﻿MUSSEL 
  RESOUECES 
  OF 
  THE 
  ILLINOIS 
  RIVER. 
  45 
  

  

  40. 
  Lampsilis 
  parva 
  (Barnes). 
  — 
  A 
  rare 
  species 
  ; 
  one 
  example 
  found 
  

   in 
  Peoria 
  Lake. 
  This 
  is 
  a 
  small, 
  delicate 
  shell 
  of 
  no 
  economic 
  value. 
  

  

  41. 
  Black 
  Sand-shell, 
  Lampsilis 
  recta 
  (Lamarck). 
  — 
  The 
  black 
  

   sand-shell 
  is 
  a 
  rather 
  common 
  one 
  and 
  reaches 
  a 
  very 
  large 
  size 
  in 
  this 
  

   river. 
  It 
  is 
  found 
  in 
  the 
  lakehke 
  places 
  of 
  the 
  stream 
  and 
  in 
  the 
  

   swifter 
  parts 
  of 
  the 
  lower 
  stretches. 
  The 
  nacre 
  is 
  generally 
  pinkish 
  

   or 
  purple 
  and, 
  although 
  the 
  texture 
  is 
  good, 
  the 
  shells 
  are 
  discarded 
  

   by 
  the 
  mussel 
  fishermen 
  and 
  buyers, 
  as 
  there 
  appears 
  to 
  be 
  no 
  particu- 
  

   lar 
  demand 
  at 
  the 
  present 
  time 
  for 
  colored 
  shells. 
  The 
  white-nacred 
  

   ones, 
  though 
  much 
  less 
  abundant, 
  are 
  always 
  saved. 
  They 
  are 
  

   usually 
  classed 
  along 
  with 
  the 
  yellow 
  sand-shell, 
  and 
  are 
  mad 
  use 
  

   of 
  m 
  novelty 
  factories. 
  In 
  the 
  mussel 
  camps 
  this 
  shell 
  is 
  often 
  called 
  

   "lady's 
  slipper," 
  on 
  account 
  of 
  the 
  appearance 
  of 
  the 
  valves 
  when 
  

   opened 
  out 
  flat. 
  

  

  42. 
  Slough 
  Sand-shell, 
  Lampsilis 
  fallaciosa 
  (Smith), 
  — 
  Abund- 
  

   ant 
  ; 
  usually 
  found 
  standing 
  on 
  end 
  burrowed 
  in 
  the 
  mud' 
  of 
  sloughs 
  

   and 
  bays 
  or 
  along 
  the 
  shore 
  where 
  there 
  is 
  but 
  little 
  current. 
  When 
  

   of 
  sufficient 
  size 
  and 
  thickness, 
  they 
  are 
  classed 
  with 
  the 
  yellow 
  sand- 
  

   sheU. 
  In 
  Peoria 
  Lake 
  the 
  fallaciosa 
  are 
  beautifully 
  rayed. 
  

  

  Some 
  doubt 
  has 
  arisen 
  as 
  to 
  whether 
  this 
  species 
  is 
  identical 
  with 
  

   anodontoides 
  , 
  but 
  it 
  appears 
  on 
  the 
  lUinois 
  to 
  be 
  a 
  distinct 
  species. 
  

   Our 
  examples 
  are 
  markedly 
  different 
  from 
  anodontoides 
  of 
  the 
  same 
  

   region. 
  The 
  fallaciosa 
  vary 
  greatly 
  in 
  distinctness 
  and 
  abundance 
  of 
  

   rays, 
  some 
  being 
  but 
  faintly 
  rayed, 
  others 
  with 
  many 
  broad 
  pro- 
  

   nounced 
  green 
  rays. 
  One 
  example, 
  a 
  fine 
  large 
  male, 
  is 
  so 
  heavily 
  

   rayed 
  as 
  to 
  be 
  almost 
  green, 
  and 
  approaches 
  more 
  nearly 
  than 
  any 
  

   of 
  the 
  others 
  the 
  general 
  form 
  of 
  anodontoides, 
  but 
  could 
  not 
  weU 
  be 
  

   confused 
  with 
  that 
  species. 
  A 
  well-rayed 
  female 
  of 
  moderate 
  size 
  

   is 
  noteworthy 
  for 
  a 
  marked 
  reddish-orange 
  cast 
  of 
  the 
  epidermis, 
  the 
  

   shell 
  beneath 
  having 
  a 
  rosy 
  tinge. 
  Another 
  constant 
  difference 
  in 
  

   our 
  examples 
  is 
  the 
  cardinal 
  tooth 
  of 
  the 
  right 
  valve, 
  which 
  is 
  com- 
  

   pressed 
  and 
  almost 
  lamelliform 
  in 
  fallaciosa, 
  while 
  in 
  anodontoides 
  it 
  

   is 
  more 
  triangular. 
  

  

  It 
  is 
  quite 
  possible 
  that 
  the 
  convergence 
  of 
  the 
  two 
  species 
  in 
  the 
  

   southern 
  and 
  southwestern 
  portions 
  of 
  the 
  United 
  States 
  is 
  due 
  to 
  

   the 
  different 
  features 
  of 
  bottom 
  and 
  general 
  abundance 
  of 
  silt 
  and 
  

   slough-like 
  conditions 
  in 
  the 
  lower 
  courses 
  of 
  rivers, 
  which 
  would 
  

   cause 
  aU 
  to 
  assume 
  the 
  characters 
  of 
  the 
  slough-dweUing 
  form. 
  

  

  43. 
  Yellow 
  Sand-shell, 
  Lampsilis 
  anodontoides 
  (Lea). 
  — 
  This 
  

   species 
  is 
  found 
  sparingly 
  throughout 
  the 
  upper 
  river, 
  but 
  is 
  fairly 
  

   abmidant 
  in 
  the 
  Hardin 
  district, 
  where 
  it 
  is 
  in 
  sufficient 
  quantity 
  to 
  

   be 
  sorted 
  out 
  and 
  sold 
  separately 
  at 
  an 
  advanced 
  price. 
  This 
  shell 
  

   is 
  the 
  most 
  valuable 
  of 
  the 
  fresh-water 
  mussels, 
  and 
  as 
  it 
  is 
  easily 
  

   propagated, 
  many 
  of 
  the 
  beds 
  where 
  the 
  conditions 
  are 
  favorable 
  

   could 
  be 
  restored. 
  It 
  prefers 
  deep 
  water 
  and 
  clean 
  sandy 
  bottoms. 
  

  

  