﻿268 
  PROCEEDINGS 
  OF 
  THE 
  NATIONAL 
  MUSEUM. 
  vol. 
  44. 
  

  

  It 
  is 
  therefore 
  remarkable 
  that 
  this 
  sinj^le 
  exception 
  should 
  dej^al-t 
  

   so 
  radically 
  from 
  the 
  habits 
  of 
  its 
  relatives. 
  And 
  then, 
  in 
  spite 
  of 
  

   the 
  parasitism, 
  it 
  is 
  still 
  normally 
  developed 
  like 
  all 
  the 
  other 
  genera 
  

   in 
  the 
  group 
  and 
  it 
  has 
  lost 
  none 
  of 
  its 
  ability 
  to 
  swim 
  freely. 
  Its 
  

   life 
  history, 
  when 
  fully 
  worked 
  out, 
  ought 
  to 
  possess 
  unusual 
  interest. 
  

  

  PARASITIC 
  OSTRACODS. 
  

  

  Very 
  little 
  is 
  kno^\^l 
  with 
  reference 
  to 
  the 
  habits 
  of 
  the 
  ostracods. 
  

   The 
  earlier 
  authors 
  like 
  Linnaeus, 
  Geofl'roy, 
  Fabricius, 
  O. 
  F. 
  Mtiller, 
  

   Desmarest, 
  and 
  even 
  Milne 
  Edwards 
  give 
  a 
  variety 
  of 
  details 
  with 
  

   regard 
  to 
  the 
  different 
  genera 
  and 
  species. 
  But 
  they 
  are 
  all 
  content 
  

   with 
  a 
  very 
  few 
  general 
  observations 
  on 
  their 
  habits 
  and 
  mode 
  of 
  

   life. 
  

  

  Baird 
  (1850) 
  was 
  the 
  fu'st 
  to 
  give 
  us 
  any 
  real 
  knowledge 
  of 
  the 
  

   food 
  and 
  activities 
  of 
  these 
  entomostracans. 
  But 
  although 
  he 
  said 
  

   that 
  ''most 
  of 
  the 
  entomostraca 
  are 
  essentially 
  carnivorous," 
  and 
  

   gave 
  numerous 
  examples 
  of 
  species 
  which 
  hunt 
  and 
  kill 
  their 
  prey, 
  

   he 
  made 
  no 
  mention 
  of 
  any 
  ostracod 
  that 
  was 
  parasitic. 
  

  

  In 
  Brady's 
  Report 
  on 
  the 
  Ostracods 
  of 
  the 
  Challenger 
  Expedition 
  

   nothing 
  is 
  said 
  with 
  regard 
  to 
  their 
  food, 
  but 
  he 
  mentions 
  the 
  fact 
  

   that 
  the 
  Cypridinae 
  ''appear 
  to 
  be 
  most 
  abundant 
  in 
  the 
  warm 
  surface 
  

   waters 
  of 
  the 
  tropical 
  seas, 
  contributing 
  largely 
  to 
  the 
  phosphores- 
  

   cence 
  of 
  those 
  regions." 
  He 
  also 
  calls 
  attention 
  to 
  the 
  fact 
  that 
  only 
  

   the 
  males 
  can 
  swim, 
  the 
  females 
  lacking 
  the 
  rowing 
  setae 
  on 
  the 
  

   antennae, 
  and 
  in 
  consequence 
  living 
  at 
  the 
  bottom 
  in 
  the 
  sand 
  or 
  

   mud 
  (p. 
  151). 
  

  

  G. 
  W. 
  Mtiller 
  in 
  his 
  monograph 
  on 
  the 
  Ostracods, 
  which 
  constitutes 
  

   the 
  twenty-first 
  volume 
  of 
  the 
  Fauna 
  and 
  Flora 
  of 
  the 
  Bay 
  of 
  Naples, 
  

   when 
  speaking 
  of 
  their 
  food, 
  mentions 
  finding 
  diatom 
  shells 
  in 
  the 
  

   stomachs 
  of 
  some 
  species, 
  while 
  he 
  found 
  one-celled 
  algae 
  and 
  the 
  

   setae 
  of 
  some 
  small 
  Crustacea 
  in 
  the 
  stomach 
  of 
  another 
  species. 
  A 
  

   representative 
  of 
  the 
  genus 
  Macrocypris, 
  kept 
  in 
  captivity, 
  ate 
  

   freely 
  of 
  small 
  dead 
  copepods, 
  and 
  ConclicBcia 
  spinirostris 
  had 
  in 
  its 
  

   stomach 
  the 
  apparent 
  remains 
  of 
  copepods. 
  

  

  A 
  young 
  Oypridina 
  mediterranea, 
  while 
  in 
  captivity, 
  ate 
  greedily 
  

   of 
  a 
  small 
  dead 
  annulate. 
  Such 
  observations 
  as 
  these 
  suggest 
  that 
  

   a 
  carnivorous 
  ostracod 
  might 
  very 
  well 
  become 
  parasitic 
  under 
  

   favorable 
  conditions. 
  It 
  would 
  not 
  necessitate 
  very 
  much 
  of 
  a 
  

   change 
  in 
  habits 
  or 
  structure. 
  

  

  And 
  finally, 
  in 
  Lankester's 
  Treatise 
  on 
  Zoology, 
  Caiman, 
  who 
  

   wrote 
  the 
  volume 
  dealing 
  with 
  the 
  Crustacea 
  (1909), 
  devotes 
  only 
  a 
  

   few 
  lines 
  to 
  the 
  habits 
  of 
  the 
  ostracods, 
  in 
  which 
  he 
  says: 
  "None 
  are 
  

   definitely 
  known 
  to 
  be 
  parasitic, 
  but 
  one 
  species 
  found 
  in 
  the 
  gill 
  

   chambers 
  of 
  crayfish 
  in 
  North 
  America 
  may 
  be 
  so" 
  (p. 
  67). 
  

  

  