﻿OYSTER 
  INDUSTEY 
  OF 
  NORTH 
  CAROLINA. 
  287 
  

  

  The 
  bulk 
  of 
  the 
  food 
  .supply 
  in 
  Wj^esocking 
  Bay 
  consisted 
  of 
  eight 
  

   species 
  of 
  plant 
  forms 
  — 
  live 
  diatoms 
  and 
  three 
  Peridinea?. 
  Several 
  

   other 
  diatoms 
  and 
  Peridinete 
  were 
  occasionall}^ 
  found 
  in 
  the 
  03^ 
  sters' 
  

   stomachs, 
  ])ut 
  not 
  in 
  sufficient 
  numbers 
  to 
  be 
  considered 
  important 
  

   elements 
  of 
  their 
  diet. 
  

  

  The 
  plant 
  that 
  appeared 
  most 
  abundantl}' 
  was 
  a 
  beautiful 
  disk-shaped 
  

   diatom, 
  Coscinodlscuspei'foratus 
  (fig. 
  10). 
  It 
  lived 
  mainly 
  in 
  the 
  water 
  

   above 
  the 
  surface 
  of 
  the 
  bottom 
  and, 
  as 
  is 
  evident 
  from 
  the 
  table, 
  was 
  

   not 
  so 
  available 
  to 
  the 
  o^^sters 
  as 
  the 
  one 
  next 
  referred 
  to. 
  It 
  was 
  

   very 
  much 
  more 
  abundant 
  in 
  the 
  water 
  in 
  March 
  than 
  in 
  November 
  and 
  

   December. 
  

  

  An 
  undetermined 
  species 
  of 
  MeJoslra 
  (fig. 
  8) 
  was 
  the 
  next 
  most 
  

   important 
  constituent 
  of 
  food 
  in 
  this 
  section, 
  and, 
  with 
  one 
  exception, 
  

   it 
  seems 
  to 
  be 
  the 
  most 
  constant 
  element. 
  The 
  individuals 
  of 
  this 
  

   species 
  are 
  much 
  smaller 
  than 
  those 
  of 
  Melosira 
  sculpta^ 
  but, 
  like 
  the 
  

   latter, 
  they 
  adhere 
  end 
  to 
  end, 
  forming 
  filaments, 
  and 
  are 
  found 
  in 
  

   greatest 
  abundance 
  near 
  and 
  upon 
  the 
  bottom. 
  

  

  Pleurosigma 
  spencerii 
  and 
  Nanicula 
  didyma 
  are 
  the 
  only 
  species 
  

   common 
  to 
  the 
  food 
  supply 
  of 
  section 
  10 
  and 
  the 
  Beaufort 
  region. 
  

   The 
  former 
  had 
  diminished 
  in 
  numbers 
  in 
  Wyesocking* 
  Bay 
  from 
  

   March 
  to 
  November, 
  but 
  a 
  slight 
  increase 
  had 
  taken 
  place 
  in 
  the 
  quan- 
  

   tity 
  of 
  the 
  latter. 
  

  

  The 
  fifth 
  diatom 
  present 
  in 
  abundance 
  in 
  both 
  the 
  oysters 
  and 
  water 
  

   I 
  have 
  been 
  unable 
  to 
  identify. 
  It 
  is 
  an 
  elongated 
  form, 
  the 
  individ- 
  

   uals 
  of 
  which 
  lie 
  side 
  by 
  side 
  in 
  small 
  colonies, 
  as 
  1 
  have 
  shown 
  rough!}'- 
  

   in 
  figure 
  2 
  on 
  page 
  285. 
  Less 
  difference 
  was 
  noted 
  in 
  the 
  abundance 
  

   of 
  this 
  species 
  during 
  March 
  and 
  November 
  than 
  for 
  an}- 
  other. 
  It 
  

   seemed 
  to 
  thrive 
  as 
  well 
  in 
  salt 
  as 
  in 
  brackish 
  w^ater. 
  

  

  None 
  of 
  the 
  Peri 
  dinese 
  could 
  be 
  specifically 
  identified, 
  but 
  the 
  genera 
  

   to 
  which 
  they 
  belonged 
  were 
  determined. 
  The 
  species 
  of 
  Glenodl- 
  

   n'lum 
  (fig. 
  5) 
  was 
  conjugating 
  in 
  March 
  and, 
  because 
  of 
  the 
  large 
  

   buoyant 
  gelatinous 
  capsules 
  secreted 
  about 
  them, 
  the 
  individuals 
  were 
  

   quite 
  evenl}^ 
  distributed 
  through 
  the 
  water. 
  Tho§e 
  not 
  inclosed 
  in 
  

   capsules 
  were 
  not 
  dependent 
  upon 
  the 
  currents 
  in 
  the 
  water 
  for 
  their 
  

   distribution, 
  but 
  moved 
  about 
  activel}^ 
  This 
  species 
  had 
  almost 
  com- 
  

   pletely 
  disappeared 
  in 
  November. 
  Heterompsa 
  (fig. 
  4) 
  is 
  found 
  in 
  

   greater 
  abundance 
  near 
  the 
  bottom 
  than 
  at 
  higher 
  levels 
  or 
  at 
  the 
  sur- 
  

   face 
  of 
  the 
  water, 
  and 
  is 
  more 
  abundant 
  near 
  the 
  mainland 
  and 
  marshes 
  

   than 
  over 
  beds 
  offshore. 
  It, 
  too, 
  had 
  almost 
  disappeared 
  in 
  Novem- 
  

   ber. 
  The 
  species 
  of 
  Prorocentrum 
  (fig. 
  3), 
  on 
  the 
  other 
  hand, 
  was 
  very 
  

   much 
  more 
  numerous 
  in 
  November 
  than 
  in 
  March. 
  Individuals 
  were 
  

   occasionally 
  found 
  in 
  the 
  03^sters 
  from 
  the 
  beds 
  near 
  the 
  mouths 
  of 
  

   Newport 
  and 
  North 
  rivers 
  and 
  in 
  Jarrats 
  Bay, 
  which 
  indicates 
  that 
  

   this 
  form 
  is 
  adapted 
  to 
  water 
  with 
  a 
  high 
  density, 
  such 
  as 
  prevails 
  in 
  

  

  