﻿THE 
  MUSSEL 
  FAUNA 
  OF 
  CENTRAL 
  AND 
  NORTHERN 
  MINNESOTA. 
  

  

  By 
  Charles 
  B. 
  Wilson 
  and 
  Ernest 
  Danglade. 
  

  

  INTRODUCTION. 
  

  

  As 
  a 
  part 
  of 
  the 
  fresh-water 
  mussel 
  mvestigations 
  conducted 
  by 
  

   the 
  Bureau 
  of 
  Fisheries, 
  the 
  central 
  and 
  northern 
  portions 
  of 
  Minne- 
  

   sota 
  were 
  examined 
  during 
  the 
  summer 
  of 
  1912 
  with 
  regard 
  to 
  the 
  

   kinds 
  and 
  numbers 
  of 
  mussels 
  to 
  be 
  found 
  in 
  the 
  lakes 
  and 
  rivers. 
  

   The 
  mussel 
  fauna 
  of 
  the 
  Mississippi 
  River 
  in 
  Minnesota 
  below 
  St. 
  

   Paul 
  and 
  of 
  the 
  IVIinnesota 
  River 
  have 
  been 
  thoroughly 
  investigated 
  

   by 
  representatives 
  of 
  the 
  various 
  pearl-button 
  companies, 
  and 
  the 
  

   quaUty 
  and 
  amount 
  of 
  shells 
  which 
  they 
  produce 
  have 
  become 
  fairly 
  

   well 
  known. 
  The 
  central 
  and 
  northern 
  portions 
  of 
  the 
  State 
  had 
  never 
  

   been 
  examined 
  except 
  by 
  mussel 
  fishermen. 
  The 
  shells 
  obtained 
  

   by 
  some 
  of 
  these 
  fishermen, 
  however, 
  and 
  shipped 
  to 
  the 
  button 
  

   factories 
  were 
  of 
  such 
  exceptional 
  quaUty 
  as 
  to 
  attract 
  the 
  attention 
  

   not 
  only 
  of 
  the 
  manufacturers 
  but 
  also 
  of 
  the 
  Government 
  experts 
  

   at 
  the 
  biological 
  laboratory 
  at 
  Fairport, 
  Iowa. 
  Since 
  some 
  of 
  these 
  

   shells 
  were 
  obtained 
  from 
  lakes 
  and 
  others 
  from 
  rivers, 
  it 
  was 
  deter- 
  

   mined 
  to 
  make 
  a 
  prehminary 
  survey 
  of 
  both 
  lakes 
  and 
  rivers 
  through 
  

   the 
  central 
  and 
  northern 
  portions 
  of 
  the 
  State. 
  

  

  This 
  survey 
  had 
  a 
  threefold 
  object: 
  First, 
  to 
  determine 
  the 
  geo- 
  

   graphic 
  distribution 
  of 
  the 
  various 
  mussels 
  in 
  those 
  portions 
  of 
  the 
  

   State. 
  Incidentally, 
  of 
  course, 
  tliis 
  would 
  answer 
  the 
  question 
  whether 
  

   the 
  exceptionally 
  fine 
  shells 
  were 
  locally 
  or 
  generally 
  chstributed, 
  

   and 
  where 
  they 
  were 
  to 
  be 
  found. 
  

  

  Second, 
  to 
  make 
  as 
  careful 
  a 
  survey 
  as 
  possible 
  of 
  the 
  various 
  

   conditions, 
  conducive 
  or 
  adverse 
  to 
  mussel 
  development, 
  in 
  the 
  differ- 
  

   ent 
  locahties 
  visited. 
  This 
  would 
  not 
  only 
  throw 
  some 
  light 
  on 
  the 
  

   presence 
  of 
  exceptional 
  mussels 
  in 
  certain 
  locahties, 
  but 
  would 
  also 
  

   serve 
  as 
  a 
  basis 
  for 
  the 
  final 
  object 
  of 
  the 
  survey. 
  

  

  Tliird, 
  to 
  ascertain 
  whether 
  it 
  would 
  be 
  profitable 
  to 
  introduce 
  

   artificial 
  propagation 
  in 
  any 
  of 
  the 
  lakes 
  or 
  rivers, 
  and 
  if 
  so, 
  what 
  

   species 
  would 
  be 
  best 
  adapted 
  to 
  the 
  locahty. 
  

  

  The 
  investigating 
  party 
  consisted 
  of 
  the 
  two 
  authors, 
  and 
  in 
  conse- 
  

   quence 
  of 
  the 
  large 
  territory 
  to 
  be 
  covered 
  and 
  the 
  isolation 
  of 
  many 
  

   of 
  the 
  locahties 
  visited 
  it 
  was 
  necessary 
  to 
  travel 
  entirely 
  by 
  rail- 
  

  

  5 
  

  

  