﻿PROPAGATION 
  OF 
  FEESH-WATER 
  MUSSELS. 
  23 
  

  

  herring 
  as 
  the 
  host 
  fish. 
  The 
  cause 
  for 
  the 
  increasing 
  scarcity 
  of 
  the 
  

   herring 
  seems 
  not 
  to 
  be 
  due 
  to 
  capture 
  in 
  large 
  numbers, 
  as 
  the 
  fish 
  

   is 
  not 
  commonly 
  used 
  for 
  food 
  throughout 
  its 
  range. 
  It 
  is 
  more 
  

   probable 
  that 
  it 
  is 
  due 
  to 
  artificial 
  conditions, 
  such 
  as 
  the 
  obstruction 
  

   of 
  its 
  natural 
  migrations 
  by 
  dams 
  and 
  the 
  introduction 
  into 
  the 
  

   rivers 
  of 
  nonoxygenated 
  sewage 
  and 
  the 
  injurious 
  wastes 
  of 
  manu- 
  

   facturing 
  plants 
  and 
  tlie 
  like. 
  

  

  Quadrula 
  solida 
  (Lea). 
  [PI. 
  vi, 
  fig. 
  46, 
  47.] 
  

  

  Quadrula 
  solida 
  closely 
  resembles 
  Q. 
  ebena. 
  I 
  have 
  investigated 
  

   this 
  species 
  only 
  so 
  far 
  as 
  to 
  make 
  some 
  observations 
  upon 
  its 
  breed- 
  

   ing. 
  I 
  found 
  gravid 
  females 
  May 
  .31 
  and 
  July 
  2.3. 
  In 
  one 
  specimen 
  

   glochidia 
  were 
  present 
  in 
  both 
  inner 
  and 
  outer 
  gills; 
  in 
  the 
  other 
  

   cases 
  only 
  the 
  outer 
  gills 
  were 
  charged. 
  Glochidia 
  were 
  found 
  mature 
  

   on 
  both 
  the 
  dates 
  mentioned. 
  The 
  glochidium 
  (pi. 
  v, 
  fig. 
  34) 
  has 
  

   the 
  subsemicircular 
  form 
  slightly 
  more 
  rounded 
  than 
  Q. 
  ebena. 
  

  

  Dimensions: 
  Height, 
  0.145 
  mm. 
  to 
  0.16 
  mm.; 
  length, 
  0.155 
  mm. 
  

   to 
  0.160 
  mm. 
  See 
  also 
  Surber 
  (1912), 
  to 
  whom 
  the 
  material 
  was 
  

   referred 
  for 
  description. 
  I 
  have 
  found 
  no 
  natural 
  infections 
  that 
  

   could 
  with 
  certainty 
  be 
  ascribed 
  to 
  this 
  species. 
  Mr. 
  Surber 
  reported 
  

   a 
  single 
  glochidium 
  on 
  a 
  Pomolohus 
  infected 
  mth 
  many 
  of 
  Q. 
  eiena. 
  

   It 
  would 
  not 
  be 
  surprising 
  if 
  they 
  are 
  found 
  to 
  have 
  the 
  same 
  fish 
  for 
  

   host. 
  

  

  The 
  Pig-toe, 
  Quadrula 
  trigona 
  (Lea). 
  [PI. 
  i, 
  fig. 
  10, 
  11.] 
  

  

  The 
  brilliant 
  orange-colored 
  flesh 
  of 
  the 
  pig-toe 
  is 
  characteristic, 
  

   although 
  occasionally 
  it 
  is 
  found 
  yellow 
  or 
  white. 
  The 
  nacre 
  is 
  a 
  

   beautiful 
  silvery 
  white, 
  more 
  or 
  less 
  iridescent; 
  rarely 
  the 
  nacre 
  is 
  

   pink. 
  In 
  the 
  manufacture 
  of 
  buttons 
  it 
  is 
  less 
  desirable 
  than 
  the 
  

   niggerhead 
  because 
  of 
  less 
  uniform 
  thickness. 
  

  

  Habitat. 
  — 
  In 
  the 
  larger 
  rivers, 
  on 
  a 
  muddy 
  bottom 
  in 
  rather 
  deep 
  

   water. 
  

  

  Distribution. 
  — 
  Western 
  New 
  York 
  to 
  Minnesota, 
  and 
  Iowa, 
  and 
  

   Kansas 
  to 
  Texas, 
  east 
  to 
  Mississippi 
  and 
  Tennessee. 
  (Call, 
  from 
  

   Baker, 
  1898.) 
  

  

  Juvenile. 
  — 
  The 
  juveniles 
  were 
  the 
  second 
  most 
  abundant 
  of 
  the 
  27 
  

   species 
  I 
  have 
  collected 
  and 
  first 
  in 
  abundance 
  among 
  the 
  Quadrulas. 
  

   They 
  were 
  taken 
  on 
  both 
  mud 
  and 
  sand 
  bottoms. 
  I 
  have 
  found 
  this 
  

   species 
  in 
  the 
  artificial 
  ponds 
  at 
  Fairport, 
  Iowa, 
  introduced 
  in 
  tlie 
  

   parasitic 
  stage 
  on 
  fishes 
  — 
  the 
  second 
  of 
  the 
  river-inhabiting 
  Quadrulas 
  

   to 
  be 
  found 
  under 
  such 
  conditions. 
  

  

  Glocliidium 
  (pi. 
  V, 
  fig. 
  33). 
  — 
  The 
  breeding 
  records 
  of 
  the 
  Fairport 
  

   biological 
  station 
  for 
  the 
  past 
  tliree 
  years 
  give 
  June, 
  July, 
  and 
  August 
  

   as 
  months 
  in 
  which 
  tlie 
  glochidia 
  of 
  this 
  species 
  have 
  been 
  taken. 
  I 
  

   found 
  seven 
  mussels 
  with 
  early 
  embryos 
  of 
  this 
  species 
  August 
  27 
  and 
  

   28, 
  1913. 
  and 
  one 
  with 
  mature 
  glochidia 
  on 
  September 
  10, 
  thus 
  ex- 
  

  

  