﻿16 
  PROPAGATION 
  OF 
  FRESH-WATER 
  MUSSELS. 
  

  

  The 
  Purple 
  Warty-back 
  Quadrula 
  granijera 
  (Lea). 
  PPI. 
  vi, 
  fig. 
  

   40, 
  41.] 
  

   The 
  shell 
  of 
  this 
  species 
  has 
  purple 
  nacre 
  and 
  is 
  therefore 
  not 
  usually 
  

   saved 
  by 
  clammers. 
  The 
  juveniles 
  are 
  very 
  handsome 
  because 
  of 
  the 
  

   fine 
  crenulations 
  of 
  the 
  umbones. 
  The 
  glochidium 
  is 
  of 
  large 
  size 
  

   having 
  the 
  following 
  dimensions: 
  Height, 
  0.355 
  mm.; 
  length, 
  0.29 
  

   mm. 
  (Surber, 
  1912.) 
  

  

  The 
  Maple-Leaf, 
  Quadrula 
  lachrymosa 
  (Lea). 
  [PI. 
  vi, 
  fig. 
  43, 
  44.] 
  

  

  The 
  odd 
  sculpturing 
  of 
  tliis 
  shell, 
  with 
  the 
  coloring 
  of 
  the 
  epidermis, 
  

   makes 
  it 
  a 
  handsome 
  species. 
  It 
  seems 
  not 
  to 
  be 
  very 
  common 
  in 
  the 
  

   Mississippi 
  in 
  the 
  region 
  I 
  have 
  investigated, 
  viz, 
  between 
  Hampton, 
  

   111., 
  and 
  Muscatine, 
  Iowa. 
  

  

  Distribution. 
  ^S^ 
  &'&ievn 
  New 
  Yorls 
  to 
  Kansas 
  and 
  IVIinnesota, 
  and 
  

   south 
  to 
  Texas 
  and 
  Alabama. 
  (Call.) 
  

  

  Habitat. 
  — 
  The 
  larger 
  lakes 
  and 
  rivers 
  on 
  a 
  muddy 
  or 
  sandy 
  bottom 
  

   in 
  somewhat 
  shallow 
  water. 
  (Baker, 
  1898.) 
  

  

  Juvenile. 
  — 
  I 
  have 
  myself 
  taken 
  only 
  a 
  few 
  juveniles 
  of 
  this 
  species. 
  

   These 
  were 
  found 
  in 
  shallow 
  water 
  in 
  a 
  rather 
  swift 
  current. 
  The 
  

   form 
  is 
  so 
  much 
  Kke 
  the 
  adult 
  that 
  it 
  may 
  be 
  readily 
  recognized. 
  

  

  Glochidium 
  (pi. 
  v, 
  fig. 
  29). 
  — 
  Eggs 
  were 
  observed 
  the 
  middle 
  of 
  June; 
  

   they 
  were 
  white 
  in 
  color 
  and 
  occupied 
  aU 
  four 
  giUs. 
  Early 
  embryos 
  

   of 
  this 
  species 
  were 
  found 
  in 
  four 
  out 
  of 
  five 
  specimens 
  examined 
  June 
  

   27. 
  According 
  to 
  these 
  observations, 
  mature 
  glochidia 
  would 
  be 
  

   found 
  during 
  July 
  in 
  this 
  region. 
  Mature 
  glochidia 
  were 
  obtained 
  

   in 
  August, 
  1912, 
  from 
  a 
  tributary 
  of 
  Fall 
  River, 
  Glen 
  wood 
  County, 
  

   Kans.," 
  and 
  also 
  June 
  12, 
  1913, 
  at 
  Fairport, 
  Iowa. 
  Form, 
  of 
  the 
  

   purse-shaped 
  type, 
  similar 
  to 
  Q. 
  metanevra. 
  

  

  Dimensions: 
  Height, 
  0.085 
  mm.; 
  length, 
  0.078 
  mm. 
  This 
  is 
  the 
  

   smallest 
  glochidium 
  ol 
  the 
  Quadrula 
  group 
  that 
  I 
  have 
  seen. 
  Ort- 
  

   mann 
  (1912) 
  places 
  Tritogonia 
  tuberculata 
  (Simpson) 
  in 
  the 
  genus 
  

   Quadrula 
  on 
  the 
  basis 
  of 
  its 
  anatomical 
  structure. 
  In 
  its 
  shell 
  

   sculpture, 
  though 
  pecuhar, 
  he 
  recognizes 
  a 
  relationship 
  to 
  the 
  group 
  

   of 
  Quadrula 
  lachrymosa. 
  The 
  extremely 
  small 
  size 
  and 
  similar 
  form 
  

   of 
  the 
  glochidia 
  of 
  these 
  two 
  species 
  is 
  another 
  feature 
  supporting 
  

   this 
  view. 
  

  

  Propagation. 
  — 
  No 
  observations 
  have 
  beea 
  made 
  upon 
  natura 
  

   infections. 
  Experiments 
  in 
  propagation 
  would 
  be 
  practicable 
  in 
  

   regions 
  where 
  the 
  species 
  is 
  not 
  uncommon. 
  Scammon 
  (1906) 
  

   reports 
  it 
  abundant 
  in 
  Kansas 
  and 
  it 
  is 
  reported 
  common 
  in 
  Indiana, 
  

   and 
  the 
  closely 
  allied 
  species, 
  Q.fragosa 
  and 
  Q. 
  nobilis, 
  are 
  abundant 
  

   in 
  Arkansas. 
  

  

  » 
  I 
  am 
  indebted 
  to 
  Dr. 
  Roy 
  L. 
  Moodie, 
  of 
  the 
  University 
  of 
  Kansas, 
  for 
  this 
  material. 
  

  

  