;  their  apices  appear  to  be  coalesc- 
ent,  and  are  fixed  to  a  moderately  large  horizontal 
appendage  which  is  cartilaginous  and  of  a  brownish 
colour.  This  appendage,  when  perfect,  is  somewhat 
boat-shaped  with  the  extremities  slightly  turned  up ;  it 
has  a  resemblance  to  the  cartilaginous  bar  clasped  by  the 
enlarged  apices  of  the  second  maxillipeds  of  Charopinus 
Jalmanni,  but  there  the  resemblance  ends,  for  in  that 
species  the  ends  of  the  second  maxillipeds  when  freed 
from  the  cartilaginous  bar  separate  freely,  whereas  in 
the  species  under  consideration  they  remain  fixed 
together  by  a  small  hardened  plug  as  in  Lernaeopodn, 
and  do  not  separate  freely.  The  two  pairs  of  antennae, 
the  mandibles,  and  other  mouth-organs  do  not  appear  to 
differ  greatly  from  those  of  Charopinus  dalmanni.  The 
ventral  appendages  at  the  posterior  end  of  the  genital 
segment  are  also  similar.  Length  of  one  of  the  larger 
specimens  :  maxillipeds  11  mm.,  cephalothorax  6  mm., 
genital  segment  8'5  mm.,  posterior  appendages  4  mm., 
egg-strings  18  mm.,  and  from  the  chitinic  bar  to  which 
the  maxillipeds  are  fixed  to  the  end  of  the  posterior 
appendages,  26  mm. 

No  males  of  this  species  have  been  observed. 

Habitat. — Parasitic  on  the  gills  and  gill-arches  of 
the  cuckoo  ray  (Raici  circularis)  chiefly,  and  less  fre- 
quently on  other  skates,  Firth  of  Clyde  and  Fish-Market, 
Aberdeen  (T.  Scott).  On  Raia  fidlonica  captured  off 
Dubh  Artach  (A.  Scott). 

3.  Charopinus  ramosus  Kroyer. 
(Plate  LV,  figs.  6,  7  ;  Plate  LIV,  figs.  18-22.) 

1863.  Charopinus  ramosus  Kroyer.     (71)  p.  284,  pi.  xiv,  fig.  5. a-i. 
1901.  Charopinus  ramosus  T.  Scott,     (113)  p.  130,  pi.  vii,  figs.  17--.2:;. 
1904.  Charopinus  ramosus  A.  Scott.     (109)  p.  43. 

Female. — In  this  species  the  "cephalothorax  is  not 
deflexed  in  front  of  the  bases  of  the  second  maxilli- 
peds, but  is  projected  forward  as  in  Lernaeopoda 


192  BRITISH    PARASITIC    COPEPODA. 

It  lias  also  an  ovate  or  pyriform  outline,  narrow  in 
front.  Genital  segment  elongated,  narrow,  and  only 
slightly  enlarged  towards  the  posterior  end. 

Antennnles  short  and  composed  of  two  joints,  a 
stout  basal  joint  and  a  narrow  end  one  which  is 
furnished  with  a  few  apical  spines,  a  small  bristle  also 
springing  from  near  the  end  of  the  basal  joint. 
Antennas,  like  those  of  Charopinus  dubius,  short  and 
stoat,  the  outer  ramus  consisting  of  a  small  joint 
articulated  to  the  inner  ramus  and  provided  with  two 
short  unequal  spines ;  the  inner  ramus  stout  with  a 
gibbous  rounded  end,  both  rami  covered  with  micro- 
scopic prickles.  Mandibles  narrow,  oblong,  the  apex 
obliquely  truncate  and  coarsely  serrated ;  maxilla? 
small,  moderately  stout,  biarticulate,  and  furnished 
with  three  apical  and  subapical  spines  and  a  small 
setiferous  process.  First  maxillipeds  three-jointed; 
second  joint  with  a  small  setiferous  knob  near  the 
proximal  end  of  the  inner  margin;  end  joint  slender, 
and  armed  at  the  apex  with  two  minute  spines  and  a 
small  slightly-curved  claw.  Second  maxillipeds  slender 
and  about  as  long  as  the  body,  exclusive  of  the  posterior 
appendages,  becoming  considerably  altered  at  the  distal 
end  where  their  inner  surfaces  are  closely  adherent,  and 
extending  on  each  side  into  biramose  processes  which 
penetrate  the  tissues  of  the  host  and  form  a  secure 
anchorage  for  the  parasite.  The  genital  segment 
furnished  with  two  posterior  appendages  moderately 
short  and  slightly  divaricate. 

Male. — "We  have  not  ourselves  noticed  the  male  of 
this  species,  but  Kroyer  describes  and  figures  it  in  the 
work  quoted  above.*  It  is,  though  smaller,  very  like  the 
male  of  Cliaropinus  dalmanni,  and  is  characterized  by  a 
similar  stout  proboscis  in  front  of  the  head  and  by 
powerful  maxillipeds  fitted  for  grasping. 

Habitat. — Parasitic  on  the  gills  and  gill-arches  of 
Raia  durntii  and  Raid  macula  ta.  Fish-Market,  Aber- 

*  "  Bidrag  til  Kundskab  om  Synltekrebsene,"  '  Natur.  Tidssk.,'  3  Raekke, 
2  Bind,  p.  287. 


CHAROPINTJS    RAMOSUS.  193 

deen  (T.  Scott).    Irish  Sea  (A.  Scott).    This  appears  to 
be  a  moderately  rare  species  in  British  waters. 

Genus  40.  ACHTHERES  Nordmann,  1832. 

Female. — Cephalothorax  short  and  broadly  ovate, 
separated  from  the  genital  segment  by  a  tolerably  dis- 
tinct constriction.  Genital  segment  oval  or  subglobose, 
and  sometimes  exhibiting  a  more  or  less  segmented 
structure.  The  two  pairs  of  antennae  and  the  mouth- 
appendages  not  differing  much  from  those  of  Lernseo- 
poda  ;  second  maxillipeds  short,  stout,  free,  but  united 
at  the  tip  to  a  circular  chitinous  disk,  which  is  expanded 
in  front.  Genital  segment  usually  furnished  with  two 
small  processes  at  the  distal  extremity.  Egg-strings 
short,  dilated  or  saccate ;  ova  tolerably  large. 

Male. — Very  small ;  first  maxillipeds  short,  very 
robust,  strongly  uncinate;  second  maxillipeds  elongated, 
stout;  terminal  claws  small. 

Parasitic  for  the  most  part  on  freshwater  fishes. 

1.  Achtheres  percarum  Nordmann. 

(Plate  L,  figs.  6-8  ;  Plate  LIX,  figs.  7,  8;  Plate  LXIV, 

figs.  1-3.) 

1832.  Achtheres  percarum  Nordmann.     (89)  p.  63,  pi.  iv. 
1838.  Achtheres  percarum  Kroyer.     (70)  ii,  p.  143,  pi.  iii,  fig.  6. 
1840.  Achtheres  percarum  M.  Edwards.     (43)  p.  511,  pi.  xl,  fig.  8. 
1861.  Achtheres  percarum  Claus.     (32)  p.  287,  pis.  23,  24. 
1899.  Adheres  percarum  Bassett-Smith.     (8)  p.  498. 
1901.  Actheres  percarum  T.  Scott.     (113)  p.  132. 
1904.  Achteres  percarum  Pehr  Gadd.     (47)  p.  21. 
1906.  Achtheres  percarum  Brian.     (21)  p.  101. 

Female. — Cephalothorax  of  moderate  size,  narrower 
in  front  than  behind.  Genital  segment  sub-globose, 
rather  longer  than  broad,  separated  from  the  Cephalo- 
thorax by  a  distinct  constriction  ;  the  posterior  end  of 
the  segment  slightly  angular,  bearing  two  minute  pro- 
cesses— one  on  each  side  of  the  median  line.  Abdomen 
obsolete.  Egg-strings  short,  stout,  saccate,  scarcely 
equal  in  length  to  the  genital  segment.  Ova  large. 

VOL.  i.  13 


194  BltiTlSH    PAKAS1T1C    COPEl'ODA. 

Antennae  and  mouth-appendages  somewhat  similar 
to  those  of  Lernseopoda  salmonea.  The  second  maxil- 
lipeds  nearly  as  long  as  the  genital  segment,  free 
except  at  the  tips  where  they  are  united  to  a  smalt 
obconical  chitinous  plug. 

We  have  not  seen  the  male  of  Achtheres  percarvrn, 
but  it  has  been  described  by  Nordmann.  It  is  very 
small,  measuring  little  more  than  a  millimetre  in 
length. 

Habitat. — Parasitic  on  the  gills  of  fresh-water  perch 
and  trout.  On  the  gills  of  the  common  trout,  Moray 
Firth  district  (T.  Edward,  in  'Museum  Normanianum'). 
On  the  gills  of  a  trout  captured  by  Mr.  W.  S.  Caine 
in  Loch  Awe,  a  small  fresh-water  loch  in  Assynt, 
Sutherlandshire  ('/'.  Scott}.*  On  the  gills  of  a  trout 
captured  in  Loch  Tay,  Perthshire,  by  Dr.  Williamson, 
to  whom  we  are  indebted  for  the  specimen. 

The  specimens  recorded  above  agree  generally  with  the 
form  described  and  figured  by  Nordmann,  except  that  the 
genital  segment  is  not  segmented  as  his  drawing  shows  it  to 
be  (this  drawing  is  reproduced  on  PI.  L,  fig.  6,  for  com- 
parison with  Scottish  specimens). 

The  chitinous  plug  by  which  the  female  Achtheres  is  fixed  to 
its  host  is  considerably  and  regularly  expanded  in  front,  as 
shown  by  fig.  7,  PI.  LIX.  This  form  of  plug  appears  to  be 
characteristic  of  the  genus,  and  differs  entirely  from  that  of 
the  closely  allied  Lernseopoda  salmonea,  which  is  of  a  broadly 
lingulate  form. 

Dr.  Pehr  Gadd,  in  his  account  of  the  Copepod  parasites 
found  on  the  fislies  of  Finland,  describes  a  species  parasitic 
on  the  fresh-water  fish  Lucioperca  sandra,  under  the  name  of 
Achtheres  sandrse.'f  In  that  species  the  genital  jsegraent  is 
not  segmented,  resembling-,  in  that  respect,  the  specimens 
described  above. 

*  "  The  Invertebrate  Fauna  of  the  Inland  Waters  of  Scotland,"  '  Twelfth 
Annual  Keport  of  the  Fishery  Board  for  Scotland,'  Part  III,  p.  287  (1894). 

f  "  Parasit-Copepoder  I  Finland,"  '  Acta  Societatis  pro  fauna  et  flora 
Fennica,'  vol.  xxvi,  No.  8,  p.  22,  pi.  i,  fig.  1  (1904). 


LERNEOPODA.  195 

Genus  41.  LERN-EOPODA  Blainville,  1822. 

Female. — Body  generally  elongated;  cephalothorax 
short,  wider  behind  than  in  front,  more  or  less  dis- 
tinctly separated  from  the  remaining  part  of  the  body, 
and  sometimes  with  a  chitinous  shield-like  dor  sum. 
Genital  segment  elongated,  sometimes  ovoid  or  saccate, 
and  unsegmented.  Abdomen  obsolete  or  nearly  so ; 
posterior  processes  two,  short,  or  none.  First  maxilli- 
peds  near  and  a  little  behind  the  mouth.  Second 
maxillipeds  long  or  moderately  short,  slender,  wide 
apart,  and  only  united  at  the  tip  to  a  chitinous  button 
or  plug  usually  buried  in  the  tissues  of  the  host. 

Male. — Much  smaller  than  the  female,  somewhat 
elongated  and  distinctly  segmented.  Cephalothorax 
sometimes  provided  with  a  dorsal  shield,  and  usually 
separated  from  the  abdomen  by  an  obvious  articulation. 
Abdomen  usually  segmented.  Antennules  small,  two- 
or  three-jointed.  Antennae  tolerably  large.  Mouth  in 
the  form  of  a  short  conical  siphon.  Maxillipeds  large 
and  uncinate. 

1.  Lernaeopoda  elongata  (Grant). 
(Plate  LXI,  figs.  5,  C5;  Plate  LVII,  figs.  13-17.) 

1827.  Lernsea  elongata  Grant.     (53)  vol.  vii,  p.  147,  pi.  ii,  fig.  5. 

1838.  Lerneopoda  elongata  Kroyer.     (70)  i,  pi.  2,  fig.  12 ;  pi.  3,  fig.  3  «. 

1840.  Lenueopoda  elongata  M.  Edwai-ds.     (43)  p.  515. 

1850.  Lerneopoda  elongata  Baird.     (4)  p.  333,  pi.  xxxv,  fig.  5. 

1861.  Lernfeopoda  elongata  Stp.  &  Ltk.     (127)  p.  422,  pi.  xv,  fig.  37. 

1861.  Lerneopoda  elongata  P.  J.  van  Beiieden.     (15)  p.  154. 

1862.  Lerneopoda  elongata  Turner  &  Wilson.     (140)  p.  85. 

1900.  Lern&opoda  elongata  T.  Scott.     (112)  p.  171,  pi.  viii,  figs.  11-15. 

Female. — Cephalothorax  distinct,  ovate,  flattened, 
obtusely  and  narrowly  rounded  in  front,  but  becoming 
gradually  wider  and  thicker  behind,  the  posterior 
margin  being  rounded  and  somewhat  gibbous.  Genital 
segment  elongate,  subcylindrical,  slightly  depressed, 
about  as  wide  as  the  cephalothorax  but  distinctly 
narrower  where  it  joins  the  head ;  distal  end  truncated 
and  provided  with  two  small  appendages  on  the  ventral 


196  BRITISH    PARASITIC    COPEPODA. 

aspect — one  on  either  side  of  the  median  line  and  in 
front  of  the  origin  of  the  egg-strings.  Abdomen  very 
minute,  the  genital  segment  showing  no  trace  of 
segmentation. 

Antennules  short,  basal  joint  stout,  the  others 
narrower.  Antenna3  very  short,  stout,  and  bluntly 
orunded  at  the  end, furnished  with  a  minute  branch  near 
the  distal  end  (PL  LVII,  fig.  14).  Mandibles  small, 
elongate,  narrow,  and  having  the  inner  margin  near 
the  distal  end  distinctly  serrated.  First  maxillipeds 
short,  stout,  armed  with  moderately  strong  terminal 
claws.  Second  maxillipeds  long  and  slender,  exceed- 
ing the  length  of  the  body ;  they  "  taper  abruptly  at 
their  distal  ends  and  are  connected  to  a  small,  rounded, 
horny,  or  chitinous  disk."*  The  extremities  of  the 
arms,  where  they  join,  closely  contiguous  but  not 
coalescent  with  each  other.  Length  from  posterior 
end  of  the  genital  segment  to  the  tips  of  the  second 
maxillipeds  about  40  mm.,  the  maxillipeds  alone 
measuring  over  20  mm. 

Male. — We  have  not  seen  the  male  of  this  species,  but 
Steenstrup  and  Liitken  (op.  cit.,  p.  423)  give  the  size  as 
about  1  mm.,  and  their  figure  shows  that  the  cephalo- 
thorax,  which  is  provided  with  large  uncinate  maxilli- 
peds, is  separated  from  the  abdomen  by  a  not  very 
strongly  defined  segment ;  the  abdomen  is  more  dilated 
than  the  cephalothorax  and  is  also  unsegmented. 

Habitat. — Parasitic  usually  on  the  eyes  of  the  Green- 
land shark  (Lamna  cormibica).  Obtained  on  a  Green- 
land shark  caught  on  the  English  coast  in  the  winter 
of  1848  by  Mr.  Yarrell,  who  gave  the  specimen  to  Dr. 
Baird  ('  Entom.,'  p.  334).  Taken  on  the  smooth 
hound  (Mustelus  vulgaris)  at  Polperro  (A.  M.  Norman). 
A  specimen  was  obtained  by  Mr.  H.  Dannevig  on  the 
eye  of  a  shark  captured  east  of  Fair  Isle  between 
Orkney  and  Shetland  in  October  1900.  Another  was 
obtained  by  Mr.  Ingram,  Fishery  Officer,  on  a  Green- 

*  Turner  and  Wilson, "  Observations  on  the  Parasitic  Crustacea,  Chondra- 
canthus  Lophii  and  Lerneopoda  dalmanni,"  'Trans.  Roy.  Soc.  Edinb./  vol. 
xxiii,  Pt.  1,  p.  85  (1862). 


LERN^OPODA    ELONGATA.  197 

land  shark  captured  in  the  North  Sea  and  landed  at 
Aberdeen  Fish-Market  in  April  1901.  Both  specimens 
were  examined  by  us. 

2.  Lernasopoda  galei  Kroyer. 

(Plate  LX,  figs.  4-6;  Plate  LVIII,  figs.  9-15;  Plate 
LXIII,  fig.  1.) 

1837.  Lernseopoda  galei  Kroyer.     (TO)  p.  272,  pi.  iii,  fig.  5. 
1840.  Lernveopoda  galei  M.  Edwards.     (43)  p.  516. 

1850.  Lerneopoda  gahi  Baird.     (4)  p.  334,  pi.  xxxv,  fig.  7. 

1851.  Lertweopoda  galei  P.  J.  van  Beneden.     (11)  p.  120,  pi.  iv. 
1896.  Lernaeopoda  galei  Bassett-Srnith.     (7)  p.  163. 

1900.  Lei-nxopoda  galei  T.  Scott.     (112)  p.  172,  pi.  vdii,  figs.  16-25. 

Female.— Cephalo thorax  short,  flattened,  and  of  an 
oval  shape;  the  dorsum  chitinous  and  forming  a  shield- 
like  covering.  Genital  segment  elongated,  subcylin- 
clrical,  proximal  end  narrower  than  the  cephalothorax 
but  becoming  slightly  enlarged  towards  the  posterior 
extremity ;  distal  end  provided  with  two  small 
cylindrical  processes,  one  on  each  side  of  the  minute 
abdomen.  Egg  -  strings  narrow,  cylindrical,  and 
tolerably  elongated. 

Antennules  short,  enlarged  at  the  base;  end  joints 
three,  narrow,  and  furnished  with  a  few  minute  apical 
setaa.  Antennas,  mandibles,  and  maxillas  similar  to 
those  of  Lernseopoda  elongate.  First  maxillipeds  short, 
stout,  armed  with  strong  terminal  claws.  Second 
maxillipeds  slender,  considerably  shorter  than  the  body, 
and  united  at  the  tip  to  a  chitinous  disk  or  plug  inserted 
into  the  tissues  of  the  host.  Length  from  the  forehead 
to  the  end  of  the  posterior  appendages  13  to  14mm. 
Length  of  the  posterior  appendages  fully  2  mm.,  and 
of  the  second  maxillipeds  between  4  and  5  mm. 

Male. — The  male  is  small.  The  cephalothorax  is 
nearly  equal  in  length  to  the  genital  segment,  and  the 
form  is  ovoid ;  genital  segment  elongate-ovate,  fully 
twice  as  long  as  broad,  and  having  at  the  distal  end 
two  short  reflexed  oval  appendages,  one  on  each  side  of 
the  nearly  obsolete  abdomen.  Both  pairs  of  maxilli- 


198  BRITISH    PARASITIC   COPEPODA. 

peds  short,  stout,  and  furnished  with  strong  terminal 
claws. 

Habitat. — Found  parasitic  on  various  dog-fishes, 
usually  adhering  to  the  ventral  and  anal  fins.  At 
Polperro  on  the  toper  (Galeus  vulgaris),  and  from 
cod  (A.  M.  Norman).  At  Plymouth  "from  Galeus 
vulgaris,  Mustelus  vulgaris,  and  Acanthias  vulgaris  '* 
(Bassett-Smith).  Belfast,  1839  (W.  Thompson).  Off 
Valentia  (W.  F.  Kane).  Irish  Sea  (A.  Scott).  The 
Firth  of  Clyde,  Moray  Firth,  Aberdeen  (T.  Scott). 

3.  Lernaeopoda  cluthse  T.  Scott. 

(Plate  LX,  figs.  1-3;   Plate  LVII,  figs.  1-7;  Plate 
LVIII,  fig.  16.) 

1900.  Lernxopoda  duthx  T.  Scott.     (112)  p.  173,  pi.  viii,  figs.  27-37. 
1909.  Lernaeopoda  cltithie  May  E.  Bainbridge.     (3)  p.  49,  pi.  10,  figs, 
24-27. 

Female. — Cephalothorax  small,  subtriangular,  a  dis- 
tinct and  narrow  neck  connecting  it  with  the  posterior 
portion  of  the  body,  which  is  somewhat  dilated  and 
subcylindrical,  and  exhibits  a  few  pseudo-constrictions. 
Two  short  processes  springing  from  the  distal  end  of 
the  genital  segment ;  the  abdomen,  situated  between 
them,  very  small.  The  two  pairs  of  antennas  similar 
to  those  of  the  species  already  described.  Mandibles 
small  and  their  biting  margins,  which  are  obliquely 
truncated,  finely  and  somewhat-  irregularly  serrated, 
and  differing  very  markedly  from  the  same  appendages 
in  Lemseopdda  galei;  maxillae  small,  end  joint  provided 
with  two  tolerably  long  and  stout  terminal  spines. 
The  first  maxillipeds  more  slender  and  rather  more 
elongate  than  those  of  L.  galei.  Length,  from  the 
forehead  to  the  end  of  the  posterior  appendages, 
5  mm. ;  length  of  the  second  maxillipeds  nearly  3'5  mm. 

Male. — The  male  differs  considerably  from  that  of 
the  species  just  described  (L.  galei) ,  particularly  in 
the  structure  of  the  abdomen  and  of  the  caudal  rami. 
In  the  species  under  consideration  the  abdomen  of  the 
male  is  distinctly  segmented,  and  the  caudal  rami, 


LERN^OPODA    CLUTH^.  199 

which  are  not  divergent,  consist  of  two  short  slender 
processes  instead  of  being  broadly  oval  or  claviform 
and  reflexed  upon  the  abdomen. 

Habitat. — Parasitic  on  the  gill-filaments  of  the 
Fuller's  ray  (Raia  fullonica).  Firth  of  Clyde,  May, 
1897  (T.  Scott).  Northumberland  coast  (May  E. 
Bainbridge)  on  Raia  radiata. 

This  species  has  not  been  observed  on  any  of  the 
dog-fishes,  but  only  on  the  gill-filaments  of  the  rays 
mentioned. 

P.  Olsson  has  described  a  Lcrnxopoda  (L.  longimana) 
from  the  same  species  of  skate.*  The  female  only  is  described, 
and  it  appears  from  his  description  and  figures  to  be  distinct 
from  the  species  recorded  here. 

4.  Lernseopoda  salmonea  (Linn.). 
(Plate  LIX,  figs.  1-6  ;  Plate  XL VIII,  figs.  8-12.) 

1761.  Lermea  salmonea  Linn.     (77)  p.  509,  No.  2102. 

1780.  Lerniea  salmonea  Cordiner.     (36)  p.  7,  8,  pi.  6,  fig.  2. 

1816.  Entomoda  salmonea  Lamarck.     (72)  p.  233. 

1822.  Lerneopoda  salmonea  Blainville.     (24)  p.  127. 

1837.  Lernseopoda  carpionis  (?)  Krdyer.     (70;  (1)  pi.  ii,  fig.  6. 

1840.  Basenistes  salmonea  M.  Edwards.     (43)  p.  509,  pi.  xli,  fig.  S. 

1850.  Lerneopoda  salmonea  Baird.     (4)  p.  335,  pi.  xxxv,  fig.  6. 

1863.  Lernveopoda  salmonea  Kroyer.     (71)  p.  275,  pi.  xiv,  fig.  3  c.-f. 

1900.  Lernneopoda  salmonea  T.  Scott.     (112)  p.  173,  pi.  viii,  fig.  26. 

Female. — Cephalothorax,  seen  from  above,  sub- 
triangular,  small,  enlarged  behind  and  distinctly 
separated  from  the  posterior  part  of  the  body.  The 
genital  segment,  where  it  joins  the  cephalothorax, 
narrowed  and  forming  a  kind  of  neck ;  the  segment 
then  becoming  considerably  enlarged  and  ovoid  or 
pyriform,  the  posterior  end  rounded  and  provided 
with  two  minute  apical  knobs,  one  on  each  side  of  the 
abdomen  which  is  very  small. 

The  two  pairs  of  antennae  and  the  appendages  of 
the  thorax  somewhat  similar  to  those  of  Lernseopoda 
(jalei  except  that  the  second  maxillipeds  are  tolerably 
stout  and  short,  and  the  chitinous  plug  to  which  they 

*  "  Prodr.  fauna  Copep.  parasit.  Scand.,"  '  Acta  Universitatis  Lundensis/ 
1808 ;  '  Lunds  Univ.  Arsskrift,'  iii,  p.  30,  pi.  2,  figs.  13-15. 


200  BRITISH    PARASITIC    COPEPODA. 

are  united  at  the  tip  is  proportionally  large.  Entire 
length  from  the  posterior  end  of  the  genital  segment 
to  the  tip  of  the  second  maxillipeds  about  6  mm. 

The  male  has  not  been  observed  by  us. 

Habitat. — Parasitic  on  the  gills  of  the  salmon. 
London  Market  (W.  Baird).  North  of  Ireland,  1856 
(W.  Thompson}.  Plymouth  (Bassett- Smith).  On  a 
diseased  salmon  from  the  Firth  of  Tay  (T.  Scott).  On 
"the  gills  of  salmon  taken  in  the  Coquet,  1908"* 
(E.  L.  Gill).  This  species  Avas  also  obtained  on  the 
gills  of  salmon  by  Thomas  Edward  of  Banff.f 

A  salmon  captured  in  tlie  river  Dee  near  Aberdeen  was 
infested  hy  these  parasites  :  they  could  be  observed  adhering 
to  the  ends  of  the  gill-filaments  in  considerable  numbers,  the 
white  colour  of  the  parasites  showing  distinctly  against  the 
red  colour  of  the  gill  filaments.  (See  Plate  B,  fig.  3). 

5.  Lernaeopoda  bidiscalis  W.  F.  de  Visme  Kane. 
(Plate  LXI,  figs.  1,  2;  Plate  LVII,  figs.  8-12.) 

1892.  Lernxopoda  lidiscalis  W.  F.  de  Visme  Kane.  (68)  (3)  vol.  ii, 
p.  203,  pis.  ix,  x. 

1900.  Lernneupoda  lidiscalis  T.  Scott.     (112)  p.  172. 

Female. — Cephalothorax,  seen  from  above,  oblong 
in  shape  and  rather  longer  than  broad,  but  in  profile 
somewhat  pyriform,  sloping  dorsally  upwards  and 
backwards,  and  terminating  abruptly  behind ;  a  con- 
striction which  is  distinct,  but  which  can  scarcely  be 
described  as  a  "  neck,"  separating  the  Cephalothorax 
from  the  genital  segment.  Genital  segment  short, 
considerably  enlarged,  and  nearly  as  broad  as  long  ;  an 
indistinct  median  dorsal  groove  present  in  some  speci- 
mens, the  posterior  end  somewhat  truncated,  and  the 
postero-lateral  corners  rounded  and  slightly  lobate. 
The  genital  segment  provided  with  two  short,  inter- 
mediate, fusiform  appendages  which  spring  from  the 
ventral  aspect  near  the  origin  of  the  egg-strings. 
Abdomen  nearly  obsolete. 

*  Cf.  '  Crustacea  of  Northumberland  and  Durham,'  by  Brady  and 
Norman  (1910). 

t  Cf.  Smiles, '  Life  of  a  Scottish  Naturalist/  2nd  ed.  (1877),  p.  437. 


LERN-EOrODA   BIDISCALIS.  201 

Antennules  nearly  as  in  Lernxopoda  galei.  Antenna? 
very  short,  stout,  and  prehensile.  The  mandibles  and 
other  mouth-organs  not  differing  much  from  those  of 
L.  galei.  The  second  maxillipeds  very  short  and 
stout,  each  terminating  in  a  very  large,  fleshy,  circular 
or  ear-shaped  disk ;  the  disks  united  together  by  a 
horn-coloured  chitinous  plug.  Colour  usually  opaque- 
white,  more  or  less  tinged  with  red,  sometimes  highly 
coloured.  Length  :  forehead  to  the  end  of  the 
posterior  appendages  about  7  mm.,  excluding  the 
appendages,  5'5  mm. 

Male. — Though  small,  proportionally  rather  larger 
than  the  male  of  Lernxopoda  cjalei,  but  in  its  general 
form  and  in  the  structure  of  its  appendages  having 
a  close  resemblance  to  the  male  of  that  species. 

Habitat. — Parasitic  chiefly  on  the  claspers  of  male 
specimens  of  the  tope  (or  toper),  Galeus  canis.  On 
topers  captured  off  Valentia,  Ireland  (cle  VismeKane). 
Firth  of  Clyde  (Mr.  Duthie,  Fishery  Officer).  Aber- 
deen (T.  Scott}.  Irish  Sea  (A.  Scott).  Taken  also  on 
the  smooth  hound.  (Mustelus  wlgaris)  at  Polperro,  Corn- 
wall by  Mr.  W.  Laughrin  about  1862  (A.  M.  Norman). 

The  dog-fishes  on  which  these  parasites  were  obtained  were 
adult  males,  and  they  were  usually  found  adhering  on,  or 
near  the  ends  of,  the  claspers.  We  have  rarely  observed 
them  on  the  claspers  of  young  males.  Moreover,  as  men- 
tioned by  the  describer  of  the  species,  we  almost  invariably 
found  that  the  ends  of  the  claspers  on  which  the  parasites 
occurred  were  torn  and  bleeding,  but  whether  the  wounds 
were  caused  directly  by  the  parasites,  or  through  the  efforts 
made  by  the  fish  to  throw  off  its  tormentors,  was  not  very 
clear.  Occasionally  both  claspers  had  parasites  adhering  to 
them. 

The  specimens  observed  by  us  had  usually  the  front 
portion  of  the  head  of  a  bright  red  colour,  and  sometimes 
there  were  blotches  of  the  same  colour  on  other  parts  of  the 
body;  frequently  also  we  found  one,  and  more  rarely  two, 
males  adhering  to  the  femnle. 

Among  the  more  prominent  features  by  which  this  Ler- 
naeopod  is  distinguished  is  the  comparatively  large  size  of 
the  nearly  circular  disks  which  terminate  the  short  second 


202  UUITISH    PARASITIC    COPEPODA. 

maxillipeds ;  the  whole  animal  is  also  short  and  robust,  and 
very  different  from  the  more  elegant  L.  galei  which  is  also 
sometimes  met  with  at  the  base  of  the  claspers. 


6.  Lernaeopoda  similis  sp.  HOV. 
(Plate  LXI,  figs.  3,  4.) 

Female. — Somewhat  similar  in  general  appearance 
to  Lernseopoda  cluthse,  but  the  head  tolerably  elongated ; 
the  second  maxillipeds  short,  free  except  at  the  ex- 
tremities, where  they  become  united  to  a  chitinous, 
horn-coloured  button  which  penetrates  the  tissues  of 
the  host.  Genital  segment  elongate-pyriform,  widest 
posteriorly.  Abdomen  nearly  obsolete,  furnished  with 
two  tolerably  long  digitiform  processes.  Egg-strings 
long,  narrow-cylindrical ;  ova  small,  numerous. 

Mouth-appendages  apparently  somewhat  similar  to 
those  of  Lernseopoda  cluthse.  Colour  yellowish  grey. 
Length  to  the  end  of  the  posterior  processes  about 
8  mm. 

Habitat. — Parasitic  on  the  gills  of  the  blue  or  grey 
skate  (Eaia  batiti)  captured  in  the  Firth  of  Clyde  at 
Stations  I  and  II  in  December  1899. 

This  species  may  be  distinguished  from  L.  cliithte,  which 
it  somewhat  resembles,  by  the  short  second  maxillipeds, 
and  by  the  form  of  the  head. 

7.  ?  Lernaeopoda  lampri  sp.  nov.  $  . 
(Plate  XXXIII,  fig.  G;  Plate  XLIX,  figs.  12-16.) 

1901.  ?  Lernvopoda  sp.  <J,  T.  Scott.     (113)  p.  136,  pi.  viii,  figs.  4-10. 

"  A  few  male  specimens  of  what  appears  to  be  a 
species  of  Lernseopoda  were  obtained  on  the  gills  of  an 
opah  or  king-fish,  Lampris  pelagicus  ( Gun  n.)  =  Lamp  m 
lima,  Gmel.),  forwarded  from  Shetland  to  the  Fishery 
Board's  Laboratory  at  Bay  of  Nigg,  10th  October 
1900 ;  no  females  were  observed.  .  .  .  The  body 
of  this  parasite  of  the  king-fish  is  comparatively 
slender ;  it  tapers  more  or  less  gradually  towards  the 


?   LERN.EOPODA   LAMPRI.  203 

posterior  end.  The  antennules  are  small  and  four- 
jointed,  the  penultimate  joint  being  shorter  than  the 
others.  The  antennas  are  moderately  robust  except 
the  last  two  joints,  which  are  small,  and  the  end  joint 
is  very  feebly  clawed.  The  mandibles  are  small,  but 
somewhat  similar  in  form  and  armature  to  those  of 
Charopinus  dalmanni.  The  maxilla?  are  also  somewhat 
similar  to  those  of  that  species,  except  that  the  ends 
are  furnished  with  two  instead  of  three  spiniform 
appendages.  The  first  and  second  maxillipeds  are 
very  robust  and  armed  with  short  but  powerful 
hooked  terminal  claws. 

"  The  form  of  the  various  appendages  shows  a  close 
relationship  with  the  Lerna3opodida3,  closer  perhaps 
with  Charopinus  than  with  Lernxopoda." 

The  male  specimens,  of  which  the  above  is  a  short  descrip- 
tion, have  been  doubtfully  referred  to  the  genus  Lernteopoda, 
but  as  they  are  considerably  larger  than  the  males  of  any 
species  of  that  genus  the  females  of  which  are  known  to  us, 
they  probably  do  not  represent  Lernxopoda  at  all,  but  if  so,  it 
is  a  genus  closely  related  to  it,  as  indicated  by  their  form  and 
anatomical  details.  One  of  the  males  figured  in  the  Fishery 
Board's  Eeport  mentioned  above  measured  4'3  mm.  If  the 
size  of  the  female  is  of  about  the  same  proportion  as  Ave  find 
it  to  be  in  some  of  the  other  species  of  the  Lernseopoda,  it 
should  reach  to  about  16  or  18  mm.  in  length. 


Genus  42.  BRACHIELLA  Cuvier,  1817. 

Nearly  related  to  Lernseopoda,  but  the  female  differ- 
ing in  having  the  cephalothorax  usually  more  elon- 
gated and  without  a  shield-like  dorsum,  the  distance 
from  the  base  of  the  second  maxillipeds  also  being 
usually  greater.  The  second  maxillipeds  separate 
except  at  the  tip  as  in  Leniaepoda,  but  usually  shorter, 
rarely  elongated.  Genital  segment  short  and  robust, 
rarely  elongate,  and  furnished  with  one,  sometimes 
with  two  pairs  of  posterior  appendages. 

Male  very  minute  ;  the  cephalothorax  and  abdomen 
of  nearly  equal  thickness  and  not  very  distinctly 


204  BRITISH    PARASITIC    COPEPODA. 

defined.      Both    pairs    of   maxillipeds  large  and  1111- 
cinate. 

The  male  shows  a  closer  relationship  with  the  male  of 
Clavella  than  with  that  of  Lernieopoda. 

1.  Brachiella  thynni  Cuvier. 
(Plate  LXIV,  figs.  4-6.) 

1817.  Brachiella  thynni  Cuv.     (37)  p.  287,  pi.  xv,  fig.  5. 

1829-1843.  Brachiella  thynni  Guerin-Meneville.     (55)  pi.  ix,  fig.  6  a-c. 

1832.  Brachiella  thynni  Nordmann.     (89)  p.  90. 

1840.  Brachiella  thynni  M.  Edwards.     (43)  p.  512. 

1851.  Brachiella  thynni  P.  J.  van  Beneden.     (11)  p.  128. 

1861.  Brachiella  thynni  Stp.  &  Liitk.     (127)  p.  420,  pi.  xv,  fig.  36. 

1877.  Brachiella  thynni  G.  Yogt.     (142)  p.  426. 

1896.  Brachiella  thynni  Bassett-Smitb.     (7)  p.  162. 

1906.  Brachiella  thynni  Norman  &  T.  Scott.     (88)  p.  219. 

Female. — Ceplialotliorax  slender,  flexuose,  fully  as 
long  as  the  genital  segment,  and  separated  from  it  by 
a  more  or  less  distinct  articulation  or  constriction. 
Genital  segment  narrow  at  its  union  with  the  cephalo- 
thorax  but  becoming  gradually  enlarged  towards  the 
posterior  end,  where  the  width  is  equal  to  about  half 
the  length ;  the  posterior  end  abruptly  truncated  and 
furnished  with  two  pairs  of  elongated  and  moderately 
slender  appendages,  one  pair  springing  in  front  of  and 
the  other  behind  the  base  of  the  egg-strings,  which 
thus  issue  from  between  them,  each  having  at  its 
base  an  appendage  both  in  front  and  behind ;  the 
appendages  on  the  ventral  aspect  scarcely  so  elongated 
as  the  others,  and  about  as  long  as  the  genital  seg- 
ment. That  segment  also  somewhat  flattened  and 
with  several  transverse  constrictions  more  or  less  indis- 
tinct, imparting  to  it  an  obscure  lobate  appearance. 

Antennules  small,  three- jointed.  Antennae  stout, 
moderately  large,  and  furnished  with  a  few  apical 
spines.  Mandibles  narrow,  elongated,  inner  margin 
near  the  distal  end  coarsely  toothed,  the  teeth  being 
to  some  extent  alternately  larger  and  smaller.  Maxillas 
small,  furnished  Avith  two  or  three  moderately  stout 
apical  setae  and  one  or  two  minute  submarginal 


BRACHIELLA    THYNNI.  205 

spines.  First  maxillipeds  short,  stout,  and  strongly 
uncinate.  The  second  maxillipeds,  which  are  equal 
to  about  two-thirds  of  the  length  of  the  genital  seg- 
ment, slender  and  free  except  at  the  tip,  where  they 
are  joined  to  a  reddish-brown  coloured  chitinous  plug. 
Length  from  the  forehead  to  the  end  of  the  posterior 
appendages  of  a  full-grown  specimen  about  32  mm. ; 
length  of  cephalothorax  about  14  mm.,  of  the  genital 
segment  about  9  mm.,  and  of  the  posterior  appendages 
9  mm. 

Male. — Very  small,  being  about  a  millimetre  in 
length ;  having  a  closer  resemblance  to  the  male  of 
Lernaeopoda  than  to  that  of  a  true  Brachiella. 

Habitat. — Parasitic  on  the  gills  of  the  tunny  (Om/- 
nus  thynnus),  and  other  nearly  related  fishes.  Four 
specimens  were  obtained  by  Dr.  Bassett-Smith  on  a 
tunny  captured  at  Plymouth. 

The  female  of  this  species  is  somewhat  similar  to  B.  rostrata 
in  general  appearance,  but  the  cephalothorax  is  distinctly 
longer,  and  the  posterior  appendages  are  four  in  number  and 
much  more  elongated. 

2.  Brachiella  rostrata  Kroyer. 

(Plate  XLV,  fig.  8 ;  Plate  LXII,  fig.  3 ;  Plate  LXIII, 

figs.  2-8.) 

1837.  Brachiella  rostrala  Kroyer.     (70)  Rekka  1,  p.  207,  pi.  ii,  fig.  1. 

1840.  Brachiella  rostrata  M.  Edwards.     (43)  vol.  iii,  p.  415. 

1863.  Brachiella  rostrata  Kroyer.     (71)  p.  290,  pi.  xviii,  figs.  8,  a-i. 

1877.  Brachiella  rostrata  C.  Vogt.     (142)  p.  426. 

1900.  Brachiella  rostrata  T.  Scott.     (112)  p.  174,  pi.  viii,  figs.  38,  39. 

Female. — Cephalothorax  elongated,  flexuose  or 
vermiform,  and  separated  from  the  genital  segment 
by  a  more  or  less  clearly-defined  constriction.  Genital 
segment  narrow,  subcylindrical,  fully  three  times 
longer  than  broad  and  equal  to  about  one  and  one- 
third  times  the  length  of  the  cephalothorax  ;  posterior 
end  subtruncated  and  furnished  with  two  subapical 
appendages.  Abdomen  obsolete  or  nearly  so.  The 
egg-strings,  which  are  tolerably  elongated,  arising 
immediately  outside  of  the  subapical  appendages. 


206  BRITISH    PARASITIC    COPEPODA. 

Antennules  small,  apparently  four-jointed,  but  the 
articulation  between  the  first  two  joints  indistinct. 
Antennae  and  mouth-organs  somewhat  similar  to  those 
of  Brar.hieUa  thynn't.  The  second  maxillipeds  spring- 
ing from  the  lower  half  of  the  cephalothorax  and 
reaching  to  about  the  proximal  end  of  it ;  free  except 
at  the  tip,  where  they  are  jointed  to  a  horn-coloured 
chitinous  plug.  Length  from  the  extremity  of  the 
cephalothorax  to  the  end  of  the  genital  segment 
about  15  mm.,  and  17  mm.  to  the  tip  of  the  posterior 
appendages. 

Male. — The  male  is  nearly  twice  as  long  as  broad 
and  measures  about  2  mm.  in  length;  it  is  compara- 
tively robust,  the  cephalothoracic  appendages  are 
somewhat  crowded  together  at  the  proximal  end,  and 
there  is  no  distinct  division  between  the  cephalothorax 
and  abdomen.  The  antennas  (both  pairs),  mandibles, 
and  maxillaa  are  nearly  as  in  the  female  ;  but  both 
pairs  of  maxillipeds,  though  short,  are  furnished  with 
strong  terminal  claws.  Abdominal  appendages  very 
small. 

Habitat. — Parasitic  on  the  gills  of  halibut  (Hippo- 
glossus  vulgaris).  On  large  halibut  captured  in  the 
North  Sea.  and  landed  at  the  Fish-Market,  Aberdeen. 

Kroyer  records  two  forms,  apparently  distinct,  under  B. 
rostrata,  one  from  the  Hippoglossus  here  mentioned  and  the 
other — a  shorter  form — from  Hippoglossus  pinguis.  This 
form  we  have  not  seen. 

3.  Brachiella  insidiosa  Heller. 

(Plate  XLVIII,   fig.   18;    Plate  LXII,   fig.   2;  Plate 
LXIII,  figs.  9-16.) 

1865.  Brachiella  insidiosa  Heller.     (58)  p.  239,  pL  xxiv,  fig.  1. 
1896.  Brachiella  insidiosa  Bassett-Smith.     (6)  voL  xviii,  p.  14,  pi.  vi, 
fig.  2. 

1900.  Brachiella  insidiosa  T.  Scott.     (112)  p.  175,  pL  viii,  figs.  40,  41. 
1906.  Brachiella  insidiosa  Brian.     (21)  p.  104,  pi.  viii.  figs.  1  and  4. 

Female. — Body  tolerably  robust.  Cephalothorax 
short,  flexuose,  and  vermiform.  Genital  segment 


BRACHIELLA    INSIDIOSA.  207 

subcylindrical,  flattened,  about  two  and  a  half  times 
longer  than  broad ;  the  width  increasing  slightly 
towards  the  posterior  end,  which  is  truncated  and 
provided  with  two  pairs  of  appendages.  The  two 
lateral  appendages  moderately  elongated  and  slender, 
but  the  intermediate  pair  short,  and  springing  from 
each  side  of  the  very  small  abdomen. 

Antennules  short  and  stout,  and  each  composed  of 
about  three  joints ;  antennas  robust,  and  somewhat 
similar  to  those  of  Lernseopoda  galei.  Mandibles 
narrow  at  the  base  but  wider  towards  the  posterior 
end,  and  armed  with  irregular  coarse  teeth  on  the 
obliquely-truncated  distal  extremity.  Maxillas  small, 
simple,  and  provided  with  a  few  apical  spines.  First 
maxillipeds  robust,  and  strongly  uncinate ;  second 
maxillipeds  short,  and  having  the  appearance  of  being 
a  prolongation  of  the  cephalothorax.  Length  from 
the  extremity  of  the  cephalothorax  to  the  end  of  the 
longer  posterior  appendages  about  14  mm.  Egg- 
strings  long  and  slender. 

Male. — Very  small,  stout,  about  twice  longer  than 
broad  and  similar  in  structure  to  the  male  of  Brachiella 
rostrata, ;  the  antennae  and  both  pairs  of  maxillipeds 
strongly  uncinate. 

Habitat. — Parasitic  on  the  gill-rays  of  the  hake 
(Merluccius  vulgar  is],  moderately  common.  Plymouth 
(Bassett-Smitli).  Firths  of  Forth  and  Clyde,  and  at 
Aberdeen  Fish-Market  (T.  Scott).  Irish  Sea  (A.  Scott). 

4.  Brachiella  merluccii  Bassett-Smith. 
(Plate  LXII,  figs.  4,  5;  Plate  LXIII,  figs.  17-20.) 

1896.  Brachiella  merluccii  Bassett-Smitli.     (7)  vol.  iv,  p.  163. 
1896.  Brachiella  merluccii  idem.     (6)  (6)  vol.  xviii,  p.  14,  pi.  vi.  fig.  1. 
1900.  Brachiella  merluccii  T.  Scott.     (112)  p.  175,  pi.  viii,  fig.  42. 
1906.  Brachiella  merlucii  Brian.     (21)  p.  107,  pL  viii,  fig.  3. 

Female. — This  species  of  Brachiella  differs  from 
most  of  the  others  by  its  bizarre  appearance.  Cephalo- 
thorax not  very  clearly  defined  from  the  genital 
portion  of  the  body ;  bending  round  and  forward  at 


208  BK1TISH    PAKASITIC    COPEPODA. 

nearly  a  right  angle  to  the  dorsum,  so  that  the  animal 
appears  to  be  very  short  and  dilated  when  viewed 
from  above.  Grenital  segment  considerably  enlarged 
and  furnished  with  two  pairs  of  appendages ;  one 
pair  moderately  short  prolongations  of  the  postero- 
lateral  corners  of  the  segment,  the  other  pair  tolerably 
elongated,  springing  from  the  ventral  surface  in  front 
of  the  egg-strings,  extending  backward,  curving  round, 
and  partly  inclosing  them. 

Antennules  stout  and  composed  of  three  joints ; 
the  mandibles  and  maxilla?,  as  well  as  the  second  pair 
of  antennae,  somewhat  similar  to  those  of  Brachiella 
insidiosa ;  the  first  maxillipeds,  however,  scarcely  so 
robust,  but  furnished  with  more  powerful  terminal 
claws.  The  second  maxillipeds  very  short  and 
enclosed  together  within  a  gelatinous  envelope : 
though  thus  enclosed,  not  coalescent,  but  may  be  seen 
through  the  semi-transparent  envelope  extending 
alongside  each  other  to  where  at  the  apex  they  are 
united  to  a  hard  chitinous  plug.  Length  about  8  mm. 

Male. — We  have  not  observed  the  male  of  this 
species,  but  Dr.  Bassett-Smith  describes  it  and  states 
that  the  cephalothorax  is  large,  and  distinct  from 
the  posterior  portion  of  the  body,  this  portion  being 
divided  into  five  indistinct  segments,  and  furnished  at 
the  posterior  end  with  a  pair  of  short  two-jointed 
processes  with  pointed  ends.  The  two  pairs  of  an- 
tenna?, and  the  various  other  thoracic  appendages,, 
apparently  similar  to  those  of  the  male  of  Brachiella 
insidiosa. 

Habitat. — Parasitic  on  the  gill-rakers  of  the  hake 
(Merluccius  vulgar  is),  and  not,  like  Brachiella  insidiosa, 
attached  to  the  gill-rays.  Plymouth  (Bassett- Smith). 
Firth  of  Forth  and  Aberdeen  Fish-Market  (T.  Scott). 

Brachiella  merhtccii  does  not  appear  to  be  so  common  as  the 
species  just  alluded  to;  and  the  general  structure  of  the 
female,  and  especially  the  partial  union  of  the  second  maxilli^ 
ped*,  show,  as  pointed  out  by  Dr.  Bassett-Smith,  a  tolerably 
close  relationship  with  Clavella  (Anchorella). 


BRACHIEf-LA    TEIGL^.  209 

5.  Brachiella  triglae  Glaus. 
(Plate  LXII,  fig.  1 ;  Plate  LXIII,  figs.  21-25.) 

I860.  Brachiella  triglae  Glaus.  (30a)  Wurzburger  naturwiss.  Zeitschi-., 
voL  i,  p.  32,  pi.  i,  fig.  6. 

1877.  Anchorella  triglse  Kurz.  (71a)  Zeitschr.  f.  wiss.  Zool.,  vol.  xxix, 
p.  404,  pi.  xxv,  figs.  13-15. 

1896.  Brachiella  triglx  Bassett-Smith.     (7)  p.  163. 

1901.  Brachiella  triglie  T.  Scott.     (113)  p.  133,  pi.  vii,  figs.  24-29. 

Female. — Small  but  moderately  stout;  cephalo- 
thorax  moderately  short  and  flexuose ;  somewhat 
vermiform,  and  about  as  long  as  the  genital  segment. 
Genital  segment  considerably  expanded,  the  width 
being  rather  greater  than  the  length  ;  lateral  margins 
more  or  less  irregularly  lobate,  and  the  postero-lateral 
produced  into  bluntly-rounded  lobes;  also  provided 
with  two  short  posterior  appendages,  situated  one  on 
each  side  of  the  nearly  obsolete  abdomen. 

Antennules  short,  tapering,  and  composed  of  four 
joints,  end  joint  rather  longer  than  the  preceding  one. 
Antennae  moderately  short  and  stout,  the  end  joint 
with  a  small  terminal  spike ;  outer  ramus  very  short, 
biarticulated,  and  bearing  two  or  three  minute  apical 
spines.  Mandibles  slender  and  obliquely  truncated, 
the  truncated  margin  being  rather  coarsely  serrated ; 
maxilla?  moderately  stout,  bearing  three  elongated 
apical  spines,  and  two  others  at  the  end  of  a  small 
lateral  process.  First  maxillipeds  short,  robust,  and 
provided  with  small  terminal  claws.  Second  maxilli- 
peds very  short  and  stout,  free  except  at  the  tips, 
where  they  are  joined  to  a  chitinous  horn-coloured 
disk.  Length  about  4'5  mm.,  varying  slightly  in 
different  specimens. 

Male. — We  have  not  observed  the  male  of  this 
species,  but  Dr.  Bassett-Smith  has  figured  one  which 
apparently  does  not  differ  much  from  the  males  of 
other  species  of  Braehietta. 

Habitat. — Parasitic  on  the  gills  and  gill-arches  of 
Trivia  spp.  On  Triglagurnardus9cuctdu8ttt&hirv/ndo 
at  Plymouth  (Bassett-Smith).  OnTru/i"  //,/'•"/</,  Firths 
of  Forth  and  Clyde  (7T.  Scott).  It  has  also  been 

VOL.  T.  14 


210  BRITISH    PARASITIC    COPEPODA. 

obtained  on  the   gill-arches   of   Triyla  Hueata  in  the 
Adriatic. 

6.  Brachiella  ovalis  (Kroyer). 
(Plate  LX,  fig.  7 ;  Plate  LXIII,  figs.  26-30.) 

1837.  Anchorella  ovalis  Kroyer.     (70)  p.  289,  pi.  iii,  fig.  6. 
1870.  Anchorella  ovalis  P.  J.  van  Beneden.     (16)  p.  31,  pi.  ii,  fig.  8. 
1901.  Brachiella  ovalis  T.  Scott,     (113)  p.  133,  pi.  vii,  figs.  30-35. 
1904.  Brachiella  ovalis  A.  Scott.     (109)  No.  12,  p.  44. 

Female. — Cephalothorax  stout,  moderately  short, 
but  rather  longer  than  the  genital  segment.  Genital 
segment  subpyriform,  considerably  expanded  pos- 
teriorly and  narrowed  at  the  proximal  end  to  nearly 
the  width  of  the  cephalothorax ;  the  posterior  margin 
sloping  backward  slightly,  and  equally  from  both 
sides,  and  forming  an  obtuse  angle  at  the  base  of  the 
abdomen  ;  a  short  submedian  appendage  occurring  on 
each  side  of  the  abdomen  midway  between  it  and 
origin  of  the  subglobular  egg-strings,  these  append- 
ages usually  being  more  or  less  concealed  by  the  egg- 
strings.  Abdomen  very  small. 

Antennules  apparently  composed  of  four  joints,  the 
first  dilated  and  the  others  small,  the  third  being 
much  shorter  than  either  the  second  or  fourth. 
Antennae  tolerably  large ;  end  joint  narrowly  rounded 
at  the  apex  and  covered  with  minute  bristles,  the 
outer  ramus  consisting  of  two  small  subequal  joints 
bearing  three  very  small  apical  spines.  Mandibles 
moderately  stout  and  slightly  expanded  towards 
the  distal  end,  the  inner  margin  at  this  end  being 
armed  with  a  series  of  somewhat  coarse  teeth, 
alternately  larger  and  smaller.  Maxilla  and  first 
maxillipeds  somewhat  similar  to  those  of  Brachiella 
triglse.  Second  maxillipeds  very  short,  stout,  and  re- 
curved, free  except  at  the  distal  end,  where  they  are 
united  to  a  chitinous  plug  fixed  in  the  gill-arches  of 
the  host.  Length  about  3 '5  mm. 

AVe  have  been  unable  to  obtain  the  male  of  this  species. 

1 1, thiii.it. — Parasitic    on    the    gill-arches    of    Tri<jl<i- 


BRACHIELLA   OVALIS.  211 

gurnardus.  Moray  Firth,  in  April  and  May  1900  (T. 
Scott}.  Irish  Sea  (A.  Scott).  Apparently  more  fre- 
quent on  young  fishes  than  on  adults.  Both  Kroyer 
and  P.  J.  van  Beneden  record  this  Brachiella  from 
Trigla  gurnardus. 

7.  Brachiella  bispinosa  Nordmann. 
(Plate  L,  fig.  9  ;  Plate  LXIV,  fig.  9.) 

1832.  Brachiella  bispinosa  Nordmann.     (89)  p.  94,  pi.  viii,  figs.  4-7. 

1840.  Hrachiella  bispinosa  M.  Edwards.     (43)  p.  513. 

1877.  Brachiella  bispinosa  C.  Vogt.     (142)  p.  456. 

1901.  Brachiella  bispinosa  T.  Scott.     (113)  p.  132. 

1906.  Brachiella  bispinosa  Norman  &  T.  Scott.     (88)  p.  220. 

Female. — Cephalothorax  narrow,  rather  shorter  than 
the.  genital  segment  and  usually  more  or  less  doubled 
back  upon  it.  Genital  segment  seen  from  above 
oblong  or  somewhat  lyre-shaped,  nearly  twice  longer 
than  broad ;  posterior  end  broadly  rounded,  not 
angular,  and  provided  with  two  small  submedian 
spiniform  appendages. 

Antennules  short,  slender,  and  composed  of  three 
or  four  joints.  First  maxillipeds  strongly  uncinate. 
Second  maxillipeds  scarcely  reaching  to  the  end  of 
the  cephalothorax,  free  but  united  at  the  apex  to  a 
round  chitinous  knob.  Length  about  8  mm. 

We  have  not  seen  the  male  of  this  species,  but 
Dr.  Bassett-Smith  states  that  it  resembles  the  male  of 
Thijsanote  impudica  (Nordmann).* 

Habitat. — Parasitic  on  the  gill-arches  of  Trigla 
spp.  Plymouth,  on  Trigla  cuculus,  Trigla  gurnardus, 
and  Trigla  lyra  (Bassett- Smith).  Moray  Firth,  on 
Trigla  sp.  (T.  Edward:  'Museum  Normanianum  '). 

8.  Brachiella  pastinaca  P.  J.  van  Beneden. 
(Plate  LXIV,  fig.  8.) 

1851.  Brachiella  pastinaca  P.  J.  van  Beneden.  (11)  p.  118,  pi.  4,  figs.  8. 9. 

1877.  Brachiella  pastinaca  Knrz.  (71a)  Zeitsclir.  f.  wiss.  Zool.,  vol. 
xxix.  pis.  25,  26,  27,  figs.  2,  3,  36,  45. 

1880.  Brachiella  pastinaca  A.  Valle.  (141a)  Boll.  Soc.  Adriat.  Sc. 
Nat.,  vol.  iv,  fasc.  i,  p.  77. 

1904.  Brachiella  pastinaca  T.  Scott.     (115)  p.  278. 

*  '  Journ.  Mar.  Biol.  Assoc.'  (N.S.),  vol.  iv,  No.  2  (February  1896),  p.  163. 


212  K1UT1SH    PARASITIC    COPEPODA. 

1906.  Brachiella  pastinacae  Brian.     (21)  p.  103. 

1909.  Brachiella  pastinaca  May  E.  Bainbridge.     (3)  p.  50.  pi.  8,  figs. 
6,  7  ;  pi.  9,  fig.  8. 

Female.  —  Ceplialothorax  tolerably  enlarged  and 
somewhat  gibbous  behind  on  the  dorsal  aspect,  con- 
nected with  the  genital  segment  by  a  narrow  neck. 
Genital  segment  oblong,  robust,  and  at  the  distal  end 
bearing  two  slender  submedian  appendages  nearly  half 
as  long  as  the  segment.  Abdomen  obsolete  or  nearly  so. 

Antennules  moderately  slender  and  four-jointed ; 
antennas  stout,  composed  of  two  joints,  and  fur- 
nished with  a  small  rudimentary  outer  ram  us. 
Mandibles  tolerably  slender  and  armed  with  several 
coarse  teeth  at  the  distal  end  of  the  inner  margin. 
The  first  maxillipeds  tolerably  large  and  strongly 
uncinate.  The  second  maxillipeds  nearly  as  long 
as  the  cephalothorax,  free  except  at  the  tips  where 
they  are  united  to  a  horn-coloured  chitinous  plug. 
Length  about  7'5  mm. 

Habitat. — Parasitic  in  the  nasal  fossae  of  Trig  on 
pastinaca  and  also  of  the  piked  dog-fish  (Acantkias 
vulgaris).  In  the  nasal  fossaa  of  a  Trigou  captured  in 
the  Dornoch  Firth  in  October,  1903  (T.  Scott).  In 
the  spiracle  of  a  spiked  dog-fish  captured  off  the 
coast  of  Northumberland  (Ma;/  E.  Bainbridge).* 

9.  Brachiella  parkeri  G.  M.  Thomson. 
(Plate  LXIV,  fig.  7.) 

1889.  Brachiella  parkeri  Thomson.     (132)  p.  374,  pi.  10,  figs.  18-23. 
1909.  Brachiella  parkeri  May  E.  Bainbridge.      (3)  p.  52,  pi.  9.  figs, 
16, 17  ;  pi.  10,  figs.  18-23. 

Female. — Cephalothorax  moderately  stout,  deflected 
so  as  usually  to  be  nearly  at  right  angles  to  the  genital 
segment,  and  equal  to  about  two-thirds  the  length  of  it. 
Genital  segment  of  an  ovate  form,  moderately  dilated, 
and  provided  with  two  elongated  and  rather  slender 
distal  appendages,  one  on  each  side  of  the  papilliform 
abdomen.  Antennules  moderately  elongated,  slender, 
and  composed  of  two  articulations;  antennas  some- 

*  Miss  May  Evelina  Bainbridge,  now  the  Hon.  Mrs.  Henn  Collins. 


BRACHIELLA    PARKEKI.  213 

what  similar  in  structure  to  those  of  Braclriella  pas- 
tinaca.  Rostrum  somewhat  prominent;  mandibles 
slender,  their  inner  margins  armed  at  the  distal  end 
with  about  four  tolerably  large  teeth  and  with  smaller 
teeth  between.  Maxillae  of  the  usual  type,  resembling 
those  of  Brachiella  triglse.  First  maxillipeds  stout 
but  somewhat  rudimentary  and  only  feebly  uncinate  ; 
second  maxillipeds  long  and  slender,  fully  twice  the 
length  of  the  cephalothorax,  and  entirely  free  except 
at  the  tip,  where  they  are  united  to  a  chitinous  horn- 
coloured  disk. 

Habitat. — Obtained  on  the  gills  of  a  long-nosed 
skate  (Raia  oxyrliynclms)  captured  off  the  Northumber- 
land coast  in  May  1908  (May  E.  Bainbridge). 

We  have  not  met  with  this  species,  but  Miss  Bainbridge,  in  her 
paper  referred  to  above,  gives  a  careful  description  of  it.  Her 
desci-iption  and  drawings  agree  very  well  with  those  of  G.  M. 
Thomson.  The  following  measurements  of  the  specimen 
examined  are  given  by  Miss  Bainbridge  : — 

Length  from  top  of  arms  to  end  of  abdomen       9*2  mm. 
„       from  end  of  head  to  extremity  of 

attachment  ....  19'0 
„  of  arms  .....  14*5 
„  of  body  from  bend  of  neck  to  end 

of  abdomen      ....       8'0 

„       of  head  to  bend  of  ^ieck       .          .       5*3 

„       of  process    .....       4'0 

Width  of  neck          .....       To 

„      of  genital  segment        .         .         .       5'2 

Genus  43.  CLAVELLA  OJcen,  1815. 

Syn.  Schisturus  Oken  (1815).  a  name  preoccupied  by  Rudolph!  (1809) 
for  a  genus  of  Vermes.  Anchorella  Cuv.  (1817).  Lerneomyzon  Blainville 
(1822). 

Female. — Body  usually  short  and  somewhat  swollen. 
Head  small,  situated  at  the  end  of  a  long  flexuous 
neck  which  is  usually  more  or  less  deflexed.  Both 
pairs  of  antennae  small  and  somewhat  rudimentary; 
the  mandibles,  maxilla?,  and  first  maxillipeds  resem- 
bling those  in  Lernseopoda,  and,  together  with  the  two 


214  BRITISH    PARASITIC    COPEPODA. 

pairs  of  antennae,  placed  at  the  end  of  the  elongated 
neck,  or  cephalothorax.  The  second  maxillipeds,  by 
which  the  parasite  fixes  itself  to  its  host,  situated  at 
the  base  of  the  cephalothorax,  and  coalescent  so  that 
they  appear  to  consist  of  a  single  organ ;  this  organ  is 
usually  short,  sometimes  very  small  and  papilliform, 
and  united  at  the  tip  to  a  horn-coloured  chitinous  plug 
which  penetrates  the  tissues  of  the  fish.  Genital  seg- 
ment usually  unprovided  with  terminal  or  lateral  pro- 
cesses, but  if  present  they  are  generally  very  small. 
Abdomen  obsolete  or  nearly  so.  Egg-strings  moderately 
elongated. 

Male. — The  male  is  very  small  and  proportionally 
shorter  than  the  male  of  Bracliiella,  which  it  more 
nearly  resembles  than  that  of  the  genus  Lernasopoda ; 
the  clorsum,  however,  is  more  boldly  arched,  and  the 
height  is  usually  greater  than  the  length.  The  append- 
ages of  the  cephalon  and  thorax  are  somewhat  similar 
to  those  of  the  male  of  Brachiella. 

The  genus  comprises  a  large  number  of  species,  and  those 
described  below  have  been  obtained  on  British  fishes. 

1.  Clavella  uncinata  (0.  F.  Miiller). 
(Plate  LXV,  figs.  2,  3,  6 ;  Plate  LXVI,  figs.  21-23.) 

1777.  Lenisea  uncinata  O.  F.  Miiller.     (85)  p.  120,  pi.  xxxiii,  fig.  2. 

1815.  Schisturus  uncinatus  Oken.     (91)  part  iii,  p.  183. 

1815.  Clavella  uncinata  idem.     (91)  part  iii,  p.  (?)  357. 

1817.  Anchorella  uncinata  Cuv.     (37)  Icon,  du  Resrne  Anim.,  pi.   9. 

r>  f 

fig.  5. 

1822.  Lerneomyzon  uncinatum  Blainville.  (24)  Joum.  de  Physique, 
vol.  95,  p.  438. 

1832.  Anchorella  uncinata  Nordmann.  (89)  p.  102,  pi.  8,  figs.  8-12 ; 
pi.  10,  figs.  1-5. 

1850.  Anchorella  uncinata  Baird.     (4)  p.  337,  pi.  xxxv,  fig.  9. 

1900.  Anchorella  uncinata  T.  Scott.     (112)  p.  177,  pi.  viii,  figs.  43,  44. 

1906.   Clavella  uncinata  Brian.     (21)  p.  110. 

1909.  Anchorella  uncinata  May  E.  Bainbridge.  (3)  p.  57,  pi.  ii,  figs. 
43-46. 

Female.  —  Cephalothorax  moderately  slender  and 
about  as  long  as  the  genital  segment.  Genital  segment 
ovate,  slightly  flattened,  and  moderately  elongated, 


CLAVELLA    UNCIXATA.  215 

being  fully  twice  as  long  as  broad.  Abdomen  small 
but  quite  distinct. 

Antennules  three-jointed,  the  proximal  joint  large 
but  tapering  towards  the  distal  end;  other  joints  small 
and  subequal  but  the  end  one  rather  the  larger.  Man- 
dibles small,  biting  part  serrated  on  the  inner  edge. 
Maxillae  small,  expanded  towards  the  distal  end,  with 
the  outer  margin  somewhat  gibbous ;  each  bearing  a 
couple  of  terminal  spines  and  also  a  small  subterminal 
lobe  with  two  spinules  at  its  apex.  The  first  maxilli- 
peds  rather  diminutive  in  size  but  provided  with 
moderately  stout  terminal  claws.  The  second  maxilli- 
peds  completely  coalescent,  very  short,  expanded  at 
the  apex,  and  fixed  to  a  nipple-like  plug  which  pene- 
trates the  tissues  of  the  fish.  Egg-strings  tolerably 
slender  and  fully  twice  as  long  as  the  genital  segment. 
Length  of  the  specimen  represented  by  figure  2, 
PI.  LXV,  exclusive  of  the  cephalothorax,  about 
6'5  mm.,  but  the  size  is  somewhat  variable. 

Male. — The  male  is  very  small,  and,  viewed  laterally, 
the  height  is  equal  to  about  one  and  a  half  times  the 
length ;  the  dorsum  tapers  upwards  and  assumes  a 
somewhat  conical  outline,  but  with  the  apex  boldly 
rounded.  Both  pairs  of  maxillipeds  short  but  tolerably 
stout  and  strongly  uncinate ;  other  cephalothoracic 
appendages  small  and  somewhat  rudimentary.  Length 
about  1  mm. 

Habitat. — Found  parasitic  on  the  whiting  (Gadua 
merlangus)  and  other  Gadoids.  This  tolerably  common 
species  has  been  recorded  from  various  places  round 
the  British  coasts.  Larne  and  Dublin  (W.  Thompson). 
Polperro  and  Falmouth  (A.  M.  Norman).  Plymouth 
(Bassett- Smith).  Irish  Sea  (A.  Scott),  and  also  from 
various  Scottish  localities. 

A  young  Clavella  uncincita  with  two  males  adhering  to  it 
is  represented  by  fig.  6  on  PI.  LXV.  In  this  specimen 
the  genital  segment  is  much  less  robust,  and  the  mouth- 
appendages  are  more  rudimentary. 


216  BRITISH    PARASITIC    COPEPODA. 

2.  Clavella  rugosa  (Kroyer). 
(Plate  LXV,  figs.  4,  5 ;  Plate  LXVI,  figs.  1-7.) 

1837.  Anchorella  ruffosa  Kroyer.     (70)  pi.  1,  vol.  i,  p.  294,  pi.  iii,  fig.  6. 

1850.  Anchorella  rugosa  Baircl.     (4)  p.  338,  pi.  xxxv,  fig.  8. 

1851.  Anchorella  rugosa  P.  J.  van  Beneden.     (11)  p.  114,  pi.  vi,  fig.  7. 
1900.  Anchorella  rugosa  T.  Scott.     (112)  p.  176,  pi.  viii,  figs.  45-48. 

Femah. — Cephalothorax  tolerably  elongated  and 
vermiform,  about  one  and  a  half  times  longer  than  the 
genital  segment ;  usually  more  or  less  recurved  and 
reaching  considerably  beyond  the  distal  end  of  the 
segment.  Genital  segment  stout,  rugose,  quadriform, 
and  somewhat  flattened,  length  and  width  about  equal. 
Abdomen  obsolete  or  nearly  so. 

Antennules  composed  of  three  joints,  the  first 
moderately  large  and  stout,  the  other  two  smaller 
but  the  end  joint  rather  longer  than  the  preceding  one ; 
antennae  stout  and  somewhat  similar  in  structure  to 
those  of  Brachiella.  Mandibles  small,  slender,  and 
coarsely  dentate  near  the  distal  end  of  the  inner 
margin.  Maxilla3  furnished  with  three  moderately 
stout  terminal  spines,  and  two  smaller  ones  on  a  some- 
what rudimentary  subterminal  lobe.  First  maxillipeds 
short,  stout,  and  strongly  uncinate.  Second  maxilli- 
peds rudimentary,  being  reduced  to  a  small  button-like 
projection  at  the  anterior  end  of  the  genital  segment, 
which  is  fixed  to  a  horn-coloured  chitinous  plug  that 
penetrates  the  tissues  of  the  fish.  Egg-strings  toler- 
ably stout  and  elongated,  more  than  twice  the  length 
of  the  genital  segment,  and  containing  numerous  ova. 
Length  exclusive  of  the  cephalothorax  about  4  mm., 
but  the  size  is  slightly  variable. 

Male. — The  male  is  very  small  and  short,  the  height 
being  equal  to  fully  one  and  a  half  times  the  length; 
the  general  outline,  seen  from  the  side,  is  subconical. 
Both  pairs  of  maxillipeds,  though  short,  are  furnished 
with  stout  terminal  claws. 

Halitat. — Parasitic  on  the  gills  and  gill-covers  of 
cat-fishes  (Anarrliirl/nx  la-juts').  On  cat-fishes  captured 


CLAVELLA    EUGOSA.  217 

in  the  Firths  of  Forth  and  Clyde,  off  Aberdeen,  and  in 
the  Mora}'  Firth  (T.  Scott).  Off  the  coast  of  Northum- 
berland and  Durham  (May  E.  Bainbridge).  Larne, 
Ireland  (TF.  Thompson). 

3.  Clavella  dubia  T.  £  A.  Scott. 
(Plate  LXV,  fig.  7;  Plate  LXVI,  figs.  8-11.) 

1900.  Anchorella  rugosa  var.  T.  Scott.     (112)  p.  177,  pi.  viii,  fig.  52. 

Female. — Generally  resembling  the  female  of  C.un- 
cinatvs,  but  having  the  cephalothorax  rather  shorter, 
and  the  second  maxillipeds  or  fixative  organ  scarcely 
so  prominent ;  the  genital  segment  also  being  more 
robust. 

Antennules  short  and  three-jointed,  the  first  joint 
robust,  but  tapering  quickly  towards  the  distal  end ; 
the  second  small,  and  the  end  one  about  twice  as  long 
as  the  preceding  joint,  and  very  sparingly  setiferous 
at  the  apex.  Mandibles  tolerably  stout,  somewhat 
expanded  near  the  middle,  and  the  biting  part  of  the 
inner  margin  provided  with  about  four  coarse  teeth 
and  two  or  three  smaller  ones  ;  the  first  two  teeth 
nearly  close  together,  a  slight  gap  in  which  is  a  small 
denticle  dividing  these  two  from  the  next  one,  but  a 
considerable  distance  separating  it  from  the  end  tooth, 
and  the  intervening  space  occupied  by  two  denticles. 
Maxilla3  moderately  elongated,  and  provided  with  two 
narrow  terminal  lobes  ending  in  tolerably  long  spines. 
First  maxillipeds  short,  moderately  robust,  and  pos- 
sessing fairly  stout  terminal  claws. 

Habitat. — Found  adhering  to  a  haddock  (Gadux 
seglefinus)  from  the  North  Sea. 

This  form  was  at  first  regarded  as  a  vai-iety  of  Clavella 
rugosa,  but  further  examination  reveals  differences  both  in  its 
form  and  structure  which,  though  showing-  some  relationship 
with  its  two  nearest  allies,  C.  rugosa  and  C.  nncinata,  cannot 
be  reconciled  with  either.  We  therefore  prefer  to  describe  it 
under  a  distinct  name. 


218  BRITISH    PARASITIC    COPEPODA. 

4.  Clavella  emarginata  Kroyer. 
(Plate  LXIX,  fig.  7 ;  Plate  LXVI,  fig.  17-20.) 

1837.  Anchorella  emarginata  Kroyer.  (70)  pL  i,  voL  i,  p.  287,  pi.  iii,  fig.  vi. 
1851.  Anchorella  emarginata  P.  J.  van  Beneden.  (11)  p.  113,  pi.  vi,  fig.  4. 
1877.  Anchorella  emarginata  Kurz.     (71a)  Zeitschr.  f.  wiss.  Zool.,  voL 
xxix,  p.  398.  pi.  xxv,  fig.  8. 

1900.  Anchorella  emarginata  T.  Scott.     (112)  p.  176,  pi.  viii,  figs.  49-51. 
1906.  Clavella  emarginata  Brian.     (21)  p.  109,  pi.  x,  fig.  3. 

Female.  —  Cephalothorax  very  long  and  slender, 
twice  as  long  as  the  genital  segment ;  head  small  and 
separated  from  the  long  neck  by  a  slight  constriction. 
Genital  segment  subquadriform,  considerably  dilated, 
and  somewhat  truncated  at  the  posterior  end.  Ab- 
domen obsolete  or  nearly  so.  Egg-strings  short  and 
tolerably  thick. 

Antennules  short,  composed  of  three  articulations. 
Mandibles  small  and  armed  with  only  moderately 
large  teeth ;  maxillae  narrow,  provided  with  three 
apical  spines  and  with  two  small  ones  on  a  rudimen- 
tary branch  near  the  middle  of  the  joint.  First  maxil- 
lipeds  moderately  small  and  uncinate.  Second  maxil- 
lipeds  moderately  thick,  very  short,  and  not  completely 
united  except  at  the  tip,  where  they  are  joined  together 
to  a  chitinous  plug.  Length. — The  specimen  repre- 
sented by  the  drawing  measures,  exclusive  of  the 
cephalothorax,  about  2*5  mm.,  while  the  cephalo- 
thorax  alone  measures  3 '5  mm. 

We  have  not  seen  the  male  of  this  species. 

Habitat. — Parasitic  on  the  gill-arches  of  the  allis 
shad  (Clupea  alosa)  and  of  the  twaite  shad  (Clupea 
finta}.  Plymouth  on  Clupea  (Bassett- Smith).  Dun  bar, 
Firth  of  Forth,  on  Clupea  finta  (T.  Scott). 

This  species  is  readily  distinguished  by  the  long,  slender 
cephalothorax,  the  dilated  genital  segment,  and  by  the 
imperfectly  united  second  maxillipeds. 

5.  Clavella  scombri  Kurz. 
(Plate  LXVII,  figs.  1-3 ;  Plate  LXVIII,  figs.  1-7.) 

1877.  Anchorella  scombri  Knrz.  (71a)  Op.  cit.,  p.  403,  pi.  xxv,  figs.  12, 
35. 41. 


CLAVELLA    SCOMBRI.  219 

1 '.">!.  Auchorella  scombri  T.  Scott.     (113)  p.  135,  pi.  viii,  fig.  3. 
1906.  Anchorella  scomberi  A.  Scott.     (110)  p.  53,  pi.  vii. 
1906.  Clavella  scombri  Brian.     (21)  p.  116,  pL  x,  fig.  6. 

Female. — Ceplialothorax  extremely  elongated,  flex- 
uose,  vermiform,  and  nearly  three  times  as  long  as 
the  genital  segment,  the  proximal  half  moderately 
stout,  the  distal  portion  rather  more  slender.  More- 
over, the  proximal  portion  of  the  cephalothorax  bends 
gently  downwards,  but  near  the  middle  there  is  a 
somewhat  abrupt  change  of  curvature  in  the  opposite 
direction,  which  causes  the  cephalothorax  to  assume 
a  geniculated  or  sigmoid  appearance.  Genital  seg- 
ment of  a  subglobular  form,  rather  longer  than  broad, 
and  small  in  comparison  with  the  cephalothorax,  also 
appearing  to  be  unprovided  with  distal  appendages 
of  any  kind.  Abdomen  rudimentary  or  obsolete. 
Egg-strings  small  and  saccate. 

Antennules  small,  two-jointed,  and  furnished  with  a 
few  small  apical  setas.  Antennas  short,  stout,  and 
somewhat  rudimentary ;  outer  ramus  very  small. 
.Mandibles  and  other  mouth-organs  similar  to  those  of 
Clacella  emanji intf'i.  Second  maxillipeds  entirely 
coalescent,  extremely  short,  and  united  at  the  apex 
to  a  small  horn-coloured  chitinous  plug.  Length,  ex- 
clusive of  the  cephalothorax,  about  2'5  mm.  Length 
of  cephalothorax  fully  6  mm. 

Mule. — Extremely  small,  and  its  form  that  which 
appears  to  be  characteristic  of  the  males  of  this  genus, 
being  very  short  and  with  the  dorsum  elevated  so  that 
the  height  is  distinctly  greater  than  the  length.  Both 
pairs  of  maxillipeds  short,  stout,  and  strongly  uncinate. 

Habitat. — Parasitic  on  the  gill-archps  of  mackerel 
(Scomber  .sv»i///A, •?«*).  Found  on  mackerel  captured 
in  the  neighbourhood  of  Aberdeen  in  August,  1900 
(T.  Scott}.  On  mackerel  captured  in  the  Irish  Sea 
off  Walney  Island,  and  in  Carnarvon  Bay  in  1905 
(A.  Scott").  Recorded  by  Dr.  Ed.  Graeffe  as  parasitic 
on  mackerel  captured  in  the  Gulf  of  Trieste.* 

*  'Arbeiten  dor  zoolog.  Tnstitut  zu  Wion,'  T.  xiii,  Heft  1,  p.  17  (1900). 


220  BRITISH    PAKASITIC    COPEPODA. 

6.  Clavella  brevicollis  M.  Edwards. 
(Plate  LXV,  fig.  1 ;  Plate  LXVI,  figs.  12-16.) 

1840.  Anchorella  brevicollis  M.  Edwards.     (43)  vol.  iii,  p.  518. 

1877.  Anchorella  brevicollis  C.  Vogt.     (142)  p.  432. 

1901.  Anchordla  brevicollis  T.  Scott.     (113)  p.  135,  pi.  viii,  figs.  11-16. 

Female. — Resembling  Clavella  nncinata  in  some 
respects  but  differing  considerably  in  the  following 
particulars :  cephalothorax  comparatively  much  shorter 
and  stouter,  and  appearing  rather  to  be  a  prolonga- 
tion of  the  posterior  portion  of  the  body  forwards, 
the  only  limitation  being  a  slight  constriction  imme- 
diately behind  the  second  maxillipeds.  Genital  seg- 
ment subglobular,  rather  longer  than  broad,  and 
without  posterior  appendages.  Abdomen  small,  dis- 
tinct. Antennules  short,  two-jointed,  basal  joint  large, 
end  joint  small  and  furnished  with  a  few  apical 
setae.  Antennae  simple,  rudimentary,  but  stout  and 
apparently  uniarticulate.  Mandibles  slender,  their 
armature  consisting  of  a  few  comparatively  large 
teeth  with  intermediate  smaller  ones.  Maxillae  mode- 
rately stout,  provided  with  two  subapical  processes 
bearing  short  terminal  spines,  and  two  minute  lateral 
spines  on  the  same  side  as  the  processes.  The  first 
maxillipeds  large,  with  strong  terminal  claws.  The 
second  maxillipeds  entirely  coalescent,  very  short  and 
stout,  and  terminating  in  a  chitinous  knob.  Length 
about  4*5  mm. 

Male  not  observed. 

Habitat. — Parasitic  near  the  base  of  the  anal  fin  of 
a  haddock  captured  in  the  Firth  of  Forth  in  January 
1896.  P.  J.  van  Beneden  records  this  species  as 
parasitic  on  the  body  (not  on  the  gills)  of  haddocks ; 
so  also  does  M.  Edwards. 

7.   Clavella  stellata  (Kroyer). 
(Plate  LXV,  figs.  8,  9.) 

1837-1838.  Anchorella  stellata  Kroyer.  (70)  pi.  i,  vol.  ii,  p.  142,  pi.  iii, 
fig.  5. 

1877.  Anchorella  stellata  C.  Vogt.     (142)  vol.  xiv,  p.  432. 


CLAVELLA    STELLATA.  221 

1900.  Anchm-ella  stellata  T.  Scott.     (112)  p.  178. 

1901.  Anchorella  stellaia  idem.     (113)  p.  134,  pi.  viii,  figs.  1,  2. 

1909.  Anchorella  stellata  May  E.  Bainbridge.     (3)  p.  57,  pL  ii,  figs. 
38-42. 

Female.  —  Cephalo thorax  tolerably  elongated  and 
slender,  and  appearing  to  be  but  a  prolongation  of 
the  coalescent  second  maxillipeds,  having  the  head- 
appendages  at  the  end  of  it.  Genital  segment  short, 
moderately  stout,  ovoid  in  shape,  and  joined  to  the 
cephalothorax  by  a  narrow  neck.  Abdomen  rudi- 
mentary, appearing  as  a  slightly  produced  middle 
portion  of  the  posterior  end  of  the  genital  segment ; 
on  each  side  of  the  abdomen  a  small  tubercle,  which, 
Avith  the  rudimentary  abdomen,  imparts  a  slightly 
trilobed  appearance  to  the  end  of  the  segment. 

The  two  pairs  of  antennas,  the  mandibles,  and  other 
mouth-organs  are  apparently  similar  to  those  of 
Clavella  uncinata.  The  whole  animal  including  the 
maxillipeds  appeared  to  be,  in  the  living  state, 
surrounded  by  semi-transparent  gelatinous  matter 
through  which  some  of  the  structures  could  be  plainly 
seen ;  the  two  second  maxillipeds  were  visible  within  the 
gelatinous  investment,  extending  alongside  each  other 
to  where  they  joined  the  chitinous  disk  by  which  the 
parasite  was  anchored  to  its  host.  All  the  specimens 
observed  were  fixed  to  scales,  and  the  chitinous  fixture, 
after  piercing  the  outer  surface  of  the  scale,  spread 
out  into  an  extremely  thin  and  dark  horn-coloured 
circular  disk ;  the  disk  was  ornamented  all  round  with 
pellucid,  oval  markings  arranged  at  more  or  less 
regular  intervals  and  in  the  manner  of  radii  which 
did  not  quite  extend  to  the  circumference  of  the  disk. 
The  parasite  could  not  easily  be  removed  without 
also  removing  the  scale  to  which  it  was  attached  or 
by  severing  the  attachment  where  it  penetrated  the 
scale.  The  specimen  represented  by  the  drawing 
(PL  LXV,  fig.  8)  measured  from  the  forehead  to  the 
apex  of  the  second  maxillipeds  about  6  mm.,  and  the 
genital  segment  about  4  mm.  in  length  by  fully  2  mm. 
in  thickness. 


222  BRITISH    PARASITIC    COPEPODA. 

No  males  have  been  observed. 

Habitat. — Parasitic  on  the  skin  of  the  hake 
cius  vulgar  is).  The  specimens  were  found  adhering 
to  scales  near  the  base  of  the  pectoral  and  ventral 
fins  of  a  hake  captured  in  the  Firth  of  Clyde  in 
December  1899.  The  whole  parasite  was  enveloped 
in  some  soft,  nearly  transparent,  jelly-like  matter,  and 
at  first  sight  had  the  appearance  of  a  small  roundish 
mass  of  mucus,  and  thus  easily  escaped  notice  :  when 
preserved,  the  mucus  assumed  a  whitish  colour.  Mi» 
Bainbridge  (op.  fit.}  described  some  specimens  found 
on  the  skin  of  a  hake,  "  purchased  at  Sheringham, 
Norfolk." 

8.  Clavella  paradoxa  P.  J.  van  Beneden. 
(Plate  LXVII,  figs.  4-6  ;    Plate  LXVIIT,  figs.  8-14.) 

1853.  Anclwrella  paradoxa  P.  J.  van  Beneden.     (11)  vol.  xvi,  p.  117, 
pi.  vi,  fig.  1. 

1896.  Anchorella  paradoxa  Bassett-Smith.     (6)  p.  15.  pi.  v.  fig.  2. 
1906.  Anchorella  paradoxa  A.  Scott.      (110)  p.  53.  pi.  vii. 

Female. — Cephalothorax  tolerably  elongated,  usually 
deflected  backward  upon  the  genital  segment,  and 
extending  somewhat  beyond  its  distal  end.  Genital 
segment  subquadriform,  the  postero-lateral  corner- 
prolonged  backward  and  slightly  outward  in  the  form 
of  narrow  subtriangular  processes,  their  width  at  the 
base  being  equal  to  about  half  the  length  and  with  the 
apex  bluntly  pointed;  genital  segment  exclusive  of 
the  lateral  prolongations  about  as  broad  as  long. 
Abdomen  intermediate  between  the  processes,  com- 
paratively rather  longer  than  broad  and  bluntly 
rounded  at  the  end.  Three  shallow  knobs  at  the 
anterior  end  of  the  genital  segment,  on  the  dorsal 
aspect,  one  on  each  of  the  flatly-rounded  corners,  and 
one  intermediate  arid  somewhat  behind  the  others  : 
two  similar  but  smaller  knobs  also  present  on  the  fore- 
head as  shown  in  the  figure  (PL  LXVII,  fig.  4). 

Antenmiles  nearly  as  in  Clarella  scombri,  but  the 
antennae,  which  are  three-jointed,  are  scarcely  so 


CLAVELLA    PARADOXA.  223 

robust.  Mandibles  somewhat  similar  to  those  of  that 
species,  but  the  maxillae  are  slender  and  provided  with 
three  digitate  terminal  processes.  First  maxillipeds 
similar  to  those  of  Clavella  scombri ;  second  maxillipeds 
very  short,  coalescent,  and  fixed  to  a  terminal  chitinous 
plug.  Length,  exclusive  of  the  cephalothorax,  about 
4  mm. 

Male. — Very  small,  nearly  globular  in  shape,  and 
somewhat  similar  in  structure  and  appendages  to  the 
males  of  other  species  of  Clavella.* 

Habitat. — Parasitic  on  the  gill-filaments  of  mackerel 
(Scomber  scombr us).  Plymouth  (Bass  ett- Smith).  Irish 
Sea  (A.  Scott). 

9.  Clavella  quadrata  Bassett-Smith. 
(Plate  LXVIII,  fig.  15.) 

1896.  Anchorella  quadrata  Bassett-Smith.     (6)  p.  15,  pi.  iv,  fig.  5. 

1899.  Anchorella  quadrata  idem.     (8)  p.  504. 

1906.  Anchorella  quadrata  Norman  &  T.  Scott.     (88)  p.  221. 

Female.  —  Cephalothorax  much  longer  than  the 
genital  segment.  Genital  segment  almost  quadri- 
lateral in  outline.  Abdomen  of  extraordinary  size  for 
animals  of  this  genus;  somewhat  club-shaped,  and 
equal  to  about  two-thirds  the  length  of  the  genital 
segment.  Egg-strings  small  and  broadly  ovate.  First 
pair  of  maxillipeds  placed  close  to  the  mouth,  well 
developed ;  second  pair  short,  opposite  to  the  abdomen 
and  at  the  base  of  the  neck,  thick  and  completely 
united,  terminating  in  the  organ  of  adhesion,  which 
has  the  form  of  a  cup  with  a  long  pedicel. 

This  species  is  much  like  Anchorella  falax  Heller,  in 
form,  except  for  the  great  size  of  the  abdomen. 

The  male  has  not  been  observed. 

Habitat. — Parasitic  on  the  gill-arches  of  Callionymu* 
lyra,  at  Plymouth ;  only  a  few  specimens  were  obtained 
(Bassett-Smith). 

*  One  of  the  authors,  when  first  recording  the  male  of  C.  paradoxa,  states 
that  he  could  only  find  one  pair  of  maxillipeds  (see  '  Trans.  Biol.  Soc.  Liver- 
pool,' vol.  xx,  p.  53, 1906).  This  was  evidently  due  to  the  second  pair  having 
been  accidentally  destroyed :  he  has  since  found  that  there  are  two  pairs, 
as  in  other  males  of  the  same  genus. 


224  BRITISH    PARASITIC    COPEPODA. 

The  above  is  quoted  from  Dr.  Bassett-Smith's  description 
of  this  species,  as  we  have  not  ourselves  observed  it. 

10.  Clavella  canthari  (Heller). 
(Plate  LXIX,  figs.  1-S.) 

1863.  (?)  Anchorella  pagelli  Kroyer.     (71)  p.  295,  pi.  xvi,  fig.  3. 

1865.  Anchorella  canthari  Heller.     (58)  p.  242,  pi.  xxiv,  fig.  6. 

1877.  Anchorella  pagelli  C.  Vogt.     (142)  p.  432. 

1880.  Anchorella  canthari  Richiardi.     (104)  p.  152. 

1906.  Clavella  macrotrachelus  Brian.     (21)  p.  116. 

1910.  Lerneomyzon  canthari  T.  R.  R.  Stebbing.     (125)  p.  562. 

Female.  —  Small  and  tolerably  robust,  but  the  cephalo- 
thorax is  rather  slender  and  considerably  longer  than 
the  genital  segment,  being  equal  to  fully  one  and  a 
half  times  the  length  of  that  segment  ;  the  proximal 
end  of  the  cephalothorax  bluntly  rounded  and  on  each 
side  bearing  a  small  but  fairly  distinct  lobe  ;  a  minute 
process  arising  from  between  the  two  lobes,  and  termi- 
nating in  a  fascicle  of  chitinous  bristles  which  penetrates 
the  tissue  of  the  gill  filament  and  then  gradually  be- 
comes separated  and  forms  a  brush-like  appendage. 
Genital  segment  moderately  stout  and  subcylindrical, 
the  width  equal  to  rather  more  than  half  the  length. 
A  small  gibbous  projection  at  the  proximal  end  of  the 
segment,  as  viewed  from  the  side,  separated  from  the 
segment  by  a  fairly  distinct  constriction,  and  forming 
the  base  of  the  cephalothorax.  The  distal  end  of  the 
genital  segment  truncated  and  obscurely  trilobate,  but 
only  the  middle  lobe  fairly  distinct  ;  the  lateral  lobes 
indistinct  and  scarcely  produced,  but  the  middle  one 
fairly  prominent  and  thickly  covered  with  minute 
hairs.  Egg-strings  moderately  elongated.  Length.  — 
The  following  measurements  are  taken  from  a  fairly 
typical  specimen  :— 

Genital  segment  .         .          .     about  1*8  mm. 

Cephalothorax     .          .          .     about  2*5  mm. 

Egg-strings          .         .         .     about  3'0  mm. 
M~«le.  —  Small,  somewhat  similar  to  the  male  of  C. 
Brian. 


Habitat.  —  Parasitic  on  the  gill-filaments  of  the  black 


CLAVELLA   CANTHARI.  225 

sea-bream  (GantJiarus  lineatux)  and  the  common  sea- 
bream  (Pagellus  centrodontus).  On  Cantharus  lineatus, 
captured  in  the  North  Sea  in  November  1910,  as  well 
as  on  a  few  subsequent  occasions,  fcroyer  obtained 
what  appears  to  be  the  same  species  on  Pagellus 
centrodontus. 

The  characters  by  which  this  species  seems  to  be  dis- 
tinguished are  the  proportional  length  of  the  cephalothorax, 
the  small  lobe  on  each  side  of  its  promixal  end,  the  peculiar 
appendage  by  which  the  species  is  anchored  to  the  gill 
filament,  and  the  densely  ciliated  central  lobe  of  the  posterior 
margin  of  the  genital  segment.  Some  of  the  specimens 
examined  by  us  have  exhibited  slight  differences,  but  they 
all  agree  in  the  more  important  characters  mentioned  above. 

11.  Clavella  alata  Brian. 
(Plate  LXIX,  figs.  4-6.) 

1906.  Clavella  alata  Brian.    (21)  p.  114,  pi.  iii,  fig.  5 ;  pi.  xx,  figs.  5  and  6. 

Female. — Short  and  stout.  Cephalothorax  reaching 
only  to  about,  or  slightly  beyond,  the  end  of  the  genital 
segment;  at  the  base  of  the  cephalothorax  a  small 
horn-like  process  projecting  outwards  on  each  side. 
The  second  maxillipeds  apparently  completely  coalesc- 
ent,  very  short,  tapering  slightly  towards  the  tip, 
which  is  provided  with  a  rounded  cartilaginous  knob. 
Genital  segment  short  and  stout,  subglobose  or  pyri- 
forin,  greatest  width  about  equal  to  the  length,  pos- 
terior end  subtruncate  or  broadly  rounded ;  the  middle 
portion,  however,  slightly  produced,  and  on  each  side  of 
this  slightly  produced  part  is  the  attachment  of  the  short 
and  tolerably  stout  ovisacs.  The  antennules,  antennae, 
and  several  mouth-appendages  apparently  not  differing 
greatly  from  those  of  other  species  of  the  genus. 
Antennules  short,  moderately  stout,  indistinctly  seg- 
mented, and  bearing  a  few  apical  setae ;  mandibles 
very  slender,  but  the  first  maxillipeds  tolerabty  en- 
larged and  uncinate.  The  entire  length,  exclusive  of 
the  egg-strings,  is  about  3  mm.,  while  the  egg-strings 
are  about  2  mm.  in  length.  Colour  yellowish. 

VOL.   I.  15 


226  .BRITISH    PARASITIC    COPEPODA. 

The  males,  which  are  very  small,  measure  only  about 
0*3  mm.,  and  are  provided  with  large  uncinate  maxil- 
lipeds.  Males,  however,  do  not  appear  to  be  very 
common. 

Habitat. — Parasitic  on  the  greater  fork  -  beard 
(Phycis  blennoides  (Brim.)).  It  is  usually  found  adher- 
ing to  the  gill-arches  and  not  to  the  filaments  of  the 
gills. 

One  of  the  more  obvious  characters  of  this  species  seems  to 
be  the  small  but  quite  distinct  horn-like  processes  at  the  base 
of  the  cephalothorax,  which  can  be  seen — one  on  each  side  — 
extending  outwards  at  about  right  angles  to  the  cephalo- 
thorax. 

12.  Clavella  lophii  (M.  Edwards). 
(Plate  LI,  fig.  7.) 

1840.  ?  Brachiella  lophii  M.  Edwards.     (42)  vol.  iii,  p.  514,  pi.  xli,  fig.  4. 
1877.  ?  Brachiella  lophii  Vogt.     (142)  vol.  vi,  p.  426. 

Female. — A  small  and  robust  species.  Cephalo- 
thorax moderately  short,  subcylindrical  or  subconical, 
stout  but  less  robust  in  front.  Genital  segment  some- 
what dilated,  widest  posteriorly,  postero-lateral  corners 
rounded.  Abdomen  very  short..  Egg-strings  short, 
saccate,  rather  longer  than  the  genital  segment,  and 
containing  tolerably  large  ova. 

Mouth-appendages  apparently  somewhat  similar  to 
those  of  C.  rugosa.  The  second  maxillipeds  very  short 
and  coalescent,  and  terminating  in  a  small,  horn- 
coloured,  chitinous  button.  Colour  of  the  specimen 
yellowish.  Length  about  three  and  a  half  millimetres. 

Male. — Very  small  and  of  the  usual  Clavella 
(Anchorella)  type;  short,  and  with  the  dorsum  boldly 
arched. 

Habitat. — Found  adhering  to  the  gills  of  an  angler- 
fish  (Lophius  piscatorius) ;  locality  uncertain. 

We  are  indebted  to  Mr.  W.  M.  Tattersall,  M.Sc.,  Keeper 
of  the  Manchester  Museum,  for  the  privilege  of  describing 
this  species.  The  drawing  is  made  from  the  mounted  specimen. 


ARGULUS.  227 


Genus  ARGULUS  Mutter,  1785. 

Body  flattened,  cephalothorax  scutiform;  cephalon 
and  first  thoracic  segment  coalescent ;  other  segments 
free.  Abdomen  small,  comparatively  narrow,  and 
ending  in  two  equal  lobes,  unsegmented.  Antennae 
two  pairs,  small,  first  pair  tolerably  stout  and  termi- 
nating in  a  small  hook.  Mouth  siphon-like,  enclosing 
a  flexible,  sharp-pointed,  sting-like  process  furnished 
with  a  poison-gland.  Two  pairs  of  maxillipeds,  the 
first  pair  transformed  into  sucking-discs;  posterior 
pair  prehensile,  their  integument  rough  with  minute 
prickles,  and  having  a  tridentate  plate  on  the  inferior 
aspect  of  the  basal  joint.  Swimming-legs  four  pairs, 
biramose,  and  furnished  with  plumose  hairs.  Females 
without  external  egg-strings.  Eyes  conspicuous. 

1.  Argulus  foliaceus  (Linn.). 
(Plate  LXXII,  figs.  1-10.) 

1758.  Monoculus  foliaceus  Linn.  Systema  Naturae,  lOtli  edit.,  vol.  i, 
p.  634 

1762.  Binoculus  gasterostei  Geofroy.    Insectes  de  Paris,  vol.  ii,  p.  661. 

1785.  Argulus  foliaceus  Miiller.     Entomost.,  p.  123. 

1785.  Argulus  charon  idem.     Ibidem,  pi.  20,  figs.  1,  2. 

1793.  Monoculus  arguluso  Fabr.     Entom.  Syst.,  vol.  ii,  p.  489. 

1798.  Monoculus  gyrini  Cuvier.     Tab.  element.  Hist.  Nat.,  p.  45. 

1802.  Ozolus  gasterostei  Latreille.  Hist.  Nat.  Crust,  et  Ins.,  voL  iv, 
p.  128,  pi.  29,  fig.  4. 

1814.  Argulus  argulus  Leach.     Edin.  Encyclop.,  vol.  vii,  p.  388. 

1839.  Argulus  foliaceus  Thompson.  Ann.  and  Mag.  Nat.  Hist.,  vol.  v, 
p.  221. 

1845.  Argulus  foliaceus  Vogt.  Nouv.  Mem.  Soc.  Helvet.,vol.  vii,  pi.  i, 
fig.  2. 

1850.  Argulus  foliaceus  Baird.     Entom.,  p.  255,  pi.  xxxi,  figs.  1,  2  a-l. 

Carapace  of  a  rounded  oval  shape,  rather  longer 
than  broad,  and  with  the  front  margin  slightly  pro- 
jecting forward  ;  posterior  sinus  narrow  and  extending 
forward  for  about  two-fifths  of  the  carapace.  Abdo- 
men small,  rather  longer  than  broad,  and  about  one- 
fourth  the  length  of  the  cephalothoracic  shield  ;  lobes 
bluntly  rounded  at  the  end,  separated  by  a  sinus 
extending  forward  to  about  half  the  length  of  the 


228  BRITISH    PARASITIC    COPEPODA. 

abdomen ;  inner  edges  proximally  contiguous  and 
somewhat  divaricate  at  the  distal  extremity.  An- 
tennas normal.  Sucking-discs  of  moderate  size.  Pos- 
terior maxillipeds  tolerably  large  and  stout,  their 
basal  plates  somewhat  expanded  posteriorly ;  the  distal 
margin  of  the  plates  with  three  short  and  subequal 
tooth-like  projections.  Swimming-legs  tolerably  elon- 
gated. Eyes  conspicuous.  A  black  mark  on  each 
side  near  the  base  of  the  abdomen.  Carapace  of  a 
greenish  colour  and  ornamented  on  both  sides  with 
darker  coloured  ramifications.  Size  of  the  female 
about  6  or  7  mm.  in  length.  Male  somewhat  like  the 
female,  but  smaller. 

Habitat. — Parasitic  on  various  fresh-water  fishes,  as 
carp,  sticklebacks,  trout,  pike  (Esox  luciu*),  greyling 
(Thyma.Uusvid(jaris},2ir\d.  others.  The  species  appears 
to  be  generally  distributed  throughout  the  British 
Islands.  Some  years  ago  it  was  very  common  on 
greyling  in  the  upper  waters  of  the  Clyde,  but  after  a 
few  days'  heavy  rain  which  flooded  the  river  the  Argiilu* 
had  all  disappeared.  This  species  has  also  been  obtained 
on  a  fish  captured  in  the  Faroe  Channel  by  Gr.  H. 
Fowler.  The  specimen  is  now  in  the  British  Museum, 
and  we  are  indebted  to  Dr.  "W.  T.  Caiman  for  drawing 
our  attention  to  it  and  for  the  loan  of  it  for  exami- 
nation. 

There  appears  to  be  some  uncertainty  as  to  the  relationship 
between  the  Argnlidae  and  the  species  usually  recognized  as. 
Copepoda.  Dr.  Baird  includes  the  Family  Argulidae  in  the 
same  Tribe — Peltocephala — with  the  Caligidae,  the  Pandaridae, 
and  the  Cecropidfe.*  In  1866  Gerstaecker,  revising  his 
previous  classification,  replaces  the  Argulidas  under  the 
Branchiopoda.f  Claus  in  1875  proposed  making  the  Argulidse- 
a  second  suborder  of  the  Branchiura,  under  the  Order  Cope- 
poda.J  On  the  other  hand,  the  Eev.  T.  R.  R.  Stebbing,  in 
'A  History  of  Crustacea/  places  the  carp-lice  (Argvlut)  in 
the  suborder  Branchiura  of  the  Order  Branchiopoda,  and 

*  '  Entomostraca,'  p.  15. 

t  C/._Bronn's '  Klassen  und  Ordnungen  des  Thierreichs,'  vol.  v,  p.  16. 

\  "  Cher  die  Entwickelung,  Organisation,  und  Systeuiatische  Stellung- 
der  Arguliden,"  '  Zeitsch.  f.  wissensch.  Zool./  vol.  xxv,  pp.  217-2&4,  pis. 
xiv-xviii. 


ARGULUS   FOLIACEUS.  229 

not  with  the  Copepoda.*  Dr.  Bassett-Smith,  in  his  '  System- 
atic description  of  the  parasitic  Copepoda  found  on  Fishes/ 
also  excludes  the  Family  Ai-gulidee  from  the  Order  Cope- 
poda.t  And  lastly,  in  the  first  of  an  important  series  of 
'  Memoirs  on  North  American  pai'asitic  Copepods/  by  Charles 
Branch  Wilson,  that  author  makes  the  Branchiura  a  suborder 
of  the  Copepoda,  with  Argulidse  as  the  only  Family. J 

There  is  doubtless  a  close  relationship  between  the  Argulidse 
and  the  other  parasitic  groups  enumerated  in  this  volume; 
but  apparently,  as  indicated,  there  is  also  a  considerable 
divergence  of  opinion  as  to  whether  Argulus  and  its  allies 
should  be  recognized  as  a  suborder  of  the  Copepoda.  We 
have,  however,  had  few  opportunities  for  studying  these 
interesting  forms,  as  there  is  only  a  single  British  species 
known  to  us,  and  therefore  we  do  not  propose  to  enter  further 
into  a  discussion  of  this  question. 


Tripaphylus  musteli  (P.  J.  van  Beneden).     pp.  160- 

161. 

Amended  description  of  male. 

Our  description  of  the  male  of  this  copepod  parasite  was 
copied,  to  some  extent,  from  van  Beneden's  work,  as  we  had 
not  then  seen  the  male  ourselves.  We  discovered  a  male 
attached  to  a  female  after  the  description  was  in  type,  and 
some  changes  appear  to  be  necessary  to  bring  the  description 
more  in  line  with  the  views  now  generally  accepted  regarding 
the  names  of  the  appendages,  but  it  was  too  late  to  do  this  in 
the  proper  place.  This  description,  taken  from  our  own 
specimen,  should  read  as  follows: — 

Male. — The  male  of  this  species  has  the  body  divided  into 
two  unequal  portions ;  the  anterior  portion  is  large  and  carries 
the  whole  of  the  appendages — viz.  one  pair  of  antennules,  one 
pair  of  antennae,  one  pair  of  mandibles,  one  pair  of  maxillae, 
and  two  pairs  of  maxillipeds;  the  posterior  portion  is  much 
more  narrow  and  rounded  and  is  terminated  by  short  stout 
f  urea.  The  antennules,  antennae,  mandibles,  and  maxillae  are 

*  '  A  History  of  Crustacea :  Recent  Malacostraca.'  The  International 
Scientific  Series,  vol.  Ixxiv  (1893),  pp.  10  and  49. 

t  "A  systematic  description  of  the  Copepoda  found  on  fishes,  with  an 
enumeration  of  the  known  species,"  '  Proc.  Zool.  Soc.  Lond./  April,  1899. 

J  "  North  American  Parasitic  Copepods  of  the  Family  Argulidse,"  '  Proc. 
"United  States  National  Museum,'  vol.  xxv  (1902),  pp.  635-742,  pis.  viii- 


230 


BRITISH    PARASITIC    COPEPODA. 


somewhat  rudimentary.  The  two  pairs  of  maxillipeds  are 
comparatively  well  developed  and  form  prehensile  appendages 
similar  to  those  found  in  the  males  of  many  of  the  sedentary 
female  fish-parasites.  The  appendages  described  as  feet  by 
van  Beneden,  and  also  in  the  second  paragraph  on  p.  161, 
are  the  iirst  and  second  maxillipeds.  No  appendages  corre- 
sponding to  feet  in  the  more  highly  organized  parasitic 
Copepoda  appear  to  be  present. 


LIST  OF  THE  FISHES  ON  WHICH  THE  PARASITIC  COPEPODA 
DESCRIBED  IN  THIS  VOLUME  WERE  OBTAINED. 


Acipenser  sturio  Linn. 
Agonus  cataphractus  Linn. 
Alopias  vulpes  (Gmelin) 
Anarrhichas  lupus  Linn.    . 
Bothus  maximus  (Linn.)     . 
Bothus  rhombus  (Linn.) 
Brosmius  brosme  Cuv. 
Callionymus  lyra  Linn. 
Callionymus  maculatus  Linn. 
Cantharus  lineatus  (Mont.) 
Car ch arias  glaucus  (Linn.) 
Clupea  alosa  Linn. 
Clupea  finta  Cuv. 
Clupea  sprattus  Linn. 
Conger  niger  Risso     . 
Corregonus  pollan  Thomps. 
Crenilabrus  melops  (Linn.) 
Ctenolabrus  rupestris  (Linn.) 
Cyclopterus  lumpus  Linn. . 
Cyprinus  carpio  Linn. 
Drepanopsetta  platessoides 

(Fair.} 

Engraulis  encrasicholus  Linn.    . 
Esox  lucius  Linn. 
Gadus  eeglefinus  Linn. 
Gadus  callarius  Linn. 
Gadus  luscus  Linn.     . 
Gadus  merlangus  Linn. 
Gadus  minutus  Linn. . 
Gadus  pollachius  Linn. 


Sturgeon. 

Pogge. 

Thrasher  Shark. 

Cat-fish;  Wolf-fish. 

Turbot, 

Brill. 

Torsk  or  Tusk. 

Gemmeous  Dragonet. 

Spotted  Dragonet. 

Black  Bream. 

Blue  Shark. 

A  His  Shad. 

Twaite  Shad. 

Sprat. 

Conger. 

Pollan. 

Connor;   Goldsinny. 

Jago's  Goldsinny. 

Lumpsucker. 

Carp. 

Long  Rough  Dab. 

Anchovy. 

Fresh-water  Pike. 

Haddock. 

Codfish. 

Bib  ;  Whiting  Pout. 

Whiting. 

Poor  Cod. 

Pollack. 


LIST    OF  THE    FISHES. 


231 


Gadus  virens  Linn.     .         ... 
Galeorhinus  galeus  (Linn.) 

(Galeus  canis  Bonap.) 
Gasterosteus  aculeatus  Linn. 
Gastraea  spinachia  (Linn.) 
Gobius  minutus  Gmelin 
Hippoglossus  vulgaris  Flem. 
Labrax  lupus  Cuv.  Sf  Val.  . 
Labrus  bergylta  Ascan. 
Labrus  mixtus  Linn.  . 
Lamna  cornubica  Cuv. 
Latnpris  pelagicus  (Gun.)  . 
Leuciscus  rutilus  (Linn.)    . 
Lophius  piscatorius  Linn.  . 
Luvarus  iinperialis  Rajin   . 
Macrurus  coelorhynchus  Risso    . 
Merluccius  vulgaris  (Cuv.) 
Molva  vulgaris  (Flem.) 
Mugil  chelo  Cuv.        .         ... 
Mullus  barbatus  (Linn.) 
Mustellus  vulgaris  Mull.  8f  Henle. 
Onos  cimbrius  (Linn.) 
Onos  mustelus  (Linn.)         .     .    . 
Onos  tricirratus  (Briin.) 
Orcynus  thynnus  (Linn.)    . 
Orthagoriscus  mola  (Linn.) 
Pagellus    centrodontus    (De    la 

Roche) 

Perca  fluviatilis  Linn. 
Pleuronectes  cynoglossus  Linn. . 
Pleurnoectes  flesus  Linn.    . 
Pleuronectes  limanda  Linn. 
Pleuronectes  microcephalus  Don. 
Pleuronectes  platessa  Linn. 
Pholis  gunnellus  (Linn.)     . 
Phycis  blennoides  (Briin.) 
Raia  batis  Linn. 
Raia  circularis  Couch 
Raia  clavata  Linn. 
Raia  fullonica  Linn.   . 
Raia  maculata  Mont.  . 
Raia  oxyrhynchus  Linn.     . 
Rlnna  squatina  (Linn.) 
Sal  mo  fario  Linn. 
Salmo  salar  Linn. 


Coal  fish. 
Tope  or  Toper. 

Three-spined  Stickleback. 

Fifteen-spined  Stickleback. 

Speckled  Goby. 

Halibut. 

Basse. 

Ballan  Wrasse ;  Bergylt. 

Striped  Wrasse. 

Porbeagle. 

Opah;  King-fish. 

Roach. 

Angler  or  Angler-fish. 

Grenadier-fish. 

Hake. 

Ling. 

Grey  Mullet. 

Surmullet ;  Red  Mullet. 

Smooth-hound. 

Four-bearded  Rockling. 

Five-bearded  Rockling. 

Three-bearded  Rockling. 

Tunny. 

Short  Sunfish. 

Sea-bream. 

Perch. 

Pole-dab ;  Witch-sole. 

Flounder. 

Dab. 

Lemon-sole. 

Plaice. 

Gunnel;  Butter-fish. 

Greater  Fork-beard. 

Grey  or  Blue  Skate. 

Sandy  Ray. 

Thorn  back  Skate. 

Shagreen  Rsiy. 

Homelyn  Ray. 

Long-nosed  Skate. 

Angel-fish. 

Trout. 

Salmon. 


232 


BRITISH    PARASITIC    COPEPODA. 


Salmo  trutta  Linn.    .         ... 
Sciaena  umbra  (Lacep.)       .     .    . 
Scomber  scombrus  Linn.    . 
Scylliorhinus  canicula  (Linn.)    . 

Scyllium  catulus  Guv. 
Scymnus  borealis  Flem.      .      •    . 
Sebastes  norvegicus  (Ascan.)  •    . 
Solea  vulgar  is  Quensel 
Squalus  acanthias  Linn. 

Thymallus  vulgaris  Nilss.  .  •    . 

Trigla  cuculus  Linn.  .         .  •    . 

(Trigla  pini  Block.) 

Trigla  gurnardus  Linn.  .  .  . 
Trigla  lineata  Gmelin 

Trigla  lucerna  Linn.  .         .  . 

Trigla  lyra  Linn.         .          .     .    . 

Trygon  pastinaca  (Linn.)  .  .  . 
Xiphias  gladius  Linn.  .  .  . 
Zeugopterus  punctatus  (Blainv.) 
Zeus  faber  Linn. 


Salmon  trout. 

Maigre. 

Mackerel. 

Rough-hound ;  Lesser  Spot- 
ted Dog-fish. 

Nurse  or  Nurse-hound. 

Greenland  Shark. 

Bergylt;  Norway  Haddock. 

Black  Sole. 

Spur  -  Dog  ;  Piked  Dog- 
fish. 

Grey  ling. 

Red  Gurnard. 

Grey  Gurnard. 
Streaked  Gurnard. 
Sapphirine  Gurnard;   Yel- 
low Gurnard. 
Piper;  Crowner. 
Sting-ray. 
Sword-fish. 
M tiller's  Topknot. 
Dory ;  John  Dory  ;   Doree. 


Note. — The  scientific  names  of  the  fishes  in  this  list  are,  with  a  few 
exceptions,  from  '  A  History  of  Scandinavian  Fishes,'  by  B.  Fries, 
C.  U.  Ekstrom,  and  C.  Sundevall,  2nd  edit.,  revised  by  Prof.  F.  A. 
Smitt  (1893-95). 


(233) 


LITERATURE 

CHIEFLY    REFKKEED    TO    IN    THE    PRECEDING   PAGES. 

1.  1794  Abildgaard,  P.  C.    Beskrivelse  over  tvende  nye 

Monoculi  Linn.  (Callgns  crassus  et  oblongiis,} — 
Skrit't.  Naturhist.  Selsk.  Kjobenhavn,  III,  2,  pp. 
46-54. 

2.  1865  Agassiz,  A.    Sur  un  Pennella,  parasite  de  VOrtha- 

goriscus  mola. —  Illustrated  Catalogue  of  the 
Museum  of  Comparat.  Zoology,  Cambridge,  p.  87. 

3.  1909  Bainbridge,  May  E.    (Hon.   Mrs.    Hemi  Collins). 

Notes  on  some  parasitic  Copepoda  with  a  de- 
scription of  a  new  species  of  Chondr acanthus 
(C.  inflatus), — Trans.  Linn.  Soc.  London,  Zool., 
Ser.  2,  Vol.  XI,  part  3. 

4.  1850  Baird,  Dr.  W.    The  Natural  History  of  the  British 

Entomostraca. — Ray  Society.     London. 
-5.  1783  Barbut,  /.     The  genera  Vermium  exemplified  by 
various  specimens  of  the  animals  contained  in 
the  orders  of  the  Intestina  et  Mollusca  Linnaei. 
Drawn  from  Nature.     London. 

6.  1896  Bas sett-Smith,  Dr.  P.   W.     Notes  on  the  Para- 

sitic Copepoda  of  fish  obtained  at  Plymouth 
with  descriptions  of  new  species.  —  Ann.  and 
Mag.  Nat.  Hist.  (6),  Vol.  XVIII,  pp.  8-16,  with  4 
plates. 

7.  1896  idem.      List  of  Parasitic  Copepoda  of  fish  obtained 

at  Plymouth. — Journ.  Mar.  Biol.  Assoc.,  N.S., 
Vol.  IV,  pp.  153-163. 

5.  1899  idem.      A  Systematic  Description  of  Parasitic  Cope- 

poda found  on  fishes,  with  an  enumeration  of 
the  known  species. — Proc.  Zool.  Soc.  London, 
1899,  Pt,  IT,  pp.  438-507,  with  one  plate. 

9.  1765  Baster,  Job.      Opuscula  subseciva,  Vol.  II,  p.  138. 

Harlemi. 

10.  1905  Baudouin,  J/.  Les  parasites  de  la  Sardine. — Rev. 
Scient.  Paris,  No.  23,  10  Juin,  pp.  715-722,  with 
4  text-figs. 


234  BRITISH   PARASITIC    COPKPODA. 

11.  1851  Beneden,    P.  J.  van.      Recherches  sur  quelques 

Crustaces  inferieurs. — Ann.  Scienc.  Nat.,  3  Ser. 
Zool.,  Vol.  XVI,  pp.  71-131,  pis.  2-6. 

12.  1851  idem.     Note    sur   un    Crustace    parasite    nouveau, 

avec  ^enumeration  des  especes  de  cette  classe 
qu'on  observe  sur  les  poissons  du  littoral  de 
Belgique.— Bull.  Acad.  Roy.  de  Belg.,  T.  XVIII, 
pt.  1,  pp.  286-290  avec  pi. 

13.  1852  idem.     Note   sur    un    nouveau    genre   de   Crustace 

parasite  de  la  famille  des  Peltocephales. — BulL 

Acad.  Roy.  de  Belg.,  T.  XIX,  pt,  3,  pp.  462-467, 

avec  pi. 
13a.  1852  idem.     Note    sur  quelques  parasites   d'un  poisson 

rare  sur  nos  cotes   (le  inaigre  d'Europe,  Scisena 

aqulla  Cuv.).— Bull.  Acad.  Roy.  de  Belg.,  T.  XIX, 

pt.  3,  pp.  98-109  avec  pi. 
13b.   1853  idem.      Note   sur  un  nouveau  genre  de  Crustace 

parasite,  Eudactylina    (E.  acuta). — Bull.   Acad.. 

Roy.  de  Belg.,  T.  XX,  pt.  1,  pp.  235-239. 
13c.     1853  idem.     Notice  sur  un  genre  nouveau  de  la  tribu  des- 

Caligiens  (genre  Kroyeria  van  Ben.). — Bull.  Acad. 

Roy.  de  Belg.,  T.  XX,  pt.  1,  pp.  23-30  avec  pi. 

14.  1854  idem.     Notice  sur  un  nouveau  genre  de  Siphono- 

stome  (genre  Congericola). — Bull.  Acad.  Roy.  de 
Belg.,  T.  XXI,  pt.  2,  pp.  583-589. 

14a.  1857  idem.  Sur  un  nouveau  Dinemoure  provenant  du 
Scimiius gluciali*. — Bull.  Acad.  Roy.  de  Belg.,  (2) 
T.  I,  pt,  1,  pp.  226-235  avec  pi. 

15.  1861  idem.      Recherches  sur  les  Crustaces  du  littorale  de 

Belgique.  Mem.  Acad.  Roy.  de  Belg.,  T.  XXXIII, 
H.  3,  174  pp  ,  21  pis. 

16.  1870  idem.     Les  poissons  des  cotes  de  Belgique,  leurs 

parasites  et  leurs  commensaux. — Mem.  Acad. 
Roy.  de  Belg.,  T.  XXXVIII,  n.  4,  100  pp.,  6  pis. 

17.  1864  BergSOe,  V.    Philichthys  xiphiee  Stp.,Monogra,-p\\isk 

Fremstittet.-Naturhist,  Tidkssrif  t,  3  Raek.,  3  Bind, 
pp.  87-130,  tab.  13,  Kjobenhavn;  (oppure  Ann. 
Scienc.  Natur.,  5  ser.  Zoologie,  Vol.  Ill,  p.  213, 
pi.  I,  1865). 

18.  1898  Brian,  A.     Note  preliminaire   sur   les   Copepodes- 

parasites  des  poissons. — Bull.  Instit  Oceanogr., 
No.  110,  p.  19,  with  text- tigs.  (Records  '  Pen- 
nella  filosa  '  from  Sunfish,  &c.). 


LITERATURE    CHIEFLY    REFERRED    TO.  235 

19.  1899  BRIAN,  A.   (contd.}.      Di  alcuni   Crostacei  parassiti. 

dei  pesci  dell'Isola  d'Elba. — Atti  Soc.  Lig. 
So.  Nat.  e  Geogr.,  Vol.  X,  pp.  1-10,  with  text- 
figs. 

20.  1899  idem.     Diphyllogaster   thompsoni   n.    gen.  e   sp.  di 

Caligidae  della  Dicerolatis  giornfe  Giinth. — Atti 
Soc.  Lig.  Sc.  Nat.  e  Geogr.,  Vol.  X,  pp.  1-11, 
con. tav. 

21.  1906  idem.     Copepodi  Parassiti  dei  Pesci  d'ltalia.     Con 

21  Tavole.     Geneva. 

21a.  1908  idem.  Note  preliminaire  sur  les  Copepodes  para- 
sites des  poissons  proven  ant  des  Campagnes  Scien- 
tifiques  de  S.A.S.  le  Prince  Albert  Ier  de  Monaco 
ou  deposes  dans  les  collections  du  Musee  Oceano- 
graphique. — Bull.  Instit.  Oceanogr.  No.  110. 

22.  1816  Blainville,  H.  M.  D.  de.      Prodromus  d'une  Nou- 

velle  Classification  du  Regne  Animal.     Paris. 

23.  1816  idem.     Article  Lernsea   in  Diet.  d.  Scienc.  Natur., 

Vol.  XXVI,  p.  112,  if.,  1816  (e  1823). 

24.  1822  idem.     Memoires  sur  les  Lernees. — Journ.  de  Phy- 

sique, T.  95,  pp.  372-380,  et  pp.  437-447,  avec 
Ipl. 

25.  1883  Brady,  G.  8.     Report  on  the  Copepoda  (including 

Copepoda  parasitic  on  fishes). — Voyage  of  H.M.S. 
'  Challenger/  Zool.,  Vol.  VII,  Part  XXII I. 

26.  27.  1833  Burmeister,  H.     Beschreibung  einiger  neuen 

oder  wenig  bekannten  Sclimarotzerkrebse,  nebst 
allgemeinen  Betrachtungen  iiber  die  Gruppe, 
welcher  sie  angehoren. — Nova  Acta  Acad. 
Leopold.-Carolin.,  XVII,  1,  pp.  269-336,  mit  3 
Taf. 

28.  1870  idem.     Bomolochus  helones,  occurrence  in  Mediter- 

ranean and  German  Sea. — Hartmann's  Archiv. 
Anat.  Physiol.  (1870),  pp.  116-163. 

29.  1892  Canu,  E.     Les  Copepodes  du  Boulonnais,  parasites 

des  poissons.  Annales  de  la  Statione  Aquicola 
de  Boulogne-sur-mer  (1892). 

29a.  1884  Carus,  /.  V.  Prodromus  fauna3  mediterraneae. 
Pars  I,  pp.  345-378.  Stuttgart. 

30.  1858  Claus,  C.     Ueber  den  Bau  und  die  Entwickelungs- 

geschichte  parasitischer  Crustaceen,  pp.  1-34, 
2  plates.  Cassel. 


236  BRITISH    PARASITIC    COPEPODA. 

30a.  1860  CLA.US,  C.  (contd.).  Zur  Morphologie  der  Cope- 
poden.  1.  Eine  Hemmungsbildung  von  Cyclops. 
2.  Ueber  den  Bau  von  Nicothoe.  3.  Ueber  die 
Leibesgliederung  und  die  Mundwerkzeuge  der 
Sclimarotzerkrebse. — Wiirzb.  Naturw.  Zeitschr. 
Bd.I,  pp.  20-36,  Taf.  1. 

31.  1861  idem.     Ueber  die  Familie  der  Lernaen :  Lernssocera 

gobina. — Wiirzb.  Naturw.  Zeitsclir.,  Bd.  II,  pp. 
10-22,  Taf.  1. 

32.  1861.  idem.     Ueber  den  Ban  und  die  Entwickelung  von 

Achieves  percarurn.  Zeitschr.  f.  wiss.  Zool.,  Bd. 
XI,  pp.  287-308,  Taf.  23  u.  24. 

33.  1864  idem.     Beitrage    zur  Kenntniss  der    Schmarotzer- 

krebse. — Zeitschr.  f.  wiss.  Zoo!.,  Bd.  XIV, pp.  365- 
382,  T.  33-36. 

34.  1868  idem.     Beobachtungen  tiber  Lernseocera,  Peniculus, 

und  Lernfea.  Ein  Beitrag  zur  Naturgeschichte 
der  Lemaeen,  mit  4  Taf. — Schriften  der  Gesell- 
schaft  zur  Beforderungder  jresammten  Naturwiss. 
zu  Marburg,  2  Supplement-Heft. 

35.  1875  idem.     Neue  Beitrage  zur  Kenntniss  parasitischer 

Copepoden  nebst  Bemerkungen  tiber  das  System 
derselben. — Zeitschr.  f.  wiss.  Zool.,  Bd.  XXV,  4. 
mit  3  Taf.  Leipzig. 

36.  1780  Cordiner,  Rev.  Charles.     Lernsea  salmonea  Linn. — 

Antiquities  and  Scenery  of  the  North  of  Scotland, 
pp.  7-8,  pi.  VI,  fig.  2. " 

36a.  1865  Cornalia,  E.  Sulla  Lophoura  edicardsii  di  Kol- 
liker.  Osservaziorii  zoologiche  e  anatomiche. — 
Atti  Soc.  Ital.  Sc.  Nat.,  Vol.  IX,  pp.  1-10,  tav.  1. 

36b.  1912  Cuenot,  M.  L.  Contributions  a  la  faune  du 
bassin  d'Arcachon  :  description  d'Argulus  arcas- 
sonensis,  nov.  sp. — Bull,  de  la  Station  Biol.  d'Arca- 
chon, 14c,  pp.  117-127,  pis.  1  &  2.  (Extrait.) 

37.  1817  Cuvier,   G.  L.      Regne   Animal.     Premiere    edit. 

Tom.  Ill,  pp.  60-66.     Paris. 

38.  1829  i<lem.     Regne  Animal.      Nouvelle  edit.     Tom.  IV, 

pp.  189-202.     Paris. 

39.  1838  Dana,  J.  D.  (see  Pickering  and  Dana). 

40.  1852  idem.     United  States  Exploring  Expedition  during 

the  years  1838-1842,  under  the  command  of 
Charles  Wilkes.  U.S.N.  XIII,  Crustacea.  (Atlas 
Crustacea,  Philadelphia  1855.) 


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41.  1811  De  la  Roche,  F.     Sur  deuxanimaux  vivants  surles 

branchies  des  poissons. — Nouv.  Bull.  Soc.  Philo- 
mat.,  II,  pp.  270-272. 

42.  1833  Edwards,  H.  Milne.    Memoire  sur  1'organisation  de 

la  bouche  chez  les  Crustaces  suceurs. — Ann. 
Scienc.  Natur  ,  Vol.  XXIX,  pp.  78-86. 

43.  1840  idem.     Histoire  naturelle  des  crustaces,  comprenant 

Panatomie,  la  physiologie,  et  la  classification  de 
ces  animaux.  Paris. 

44.  1763  Ellis,  /.    Philos.  Trans.,  Vol.  53,  p.  433.—  Pennatula 

filosa  and  sagifta. 

45.  1909  Elwes,  E.  V.   The  Sunfish  and  its  parasites.— Journ. 

Torquay  Nat.  Hist.  Soc.,  Vol.  I,  No.  I,  pp.  17-20. 

46.  1906  Evans,  W.     LxmargiismuricatusfromaSnniish. — 

Ann.  Scott.  Nat.  Hist.  (Jany.).    Zoological  notes. 

47.  1904  Gadd,   Pehr.     Parasit-Copepoder  i  Finland. — Acta 

Soc.  pro  Fauna  et  Flora  Fennica,  XXVI,  No.  8. 

48.  1853-54  Gerstaecker,  A.  D.     Ueber  eine  neue  und  eine 

weniger  gekannte  Siphonostomen-Gattung,  und 
Beschreibung  zweier  neuer  Siphonostomen-Gat- 
tungen. — Wiegmann's  Arcbiv  f.  Naturg.,  XIX, 
1,  pp.  58-70,  Taf.  3  u.  4 ;  XX,  pp.  185-195,  Taf.  7. 

49.  1870-71  idem.     In  Dr.  H.  G.  Bronn's  Klassen  und  Ord- 

nungen  des  Thier-Reichs.  V.  Band,  Gliederfiissler. 
Liet'erung  11-16.  Leipzig  u.  Heidelberg. 

50.  1889  Giard,  A.    Sm*\'&ssoc\a,t\ondePennellaorthagomf<ci> 

Percival  Wright,  et  de  Conchoderma  virgatum 
Spengl.— Le  Naturalise,  (2)  III,  No.  50,  p.  82. 

51.  1899  Giesbrecht,    W.     Die  Asteroclieriden  des  Golfes 

von  Neapel  und  der  Angrenzenden  Meeres. — 
Abschnitte.  (A.u.d.  Tit. :  Fauna  und  Flora  des 
Golfes  von  Neapel,  25  Monogr.) 

52.  1842.  Goodsir,  H.     Note  sur  le  developpement  des  ceufs 

du    C aligns   et    sur  les    metamorphoses    que    ce 
Crustace  eprouve. — Ann.  Scienc.  Natur.,  2  ser., 
Zool.,  Vol.  XVIII,  pp.  181-184. 

53.  1827  Grant,  R.  E.     On  the  structure  and  characters  of 

Lerntea  elongata  from  the  Arctic  Seas. — Edin- 
burgh eTourn.  of  Science,  VII,  pp.  147-154. 

54.  1828  idem.     Froriep's  Notizen,  Vol.  XIX,  p.  18. 

55.  1829-1843  Guerin-Meneville,  F.  E.     Iconographie  du 

Regne  animal.     Crustaces.      (Text,  1844.) 


238  BRITISH    PARASITIC    COPEPODA. 

56.  1879  Heider,  C.     Die  Gattung  Lernanthropus. — Arbeit. 

Zool.Instit.Wien.u.  Triest.,  T.  II,  Hft.  3,  pp.  269- 
368,  mit  5  Taf.— Auch  separ.;  Wien,  Holder,  1879. 

57.  1904  Hofer,   B.      Handbucli    der    Fischkrankheiten. — 

Verlag  der  allg.  Fischerei-Zeitung.     Miinchen. 

58.  1865  Heller,  C.     Crustaceen  der  Novara-Expedition. 

59.  1879  Hesse,  E.      Description   des   Crustaces   rares  ou 

nouveaux   des    cotes    de  France. — Ann.  Scienc. 
Nat.  6  ser.,  Zool.,  Vol.  VIII,  art.  29. 

60.  1884  idem.      Crustaces  rares  ou  nouveaux  des  cotes  de 

France. — Ann.  Scienc.   Nat.,  6  ser.,  Zool.,  Vol. 
XVI,  art.  34,  pp.  1-18,  pis.  12-14. 

61.  1783  Hermann,  J.   Helminthologische  Bemerkungen. — 

Naturforscher,  n.  19. 

61a.  1857  HcBven,  J.  van  der.  Note  sur  les  genres  Cecrops 
et  Lemargus. — Memoires  d'Entomol.  de  la  Soc. 
Entom.  des  Pays-bas,  I,  pp.  67-87. 

62.  1799  Holten,  H.  8.     Acta  Danica,  Vol.  V. 

63.  1802  idem.     Lern&a  merlucii  og  Exocreti,  to  nje  Arter. 

— Skrift.  Naturhist.  Selsk.  Kjobenhavn,  V,  2,  pp. 
135-137. 

63a.  1897  Horst,  R.  Philorthagoriscus  serratns  Kr.  (Dine- 
matura  serrata  Kr.)  With  1  pi.  Notes  Leyden 
Mus.,  Vol.  19,  N.  £.  Note  XIV,  pp.  137-144. 

64.  1824  Johnston,  G.     Notice  respecting  the  genus  Cali- 

gus  of  Leach. — Edinburgh  Philosoph.  Journ.  X, 
pp.  292-294. 

65.  1835  idem.      Lernsea  uncinata. — London's  Mao*,  of  Nat. 

Hist.,  VIII,  pp.  565-566. 

66.  1835  idem.     Pandarus  alatus  and  lamnee.     Loc.  cit.  VIII, 

pp.  202-205. 

67.  1836  idem.  Chondracanthus  lophii,  nov.  spec.      Loc.  cit. 

IX,  pp.  81-83. 

68.  1892.  Kane,    W.    V.  de   Vi&mes.      On  a  new  species  of 

Lernseopoda  (bidiscalis)  from  the  West  Coast  of 
Ireland,  and  Polperro,  Cornwall. — With  2  pis. 
Proc.  Koy.  Irish  Acad.  (3)  Vol.  2,  n.  2,  pp.  203- 
211.  Abstr. ;  Journ.  Hoy.  Micr.  Soc.  London, 
1892,  Pt.  4,  p.  480. 

68a.  1853  Kolliker,  A.  Bericht  iiber  einige  im  Herbst  1852 
in  Messina  angestellte  vergleichend  anatomische 
Untersuchungen.  Gatt.  Lophoura. — Zeitschr.  f. 
Wiss.  Zool.  IV,  p.  359. 


LITEUATUKE    CHIEFLY    11EFERRED    TO.  239 

69.  1835  Kollar,  V.     Beitrage  zur  Kenntniss  lernseenartigen 

Crustaceen.      Annal.  des  Wiener  Museums  fur 
Natiirgeschichte,  I,  1,  pp.  72-92,  mit  2  Taf. 
69a.  1877  Koren,  /.,  and  Danielssen,  D.  C.     En  ny  art  af 
slaegten  Pennella. — Faun.  litt.  Norweg.   3  Hft., 
pp.  157-163. 

70.  1837-38  Kroyer,    H.     Om    Snyltekrebsene,   isaer   med 

Hensyn  til  den  dansk  Fauna. — Naturhistorisk 
Tidsskrift,  Vol.  I.  pp.  172-208,  pp.  252-304,  pp. 
476-505,  pp.  605-628.  tab.  2-3  u.  5-6— II.  pp. 
8-52,  pp.  131-157,  tab  1  u.  3.  Kjobenhavn. 

71.  1863  idem.     Bidrag  til  Kundskab  otn  Snyltekrebsene. — 

Naturhistorisk  Tidsskrift,  3  die.  Raekke,  II  Bind, 
pp.  75-426,  tab.  1-18. — separat ;  Kjobenhavii. 
Via.  1877  Kurz,  W.     Studien  tiber  die  Familie  der  Lernaso- 
podiden. — Zeitschr.  f.  wiss.  Zool.  Bd.  XXIX. 

72.  1815-22  Lamarck,  G.  B.  P.  de.     Histoire  naturelle  des 

Animaux  sans  Vertebres,  Vol.  V.  (1818.)  Seven 
species  of  copepod  parasites  described. 

73.  1814  Leach,    1^.  E.      Crustaceology.      (In)  Edinburgh 

Encyclopedia. 

74.  1816  idem.     Supplement. — Annulosa.     loc.  cit. 

75.  1819  idem.  Article  Entomostraca  in  Diet.  d.Scienc.  Natur. 

76.  1746  Linnaeus,  C.     Fauna  Suecica.     1st  Edition.     Lug- 

duni  Batavorum. 

77.  1761  idem.     loc.  cit.     2nd  Edition.     Stockholmiae. 

78.  1766,  67,  68  idem.     Systema  Naturse.     12th  Edition. 

79.  1899  Ldnnberg,  E.     Bidrag  til  Kannedomen    oni  fritt 

lefvande  Caligider. — Verh.  Biol.  Ver.  Stock- 
holm, Bd.  I,  pp.  148-158. 

79a.  1860  Lubbock,  /.  On  some  oceanic  Entomostraca  col- 
lected by  Capt.  Toynbee. — Trans.  Linn.  Soc. 
London,  XXIII,  pp.  173-192,  pi.  29.  (Describes 
£aculus  elongatus  recognized  by  Mrazek  35  years 
later  to  be  a  larval  Pennella.) 

•80.  1890  Malard,  A.  E.  Catalogue  des  Poissons  (with  their 
parasites). — Bull.  Soc.  Philoniathique,  Paris,  8e 
ser.  Vol.  2,  No.  2. 

81.  1835-39  Mayer,  A.F.J.C.  Analekton  f iir  vergleichenden 

Anatomic.     Bonn. 
•82.  1863  M'Intosh,  W.  C.     Notes  on  the  food  and  parasites 

of  the   Salmo  salar  Linn,  of   the  Tay. — Journ. 

Linn.  Soc.  London,  Zool.,  Vol.  VII,  pp.  145-154. 


240  BRITISH   PARASITIC    COPEPODA. 

83.  1880  Miers,  E.  J.  On  a  small  collection  of  Crustacea  made 

by  Edmund  Whymper,  Esq.,  chiefly  in  the  N. 
Greenland  seas,  &c. — Journ.  Linn.  Soc.  London, 
Zool.,  Vol.  XV,  pp.  59—73  (records  Caligus  curtus, 
Dinematura  ferox,  and  Lernaeopoda  elongata). 

84.  1895  Mrazek,  Al.     Ueber  Bacnlus  Lubb.   und  Hessella- 

Brady,  ein  Beitrag  zur  Anatomie  der  Lernasiden. 
Mit  2  Taf.  und  2  Holzclm. — Sitzgsber.  K.  Bohm. 
G-es.  Wiss.,  math.-nat.  Cl.  XL1V.  Ausz.  vom. 
Verf.  Zool.  Centrabl.  3  Ihg.  n.  7,  pp.  237-238. 

85.  1777  Miiller,  0.  F.     Zoologia  Danica. 

86.  1785  idem.     Entomostraca,  seu  Insecta  testacea  quae  in 

aquis  Daniae  et  Norvegiae  reperit.  descripsit,  et 
iconibus  illustravit.  Lipsiae  et  Hafniae  (Leipzig 
and  Copenhagen). 

87.  1903  Norman,    A.   M.      Ne\v  generic  names   for  some- 

Entomostraca  and  Cirripedia.  —  Ann.  and  Mag. 
Nat.  Hist.,  (7)  XI,  pp.  367-369. 

87a.  1910  Norman,  A.  M.,  and  Brady,  G.  8.  The  Crus- 
tacea of  Northumberland  and  Durham. — Trans. 
Nat.  Hist.  Soc.  Northumberland,  Durham,  and 
Newcastle-upon-Tyne.  N.S.,  Vol.  Ill,  part  2. 

88.  1906  Norman,    A.    M.,    and    Scott,    T.     Crustacea   of 

Devon  and  Cornwall.     London. 

89.  1832  Nordmann,    A.      Mikrographische    Beitrage   zur 

Naturgeschichte  der  wirbellosen  Thiere,  2rHefte. 
Berlin. 

90.  1864  idem.     Neue  Beitrage  zur  Kenntniss  parasitischei- 

Copepodeu.  Erster  Beitrag. — Bull,  de  la  Soc. 
des  Natur.  de  Moscou,  XXXVII,  2,  pp.  461-520, 
Taf.  5-8. 

91.  1815  Oken,   L.     Lehrbuch    der    Naturgeschichte.     Th. 

Ill,  p.  184,  If.,  und  p.  357,  ff.  (Schisturus  replaced 
by  Clavella  as  the  first  name  was  occupied  by 
Rudolphe  in  1809  for  a  genus  of  Venues). 

92.  1868  Olsson,  P.     Prodromus  faunae  Copepodorurn  para- 

sitantiinn  Scandinavia?.  Lunds  Univ.  Arsskrift.^ 
Tom.  V. 

93.  1828  Otto,  A.  W.     Beschreibung  einiger   neuen,  in  den 

jahren  1818  und  1819  irn  mittellandischen  Meere- 
gefundener  Crustaceen. — Nova  Acta  Acad.  Leo- 
pold. Carolin.,  Vol.  XIV,  Pt.  1,  pp.  351-354,  Mit 
drei  Kupfertafelen. 


LITERATURE    CHIEFLY    REFERRED    TO.  241 

94.  1861  Pagenstecher,  Dr.  A.  H.     Thersites   gasterostei, 

eine  Gattung  parasitischer  Crustaceen. — Weig- 
mann's  Archiv.  f.  Naturgesch.  XXVII,  1,  pp. 
118-126,  Taf.  6. 

95.  1905  Pearson,  J.     A  list  of  the  Marine  Copepoda  of 

Ireland.  I,  Littoral  forms  and  Fish  Parasites. — 
Fish.  Ireland  Sci.  Invest.  1904,  iii. 

96.  1838  Pickering,  Ch.,  and  Dana,  /.  D.     Description  of 

a  species  of  Caligus  (C.  americamis). — Silliman's 
Americ.  Journ.  of  Science,  XXXIV,  pp.  225-266, 
pi.  3-5.  Read  before  the  Yale  Nat.  Hist.  Soc., 
Feb.  20,  1838. 

97.  1902  Poche,  F.  R.      Bemerkungen  zu  der  Arbeit  des 

Herrn  Bassett- Smith  'A  Systematic  Description 
of  Parasitic  Copepoda  found  on  Fishes,  with  an 
Enumeration  of  the  known  Species ' — Zool. 
Anzeig.,  26  Bd.  n.  685,  pp.  8-20. 

97a.  1884  Rathbun,  Rich.  Annotated  List  of  the  described 
species  of  parasitic  Copepoda  (Siphonostoma) 
from  American  Waters  contained  in  the  United 
States  National  Museum. — Proc.  U.  S.  National 
Museum,  Vol.  7,  pp.  483-492. 

98.  1887  idem.     Descriptions  of  (4)  new  species  of  parasitic 

Copepods  belonging  to  the  genera  Trebius, 
Ptrissopus,  and  Lernanthropus . — Proc.  U.  S. 
National  Museum,  Vol.  10,  pp.  559-571. 

99.  1887  idem.     Descriptions  of  parasitic  Copepoda  belong- 

ing to  the  genera  Pandarus  and  Chrondr acanthus. 
With  7  plates.— Loc.  tit.,  Vol.  9,  pp.  310-324. 
Abstr.  in  Journ.  Roy.  Microsc.  Soc.  1887,  pt.  3,. 
p.  395  (4n.  sp.). 

99a.  1839  Rathke,  E.  Bemerkungen  iiber  den  Bau  des 
DicJielesthium  sturionis  und  der  Lernseopoda  stel- 
lata. — Nova  Acta  Acad.  Leopold. -Carolin.,  Vol. 
XIX,  1,  pp.  125-168,  mit  1  plate. 

100,101.  1843  idem.  Beitrag  zur  Fauna  Nor wegens. — Nova 
Acta  Acad.  Leopold.-Carolin.,  Vol.  XX,  1,  pp. 
1-264,  mit  12  Taf. 

VOL.  I.  16 


242  BRITISH    PARASITIC    COPEPODA. 

101a.l829-31  RetzillS,  A.  Beskrifning  of ver  en  ny  Skandi- 
navisk  Lernsea  fran  Nordsjon,  kallad  Lernsea 
Dalmanni. — Kongl.  Vetensk.  Akad.  Handling, 
Stockholm,  pp.  109-119,  c.  tab.  oppure :  Be- 
schreibung  einerneuen  Scandinavischen  Lernsea 
aus  dem  Nordsee,  Lernasa  Dalmanni  gennant. 
Froriep's  Notizen,  Bd.  XXIX,  p.  6,  figs.  5-9, 
1830.  Idem  in  Isis,  1831,  p.  1345,  Taf.  IX. 

102.  1877  Richiardi,  8.     Descrizione  di  due  specie  nuove 

di  Lernasenicus  (L.  neglectus,  L.  vorax)  con 
osserv.  intorno  a  questo  ed  ai  gen.  Lernaeocera 
Bl.  e  Lernwonema  M.  Edw. — Atti  Soc.  Tosc.  Sc. 
Nat.  Pisa,  Vol.  Ill,  fasc.  1. 

103.  1878  idem.     Tripaphyhis      musteli. — Processi      verbali, 

Soc.  Tosc.  So.  Nat.  Pisa,  XX. 

104.  1880  idem.       Catalogo    sistematico    dei    crostacei    che 

vivona  sul  corpo  degli  animali  aquatici. — Cata- 
logo Sez.  Ital.  Esposiz.  Internaz.  di  Pesca, 
Berlino,  1880 — Firenze — anche  in  Pisa  tip. 
Vannucchi  1880  (8  pp.)-  For  Clavella  can- 
thari,  &c. 

105.  1826  Risso,  A.     Histoire  naturelle  des  productions  de 

1'Europe  meridionale,  Vol.  V,  p.  175  Paris. 
Refers  to  Otto's  Caligus  minimus,  &c. 

105a.  1886  Sars,  G.  0.  The  Norwegian  North  Atlantic  Ex- 
pedition 1876-1878,  Zoology — Crustacea,  Part 
II,  p.  80.  (Records  Anchorella  uncinata  and 
Hsemobaplies  cyclopterinus.) 

106.  1850  Salter,  James.   Description  of  Lerneonema  Bairdii. 

— Ann.  and  Mag.  Nat.  Hist.,  (2)  VI,  pp.  85-87, 
pi.  vii  B. 

107.  1901  Scott,  A.     Some  additions  to  the  Fauna  of  Liver- 

pool Bay. — Trans.  Biol.  Soc.  of  Liverpool, 
Vol.  XV,  pp.  342-353,  with  2  pis. 

108.  1901  idem.       Lepeophtheirus    and     Lernsea. — Liverpool 

Marine  Biology  Committee  Memoirs,  No.  VI, 
54  pp.,  with  5  plates. 

109.  1904  idem.     Some  parasites  found  on  fishes  in  the  Irish 

Sea. — Trans.  Biol.  Soc.  Liverpool,  Vol.  XVI II, 
pp.  119-125. 

110.  1906  idem.     Faunistic  Notes. — Loc.  cit.,  Vol.  XX,  pp. 

191-201.  with  pis.  ii-vii. 


LITERATURE    CHIEFLY   REFERRED   TO.  243 

111.  1907  SCOTT,   A.    (contd.).      Faunistic    Notes. — Loc.   cit., 

Vol.  XXI,  pp.  191-198,  with  pis.  i-v. 

Ilia.  1893  Scott,  T.  Additions  to  the  Fauna  of  the  Firth 
of  Forth.  Part  V. — 1 1th  Annual  Eeport  Fishery 
Board  for  Scotland,  Part  III,  p.  212,  pi.  Y,  figs. 
1-13. 

lllb.  1894  idem.  Additions  to  the  Fauna  of  the  Firth  of 
Forth.  Part  VI. — 12th  Annual  Report  loc. 
cit.  p.  233. 

lllc.  1897  idem.  The  Marine  Fishes  and  Invertebrates  of 
LochFyne. — 15th  Annual  Report  loc.  cit.  p.  155. 

Hid.  1898  idem.  On  the  distribution  of  the  pelagic  Inverte- 
brate Fauna  of  the  Firth  of  Forth  and  its 
vicinity  during  the  seven  years  from  1889  to 
1895,  both  inclusive. — 16th  Annual  Report  loc, 
cit.  p.  177. 

112.  1900  idem.      Notes    on  some    Crustacean    Parasites    of 

Fishes. — 18th  Annual  Report  loc.  cit.  pp.  144- 
188,  pis.  V-VIII. 

113.  1901  idem.     Notes  on  some  Parasites  of  Fishes. — 19th 

Annual  Report  loc.  cit.  pp.   120-151,  pis.  VII- 
VIII. 

114.  1902  idem.     Notes  on  some  Parasites  of  Fishes. — 20th 

Annual  Report  loc.  cit.  pp.  288-299,  pis.  XII, 
XIII. 

115.  1904  idem.      On  some  Parasites  of  Fishes  new  to  the 

Scottish  Marine  Fauna. — 22nd  Annual  Report 
loc.  cit.  pp.  275-278,  pi.  XVII. 

116.  1905  idem.     Observations  on  some  Parasites  of  Fishes 

new    or    rare  in   Scottish    Seas. — 23rd  Annual 
Report  loc.  cit.  pp,  108-115,  pis.  V— VI. 

117.  1907  idem.      Some  additional  notes  on   Copepoda  from 

the  Scottish  Seas. — 25th  Annual  Report  loc.  cit. 
pp.  216-218,  pi.  XV. 

118.  1909  idem.       Some    notes    on     Fish    Parasites.  —  26th 

Annual  Report  loc.  cit.  pp.  73-77,  pi.  III. 

119.  1900  idem.     On  Copepods  living  in  the  nostrils  of  Fishes. 

—Ann.  Scott.  Nat.  Hist.  pp.  153-155  (July  1900). 

120.  1901  idem.     ClavelJa  labracis,  van  Ben.,  a  Copepod  new 

to  Britain. — Ann.  Scott.  Nat.  Hist.  pp.  110-121 
(April,  1901). 


244  BRITISH    PARASITIC    COPEPODA. 

121.  1883  Smith,  8.  I.     Review  of  the  marine  Crustacea  of 

Labrador. — Proc.  U.  S.  National  Museum,  pp. 
223-232. 

121a,  1899  Stebbing,  T.  R.  R.  Genus  Sphyrion  Cuvier.— 
Rep.  Marine  Biolog.  Cape  Town,  1898,  p.  897. 

122.  1900  idem.     South  African  Crustacea,  Part  I. — Cape  of 

Good  Hope  Department  of  Agriculture,  Marine 
Investigations  in  South  Africa. — Records  Sphy- 
rion laevigatiis,  Guerin-Meneville. 

123.  1900  idem.     On  Crustacea  brought  by  Dr.  Willey  from 

the  South  Seas. — A.  Willey's  Zoological  Results, 
Pt.  V  (Cambridge  Univ.  Press),  Dec.  1900. 

124.  1905  South  African  Crustacea,  Part  iii. — Marine  Investi- 

gations in  South  Africa,  Vol.  IV. 

125.  1910  idem.      General  Catalogue  of  South  African  Crus- 

tacea. (Contains  also  descriptions  of  new 
species.) — Annals  of  the  South  African  Museum, 
Vol.  VI,  Part  IV. 

126.  1862  Steenstrup,  /.  J.  8.     Philichthy*  xiphise,  en  ny 

snylter  hos  Svaerdfisken. — Overs.  Kongel. 
Danske  Vidensk.  Selsk.  Forhandl.  1861,  pp. 
295-305,  pi.  2. 

126a.  1869  idem.  Om  Lesteira,  Silenium,  og  Pegesimallus, 
tre  af  Prof.  H.  Kroyer  opstillede  Slaegter  af 
Snyltekrebs. — Overs.  Kongel.  Danske  Vidensk. 
Selsk.  Forhandl.  1869. 

127.  1861  Steenstrup,  J.  J.  S.,  and  Liitken,  C.    Bidrag  til 

Kundskab  om  det  aabne  Havs  Synltekrebs  og 
Lernager,  etc. — Kongel.  Danske  Vidensk.  Selsk. 
Skrifter,  5te  Raekke,  naturh.  og  math.  Afdeling, 
Bd.  .V.  Kjobenhavn. 

128.  1844  Thompson,  TT*.     Report  on  the  Fauna  of  Ireland, 

div.  Invertebrata. — Report  of  the  British  Asso- 
ciation for  1843. 

129.  1847  idem.     Additions  to  the  Fauna  of  Ireland.     (Lepe- 

ophtheirus  stromi,  etc.). — Ann.  and  Mag.  Nat. 
Hist.,  Ser.  I,  Vol.  XX,  p.  248. 

130.  1856  idem.     Natural     History    of    Ireland,    Vol.    IV, 

p.  407.     London. 

131.  1885  Thomson,    G.    N.      Parasitic    Crustacea.— New 

Zealand  Journ.  of  Science,  Vol.  2,  p.  455 ;  New 
Crustacea,  loc.  cit.  p.  576. 


LITERATURE    CHIEFLY   REFERRED    TO.  245 

132.  1889  THOMSON,  G.  N.  (contd.)      Parasitic  Copepocla  of 

New  Zealand,  with  descriptions  of  new  species. 
— Trans.  New  Zealand  Instit.,  Vol.  22  (N.S. 
Vol.  5),  pp.  353-376  (13  n.  sp.),  with  5  plates. 

133.  1890  idem.     A  new   parasitic   Copepod. — Trans.  New 

Zealand  Instit.,  Vol.  23  (N.S.  Vol.  6),  pp.  227- 
229,  with  1  plate. 

134.  1889  Thompson,  I.  C.     Third  Report  on  the  Copepoda 

of  Liverpool  Bay. — Proc.  Biol.  Soc.  Liverpool, 
Vol.  Ill,  pp.  181-191,  pi.  viii. 

135.  1893  idem.     Revised  Report  on  the  Copepoda  of  Liver- 

pool Bay. — Trans.  Biol.  Soc.  Liverpool,  Vol.  VII, 
pp.  175-230,  pis.  xv— xxxv. 

136.  1897  idem.      Further  Report  upon  the  Free-Swimming 

Copepoda  of  the  West  Coast  of  Ireland. — Trans. 
Biol.  Soc.  Liverpool,  Vol.  XI,  pp.  127-131. 
Refers  to  the  swimming  habits  of  Caligus. 

137.  1900  Thompson,  I.   C.,  and  Scott,  A.     Some  recent 

additions  to  the  Copepoda  of  Liverpool  Bay. — 
Trans.  Biol.  Soc.  Liverpool,  Vol.  XIV,  pp.  139- 
144,  pi.  viii. 

138.  1903  idem.      Supplementary  Report  VII.     On  the  Cope- 

poda.— Report  to  the  Government  of  Ceylon  on 
the  Pearl  Oyster  fisheries  of  the  Gulf  of  Manaar, 
Part  I,  pp.  227-307,  with  20  plates.  Published 
by  the  Royal  Society,  London. 

139.  1905  Turner,    Sir    W.     On    Pennella    balsenopterie :   a 

Crustacean,  parasitic  on  a  firmer  Whale Balsenop- 
tera  musculus. — Trans.  Roy.  Soc.  Edinburgh, 
Vol.  XLI,  Part  II,  No.  18,  pp.  409-434,  with  4 
plates. 

140.  1862  Turner,  Sir  W.,  and  Wilson,  R.  S.    Observations 

on  Parasitic  Crustacea  C 'ho udr acanthus  lophii 
and  Lernseopoda  dalmanni. — Trans.  Roy.  Soc. 
Edinburgh,  Vol.  XXIII,  part  I,  pp.  67-87,  pi.  4. 

141.  1807  Turton,  IF.     British  Fauna,  Vol.  I. 

141a.  1880  Valle?  A.  Delia.  Crostacei  parassiti  dei  Pesci 
del  mare  Adriatico. — Boll.  Soc.  Adriat.  Sc.  Nat., 
Vol.  VI,  pp.  55-90. 

142.  1877  Vogt,  C.     Recherches   cotieres  faites  a  Roscoff ; 

Crustaces  parasites  des  Poissons.  Avec  6  pis. 
Geneve.  H.  Georg.  1877,  p.  104 — oppure  :  Arch. 
Zool.  Exper.  et  Gen.  VI,  1877,  pp.  385-456. 


246  BRITISH   PARASITIC    COPEPODA. 

143.  1879  VOGT,  C.  (contd.).     Crustaces  parasites  des  Poissons. 

— Memoires  de  1'Institut  National  Genevois,  Vol. 
XIII.  (Two  Memoirs — separate  copies)  pp.  1- 
104,  6  plates. 

143a.  1902  Wilson,  Ch.  Branch.  North  American  Parasitic 
Copepods  of  the  Family  Argulidas,  with  a  Biblio- 
graphy of  the  Group  and  a  Systematic  Review 
of  all  the  known  Species. — Proc.  U.S.  National 
Museum,  Vol.  XXV,  pp.  635-742,  with  plates 
VIII-XXVIL 

143b.  1904  idem.  A  new  species  of  Argulus,  with  a  more  com- 
plete account  of  two  species  already  described. 
—Proc.  U.  S.  National  Museum,  Vol.  XX VII, 
pp.  627-655. 

144.  1905  idem.     New  species  of  Parasitic  Copepods  from 

the  Massachusetts  Coast. — Proc.  Biol.  Soc. 
Washington,  Vol.  18,  pp.  127-131. 

145.  1905  idem.     North  American  Parasitic  Copepods  belong- 

ing to  the  Family  Caligidas.  Part  1.  The 
Caliginae. — Proc.  U.  S.  National  Museum,  Vol. 
XXVIII,  pp.  479-672,  with  plates  V-XXIX. 

146.  1906  idem.     Supplementary  Report  XXXIV.     On  some 

Parasitic  Copepoda. — Report  to  the  Government 
of  Ceylon  on  the  Pearl  Oyster  Fisheries  of  the 
Gulf  of  Manaar,  Pt.  V,  pp.  189-210,  with  5 
plates.  Published  by  the  Royal  Society,  London. 

147.  1907  idem.     North  American  Parasitic  Copepods  belong- 

ing to  the  Family  Caligidae.  Part  2,  The  Trebinae 
and  Euryphorinae. — Proc. U.S.  National  Museum, 
Vol.  XXXI,  pp.  669-720,  with  plates  XV-XX. 

148.  1907  idem.     North    American    Parasitic    Copepods   be- 

longing to  the  Family  Caligidas.  Parts  3  and  4, 
A  Revision  of  the  Pandarinag  and  the  Cecro- 
pinag. — Proc.  U.  S.  National  Museum,  Vol. 
XXXIII,  pp.  323-490,  with  plates  XVII-XLIII. 
148a.  1907  idem.  Additional  Notes  on  the  development  of 
the  Argulidse,  with  description  of  a  new 
species. — Proc.  U.  S.  National  Museum,  Vol. 
XXXII,  pp.  41 1-424,  with  plates  XXIX-XXXII. 

149.  1908  idem.     North    American    Parasitic    Copepods :    A 

list  of  those  found  upon  the  fishes  of  the  Pacific 
Coast,  with  descriptions  of  new  genera  and  spe- 
cies.—Proc.  U.  S.  National  Museum,  Vol.XXXV, 
pp.  431-481,  with  plates  LXVI-LXXXIII. 


LITERATURE    CHIEFLY   REFERRED   TO.  247 

149a.  1911  WILSON,  C.  B,  (contd.}.  North  American  Parasitic 
Copepods  belonging  to  the  Family  Ergasilidae. 
— Proc.  U.S.  ISational  Museum,  Vol.  39,  pp. 
263-400,  with  plates  41-60. 

149b.  1911  idem.  North  American  Parasitic  Copepods. — 
Part  9.  the  Lernaeopodee.  — Proc.  U.  S.  National 
Museum,  Vol.  39,  pp.  189-226,  with  plates  29-36. 

149c.  1911  idem.  North  American  Parasitic  Copepods. 
Descriptions  of  new  genera  and  species. — Proc. 
U.  S.  National  Museum,  Vol.  39,  pp.  625-634, 
with  plates  65-68. 

149d.  1912  idem.  'Descriptions  of  new  species  of  Parasitic 
Copepods  in  the  collections  of  the  United  States 
National  Museum. — Proc. U.S.  NationalMuseum, 
Vol.  42,  pp.  233-243,  with  plates  30-34. 

149e.  1912  idem.  Parasitic  Copepods  from  Nanaimo,  British 
Columbia,  including  eight  species  new  to  science. 
— Contributions  to  Canadian  Biology  being 
studies  from  the  Marine  Biological  Stations  of 
Canada  1906—1910,  pp.  85-102,  with  plates 
III-IX. 

150.  1870  Wright,  Edw.  Perceval.  On  a  new  species  of  the 
genus  Pennellu. — Ann.  and  Mag.  Nat.  Hist., 
Ser.  4,  Vol.  V,  p.  45,  pi.  1. 


(248) 


INDEX. 

(Synonyms  in  italics.) 


PAGE 

A. 

Binoculus 

abbreviatus,  Caligus 

.       50 

bispinosa,  Beach  iella 

acanthii,  Eudactylina   . 

.     128 

Bomolochus 

Achteres  . 

.     193 

boscii,  Pandarus 

Achtheres 

.     193 

Brachiella 

Aether  es  . 

.     193 

Brachiella 

acuta,  Eudactylina 

.     126 

brachyptera,  Elytrophora 

ieglifini,  Caligus 

.       45 

branchialis,  Caligus 

alata,  Clavella    . 

.     225 

branchialis,  Lernsea 

alata,  Dinemottra 

.       89 

brevicaudatus,  Caligus  . 

alatus,  Pandarus 

.       89 

brevicollis,  Anchorella     . 

ambiguus,  Huemobaphoides 

148 

brevicollis,  Clavella 

ambiguus,  Hsemobaphus 

.     148 

brevipedes,  Caligus 

ambiguus,  Nogagus 

.       78 

brevipedes,  Pseudocaligus 

ambiguus,  Nogaus 

.       78 

Anchorella 

.     213 

C. 

angustulus,  Nogagua 

.       95 

CALIGID^E 

annulatus,  Chondracanthus 

.     169 

CALIGOIDA 

Anops 

.     168 

Caligus   . 

Anthosoma 

.     108 

Caligus     . 

Argulus  . 

.     227 

canthari,  Anchorella 

argulus,  Argulus 

.     227 

canthari,  Clavella 

argulus,  Monoculus 

.     227 

canthari,  Lerneomyzon   . 

Arnaeus   . 

.       83 

carpionis,  Lerneopoda 

asellina,  Lernaea 

.     184 

caudatus,  Trebius 

asellina,  Lernentoma 

.     184 

Cecrops    . 

asellinum,  Medesicaste  . 

.     184 

Cecropsina 

asellinus,  Oralien 

.     184 

centrodonti,  Caligus 

asterodermi,  Liitkenia  . 

.       76 

charon,  Arguhis 

Charopinus 

B. 

CHONDRACANTHIDJE 

bairdi,  Lernxonema 

.     156 

Chondracanthus 

balsenopterae,  Penella     . 

.     153 

Chondracanthus  . 

Basanistes 

.     199 

clavatus,  Chondracanthus 

bicolor,  Pandarus 

.       95 

Clavella  . 

bicuspidatus,  Caligus 

.       45 

Clavella  . 

bidiscalis,  Lernseopoda 

.     200 

cluthse,  Clavella 

PAGE 

227 

211 

36 

95 

203 

187 

83 

69 

142 

56 

220 

220 

Q{ 

61 


44 

43 

44 

79 

224 

224 

224 

199 

81 

97 

75 

50 

227 

188 

166 

167 

183 

175 

213 

112 

117 


IXDEX. 


249 


cluthae,  HatscheMa 
cluthae,  Lernseopoda 
coleoptrata,  Dinematura  • 
coleoptratus,  Echthrogaleus 
Congericola 

cornigera,  Hatschekia   . 
cornuta,  Anops    . 
cornuta,  Entomoda 
cornuta,  Lernsea 
cornuta,  Lernentoma 
cornuta,  Phyllophora 
comutus,  Chondracanthus 
eornutus,  Phyllophorus  . 
cornutus,  Phyllothreus 
crass  um,  Anthosoma 
•crassus,  Caligus  . 
curt  us,  Caligus  . 
•Cyclopoida 

cyclopterina,  Hsemobaphes 
cyclopterina,  Lernsea 
cyclopterina,  Lernseocera 
Cycnus     . 

cyprinacea,  Lernsea 
cyprinacea,  Lernseocera 
cyprinacea,  Lerneocera    . 

I). 

dalmanni,  Charopiuus   . 

dalmanni,  Lernsea  . 

dalmanni,  Lernseopoda   . 

dalmanni,  Lerneopoda    . 

delarochianus,  Chondracanthus 

Demoleus 

depressus,  Chondracanthus 

diaphanus,  Caligus 

diaphanus,  Caligus 

Dichelestiidae 

Dichelestium 

Dinematura 

Dinemoura 

dubia,  Clavella  . 

dubius,  Charopinus 

E. 

Echthrogaleus   . 
edwardsi,  Lophoura 
edwardsi,  Lophura 


PAGE 

PAGE 

.       117 

edwardsi,  Rebelula 

.     162 

.     198 

elongata,  Dinematura     . 

.       86 

.       89 

elongata,  Lernsea 

.     195 

.       89 

elongata,  Lernseopoda   . 

.     195 

.     124 

elongata,  Lerneopoda 

.     195 

.     118 

elongatus,  Caligus 

.       48 

.     168 

Elytrophora 

.       82 

.     168 

emarginata,  Anchorella  . 

.     218 

.     168 

emarginata,  Clavella     . 

.     218 

.     168 

encrasicola,  Lernsea 

.     158 

.       92 

encrasicola,  Lernseenicus 

.     158 

.     168 

encrasicola,  Lerneonema 

.     158 

.       92 

Entomoda 

.     168 

.       92 

ERGASILID.S; 

.       33 

.      108 

Ergasilus 

.       34 

.     108 

esocina,  Lernsea  . 

.     154 

.       45 

esocina,  Lernseocera 

.     154 

.       33 

Eudactylina 

.     125 

.      147 

.     147 

F. 

.     147 

filrosa,  Pennella 

.     151 

.     124 

filosa,  Pennela 

.     151 

.     154 

filosa,  Pennella    . 

.     150 

.     154 

fissifrons,  Pandarus 

.       95 

.     154 

nurse,  Chondracanthus  . 

.     171 

foliaceus,  Argulus 

.     227 

foliaceus,  Monoculus 

.     227 

.     189 

.     189 

G. 

.     189 

galei,  Lernaeopoda 

.     197 

.     189 

galei,  Lerneopoda 

.     197 

us    177 

gasterostei,  Binoculus 

.     227 

.       79 

gasterostei,  Ergasilus 

.       42 

172 

gasterostei,  Ozolus 

.     227 

.       60 

gasterostei,  Ther  sites 

.       42 

.       45 

gasterostei,  Thersitina  . 

.       42 

.     105 

gibbosus,  Chondracanthus 

.     179 

.     105 

glabra,  Cecropsina 

.      76 

85,  103 

gracilis,  Caligus 

.       69 

.       85 

gracilis,  Leopeophtheirus 

.       69 

.     217 

grandis,  Nogagus 

.       79 

.     190 

gurnardi,  Caligus 

.       52 

gyrini,  Monoculus 

.     227 

.       88 

H. 

.     162 

Haemobaphes 

.     147 

.     162 

Haemobaphes 

.     148 

250 


BRITISH    PARASITIC   COPEPODA. 


PAGE 

PAGE 

Haemobaphoides 

.     148 

Lerneopoda 

.     188 

Hatschekia 

.     112 

Lesteira    . 

.     164 

hippoglossi,  Caligus 

.      67 

Lestes 

.     164 

hippoglossi,  Clavella 

.     112 

limandtB,  Chondracanthus 

.     174 

hippoglossi,  Hatschekia 

.     112 

lineata,  Kroyeria 

.     121 

hippoglossi,  Lepeophtheirus 

.       67 

lineatum,  Lonchidium    . 

.     121 

hypocephalus,  Stylophorus 

.     189 

Lonchidium 

.     12a 

lophii,  Brachiella 

.     226 

I. 

lophii,  Chondracanthus 

.     179 

imbricatus,  Caligus 

.     108 

lophii,  Clavella  . 

.     22& 

impudica,  Brachiella 

.     187 

Lophoura 

.     162 

iinpudica,  Thysanote 

.     187 

Lophura  . 

.     162 

inflatus,  Chondracanthus 

.     169 

lumpi,  Lernsea    . 

.     146 

inominatus,  Lepeophtheirus 

.       73 

lumpi,  Lesteira    . 

.     164 

insidiosa,  Brachiella 

.     2U6 

lumpi,  Lestes 

.     164 

insolens,  Eudactylina    . 

.     135 

lumpi,  Sphyrion 

.     164 

isonyx,  Caligus   . 

.       60 

lusci,  Lernsea 

.     144 

liitkeni,  Echthrogaleus 

.       90 

K. 

liitkeni,  Nogagus 

.       90 

Kroyeria 

.     120 

Liitkenia 

.       75 

kroyeri,  Lernanthropus 

.     110 

M. 

L. 

macrotrachelus,  Clavella 

.     224 

labracis,  Caligus 

.       53 

Medesicaste 

.     183 

labracis,  Clavella 

.     115 

merluccii,  Brachiella 

.     207 

labracis,  Hatschekia 

.     115 

merluccii,  Chondracanthus 

.     180 

Lsemargus 

.     100 

merlucii,  Brachiella 

.     207 

Isevirajse,  Chondracanthus 

.     169 

merlucii,  Chondracanthus 

.     181 

lamnse,  Dinemoura 

.       86 

merlucii,  Lernsea 

.     180 

lamn:c,  Pandarus 

.       86 

minimus,  Caligus 

.       46 

lampri,  ?  Lernseopoda    . 

.     202 

minuta,  Eudactylina 

.     133 

latreillii,  Cecrops 

.       98 

minuta,  Lernaea 

.     145 

latus,  Nogagus    . 

.       95 

minutus,  Caligus 

.       46 

Lepeophtheirus 

.       64 

monilaris,  Lerneonema  . 

.     156 

Lernsea   . 

.     142 

Monoculus 

.     227 

Lernsea    . 

.     184 

miilleri,  Caligus 

.       45 

Lernaeenicus 

.     156 

mulli,  Clavella    . 

.     114 

LBKN^IDJE 

.     141 

mulli,  Hatschekia 

.     114 

Lernseocera 

.     154 

muricata,  Orthagoriscicola 

.     1UO 

LERN.EOIDEA 

141    ]   muricatus,  Lsemargus 

.     100 

Lernaeopoda 

.     195 

musteli,  Lernseenicus 

.     160 

LBRN^OPODIDA;  . 

.     186 

musteli,  Lerneonema 

.     160 

Lernanthropus  . 

.     110 

musteli,  Tripaphylus     . 

.     160 

Lementoma 

167,  183 

Lerneocera 

.     154 

N. 

Lerneomyzon 

.     213 

nanus,  Ergasilus 

.       34 

Lerneonema 

.     159 

nodosa,  Lernsea   . 

.     176 

INDEX. 


251 


PAGE 

nodosa,  Lernentoma        .  .  176 

nodosus,  Chondracanthus  .  176 

Nogagus  .  .  .  .77 

Nogaus   .  .  .  .77 

nordmanni,  Caligus        .  .  66 

nordmanni,  Lepeophtheirus  .  66 

O. 

oblongum,  Dichelestium  .  106 

oblongus,  Caligus             .  .  106 

obscurus,  Caligus             .  .  70 

obscurus,  Lepeophtheirus  .  70 

obscurus,  Lepeophtheirus  .  67 

obscurus,  Lepeophtheirus  '.  69 

onosi,  Bomolochus         .  .  39 

Oralien    ....  183 

ornatus,  Chondracanthus  .  182 

orthagorisci,  Pennella  .  .  150 

Orthagoriscicola             .  .  100 

ovalis,  Anchorella            .  .  210 

ovalis,  Brachiella           .  .  210 

Ozolus      .             .'  .  227 

P. 

pagelli,  Anchorella          .  .  224 

pallida,  Congericola       .  .  124 

pallidus,  Cycnus              .  .  124 

Pandarus  .  .  .94 

paradoxa,  Anchorella     .  .  222 

paradoxa,  Clavella         .  .  222 

paradoxus,  Caligus          .  .  79 

paradoxus,  Demoleus    .  .  79 

parkeri,  Brachiella         .  .212 

pastinaca,  Brachiella     .  .211 

pastinacse,  Brachiella      .  .212 

pectoralis,  Caligus           .  .  64 

pectoralis,  Lepeophtheirus  .  64 

pectoralis,  Lernsea           .  .  64 

pelamydis,  Caligus         .  .  57 

Pennela                .             .  .  151 

Pennella              .  .  149 

percarum,  Achteres          .  .  193 

percarum,  Achtheres     .  .  193 

percarum,  Actheres          .  .  193 

PHILICHTHYID.SC             .  .  137 

Philichthys         .  .  138 

Philorthragoriscus         .  .  103 


PAGE 

Phyllophora        .             .  .92 

Phyllothreus      .             .  .92 

pollachii,  Lepeophtheirus  .       73 

pollachius,  Lepeophtheirus  .       73 

producta,  Dinematura    .  .       86 

producta,  Dinemoura    .  .       86 

productus,  Caligus          .  .       86 

productus,  Nogagus         .  .       86 

Pseudocaligus    .             .  .61 

pygmaea,  Hatschekia     .  .119 


quadrata,  Anchorella  .  .  223 

quadrata,  Clavella  .  .  223 

E. 

ramosus,  Charopinus  .  .  191 

rapax,  Caligus    .  .  .48 

Eebelula  .  .  162 

rhombi,  Lepeophtheirus  .  .  69 

rostrata,  Brachiella  .  .  205 

rugosa,  Anchorella  .  .  216 

rugosa,  Clavella  .  .  216 

S. 

salmonea,  Basenistes  .  .  199 

salmonea,  Entomoda  .  .  199 

salmonea,  Lernsea  .  199 

salmonea,  Lernseopoda  .  .  199 

salmonea,  Lerneopoda  .  .  199 

salmonis,  Caligus  .  .  71 

salmonis,  Lepeophtheirus  .  71 

Schislurus            .  .  .  213 

Scisenophilus      .  .  .62 

scomberi,  Anchorella  .  .  219 

scomberi,  Caligus  .  .  57 

scombri,  Anchorella  .  .  218 

scombri,  Clavella  .  .  218 

serrata,  Dinematura  .  .  104 

serratus,  Philorthragoriscus  .  104 

similis,  Eudactylina  .  .  130 

similis,  Lernseopoda  .  .  202 

smithii,  Anthosoma  .  .  108 

sole®,  Bomolochus  .  .  36 

solese,  Chondracanthus  .  170 

Sphyrion  .  .  164 

sprat ta,  Lernsea  .  .  .  156 


252 


BRITISH   PAUASITIC    COPEPODA. 


spratta,  Lernseenicus 
spratta,  Lermnonema 
sprattae,  Lernseenicus    . 
stellata,  Anchorella 
stellata,  Clavella 
stromi,  Lepeophtheirus    . 
stromii,  Lepeophtheirus  . 
sturionis,  Caligus 
sturionis,  Dichelestium  . 
sturionis,  Lepeophtheirus 
Stylophorus 

T. 

tenuis,  Scisenophilus 

tennis,  Scienophilus 

Thersites 

Thersitina 

thompsoni,  Lepeophtheirus 

thynni,  Arnseus    . 

thynni,  Brachiella 

Thysanote 

Trebius  . 

triglie,  Anchorella 

triglse,  Brachiella 


PAGE 

156 

triglse,  Chondracanthus  . 

156 

triglse,  Lernentoma 

156 

triglarum,  Medesicaste    . 

220 

Tripaphylus 

220 

tuberculatus,  Chondracanthus 

71 

71 

U. 

74 

uncinata,  Anchorella 

106 

uncinata,  Clavella 

74 

uncinata,  Lernsea 

189 

uncinatum,  Lerneomyzon 

uncinatus,  Schisturus 

63 

W. 

63 

williamsoni,  Chondracanthus 

41 

41 

X. 

69 

xiphiee,  Philichthys 

83 

204 

Z. 

187 

zei,  Caligus 

81 

zei,  Chondracanthus 

209 

zeugopteri,  Bomolochus 

209 

zeus,  Chondracanthus 

I'AGK 

184 
184 
185 
159 
177 


214 
214 
214 
214 
214 


176 


138 


54 

177 

40 

177 


ERRATA. 

p.  8,  line  8,  for  siphon  read  chitin  filament. 

„  31,  Genus  28,  for  cyclopterinus  read  cyclopterina. 

„    „  Genus  33,  for  TBYPAPHYLUS  read  TRIPAPHYLUS. 

„  136,  lines  13  and  14,  for  Eudactylin  aacuta  read  Eudactylina  acuta. 

„  137,  line  17,  for  Kroyeria  cineata  read  Kroyeria  lineata. 

„  199,  Synonymy,  line  6,  for  Basenistes  read  Basanistes. 


(254) 


PLATE  A. 

FIGS. 

1.  Ventral  surface  of  the  pectoral  fin  of  a  flounder  (Pleuro- 

nectes  flesus  Linn.),  with  thirty-two  adult  specimens  of 
Lepeophtheirus  pectoralis  (Miiller)  adhering  to  it. 
(x3.) 

2.  Head  of  a  whiting  (Gadnn  merlangus  Linn.),  with  part  of 

the  operculum  removed  to  shew  an  adult  female  Lerneea 
branchialis  Linn,  adhering  to  the  gills.  (  x  2.) 

3.  Part  of  the  gills  of  a  flounder  (Pleuronectes  flesus  Linn.), 

shewing  the  "Cyclopoid"  stage  of  Lernssa  branchialis 
attached  to  the  ends  of  the  gill-filaments.  (  x  2£.) 

(Reproduced  from  photographs.) 


PLATE   A 


(256) 


PLATE  B. 

Fios. 

1.  Part  of  the  gills  of  a  dory  (Zeus  faber  Linn.),  shewing  an 

adult  female  Chondr acanthus  zei  De  la  Roche  in  situ. 
(x2i.) 

2.  Adult   female  of  Chondr  acanthus  zei  removed  from  its 

host,     (x  2.) 

3.  Gill   of  a  salmon    (Salmo   salar   Linn.),   shewing   adult 

female  specimens  of  Lernaeopoda  salmonea  (Gisler) 
attached  to  the  ends  of  the  gill-filaments.  The  salmon 
was  captured  in  the  river  Dee,  near  Aberdeen;  the 
parasites  adhered  to  the  gill-filaments  in  considerable 
numbers,  their  white  colour  shewing  distinctly  against 
the  red  colour  of  the  gills.  (Nat.  size.) 

(Reproduced  from  photographs.) 


PLATE   B. 


INSTITUTED      1844 

FOR     THE     PUBLICATION    OF     WORKS     ON 
NATURAL     HISTORY 

ANNUAL  SUBSCRIPTION  ONE  GUINEA 


LIST    OF    THE    SOCIETY 

FOR   THE   YEAR   1913 


COEEECTED    TO    28iH    FEBEIJAEY,    1913 


OFFICERS   AND   COUNCIL. 

1912-13. 


THE  KT.  HON.  LOED  AVEBUEY,  P.C.,  D.C.L.,  LL.D.,  FoR.Ssc.E.A., 
F.E.S.,  F.S.A.,  F.L.S.,  ETC. 


S.  F.  HAEMEE,  M.A.,  Sc.D.,  F.E.S.,  F.Z.S. 

A.  D.  MICHAEL,  F.L.S.,  F.Z.S.,  F.E.M.S. 

E.  F.  SCHAEFF,  PH.D.,  B.Sc.,  F.L.S.,  F.Z.S. 


©ounril. 

EGBERT  ADKIN,  F.E.S.  G.  B.  LONGSTAFF,  M.D.,  F.E.S. 

Eev.  C.  E.  N.  BTJBROWS,  F.E.S.  J.  W.  S.  MEIKLEJOHN,  M.D.,  F.L.S. 

T.  A.  CHAPMAN,  M.D.,  F.Z.S.,  F.E.S.  JAMES  MURRAY,  F.Z.S.,  F.E.M.S. 

Eev.  ALFRED  FULLER,  M.A.,  F.E.S.  A.W.OKE,B.A.,LL.M.,F.L.S.,F.G.S. 

A.  E.  GIBBS,  F.L.S.,  F.Z.S.,  F.E.S.  CHARLES  OLDHAM,  F.Z.S.,  M.B.O.U. 


B.  DAYDON  JACKSON,  PH.!).,  F.L.S. 
ALBERT  H.  JONES,  Treas.E.S. 


C.  D.  SOAR,  F.L.S.,  F.E.M.S. 

W.  MARK  WEBB,  F.L.S.,  F.E.M.S. 


{treasurer. 

F.  DuCANE  GODMAN,  D.C.L.,  F.E.S.,  F.L.S.,  F.G.S.,  F.Z.S.,  F.E.S. 

Secretary. 

JOHN    HOPKINSON,  F.L.S.,  F.G.S.,  F.Z.S.,  Assoc.Inst.C.E. ; 
Weetwood,  Watford. 


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Albany  Museum ;  Grahamstown,  Cape  Colony,  S.  Africa. 
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Cambridge. 

Athenamm  Club  ;  Pall  Mall,  S.W. 
Australian  Museum ;  Sydney,  New  South  Wales. 
Avebury,  The  Right  Hon.  Lord,  P.C.,  D.C.L.,  LL.D.,  F.R.S., 

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6  LIST   OP   THE    RAY    SOCIETY. 

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Road,  Edgbaston,  Birmingham. 

Bibliotheque  Nationale  ;  Paris. 

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Birmingham  Free  Libraries ;  Birmingham. 

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House,  Waltham  Cross. 

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Institute,  North  Parade,  Bradford. 
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LIST    OP    THE    RAY    SOCIETY.  7 

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Stanford-le-Hope,  Essex. 

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Machynlleth. 

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Zealand. 
Cardiff  Free  Libraries ;   Cardiff. 

Chapman,  Thomas  Algernon,  M.D.,  F.Z.S.,  F.E.S.  ;  Betula, 

Reigate. 
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Museum,  Cheltenham. 
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Chester. 

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Street,  W. 

Cleland,  John,  M.D.,  D.Sc.,  LL.D.,  F.R.S. ;  Drumclog,  Crew- 
kerne. 
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Co.  Dublin. 
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Laboratory,  Plymouth. 
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8  LIST   OP   THE    RAY    SOCIETY. 

Dames,  Felix  L. ;  Steglitz-Berlin, 

Davies,  Arthur   Bllson,   Ph.D.,   F.L.S.,   F.C.S.;    Tweedbank, 

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Surrey. 

Dublin,  Royal,  Society  ;  Leinster  House,  Dublin. 

East  Kent  Natural  History  Society  ;  Medical  Hall,  Canterbury. 
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2    Stone   Buildings,   Lincoln's   Inn,  W.C.,    and  Struan, 

Wimbledon  Park,  S.W. 
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W.C. 

Fielding,  Clement,  M.P.S.,  Ph.C. ;  Clover  Hill,  Halifax. 
FitzGerald,   The   Rev.   H.   Purefoy,   M.A.,   F.L.S.,   F.C.S. ; 

Indwells,  Goudhurst,  Kent. 
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Agricultural  Research  Institute,  Pusa,  Bihar,  India. 
Fletcher,  W.  H.  B.,  M.A.,  F.Z.S.,  F.E.S. ;   Aldwick  Manor, 

Bognor. 

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cote,  Burton-upon- Trent. 
Fuller,  The  Rev.  Alfred,  M.A.,  F.E.S.;  The  Lodge,  Sydenham 

Hill,  S.E. 

Oarnett,  Frank  W.,  M.R.C.V.S. ;  Dalegarth,  Windermere. 


LIST   OF    THE    RAY    SOCIETY.  9 

Gascoigne,  Major  French ;  LotJierton  Hall,  Aberford,  Leeds. 
Geological  Society  of  London;  Burlington  House,  Piccadilly, 

W. 

Gerold  &  Co. ;   Vienna. 
Gibbs,    Arthur    Ernest,    F.L.S.,    F.Z.S.,    F.E.S.,    F.K.H.S.; 

Kitchener's  Meads,  St.  Albans. 
Gibson,  Miss;  Hill  House,  Saffron  Walden. 
Giles,    Harry   M.,    F.E.S. ;    Zoological    Society  >  South  Perth, 

Western  Australia. 

Glasgow  Natural  History  Society  ;  207  Bath  Street,  Glasgow. 
Glasgow,  Royal  Philosophical  Society  of;  207  Bath  Street, 

Glasgow. 

Glasgow  University  Library ;  Glasgow. 
Godman,  F.  DuCane,  D.C.L.,  F.R.S.,  F.L.S.,  F.G.S.,  F.Z.S., 

F.E.S.,  F.R.H.S.,  TREASURER;  45  Pont  Street,  Belgrave 

Square,  S.W.  :  and  South  Lodge,  Horsham. 
Gooding,  Henry  Cornish ;  Ipswich  Street,  Stowmarket. 
Gottingeu  University  Library ;  Gottingen,  Germany. 
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Green,  E.  Ernest,  F.E.S. ;  Mote  Hall,  Bearsted,  Maidstone. 
Grosvenor  Public  Library ;  Buffalo,  N.Y.,  U.S.A. 
Guille-Alles  Library;  Guernsey. 
Guitel,  Frederic,  Professeur   de  Zoologie  a    la  Faculte    des 

Sciences  ;    University  de  Rennes,  France. 
Gurney,  Robert,  F.Z.S. ;  Ingham  Old  Hall,  Stalham. 

Haileybury  College ;  Hertford. 

Halifax  Public  Library  ;  Belle  View,  Halifax. 

Hamburg,  Naturhistoriche  Museum  zu;  Steinthorwall,  Ham- 
biirg,  Germany. 

Hardy,  Alfred  Douglas,  F.L.S.,  F.R.M.S.;  State  Forests  De- 
partment, Melbourne,  Victoria,  Australia, 

Harley,  John,  M.D.,  F.R.C.P.,  F.L.S. ;  Beedings,  Pulborough, 
Sussex. 

Harmer,  Sidney  F.,  Sc.D.,  F.R.S.,  F.Z.S.,  Keeper  of  Zoology. 
British  Museum,  VICE-PRESIDENT;  British  Museum  (Nat, 
Hist.)  Cromwell  Road,  S.W.,  and  58  Albemarle  Road, 
Beckenham. 

Harvard  Museum  of  Comparative  Zoology ;  Cambridge, 
Mass.,  U.S.A. 


10  LIST    OF    THE    BAY    SOCIETY. 

Hastings  and    St.  Leonard's  Natural  History  Society;   The 

Museum,  Hastings. 

Heidelberg  University  Library  ;  Heidelberg,  Germany. 
Hertfordshire  County  Museum;  Hatfield  Road,  St.  Albans. 
Hertfordshire  Natural  History  Society  and  Field  Club  ;   Uptonf 

House,  Watford. 

Hewitt,  David  Basil,  F.R. C.S.I.;  Grove  Mount,  Davenham. 
Hope,  G.  P. ;  Havering  Grange,  Romford. 
Hopkinson,  John,  F.L.S.,  F.G.S.,  F.Z.S.,  F.E.M.S.,  F.R.Met. 

Soc.,  Assoc.Inst.C.E.,  SECRETARY;   Weetu'ood,  Watford. 
Huddersfield    Naturalist    and    Photographic    Society ;     The 

Technical  College,  Huddersjield. 
Hull  Public  Libraries  ;  Hull. 

Illinois  University  Library ;    Urlana,  III.,  U.S.A. 
India,  Geological  Survey  of;   Calcutta. 
Ireland,  National  Library  of ;  Kildare  Street,  Dublin. 
Irish,  Royal,  Academy;   19  Dawson  Street,  Dublin. 
Irving,  John,  M.D. ;    Inagh  Mount,   15  Filey    Road,    Scar- 
borough. 

Jackson,  B.  Daydon,  Ph.D.,  F.L.S.,  General  Secretary  of  the 

Linnean  Society;  21  Cautlei/  Avenue,  Ctapham  Common, 

S.W. 
James,   Robert   Detiley,    F.A.I.    (Natal),    F.R.M.S.;    Earl's 

Croome,  Durban,  Natal  (P.O.  Box  212). 
John  Crerer  Library  ;  Chicago,  III.,  U.S.A. 
Jones,  Albert  H.,  F.E.S. ;  Shrublands,  Eltham. 
Jones,  William  Llewellyn,  F.R.M.S. ;  Manley  Knoll,  Helsby, 

Warrington. 
Junk,  W. ;  201  Kurfurstendamm,  Berlin,  "W.  15. 

Kappel,  August  Wilhelm,  F.L.S.,  F.E.S.,  Librarian  of  the 
Linnean  Society ;  Creeveroe,  Golder's  Green,  N. W. 

Kenrick,  Sir  G.  H.,  F.E.S. ;  Whetstone,  Somerset  Road, 
Edgbaston,  Birmingh  am. 

Kiel  University  Library ;  Kiel,  Germany. 

Kilmarnock  Public  Library  and  Museum ;  Kilmarnock,  N.B. 

King's  Inn  Library  ;  Dublin. 

Knight,  H.  H. ;   The  Lodge,  All  Saints'  Road,  Cheltenham. 


LIST    OF    THE    RAY    SOCIETY.  11 

Laver,  Henry,  M.R.C.S. ;  43  Head  Street,  Colchester. 
Lebour,  Miss  Marie  V.,  M.Sc. ;  Eadcliffe  House,  Cartridge, 
Northumberland. 

Leeds  Philosophical  and  Literary  Society ;  The  Museum,  Leeds. 

Leeds  Public  Free  Libraries  ;  Leeds. 

Leeds  University  Library ;  Leeds. 

Leicester  Free  Public  Library ;   Wellington  Street,  Leicester. 

Lewis,   John   Spedan,   F.Z.S.  ;    Spedan  Tower,    West   Heath, 

Hampstead,  N.W.,  and  278-288  Oxford  Street,  W. 
Linnean  Society  of  London ;  Burlington  House,  Piccadilly,  W. 
Liverpool  Athenteum ;  Liverpool. 
Liverpool  Free  Public  Libraries ;  Liverpool. 
Liverpool  Microscopical  Society;  Royal  Institution, Liverpool. 

Liverpool  School  of  Tropical  Medicine  ;   Exchange  Buildings, 
Liverpool. 

London  Library;   12  St.  James's  Square,  S.W. 

Longstaff,    George    Blundell,    M.A.,    M.D.,   F.C.S.,   F.S.S. ; 

Highlands,  Putney  Heath,  S.W.,  and  TwitcJien,  Morthoe, 

Devon. 

Los  Angeles  Public  Library;  California,  U.S.A. 
Lyon  Universite  Bibliotheque  ;  Lyons,  France. 

Mclntosh,  W.  Carmichael,  M.D.,  LL.D.,  F.R.S.L.&E.,  F.L.S., 

Professor  of  Natural  History,  University  of  St.  Andrews ; 

2  Abbotsford  Crescent,  St.  Andrews,  N.B. 
McMillan,  William   Singer,    F.L.S. ;     Ardenholm,   Maghull, 

Liverpool. 

Magdalen  College;  Oxford. 
Manchester  Literary  and  Philosophical  Society ;   36  George 

Street,  Manchester. 
Manchester  Microscopical  Society  ;  397  Cheetham  Hill  Road, 

Manchester. 

Manchester  Public  Free  Libraries ;  Manchester. 
Marlborough  College  Natural  History  Society  ;  Marlborougl , 
Massey,  W.  H. ;   Twyford,  Berks. 
Meiklejohn,   John   William  S.,  M.D.,  F.L.S. ;    105   Holland 

Road,  Kensington,  W. 

Melbourne  Public  Library  ;  Melbourne,  Australia. 
Mennell,  Henry  Tuke,  F.L.S.  ;  10  St.  Dunstan's  Buildings, 

Great  Tower  Street,  E.G. 


12  LIST  OP  THE    HAY   SOCIETY. 

Michael,  Albert  Davidson,  F.L.S.,  F.Z.S.,F.R.M.S.,F.R.H.S., 

VICE-PRESIDENT  ;  The  Warren,  Studland,  Wareham. 

Middlesbrough  Free  Libraries  ;  Middlesbrough. 

Mitchell  Library;  21  Miller  Street,  Glasgow. 

Moore,  Henry;   12  Whiston  Grove,  Rotherham. 

Morey,  Frank,  F.L.S.;   Wolverton,  Carisbrooke  Road,  Newport, 

Isle  of  Wight. 

Morgan,  Ralph ;  9  Clifton  Hill,  Exeter. 

Moulton,  John  C.,  F.L.S.,  F.E.S. ;  Kuching,  Sarawak,  Borneo. 
Munich  Royal  Library ;  Munich,  Germany. 
Museum  d'Histoire  Naturelle  ;  Paris. 

Nebraska  University  Library  ;  Lincoln,  Neb.,  U.S.A. 
Newcastle-upon-Tyne   Literary   and   Philosophical    Society ; 

Westgate  Road,  Newcastle-upon-Tyne. 

Newcastle-upon-Tyne  Public  Library;  Newcastle-upon-Tyne. 
New  South  Wales,  Public  Library  of;  Sydney,  N.S.W. 
New  South  Wales,  Royal  Society  of ;  Sydney,  N.S.W. 
Newstead,  Robert,  M.Sc.,F.R.S.,A.L.S.,F.E.S.,Hon.F.R.H.S., 

Button  Memorial   Professor   of    Entomology ;    School  of 

Tropical  Medicine,  The  University,  Liverpool. 
New  York  Public  Library;  New  York,  U.S.A. 
Nicholson,  Charles;  Lansdowne  House,  Morley  Street,  Bradford. 
Niemeyer,  Dr.  Max,  Halle  a  Saale  I,  Germany. 
Noble,  Sir  Andrew,  Bart.,  K.C.B.,  D.Sc.,D.C.L.,F.R.S.,F.C.S., 

F.R.A.S. ;  Jesmond  Dene  House,  Newcastle-upon-Tyne. 
Norfolk  and  Norwich  Library ;  Norwich. 

Norman,  The  Rev.  A.  Merle,  M.  A.,  D.C.L.,LL.D.,F.R,S.,F.L.S., 
Hon.  Canon  of  Durham  ;  The  Red  House,  J3erkhamsted. 

Northumberland,  Durham,  and  Newcastle-upon-Tyne  Natural 
History  Society  ;  Hancock  Museum,  Neiccastle-upon-Tyne. 

North  Staffordshire  Field  Club ;  Stone. 

Norwich  Free  Library ;  Norwich. 

Nottingham  Free  Public  Libraries;  Nottingham. 

OKamura,  Prof.  K. ;  4  Nichone,  Shin-oganamachi,  Ushigome, 
Tokyo,  JafHtu. 

Oke,  Alfred  William,  B.A.,  LL.M.,  F.L.S.,  F.G.S. ;  32  Den- 
mark Villas,  Hove,  Brighton. 


LIST  OF  THE  KAY    SOCIETY.  13 

Oldham,    Charles,    F.Z.S.,   M.B.O.U.,  Hon.  Sec.  Herts  Nat. 

Hist.  Soc. ;  Kelvin,  Berkhamsted. 
Ontario  Agricultural  College  ;  Guelph,  Canada. 
Otago,  University  of  ;  Dunedin,  New  Zealand. 
Owens  College  (Christie  Library)  ;  Manchester. 

Pack-Beresford,    Denis  R.,   D.L.,  B.A.,  M.R.I.A. ;    Fenagh, 

Bayenalstoicn,  Co.  Carlow,  Ireland. 

Paisley  Philosophical  Institution ;  3  County  Place,  Paisley. 
Peabody  Institute ;  Baltimore,  Maryland,  U.S.A. 
Perthshire  Society  of  Natural  Science;   Tay  Street,  Perth. 
Philadelphia   Academy  of  Natural   Sciences;    Philadelphia, 

Pa.,  U.S.A. 
Pickard-Cambridge,  The  Rev.   0.,  M.A.,  F.R.S.;  Bloxworth 

Rectory,  Wareham. 

Plowman,  T. ;  Nystuen  Lodge,  Bycullah  Park,  Enfield. 
Plymouth  Institution  ;  Athenaeum,  Plymouth. 
Portsmouth  Free  Public  Library  ;   Town  Hall,  Portsmouth. 
Poulton,   Edward   B.,   M.A.,   D.Sc.,   LL.D.,   F.R.S.,   F.L.S., 

F.G.S.,  F.Z.S.,  Hope  Professor  of  Zoology,  University  of 

Oxford ;  Wykeham  House,  Oxford. 
Preston  Free  Public  Libraries  and  Museum;  Preston. 

Quaritch,  Bernard  ;  1 1  Graf  ton  Street,  Bond  Street,  W. 
Queen's  University ;  Belfast. 

Quekett  Microscopical  Club  ;  20  Hanover  Square,  W. 
Quelch,  William  Paul,  F.R.B.S.;  65  Shakespeare  Eoad,  Han- 
well,  W. 

Radcliffe  Library ;  Museum,  Oxford. 
Rashleigh,  Evelyn  William ;  Stolteton,  Saltash. 
Robertson,  James  Alexander ;  Lune  View,  Fleetwood. 
Rotherham  Naturalists'  Society;  6  Whiston  Grove,  Rotherham. 
Rothschild,  The  Hon.  Lionel  Walter,  Ph.D.,   F.R.S.,  F.L.S., 
F.Z.S.,  Pres.  Herts  Nat.  Hist.  Soc. ;  Tring  Park,  Tring. 

Royal  Academy  of  Sciences  ;  Amsterdam. 

Royal  Academy  of  Sciences ;  Stockholm,  Sweden. 

Royal  College  of  Science  ;  Dublin. 

Royal  Microscopical  Society ;  20  Hanover  Square,  W. 

Royal  Society  ;  Burlington  House,  Piccadilly,  W. 


14  LIST    OF   THE    BAY    SOCIETY. 

St.  Albans  Public  Library  ;  St.  Albans. 

St.  Andrews  University  Library ;  St.  Andrews,  N.B. 

St.  Catharine's  College  ;  Cambridge. 

Salisbury     Microscopical    Society;     14     Wyndham    Terrace, 

Salisbury. 
Scharff,  Robert  Francis,  Ph.D.,  B.Sc.,  F.L.S.,  F.Z.S.,  VICK- 

PRKSIDENT;  Knockranny,  Bray,  co.  Wiclclow. 
Schmidle,  Prof.   W. ;    Villa  Hansagarten,  Konstang,  Baden, 

Germany. 

Schmidt,  Max,  Ph.D. ;  95  iv  Eppendorfer,  Landvtrasse,  Ham- 
burg. 

Scott,  Thomas,  LL.D.,  F.L.S. ;  2  Devanha  Terrace,  Aberdeen. 
Scottish,  Royal,  Museum  ;  Edinburgh. 
Scorn-field,  David  Joseph,  F.Z.S.,  F.R.M.S. ;  63  Queen's  Road, 

Leytonstone,  N.E. 

Sears,  R.  S.  Wilson ;  1  Lisson  Grove,  Marylebone,  N.W. 
Selborne  Society ;  42  Bloomsbury  Square,  W.C. 
Sheffield  Literary  and  Philosophical  Society ;  Leopold  Street, 

Sheffield. 

Sidney-Sussex  College ;   Cambridge. 
Sion  College  Library;    Victoria  Embankment,  E.G. 
Soar,  Charles  David,  F.L.S.,  F.R.M.S. ;  37  Dryburgh  Road, 

Putney,  S.W. 
Somersetshire  Archaeological  and  Natural  History  Society ; 

The  Castle,  Taunton. 
Southport  Free  Library  ;   Southport. 
Spicer,   Henry,   B.A.,   F.L.S.,   F.G.S.;     14    Aberdeen   Park, 

Highbury,  N. 

Sprague,    T.    B.,    M.A.,    LL.D. ;    29    Buckingham    Terrace, 
Edinburgh. 

Stazione  Zoologica ;  Naples. 

Stechert,  G.  E. ;  2  Star  Yard,  Carey  Street,  W.C. 
Stoke  Newington  Public  Libraries;   Church  Street,  N. 
Storey,    J.    E.  :    26    Grosvenor  Road,    W^alley  Range,  Man- 
chester. 

Sunderland  Library   and  Literary   Society ;    Fawcett  Street, 
Runderland. 

Taverner,  Henry,  F.R.M.S. ;  319  Seven  Sisters'  Road,  Finsbury 
Park,  N. 


LIST   OF   THE    EAY    SOCIETY.  15 

Tindall,  William  B.;  39  St.  Mary  Street,  and  1315  Traders 

Bank  Buildings,  Toronto,  Canada. 
Toronto,  University  of ;   Toronto,  Canada. 
Torquay  Natural  History  Society ;  Museum,  Babbacombe  Road, 

Torquay. 

Trinity  College ;  Cambridge. 
Trinity  College  ;  Dublin. 

Trondhjem,  Royal  Library  of;  Trondhjem,  Norway. 
Tupman,    Lt.-Col.   George  Lyon,   F.G.S.,   F.Z.S.,  F.R.A.S., 

F.R.M.S. ;  Hillfoot  Observatory,  College  Road,  Harrow. 
Turner,  Charles ;  20  Minster  Road,  Cricklewood,  N.W. 

University  College ;  Cork. 

University  College,  London ;  Gower  Street,  W.C. 

Upsala  Royal  University  Library;   Upsala,  Sweden. 

Victoria  Institute  ;    Worcester. 

Wailes,   George  Herbert,  F.L.S. ;    Vancouver,  B.C.   (c/o   G. 

Wailes  &  Co.,  386  Euston  Road,  N.W.) 
Wales,  National  Library  of  ;  Aberystwyth. 
Walker,  Alfred  0.,  F.L.S.,  F.Z.S. ;   Ulcombe  Place,  Maidxtone. 
Walsingham,   The   Right  Hon.  Lord,  M.A.,  LL.D.,  F.R.S., 

F.L.S.,  F.Z.S.,  F.E.S.,  M.B.O.U. ;  Merton  Hall,  Thetford. 
Warrington  Municipal  Museum ;    Warrington. 
Webb,  Wilfred  Mark,  F.L.S.,  F.R.M.S.,  Hon.  Sec.  Selborne 

Society ;    Odstock,    Hanwell,    W.,    and    42    Bloomsbury 

Square,  W.C. 

Weg,  Max  ;   1  Leplaystrass,  Leipzig. 
Weigel,  Oswald ;   I  Konigstrasse,  Leipzig. 
Wesley,  E.  F.,  A.K.C. ;  28  Essex  Street,  Strand,  W.C. 
West  Kent  Natural  History  Society ;  42  Shooter's  Hill  Road, 

Blackheath,  S.E. 

West,  William,  F.L.S. ;  26  Woodville  Terrace,  Bradford. 
Whittle,  F.  G. ;  3  Marine  Avenue,  Southend-on-Sea. 
Williamson,  William ;  9  Pleivlands  Terrace,  Edinburgh. 
Wilson,    H.    Maclean,   M.D.,  B.Sc.,    Chief   Inspector,    West 
Riding  of  Yorkshire  Rivers  Board;   Wdkefidd. 

Wilson,    Joseph,    F.R.M.S. ;    Hillside,    Avon   Road,     Upper 
Walthamstow,  N.E. 


16  LIST    OF   THE    RAY    SOCIETY. 

Wood,  J.  H.,  M.B.;  Tarrington,  Ledbury. 
Worssam,  Cecil;  29  Ashburnham  Road,  J3edfor<L 

Yale  University  Library ;  New  Haven,  U.S.A. 
Yorkshire  Philosophical  Society  ;  Museum,  York. 

Zoological  Society  of  London;  Regent's  Park,  N.AV. 

The  Advocate's  Library,  Edinburgh  ;  the  Bodleian  Library,  Oxford  ;  the 
British  Museum  ;  Cambridge  University  Library ;  Trinity  College,  Dublin  ; 
and  the  National  Library  of  Wales ;  entered  in  the  List,  receive  the 
Society's  publications  in  accordance  with  the  Copyright  Act. 


GEOGKAPHICAL   LIST   OF   THE    SOCIETY. 

(Beyond  the  limits  of  the  London  Postal  District.} 


GREAT  BRITAIN  AND  IRELAND. 

ENGLAND. 

BEDFORDSHIRE. 
Bedford — Worssam,  C. 

BERKSHIRE. 

Newbury — Bowman,  J.  H.  Twyford — Massey,  W.  H. 

BUCKINGHAMSHIRE. 
Slough — Bentley,  E. 

CAMBRIDGESHIRE. 

Cambridge — Assheton,  E.  Cambridge — Sidney- Sussex   Col- 

Downing  College.  lege. 

Philosophical  Library.  -  Trinity  College. 


St.  Catherine's  College.  —  University  Library. 

CHESHIRE. 

Chester — Elliott,  Dr.  J.  Davenham. — Hewitt,  D.  B. 
Society  of  Natural  Science.  Helsby — Joues,  W.  L. 

CORNWALL. 

Saltash — Eashleigh,  E.  W.  Truro — Eoyal      Institution     of 

Cornwall. 

DERBYSHIRE. 
Derby — Free  Library  and  Museum. 

DEVONSHIRE. 
Exeter — Brokenshire,  F.  E.  Plymouth — Crawshay,  L.  E. 

Morgan,  E.  -  Plymouth  Institution. 

Lynmouth — Briggs,  C.  A.  Torquay — Natural   History   So- 

-  Briggs,  T.  H.  ciety. 

Nortthoe — Longstaff,  Dr.  Gr.  B. 

DORSETSHIRE. 

Wareham — Michael,  A.  D.  Wareham — Pickard- Cambridge, 

Eev.  O.  P. 

DURHAM. 
Sunderland — Library  and  Literary  Society. 


18  GEOGRAPHICAL    LIST    OF    THE    SOCIETY. 

ESSEX. 

Colchester — Laver,  H.  Southend — Whittle,  F.  Q-. 

Bomford — Hope,  G.  Stanford  -  le  -  Hope  —  Burrows, 

Saffron  Walden — Gibson,  Miss.  Eev.  C.  E.  N. 

GLOUCESTERSHIRE. 

Bristol — Museum.  Cheltenham — Knight,  H.  H. 

-  Naturalists'  Society.  -  Natural  Science  Society. 

— -  Public  Libraries. 

HAMPSHIRE. 
Neivport,  I.  W. — Morey,  F.  Portsmouth — Free  Public  Library. 

HEREFORDSHIRE. 
Ledbury — Wood,  J.  H. 

HERTFORDSHIRE. 

Berkhamsted  —  Norman,  Canon      St.  Albans. — Public  Library. 
A.  M.  Tring— Eothschild,  Hon.  W. 

Oldham,  C.  Waliham  Cross — Bowles,  E.  A. 


Hertford — Haileybury  College.  Watford— Barraud,  P.  J. 

St.  Albans — Gibbs,  A.  E.  -  Hertfordshire     Natural 

— -  Hertfordshire      County  History  Society. 

Museum.  -  Hopkinson,  J. 

KENT. 

Beckenham — Harmer,  Dr.  S.  F.  Farnborough — Avebury,  Lord. 

Bromley — Naturalists'  Society.  Folkestone — Free  Public  Library 

Canterbury — East  Kent  Natural  and  Museum. 

History  Society.  Goudhurst — Fitzgerald,  Eev.  H. 

Dover — Burr,  Dr.  M.  Maidstone — Green,  E.  E. 

Eltham — Jones,  A.  H.  -  Walker,  A.  0. 

LANCASHIRE. 

Barrow-^n-F^trness — Public  Lib-  Manchester — Literary  and  Philo- 

rary.  sophical  Society. 

Fleetwood — Eobertson,  J.  A.  -  Microscopical  Society. 

Liverpool — Bootle  Free  Library.  -  Owens  College. 

-  Free  Public  Libraries.  -  Public  Free  Libraries. 
Liverpool  Athenaeum.  -  Storey,  J.  E. 

-  Macmillan,  W.  S.  Preston — Free  Public  Libraries. 
Microscopical  Society.  St.  Helens — Cotton,  J. 

-  Newstead,  Prof.  E.  Southport — Free  Library. 

-  School  of  Tropical  Medi-  Warrington  —  Municipal      Mu- 

ciue.  seum. 


GEOGRAPHICAL    LIST   OP    THE    SOCIETY.  19 

LEICESTERSHIRE. 
Leicester — Free  Public  Library. 

MIDDLESEX. 
Enfield — Plowman,  T.  Harrow — Tupman,  Lt.-Col.  G.L. 

NORFOLK. 
Norwich — Free  Library.  Stdlham — Gurney,  E. 

—  Norfolk      and     Norwich    Thetford — Walsingham,  Lord. 
Library. 

NORTHUMBERLAND. 

Corbridye—  Lebour,  Miss  M.  Y.       Newcastle- upon -Tyne  —  Noble, 
Newcastle  -  upon  -  Tyne  —  Arm-  Sir  A. 

strong  College.  Northumberland    Natu- 

Literary  and  Philosophi-  ral  History  Society. 

cal  Society.  —  Public  Library. 

NOTTINGHAMSHIRE. 
Nottingham — Free  Public  Libraries. 

OXFORDSHIRE. 
Oxford — Bodleian  Library.  Oxford — Poulton,  Prof.  E.  B. 


Magdalen  College.  Ead cliff e  Library. 

SOMERSETSHIRE. 

Crewkerne — Cleland,  Dr.  J.  Taunton — Somersetshire  Natural 

History  Society. 

STAFFORDSHIRE. 
Burton  -  upon  -  Trent  —  Friend,     Stone  --  North       Staffordshire 

Kev.  H.  Field  Club. 

Stone — Bostoclc,  E.  D. 

SUFFOLK. 
Stoivmarket — Gooding,  H.  C. 

SURREY. 

Croydon— Public  Libraries.  Reigate — Chapman,  Dr.  T.  A. 

Godalming  —  Eastwood,  J.  E.  Wallington — Drinkwater,  J.  W. 

SUSSEX. 

Bognor — Fletcher,  W.  H.  B.  Hastings — Natural  History  So- 

Brigliton — Natural  History   So-         ciety. 

cietv.  Horsham — Godman,  Dr.  F.  D. 

-  Oke,  A.  W.  Pulborough— Harley,  Dr.  J. 

Hastings — Bloomfield,  Eev.E.N. 

WARWICKSHIRE. 

Birmingham  —  Bethune-  Baker,     Birmingham — Kenrick,  Sir  G.  H. 
G.  T.  —  Natural     History      and 

—  Free  Libraries.  Philosophical  Society. 


20  GEOGEAPHICAL    LIST    OF    THE    SOCIETY. 

WESTMORELAND. 
Windermere — Garnett,  F.  W. 

WILTSHIRE. 

Marlborough — College      Natural     Salisbury— Collins,  Hon.  Mrs.  H. 
History  Society.  -  Microscopical  Society. 

WORCESTERSHIRE. 
Bromsgrove — Dilks,  A.  C.  Worcester — Victoria  Institute. 

YORKSHIRE. 
Bradford — Bagsliaw,  W.  Leeds — University  Library. 

-  Natural     History     and     Middlesbrough — Free  Libraries. 

Microscopical  Society.  Rotherham — Moore,  H. 

-  Nicholson,  C.  —  Naturalists'  Society. 

-  West,  W.  Scarborough — Irving,  Dr.  J. 
Halifax — Fielding,  C.  Sheffield — Literary    and    Philo- 

—  Public  Library.  sophical  Society. 
Huddersfield  —  Naturalist    and     Skipton — Eddy,  J.  R. 

Photographic  Society.  Wakefield — Binks,  Mrs.  I. 
Hull — Public  Libraries.  —  Wilson,  Dr.  H.  M. 

Leeds — Gascoigne,  Major  F.  York — Yorkshire    Philosophical 

Philosophical  Society.  Society. 

Public  Free  Libraries. 

WALES. 

CARDIGANSHIRE. 

Aberystwyth — National  Library  of  Wales. 

GLAMORGANSHIRE. 
Cardiff" — Free  Libraries. 

MONTGOMERYSHIRE. 
Machynlleth — Campbell,  F.  M. 

SCOTLAND. 
ABERDEENSHIRE. 
Aberdeen — Scott,  Dr.  J.  Aberdeen — University  Library. 

AYRSHIRE. 
Kilmarnock — Public  Library  and  Museum. 

EDINBURGHSHIRE. 
Edinburgh — Advocates'  Library.     Edinburgh — Eoyal  Scottish  Mu- 

—  Crawford,  W.  C.  seum. 

-  Davies,  Dr.  A.  E.  -  Sprague,  Dr.  T.  B. 

-  Public  Library.  -  University  Library. 

—  Koyal  Society.  -  Williamson,  W. 

FlFESHIRE. 

Largoward — Cox,  B.  C.  St.  Andrews — University         Li- 

8t.  Andrews  —  Mclntosh,    Prof.         brary. 
W.  C. 


GEOGRAPHICAL    LIST    OF    THE    SOCIETY. 


21 


HADDINGTONSHIRE. 
Prestonkirk — Buchan-Hepburn,  Sir  A. 

LANARKSHIRE. 
Glasgow — Mitchell  Library.  Glasgow — Eoyal      Philosophical 


Natural  History  Society. 


Society. 
University  Library. 


PERTHSHIRE. 
Perth — Perthshire  Society  of  Natural  Science. 

EENFREWSHIRE. 
Paisley — Philosophical  Institution. 


Belfast — Belfast  Library. 


IEELAND. 

ANTRIM. 

Belfast — Quaen's  University. 
CARLOW. 
Bagenalstown — Pack-Beresfoi'd,  D.  E. 

CORE. 
Cork — University  College. 

DUBLIN. 
Dublin — King's  Inn  Library.  Dublin— Eoyal  Dublin  Society. 

National  Library  of  Ire- Eoyal  Irish  Academy. 

Trinity  College. 


land. 


Eoyal  College  of  Science.     Sandycove — Colgan,  N. 

WlCKLOW. 

Bray— Scharff,  Dr.  E.  F. 

CHANNEL  ISLANDS. 

Guernsey — G-uille-Alles  Library. 

BRITISH    DOMINIONS. 

AFEICA,  SOUTH. 

CAPE  COLONY. 
Grahamsto wn — Albany  Museum . 

NATAL. 
Durban — James,  E.  D. 

ASIA. 

BORNEO. 

Sarawak — Moulton,  J.  C. 


22  GEOGRAPHICAL   LIST   OF   THE    SOCIETY. 

AUSTEALIA. 

NEW  SOUTH  WALES. 

Sydney — Australian  Museum.         Sydney — Eoyal  Society  of  New 

-  Public  Library  of   New         South  Wales. 

South  Wales. 

SOUTH  AUSTRALIA. 
Adelaide — Public  Library. 

VICTORIA. 
Melbourne — Hardy,  A.  D.  Melbourne — Public  Library. 

WESTERN  AUSTRALIA. 
South  Perth— Giles,  H.  M. 

CANADA. 

BRITISH  COLUMBIA. 

Vancouver — Wailes,  G.  H. 

ONTARIO. 

Guelpli  —  Ontario   Agricultural     Toronto — Tindall,  W.  B. 
College.  -  University. 

INDIA. 

Bihar — Fletcher,  T.  B.  Calcutta— Geological    Survey    of 

India. 

NEW  ZEALAND. 

Christchurch — Philosophical  In-     Dunedin — University  of  Otago. 
stitutioii  of  Canterbury. 

FOREIGN  COUNTRIES. 

AMEEICA,  UNITED  STATES  OF. 

CALIFORNIA. 
Los  Angeles — Public  Library. 

COLUMBIA,  DISTRICT  OF. 
Washington— Library  of  Congress. 

ILLINOIS. 
Chicago — John  Crerer  Library.        Urbana — Illinois  University  Lib- 

-  University  Library.  rai*y. 

MARYLAND. 
Bait  im  ore — Peabody  Institute . 

MASSACHUSETTS. 

Boston — Public  Library.  Cambridge — Harvard  Museum  of 

—  Society  of  Natural  His-         Comparative  Zoology, 
tory. 


GEOGEAPH1CAL    LIST   OP    THE    SOCIETY.  23 

MICHIGAN. 
Detroit — Public  Library. 

NEBRASKA. 
Lincoln — Nebraska  University. 

NEW  HAVEN. 
Yale — University  Library. 

NEW  YOEK. 
Buffalo — GTrosvenor  Public  Lib-     New   York — American   Museum 

rary.                                                      of  Natural  History. 
Ithaca — Cornell  University.  Public  Library. 

PENNSYLVANIA. 
Philadelphia — Academy  of  Natural  Sciences. 

AUSTEIA. 
Vienna — G-erold  &  Co. 

DENMARK. 

Copenhagen — University  Library. 

FRANCE. 

Lyons — Lyon  Universite  Biblio-  Paris — Museum  d'Histoire  X;i- 

tlicque.  turelle. 

P<i,-i« — -Bibliotheque  Nationale.  Rennes — Guitel,  Prof.  F. 
— •  Institut  de  France. 

GERMANY. 

Baden — Sclmiidle,  Prof.  W.  Halle  a  Saale — Niemeyer,  Dr.  M. 

Berlin — Dames,  F.  L.  Hamburg — Naturhistoriche  Mu- 

—  Friedliinder  &  Solm.  seum. 

-  Junk,  W.  -  Schmidt,  Dr.  M. 

—  Royal  Library.  Heidelberg — University  Library. 

-  Royal     Zoological  Kiel — University  Library. 
Museum.  Leipzig — Weg,  M. 

Breslau — University  Library.  -  Wei  gel,  O. 

Fi-niilifort — Baer  &  Co.  Munich — Royal  Library. 

Gnttinyen — University  Library. 

HOLLAND. 

Leiden — Doesburgh,  S.  C.  van. 

ITALY. 

Naples — Stazione  Zoologica. 

JAPAN. 

Tokyo — OKamura,  Prof.  K. 


24  GEOGEAPHICAL  LIST  OF   THE    SOCIETY. 

NETHERLANDS. 

Amsterdam — Royal  Academy  of  Sciences. 

NORWAY. 

Bergen — Museums  Bibliotek.  Trondhjem — Royal  Library. 

Christiana — University . 

SWEDEN. 

Stockholm  —  Royal  Academy  of     Upsala — University  Library. 
Sciences. 

SWITZERLAND. 

Berne — Natural  History  Museum. 


LIST    OF    THE    PUBLICATIONS 


OF   THE 


RAY    SOCIETY. 


For  the  First  Year,  1844. 

1.  Keports  on  the  Progress  of  Zoology  and  Botany ,  1841, 
1842.     viii  +  496  +  xx  pp.     8vo.     1845. 

The  State  of  Zoology  in  Europe,  as  regards  the  Vertebrata.  By 
C.  L.  BONAPARTE.  Transl.  by  H.  E.  STKICKLAND.  pp.  1-44. 

The  Progress  of  Zoology  in  1842.  Transl.  from  the  German  by  W.  B. 
MACDONALD.  pp.  1-348. 

The  Progress  of  Physiological  Botany  in  1841.  By  H.  F.  LINK. 
Transl.  by  EDWIN  LANKESTEB.  pp.  1-104.  Index,  pp.  i-xx. 

2.  A  Monograph  of  the  British  Nudibranchiate  Mollusca. 
By  JOSHUA  ALDER  and  ALBANY  HANCOCK.    Part  I.    x  +  20  pp., 
10  plates.     Folio.     1845. 

3.  Memorials  of  JOHN  RAY,  consisting  of  his  Life  by  Dr. 
DERHAM  ;   .  .  .  with  his  Itineraries,  etc.     Edited  by  EDWIN 
LANKESTER.     xii  +  220  pp.     8vo.     1846. 

For  the  Second  Year,  1845. 

4.  On  the  Alternation  of  Generations.     By  J.  J.  S.  STEEN- 
STRUP.     Transl.  from  the  German  version  of  C.  H.  LORENZEN 
by  GEORGE  BUSK,     viii  +  132  pp.,  3  plates.     8vo.     1845. 

5.  A  Monograph  of  the  British  Nudibranchiate  Mollusca. 
By  JOSHUA  ALDER  and  ALBANY  HANCOCK.    Part  II.    iv  +  34  pp., 
13  plates.     Folio.     1846. 

6.  Reports  and  Papers  on  Botany,     viii  +  494  pp.,  7  plates. 
Svo.     1846. 

On  the  Morphology  of  the  Coniferae.  By  J.  J.  ZUCCAKINI.  Transl. 
by  GEORGE  BUSK.  pp.  1-54,  441-444,  pis.  i-v. 

Report  on  Botanical  Geography,  1842.  By  A.  GRISEBACH.  Transl. 
by  W.  B.  MACDONALD.  pp.  55-212. 

Memoir  on  the  Nuclei,  Formation,  and  Growth  of  Vegetable  Cells. 
By  CARL  NAQELI.  Transl.  by  ARTHUR  HENFRET.  pp.  213-292,  445- 
459,  pis.  vi,  vii. 

Report  on  Physiological  Botany,  1842  and  1843.  By  H.  F.  LINK. 
Transl.  by  J.  HUDSON,  pp.  293-440.  Index  pp.  461-494. 


2  PUBLICATIONS    OF   THE    BAY    SOCIETY. 

For  the  Third  Tear,  1846. 

7.  Outlines   of   the  Geography  of  Plants.      By  F.  J.   F. 
MEYEN.     Transl.  by   MARGARET  JOHNSTON,     x  -f  422  pp.,   1 
plate.     8vo.     1846. 

8.  The  Organization  of  Trilobites.  By  HERMANN  BURMEISTER. 
Edited  by  THOMAS  BELL  and  EDWARD  FORBES,     xii  +  136  pp., 
6  plates.     Folio.     1846. 

9.  A  Monograph  of  the  British  Nudibranchiate  Mollusca. 
By  JOSHUA  ALDER  and  ALBANY  HANCOCK.     Part  III.     iv  +  30 
pp.,  12  plates.     Folio.     1847. 

For  the  Fourth  Year,  1847. 

10.  Elements  of  Physiophilosopliy.    By  LORENZ  OKEN.     From 
the  German  by  ALFRED  TULK.     xx  +  666  pp.     8vo.     1847. 

11.  Reports  on  Zoology  for  1843,  1844.     Transl.  from  the 
German  by  GEORGE  BOSK,  ALFRED  TULK,  and  A.  H.  HALIDAY. 
viii  +  596  pp.     8vo.     1847. 

Progress  of  Zoology  in  1843.     pp.  1-232. 

„  1844.     pp.  233-564. 

Index,  pp.  565-596. 

12.  A  Monograph  of  the  British  Naked-eyed  Medusae.     By 
EDWARD  FORBES,     viii  +  104  pp.,  13  plates.     Folio.     1848. 

For  the  Fifth  Tear,  1848. 

13.  Bibliographia  Zoologies  et  Geologise.     A  General  Cata- 
logue  of  all  Books,  Tracts,   and   Memoirs    on  Zoology  and 
Geology.     By  Louis  AGASSIZ.     Edited  by  H.  E.  STRICKLAND. 
Vol.    I.       Periodicals,   and   A-B.      xxvi    +    506  pp.      8vo. 
1848. 

14.  The  Correspondence  of  JOHN   RAY.      Edited  by  EDWIN 
LANKESTER.     xvi  -f  502  pp.,  2  plates.     8vo.     1848. 

15.  A  Monograph   of  the  British  Nudibranchiate  Mollusca. 
By  JOSHUA  ALDER  and  ALBANY  HANCOCK.     Part  IV.     iv   + 
28  pp.,  1 2  plates.     Folio.     1848. 

For  the  Sixth  Tear,  1849. 

16.  Reports   and  Papers  on   Botany.      Edited  by   ARTHUR 
HENFREY.     viii  +  514  pp.,  3  plates.     8vo.     1849. 

On  the  Structure  of  the  Palm-stem.  By  H.  VON  MOHL.  pp.  1-92, 
495,  pi.  i. 

On  the  Nuclei,  Formation,  and  Growth  of  Vegetable  Cells.  By  CARL 
NAGELI.  Part  II.  pp.  93-158,  495-502,  pis.  ii,  iii. 

On  the  Utricular  Structures  in  the  Contents  of  Cells.  By  CARL 
NAOELI.  pp.  159-190. 

Report  on  Physiological  Botany  for  1844  and  1845.  By  H.  T.  LINK. 
pp.  191-314. 


PUBLICATIONS    OF   THE   HAY    SOCIETY.  3 

Tieport  on  Geographical  Botany  for  1844.  By  A.  GBISKBACH.  pp. 
315-414. 

Report  on  Geographical  and  Systematic  Botany  for  1845.  By  A. 
GKISEBACH.  pp.  415-494. 

17.  The  Natural  History  of  the  British  Entomostraca.     By 
W.  BAIRD.     viii  +  364  pp.,  36  plates.     8vo.     1850. 

For  the  Seventh  Tear,  1850. 

18.  Bibliographia  Zoologize  et  Geologise.     A  General  Cata- 
logue  of   all   Books,   Tracts,  and  Memoirs  on  Zoology  and 
Geology.     By  Louis  AGASSIZ.     Edited  by  H.  E.  STRICKLAND. 
Vol.  11.     C-F.     iv  +  492  pp.     8vo.     1850. 

19.  A  Monograph  of  the  British  Nudibranchiate  Mollusca. 
By  JOSHCA  ALDER  and  ALBANY  HANCOCK.     Part  V.     iv  +  62 
pp.,  16  plates.     Folio.     1851. 

For  the  Eighth  Year,  1851. 

20.  The  British  Species  of  Angiocarpous  Lichens,  elucidated 
by  their  Sporidia.     By  the  Rev.  W.  A.  LEIGHTON.     vi  -f  102 
pp.,  30  plates.     8vo.     1851. 

21.  A  Monograph  of  the  Sub-class  Cirripedia.     By  CHARLES 
DARWIN.      The  Lepadidas,  or  Pedunculated  Cirripedes.     xii  + 
400  pp.,  10  plates.     8vo.     1851. 

For  the  Ninth  Year,  1852. 

22.  Bibliographia  Zoologize  et  Geologias.     A  General  Cata- 
logue  of   all  Books,  Tracts,   and   Memoirs  on   Zoology  and 
Geology,     By  Louis  AGASSIZ.     Edited  by  H.  E.  STRICKLAND. 
Vol.111.     G-M.     vi+658pp.     8vo.     1852. 

23.  A  Monograph  of  the  British  Nudibranchiate  Mollusca. 
By  JOSHUA  ALDER  and  ALBANY  HANCOCK.     Part  VI.    iv  -f  62 
pp.,  12  plates.     Folio.     1852. 

For  the  Tenth  Year,  1853. 

24.  Botanical  and  Physiological  Memoirs.    Edited  by  ARTHUR 
HENFREY.     xvi  +  568  pp.,  6  plates.     8vo.     1853. 

The  Phenomenon  of  Rejuvenescence  in  Nature.  By  ALEXANDER 
BRAUN.  pp.  vii-xxvi,  1-342,  pis.  i-v. 

The  Animal  Xature  of  Diatomese.     By  G.  MKNIGHINI.    pp.  343-514. 

The  Natural  History  of  Protococcus  pluvicdis.  By  FERDINAND  COHN. 
pp.  515-564,  pi.  vi. 

25.  A  Monograph  of  the  Sub-class  Cirripedia.     By  CHARLES 
DARWIN.     The  Balanidae,  the  Verrucidse,  etc.     viii  +  684  pp., 
30  plates.     8vo.     1854. 


4  PUBLICATIONS    OF   THE   BAY    SOCIETY. 

For  the  Eleventh  Year,  1854. 

26.  Bibliographia  Zoologia?  et  Geologise.     A  General  Cata- 
logue of   all   Books,  Tracts,  and   Memoirs  on  Zoology  and 
Geology.     By  Louis  AGASSIZ.     Edited  by  H.  E.  STRICKLAND. 
Vol.  IV.     N-Z.     vi  +  604  pp.     8vo.     1854. 

For  the  Twelfth  Year,  1855. 

27.  A  Monograph  of  the  British  Nudibranchiate  Mollusca. 
By  JOSHUA  ALDER  and  ALBANY  HANCOCK.     Part  VII.     vi  +  54 
+  40  -f  xlvi  pp.,  9  plates.     Folio.     1855. 

For  the  Thirteenth  Year,  1856. 

28.  A  Monograph  of  the  Fresh-water  Polyzoa,  including  all 
the  known  species,  both  British  and  Foreign.     By  GEORGE 
JAMES  ALLMAN.     Yiii  +  122  +  22  pp.,  11  plates.     Folio.     1856 
[1857]. 

For  the  Fourteenth  Year,  1857. 

29.  The  Recent  Foraminifera  of  Great  Britain.     By  WILLIAM 
CRAWFORD  WILLIAMSON,      xx   +   108  pp.,   7   plates.      Folio. 
1858. 

For  the  Fifteenth  Year,  1858. 

30.  Tlie  Oceanic  Hydrozoa  ;    a  Description  of  the  Calyco- 
phorida?  and  Physophoridae.  .  .  .    By  THOMAS  HENRY  HUXLEY. 
x  +  144  +  24  pp.,  12  plates.     Folio.     1859. 

For  the  Sixteenth  Year,  1859. 

31.  A  History  of  the  Spiders  of  Great  Britain  and  Ireland. 
By  JOHN  BLACK  WALL.      [Part  I.]     vi   +   174+24  pp.,  12 
plates.     Folio.     1861. 

For  the  Seventeenth  Year,  1860. 

32.  Introduction  to   the   Study   of   the   Foraminifera.     By 
WILLIAM  B.  CARPENTER,  assisted  by  WILLIAM  K.  PARKER  and 
T.  RUPERT  JONES,     xxii  +  320  +  44  pp.,  22  plates.     Folio. 
1862. 

For  the  Eighteenth  Year,  1861. 

33.  On  the  Germination,  Development,  and  Fructification  of 
the  Higher  Cryptogamia,  and  on  the  Fructification  of  the 
Coniferae.     By  WILHELM  HOFMEI&TER.     Transl.  by  FREDERICK 
CURREY.     xviii  +  506  pp.,  65  plates.     8vo.     1862. 


PUBLICATIONS    OF   TIIR    RAY    SOCIETY.  5 

For  the  Nineteenth  Tear,  1862. 

34.  A  History  of  the  Spiders  of  Great  Britain  and  Ireland. 
By  JOHN  BLACKWALL.      Part  II.      iv  +  210  (175-384)  +  34 
pp.,  17  plates.     Folio.     1864. 

For  the  Twentieth  Tear,  1863. 

35.  The   Reptiles  of   British  India.     By  ALBERT   C.   L.  G. 
GUXTHER.     xxviii  +  452  pp.,  26  plates.     Folio.     1864. 

For  the  Twenty-first  Tear,  1864. 

36.  A   Monograph  .of  the   British   Spongiada?.     By   J.    S. 
BOWERBANK.     Vol.  I.     xx  +  290  pp.,  37  plates.     8vo.     1864. 

Fur  the  Twenty-second  Tear,  1865. 

37.  The  British  Hemiptera.    Vol.  I.    Hemiptera-Heteroptera. 
By  JOHN  WILLIAM  DOCGLAS  and  JOHN  SCOTT,      xii  +  628  + 
42  pp.,  21  plates.     8vo.     1865. 

38.  A   Monograph    of   the   British    Spongiadae.      By   J.   S. 
BOWERBANK.     Vol.  II.     xx  +  388  pp.     8vo.     1866. 

For  the  Twenty-third  Tear,  1866. 

39.  The  Miscellaneous  Botanical  Works  of  ROBERT  BUOVTN. 
[Edited  by  JOHN  J.  BENNETT.]     Vol.  I,  containing  I,  Geo- 
graphico-botanical,    and    II,    Structural    and    Physiological 
Memoirs,     viii  +  612  pp.     8vo.     1866. 

40.  Recent  Memoirs  on  the  Cetacea.     Edited  by  WILLIAM 
HENKY  FLOWER,     xii  +  312  pp.,  6  plates.     Folio.     1866. 

I.  On    the    Greenland    Eight-Whale.      By    D.   F.   ESCHRICHT  and 
J.  EEINHARDT.    pp.  1-150,  pis.  i-vi. 

II.  On  the  Species  of  the  Genus  Orca  inhabiting  the  Northern  Seas. 
By  D.  F.  ESCHRICHT.    pp.  151-188. 

III.  Pseiidorca  crassidens,  a  Cetacean  hitherto  unknown  in  the  Danish 
Fauna.     By  J.  REINHARDT.    pp.  189 -21, s. 

IV.  Synopsis  of  the  Cretaceous  Mammalia  of  Scandinavia  (Norway 
and  Sweden).     By  W.  LILLJEBORQ.    pp.  219-310. 

41.  NITZSCH'S  Pterylography,  translated  from  the  German 
Edited  by  PHILIP  LUTLEY  SCLATER.     xii  +  182  pp.,  10  plates. 
Folio.     1867. 

For  the  Twenty '-fourth  Tear,  1867. 

42.  A  Monograph  on  the    Structure  and  Development   of 
the  Shoulder-girdle   and    Sternum   in   the   Vertebrata.     By 
W.  KITCHEN  PARKEK.     xii  +  240  +  60  pp.,  30  plates.     Folio. 
1868. 


6  PUBLICATIONS   OF   THE    RAY    SOCIETY. 

43.  The  Miscellaneous  Botanical  Works  of  ROBERT  BROWN. 
[Edited  by    JOHN    J.    BENNETT.]     Vol.    II,    containing   III, 
•Systematic    Memoirs,  and    IV,  Contributions   to    Systematic 
Works,     viii  +  780  pp.     8vo.     1868. 

For  the  Twenty -fifth  Year,  1868. 

44.  The  Miscellaneous  Botanical  Works  of  ROBERT  BKOWN. 
[Edited   by  JOHN  J.  BENNETT.]     Vol.  III.     Atlas  of  Plates, 
iv  +  16  pp.,  38  plates.     Folio.     1868. 

45.  Vegetable  Teratology,  nn  Account  of  the  Principal  Devia- 
tions  from  the   Usual    Structure   of   Plants.     By    MAXWELL 
T.  MASTERS.    With  numerous  illustrations  by  E.  M.  WILLIAMS. 
xxxviii  +  534  pages.     8vo.     1869. 

For  the  Twenty-sixth  Year,  1869. 

46.  A    Monograph    of    the    Gymnoblastic    or    Tubularian 
Hydroids.     By  GEORGE  JAMKS  ALLMAN.     Part  I,  the  Hydroida 
in  General,     xxii  +  154  +  24  pp.,  12  plates.     Folio.     1871. 

For  the  Twenty-seventh  Year,  1870. 

47.  A    Monograph    of    the    Gymnoblastic    or    Tubularian 
Hydroids.     By  GEORGE  JAMES  ALLMAN.     Conclusion  of  Part  I, 
and  Part  II,  containing  descriptions  of  the  Geneva  and  Species 
of  the  Gymnoblastea.     iv  +  2  (xxiii,  xxiv)  +  296  (155-450) 
+  22  pp.,  11  plates  (xiii-xxiii).     Folio.     1872. 

For  the  Twenty-eighth  Year,  1871. 

48.  Monograph  of  the  Collembola  and  Thysanura.     By  Sir 
JOHN  LUBBOCK.     x  +  276  pp.,  78  plates.     8vo.     1873. 

For  the  Twenty-ninth  Year,  1872. 

49.  A   Monograph   of   the    British  Annelids.      By   W.    C. 
MclNTOSH.      Part  I.  The  Nemertians.      xiv  +  96  +  20  pp., 
10  plates.     Folio.     1873. 

For  the  Thirtieth  Year,  1873. 

50.  A   Monograph   of   the    British    Annelids.       By   W.    C. 
MclNTOSH.      Part  I   continued.    The  Nemertians.     iv  +  122 
(97-214,  213  a-d)    +   26  pp.,   13   plates  (xi-xxiii).     Folio. 
1874. 

For  the  Thirty-first  Year,  1874. 

51.  A    Monograph    of   the  British    Spongiadae.     By    J.  S. 
BOWERBANK.     Vol.  III.     xxviii  +  368  pp.,  92  plates.      8vo, 

1874. 


PUBLICATIONS    OP    THE   BAY    SOCIETY.  7 

For  the  Thirty-second  Year,  1875. 

52.  A    Monograph    of   the    British   Aphides.      By    GEORGE 
BONVDLER   BDCKTON.     Vol.  I.     x   +    194  +  78  pp.,  42  plates 
(A-C,  i-xxxviii,  iv  bis).      8vo.     1876. 

For  the  Thirty-third  Year,  1876. 

53.  A  Monograph  of  the  Free  and  Semi-parasitic  Copepoda 
of  the  British  Islands.     By  G.  STEWARDSON  BRADY.      Vol.  I. 
iv  +  148  +  72  pp.,  36  plates   (1-33,  10A,  24A,  24s).     8vo. 
1878. 

For  the  Thirty-fourth  Year,  1877. 

54.  A    Monograph   of    the   British   Aphides.     By   GEORGE 
BOWDLER  BDCKTON.     Vol.  II.     iv  +  176  +  100  pp.,  50  plates 
(xxxix-lxxxvi,  libis,  Ixixbis).     8vo.     1879. 

For  the  Thirty-fifth  Year,  1878. 

55.  A  Monograph  of  the  Free  and  Semi-parasitic  Copepoda 
of  the  British  Islands.     By  G.  STEWARDSON  BRADY.     Vol.  II. 
iv  +  182  +  98  pp.,  49  plates  (34-82).     8vo.     1880. 

For  the  Thirty-sixth  Year,  1879. 

56.  A  Monograph  of  the  Free  and  Semi-parasitic  Copepoda 
of  the  British  Islands.     By  G.  STEWARDSON  BRADY.     Vol.  III. 
iv  +  84  +  22  pp.,  11  plates  (83-93).     8vo.     1880. 

57.  A  Monograph  of  the  British  Spongiadae.     By  the  late 
J.   S.  BOWERBANK.     Vol.  IV  (Supplementary).     Edited,  with 
additions,  by  the  Rev.  A.  M.  NORMAN,     xviii  +  250  +  34  pp., 
17  plates.     8vo.     1882. 

For  the  Thirty-seventh  Year,  1880. 

58.  A   Monograph   of    the   British  Aphides.      By   GEORGE 
BOWDLER  BUCKTON.     Vol.  III.     vi  +  142  +  56  pp.,  28  plates 
(Ixxxvii-cxiv).     8vo.     1881. 

For  the  Thirty-eighth  Year,  1881. 

59.  A  Monograph  of  the  British  Phytophagous  Hymenop- 
tera.     By  PETER  CAMERON.     Vol.  I.     viii  +  340  +  42  pp.,  21 
plates.     8vo.     1882. 

For  the  Thirty-ninth  Year,  1882. 

60.  A    Monograph    of   the  British    Aphides.      By   GEORGE 
BOWDLER  BDCKTON.     Vol.  IV.     x  +  228  +  62  pp.,  27  plates 
D-I,  cxiv  bis,  cxv-cxxxiv).     8vo.      1883. 


8  PUBLICATIONS    OF   THE    HAY    SOCIETY. 

Fur  the  Fortieth  Year,  1883. 

61.  British  Oribatida?.     Bv  ALBERT  D.  MICHAEL.     Vol.  I.     xii 
+  33G  +  62  pp.,  31  plates  "(i-xxiv,  A-G-).     8vo.     1884. 

For  the  Forty-first  Year,  1884. 

62.  A  Monograph   of   the   British   Phytophagous   Hymen- 
optera.     By  PETER  CAMERON.     Vol.  II.     vi  +  234  +  54  pp., 
27  plates.     8vo.     1885. 

For  Hie  Forty-second  Year,  1885. 

63.  The  Larvae  of  the  British  Butterflies  and  Moths.     By 
the  late  WILLIAM  BUCKLER.     Vol.1.    (The  Butterflies.)    Edited 
by  H.  T.  STAINTON.     xvi  +  202  +  34  pp.,  17  plates.     8vo, 
1886. 

For  the  Forty-third  Year,  1886. 

64.  The  Larva?  of  the  British  Butterflies  and  Moths.     By  the 
late  WILLIAM  BUCKLER.     Vol.  II.     (The  Sphinges  or  Hawk- 
moths  and  part  of  the  Bombyces.)     Edited  by  H.  T.  STAINTON. 
xii  +  172  +  36  pp.,  18  plates  (xviii-xxxv).     8vo.     1887. 

For  the  Forty-fourth  Year,  1887. 

<>.").  British  Oribatidae.  By  ALBERT  D.  MICHAEL.  Vol.  IL 
xii  +  322  (337-658)  +  62  pp.,  31  plates  (xxv-liv,  xlviiA). 
8vo.  1888. 

For  the  Forty-fifth  Year,  1888. 

66.  The  Larvae  of  the  British  Butterflies  and  Moths.     By 
the  late  "WILLIAM  BUCKLER.     Vol.  III.     (The  concluding  por- 
tion of  the  Bombyces.)     Edited  by  H.  T.  STAINTON.     xvi  + 
80  +  36  pp.,  18  plates  (xxxvi-liii).     8vo.     1889. 

For  the  Forty-sixth  Year,  1889. 

67.  A   Monograph   of   the  British   Phytophagous   Hymen- 
optera.     By  PETER  CAMERON.     Vol.  III.     vi  +  274  +  34  pp.r 
17  plates.     8vo.     1890. 

Fur  the  Forty-seventh  Year,  1890. 

68.  The  Larvas  of  the  British  Butterflies  and  Moths.     By 
the  late  WILLIAM  BUCKLER.     Vol.  IV.     (The  first  portion  of 
the  Noctua?.)     Edited  by  H.  T.  STAINTON.     xii  +116  +  32 
pp.,  16  plates  (liv-lxix).     8vo.     1891. 


PUBLICATIONS    OF    THE    RAY    SOCIETY.  9 

For  the  Furty -eighth  Year,  1891. 

69.  The  Larvae  of  the  British  Butterflies  and  Moths.      By 
the  late  WILLIAM  BUCKLER.     Vol.  V.     (The  second  portion  of 
the  Noctuae.)     Edited  (in  part)  by  the  late  H.  T.  STAINTON. 
xii  +  90  +  34pp.,  17  plates  (Ixx-lxxxvi).     8vo.     1893. 

For  the  Forty-ninth  Year,  1892. 

70.  A   Monograph   of   the  British    Phytophagous    Hymen- 
optera.     By  PETER  CAMERON.     Vol.  IV.     vi  +  248  +  38  pp., 
19  plates.     8vo.     1893. 

For  the  Fiftieth,  Year,  1893. 

71.  The  Larva3  of  the  British   Butterflies  and  Moths.     By 
the  late  WILLIAM  BUCKLER.     Vol.  VI.     (The  third  and  con- 
cluding portion  of  the  Noctuae.)     Edited  by  GEO.  T.  PORRITT. 
xii  +  142  +  38  pp.,  19  plates  (Ixxxvii-cv).     8vo.     1895. 

For  the  Fifty -first  Year,  1894. 

I'l.  The  Larvae  of  the  British  Butterflies  and  Moths.  By 
the  late  WILLIAM  BUCKLER.  Vol.  VII.  (The  first  portion  of 
the  Geometrae.)  Edited  by  GEO.  T.  PORRITT.  xvi  +  176  + 
44  pp.,  22  plates  (cvi-cxxvii).  8vo.  1897. 

For  the  Fifty-second  Year,  1895. 

7-'!.  The  Larvae  of  the  British  Butterflies  and  Moths.  By 
tJit-  late  WILLIAM  BUCKLKK.  Vol.  VIII.  (The  concluding 
portion  of  the  Geometroe.)  Edited  by  GEO.  T.  PORRITT. 
xii  +  120  +  70  pp.,  20  plates  (cxxviii-cx'lvii).  8vo.  1899. 

Fur  the  Fifty-third  Year,  1896. 

74.  The    Tailless    Batrachians     of     Europe.       By     G.    A. 
BOULENGER.     Part  I.     viii  +  210  pp.,  10  plates.     8vo.     1897. 

For  the  Fifty-fourth  Year,  1897. 

75.  The    Tailless    Batrachians     of     Europe.       By     G.    A. 
BOULENGER,      Part  II.      ii  +  166   (211-376)    pp.,    14  plates 
(xi-xxiv).     8vo.     1898. 

For  the  Fifty-fifth  Year,  1898. 

76.  A   Monograph   of  the  British  Annelids.      By  WILLIAM 
CARMICHAEL  MC!NTOSH.     Part  II.    Polychaeta.    Amphinomidae 
to  Sigaliouidae.      x   +   228  (215-442)    +   40  pp.,  20  plates 
(xxiv-xlii,  xxviA).     Folio.     1900. 


JO  PUBLICATIONS   OP    THE   EAT    SOCIETY. 

For  the  Fifty-sixth  Year.  1899. 

»/     «/  f 

77.  The  Larvae  of  the  British  Butterflies  and  Moths.     By  the 
late  WILLIAM  BUCKLER.     Vol.  IX.     (The  Deltoides,  Pyrales, 
Crambites,  Tortrices,  Tinea3,  and   Pterophori.)       Edited   by 
G-EO.  T.  PORRITT.      xviii  +  420  +  34  pp.,  17  plates  (cxlviii- 
clxiv).     8vo.     1901. 

For  the  Fifty-seventh  Tear,  1900. 

78.  Monograph   of   the   Coccida?  of  the  British  Isles.     By 
ROBERT  NEWSTEAD.     Vol.  I.     xii  +  220  +  78  pp.,  39  plates 
(A-E,  i-xxxiv).     8vo.     1901. 

For  the  Fifty -eighth  Year,  1901. 

79.  British  Tyroglyphidas.     By  ALBERT  D.  MICHAEL.     Vol.  I. 
xvi  +  294  +  44  pp.,  22  plates  (A-C,  i-xix).     8vo.     1901. 

For  the  Fifty-ninth  Year,  1902. 

80.  Monograph  of  the  Coccidaa  of   the   British  Isles.     By 
ROBERT  NEWSTEAD.     Vol.  II.     viii  +  270  +  84  pp.,  42  plates 
(p,  xxxv-lxxv).     8vo.     1903. 

For  the  Sixtieth  Year,  1903. 

81.  British  Tyroglyphidae.   By  ALBERT  D.  MICHAEL.    Vol.  II. 
xii  +  184  +  40  pp.,  20  plates  (xx-xxxix).     8vo.     1903. 

For  the  Sixty-first  Year,  1904. 

82.  A  Monograph  of  the  British  Desmidiaceas.     By  W.  and 
G.  S.  WEST.      Vol.  I.      xxxvi  +  224  +  64   pp.,  32  plates. 
8vo.     1904. 

83.  British  Tunicata.      By  the  late  JOSHUA  ALDER  and  the 
late  ALBANY  HANCOCK.      Edited  by  JOHN  HOPKINSON.     Vol.  I. 
With  a   History    of   the  Work   by   Canon  A.   M.   NORMAN. 
xvi   +    146   +   42   pp.,   20   plates,    and   frontispiece.      8vo. 
1905. 

For  the  Sixty-second  Year,  1905. 

84.  A  Monograph  of  the  British  Desmidiaceae.     By  W.  and 
G.  S.  WEST.     Vol.  II.     x  +  206  +  64  pp.,  32  plates.     8vo. 
1905. 

85.  The  British  Freshwater   Rhizopoda   and  Heliozoa.     By 
JAMES  CASH,   assisted   by   JOHN   HOPKINSON.      Vol.  I.      The 
Rhizopoda,  Part  I.     x  +  150  +  32  pp.,  16  plates.    8vo.    1905. 


PUBLICATIONS    OF   THE    RAY    SOCIETY.  11 

For  the  Sixty-third  Year,  1906. 

86.  The  British  Tunicata.    By  the  late  JOSHUA  ALDER  and  the 
late  ALBANY  HANCOCK.      Edited  by  JOHN  HOPKINSON.      Vol. 
II.     With   Lives   of   the   Authors   by   Canon  Norman  and 
Dennis  Embleton.     xxviii  +  164  -f-  62  pp.,  30  plates  (xxi-1), 
and  frontispiece.     8vo.     1907. 

For  the  Sixty-fourth  Year,  1907. 

87.  A  Monograph  of  the  British  Annelids.      By  WILLIAM 
CARMICHAEL  MC!NTOSH.     Vol.  II,  Part  1.     Polychseta.     Neph- 
thydidee  to  Syllidse.     viii  +  232  +  46  pp.,  22  plates  (xliii-1, 
Ivii-lxx).     Folio.     1908. 

For  the  Sixty-fifth  Year,  1908. 

88.  A  Monograph  of  the  British  Desmidiacea3.    By  W.  and 
G.  S.  WEST.     Vol.  III.     xvi  +  274  +  62  pp.,  31  plates  (Ixv- 
xcv).     8vo.     1908. 

89.  The  British   Freshwater  Rhizopoda  and  Heliozoa.     By 
the  late  JAMES  CASH,  assisted  by  JOHN  HOPKINSON.     Vol.  II. 
The  Rhizopoda,  Part  II.      xviii  +  168  +  32  pp.,  16  plates 
(xvii-xxxii),  and  frontispiece.     8vo.     1909. 

For  the  Sixty-sixth  Year,  1909. 

90.  The    British    Nudibranchiate    Mollusca.       By   the   late 
JOSHUA  ALDER  and  the  late  ALBANY  HANCOCK.    Part  8  (supple- 
mentary).    Text  by  Sir  CHARLES  ELIOT,     viii  +  198  +  18  pp., 
8  plates.     Folio.     1910. 

For  the  Sixty-seventh  Year,  1910. 

91.  A  Monograph  of  the  British  Annelids.     By  WILLIAM 
CARMICHAEL  MC!NTOSH.    Vol.  II,  Part  2.    Polychasta.     Syllidas 
to  Ariciidse.     vii  +  292  (233-524)  +  46  pp.,  23  plates  (li-lvi, 
Ixxi-lxxxvii).     Folio.     1910. 

For  the  Sixty-eighth  Year,  1911. 

92.  A  Monograph  of  the  British  Desmidiacea3.     By  W.  and 
G.  S.  WEST.      Vol.  IV.      xiv    +    194    -f    66  pp.,  33  plates 
(xcvi-cxxviii).     8vo.     1912. 

93.  The  British  Tunicata.     By  the  late  JOSHUA  ALDER  and 
the  late  ALBANY  HANCOCK.     Edited  by  JOHN  HOPKINSON.    Vol. 
III.     xii  +114  +  34  pp.,  16  plates  (li-lxvi),  and  frontispiece. 
8vo.     1912. 


12  PUBLICATIONS    OF    THE    HAY    SOCIETY. 

F<»-  tlir  Si.i'fi/--n/utJi  Year,  1912. 

94.  A  Bibliography  of  the  Tnnicata.      Bv  JOHN  HOPKIV 
xii  +  288  pp.     8vo.     1913. 

95.  The  British  Parasitic-  Copepoda.     By  Dr.  THOMAS  SCOTT 
and  ANDREW  SCOTT.     Vol.  I   (Copepoda  parasitic  on  Fishes, 
Part  I),     xii  +  256  pp.,  2  plates.     8vo.     1913. 


Li  Conrxt'  of  Publication. 

The  British  Desmidiare;e.      My  W.  WKST  and   Prof.  G.  S. 
WEST. 

The    British    Freshwater    Hhi/opoda    and    Heliozoa.       Bv 
the  late  JAMES  CASH  and  (niter  Vol.  .11)  (!.  II.  WAII.KS. 
The  British  Marine  Annelids.     By  Prof.  \V.  ('.  M 
The   British   Parasitic  Copepuda.     ]iy   Dr.   THO:I 
and  ANDREW  SCOTT.     (Vol.  II  for  191-3.) 


Preparing  for  Publication. 

The  British  Centipedes  and  Millepedes.      By  AV.  M. 

The  British  Earthworms.     By  the  Kev.  HILDERIC 

The     British     Hydrachnidio.       By     C.    D.    SOAR    and    W. 

AVlLI.IAMSOX. 

The  British  Ixodoidea.  By  W.  F.  COOI-MR  and  L.  !•].  Ko];ixs«»x. 
The  Earwigs  of  the  World.     By  Dr.  MALCOLM  BU;R. 


Mnrch,  1913. 


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