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  KEPOKT 
  OF 
  COMMISSIONER 
  OF 
  FISH 
  AND 
  FISHERIES. 
  

   SEASONAL 
  DISTRIBUTION. 
  

  

  Hardly 
  enough 
  data 
  have 
  been 
  collected 
  to 
  draw 
  any 
  conclusions 
  in 
  

   regard 
  to 
  the 
  seasonal 
  distribution 
  of 
  the 
  diatoms 
  affecting 
  the 
  lobster 
  

   fry. 
  A 
  few 
  facts 
  have 
  been 
  noted, 
  however. 
  During 
  the 
  time 
  that 
  

   lobster 
  fry 
  were 
  being 
  reared 
  at 
  Woods«Hole, 
  from 
  June 
  1, 
  1902, 
  until 
  

   the 
  middle 
  of 
  July, 
  about 
  the 
  same 
  relative 
  abundance 
  of 
  species 
  

   growing 
  on 
  the 
  fry 
  obtained 
  from 
  first 
  to 
  last. 
  Licmopliora 
  tincta 
  

   was 
  always 
  the 
  most 
  jjlentif 
  ul. 
  Licmopliora 
  flahellata 
  was 
  occasionally 
  

   present 
  early 
  in 
  the 
  season, 
  but 
  later, 
  about 
  July 
  5, 
  1902, 
  it 
  became 
  

   much 
  more 
  abundant. 
  In 
  some 
  cases 
  this 
  species 
  was 
  practicall}^ 
  the 
  

   only 
  species 
  attached 
  to 
  the 
  carapace, 
  Licmopliora 
  tincta 
  and 
  the 
  other 
  

   species 
  being 
  confined 
  to 
  the 
  limbs 
  and 
  abdomen. 
  

  

  That 
  the 
  later 
  appearance 
  of 
  the 
  diatoms 
  on 
  the 
  fry 
  at 
  Wickford 
  

   had 
  anything 
  to 
  do 
  with 
  their 
  seasonal 
  distribution 
  is 
  doubtful; 
  the 
  

   temperature 
  of 
  the 
  water 
  may 
  have 
  had 
  some 
  influence, 
  but 
  it 
  seems 
  

   hardly 
  probable 
  because 
  of 
  their 
  absence 
  the 
  previous 
  season, 
  and 
  also 
  

   because 
  Wickford 
  temperatures 
  are, 
  as 
  a 
  rule, 
  higher 
  than 
  those 
  at 
  

   Woods 
  Hole. 
  The 
  explanation 
  already 
  given— 
  the 
  infection 
  of 
  the 
  

   bags 
  by 
  the 
  fry 
  brought 
  from 
  Woods 
  Hole 
  — 
  seems 
  more 
  reasonable. 
  

  

  SPECIES 
  OF 
  DIATOMS 
  FOUND 
  ON 
  LOBSTER 
  FRY. 
  

  

  Below 
  is 
  a 
  list 
  of 
  all 
  diatoms 
  found 
  on 
  lobster 
  fry 
  hatched 
  and 
  reared 
  

   at 
  Woods 
  Hole, 
  in 
  the 
  order 
  of 
  their 
  abundance: 
  

  

  Licmophora 
  tincta 
  Grunow'. 
  

  

  Diatoma 
  hyalinum 
  (Klitzing) 
  Grunow. 
  

  

  Rhabdonema 
  arcuatuni 
  ( 
  Lyngby 
  ) 
  Kiitzing. 
  

  

  Tabellaria 
  (Striatella) 
  unipunctata 
  Agardh. 
  

  

  Licmophora 
  flabellata 
  (Carmichael) 
  Agardh. 
  

  

  Synedra 
  gallionii 
  Ehrenberg. 
  

  

  Synedra 
  affiiiis 
  Kiitzing. 
  

  

  Grammatophora 
  marina 
  (Lyngby) 
  Kiitzing. 
  

  

  Grammatophora 
  subtilUssima 
  Bailey. 
  

  

  Melosira 
  sculpta 
  Kiitzing. 
  

  

  Cocconeis 
  scutellum 
  Ehrenberg. 
  

  

  Actinoptychus 
  undulatus 
  Ralfs. 
  

  

  Hyalodiscus 
  subtiles 
  Castracane. 
  

  

  Coscinodiscus 
  concavus 
  Ehrenberg. 
  

  

  Navicula 
  lyra 
  Ehrenberg. 
  

  

  Navicula 
  didyma 
  Ehrenberg. 
  

  

  Nitzschia 
  vivax 
  W. 
  Smith. 
  

  

  Nitzschia 
  longissima 
  (Brebisson) 
  Ralfs. 
  

  

  Schizonema 
  americanum 
  Grunow. 
  

  

  Navicula 
  sp. 
  

  

  Rhabdonema 
  adriaticum 
  Kiitzing. 
  

  

  Campylodiscus 
  sp. 
  

  

  Actinoptychus 
  sp. 
  

  

  Amphora 
  sp. 
  

  

  