﻿16 
  MUSSELS 
  IN 
  TRIBUTAEIES 
  OF 
  [JPPER 
  MISSOURI 
  RIVER, 
  

  

  mussel 
  resources. 
  The 
  James 
  and 
  Vermilion 
  Rivers 
  are 
  exceptions, 
  

   the 
  James 
  River 
  particularly 
  having 
  supported 
  during 
  the 
  past 
  year 
  

   (1913) 
  a 
  shell 
  fishery 
  of 
  some 
  importance. 
  Pearl 
  fishing 
  has 
  been 
  

   pursued 
  in 
  both 
  streams 
  for 
  some 
  years. 
  The 
  shell 
  fishery 
  on 
  the 
  

   James 
  River 
  is 
  principally 
  between 
  Riverside 
  and 
  Lesterville. 
  Modi- 
  

   fications 
  of 
  the 
  usual 
  methods 
  of 
  fisliing 
  are 
  employed 
  to 
  advantage. 
  

   (See 
  p. 
  9, 
  10.) 
  

  

  The 
  principal 
  shell 
  is 
  the 
  Q. 
  undulata 
  (three-ridge). 
  Several 
  other 
  

   economic 
  species 
  are 
  found 
  in 
  less 
  abundance. 
  The 
  variety 
  of 
  shells 
  

   is 
  hmited, 
  14 
  species 
  in 
  all 
  being 
  collected. 
  

  

  Pearl 
  fishing 
  has 
  been 
  pursued 
  on 
  the 
  Vermilion 
  River 
  and 
  some 
  

   shipments 
  of 
  shells 
  have 
  been 
  made 
  recently, 
  but 
  the 
  stream 
  is 
  too 
  

   small 
  to 
  be 
  important. 
  

  

  It 
  is 
  probable 
  that 
  the 
  self-perpetuation 
  of 
  the 
  mussel 
  beds 
  in 
  the 
  

   James 
  River 
  depends 
  upon 
  the 
  occurrence 
  of 
  unusual 
  flood 
  stages 
  

   that 
  allow 
  opportunity 
  for 
  the 
  entrance 
  of 
  fishes 
  from 
  the 
  Missouri 
  

   River. 
  

  

  