﻿POMATIOPSIS 
  LAPIDARIA 
  — 
  ABBOTT 
  63 
  

  

  tively 
  phototropic, 
  a 
  condition 
  unknown 
  in 
  Oiicomelania. 
  Adults 
  can 
  

   withstand 
  one 
  to 
  two 
  months' 
  desiccation 
  in 
  shade 
  at 
  room 
  temper- 
  

   ature. 
  

  

  Poonatiopsis 
  lapidaria 
  occurs 
  in 
  colonies 
  ranging 
  from 
  a 
  few 
  dozen 
  

   to 
  many 
  thousand 
  individuals. 
  The 
  colonies 
  are 
  usually 
  found 
  spo- 
  

   radically 
  in 
  moist 
  shaded 
  areas 
  near 
  fresh 
  ponds, 
  the 
  banks 
  of 
  stream- 
  

   cut 
  glens 
  or 
  the 
  overflow 
  lowlands 
  bordering 
  a 
  large 
  river. 
  They 
  are 
  

   able 
  to 
  tolerate 
  a 
  considerable 
  amount 
  of 
  fine 
  silt 
  from 
  large 
  rivers, 
  

   an 
  accomplisliment 
  not 
  known 
  in 
  Oncomelania. 
  Very 
  often 
  colonies 
  

   increase 
  to 
  noticeable 
  size 
  in 
  the 
  spring, 
  flourish 
  for 
  a 
  few 
  seasons, 
  and 
  

   then 
  with 
  environmental 
  changes 
  are 
  completely 
  wiped 
  out. 
  

  

  In 
  their 
  more 
  terrestrial 
  habitats 
  their 
  molluscan 
  associates 
  are 
  the 
  

   nonoperculate 
  land 
  genera 
  Polygyra^ 
  CochUcopa^ 
  Succinea 
  (land 
  

   snails), 
  and 
  Agriolimax 
  (land 
  slugs). 
  

  

  Copulation 
  takes 
  place 
  in 
  spring 
  and 
  early 
  in 
  summer. 
  A 
  few 
  

   weeks 
  later 
  and 
  during 
  most 
  of 
  the 
  summer 
  young 
  appear 
  in 
  the 
  water. 
  

  

  Range. 
  — 
  ^Minnesota 
  east 
  through 
  southern 
  Ontario 
  to 
  southern 
  New 
  

   York. 
  South 
  to 
  Alabama 
  and 
  Texas. 
  Eastern 
  Atlantic 
  seaboard 
  

   from 
  Pennsylvania 
  south 
  to 
  Virginia. 
  No 
  records 
  in 
  New 
  England, 
  

   the 
  Carolinas, 
  Georgia, 
  or 
  Florida. 
  It 
  has 
  been 
  unable 
  to 
  establish 
  

   itself 
  on 
  or 
  west 
  of 
  the 
  Great 
  Plains. 
  Known 
  also 
  from 
  loess 
  deposits 
  

   of 
  the 
  Pleistocene 
  in 
  the 
  Midwest. 
  

  

  Selected 
  locality 
  records 
  (also 
  see 
  map). 
  — 
  Canada: 
  Ontario: 
  

   Along 
  river 
  bank 
  about 
  one-half 
  mile 
  upstream 
  from 
  bridge 
  at 
  Marsh's 
  

   Mill, 
  Aux 
  Sables 
  River, 
  Arkona. 
  United 
  States: 
  New 
  York: 
  On 
  

   moss 
  and 
  rocks 
  at 
  foot 
  of 
  American 
  Falls, 
  Niagara 
  ; 
  Cruger, 
  Duchess 
  

   County. 
  Michigan 
  : 
  Mill 
  Pond, 
  one-quarter 
  mile 
  above 
  Geddes, 
  4 
  miles 
  

   southeast 
  of 
  Ann 
  Arbor. 
  Alabama: 
  East 
  side 
  of 
  tributary 
  of 
  Shoal 
  

   Creek, 
  8% 
  miles 
  northeast 
  of 
  Florence, 
  Lauderdale 
  County. 
  Mary- 
  

   land: 
  Margin 
  of 
  Susquehanna 
  Flats, 
  Havre 
  de 
  Grace, 
  Harford 
  County. 
  

   District 
  of 
  Columbia 
  : 
  Woodland 
  swamp 
  on 
  south 
  bank 
  of 
  Potomac 
  

   River, 
  one-quarter 
  mile 
  southeast 
  of 
  Key 
  Bridge; 
  canal 
  near 
  Chain 
  

   Bridge; 
  Fox 
  Ferry, 
  Potomac 
  Eiver. 
  Virginia: 
  On 
  wet 
  rotten 
  logs 
  

   in 
  swamp, 
  Lanexa, 
  New 
  Kent 
  County. 
  Pennsylvania: 
  Monocasy 
  

   Creek, 
  near 
  Bethlehem, 
  Northampton 
  County. 
  VTisconsin: 
  Banks 
  of 
  

   Suamico 
  River, 
  4 
  miles 
  southwest 
  of 
  Suamico, 
  Brown 
  County. 
  

  

  Parasitology. 
  — 
  Pomatio'psis 
  lajndaria 
  (Say) 
  was 
  originally 
  impli- 
  

   cated 
  as 
  a 
  first 
  intermediate 
  host 
  of 
  the 
  North 
  American 
  lung 
  fluke, 
  

   Paragonimus 
  hellicotti 
  Ward, 
  by 
  D. 
  J. 
  Ameel 
  in 
  1932. 
  Other 
  cercariae 
  

   harbored 
  by 
  this 
  snail 
  are 
  Cercaria 
  pomatiopsidis 
  Stimpson, 
  1865 
  (re- 
  

   described 
  by 
  Ameel 
  in 
  1939), 
  Cercaria 
  geddesi 
  Ameel, 
  1939, 
  Cercaria 
  

   marilli 
  Ameel, 
  1939, 
  later 
  shown 
  (Ameel, 
  1944) 
  to 
  be 
  the 
  larval 
  stage 
  

   of 
  Nudacotyle 
  novicia 
  Barker, 
  and 
  the 
  cercaria 
  of 
  Euryhelmis 
  onon- 
  

   orchis 
  Ameel, 
  1938 
  (Ameel, 
  1939). 
  Ameel 
  found 
  that 
  adult 
  snails 
  

   could 
  not 
  be 
  infected 
  experimentally 
  with 
  Paragonimus 
  miracidia, 
  but 
  

  

  