﻿244 
  NEW 
  YORK 
  STATE 
  MUSEUM 
  

  

  This 
  genus 
  is 
  well 
  represented 
  among 
  the 
  recent 
  shells 
  in 
  this 
  

   vicinity. 
  They 
  may 
  be 
  found 
  in 
  all 
  the 
  streams 
  tributary 
  to 
  the 
  

   Niagara. 
  

  

  Limnaea 
  columella 
  Say 
  1817 
  (Fig. 
  171). 
  L. 
  columella 
  

   Say 
  (1817. 
  Acad. 
  nat. 
  sci. 
  Phil. 
  Jour. 
  1:14) 
  

  

  This 
  is 
  a 
  very 
  thin, 
  fragile 
  shell 
  having 
  four 
  whorls, 
  

   rapidly 
  diminishing, 
  separated 
  by 
  a 
  distinct 
  but 
  not 
  

   deeply 
  impressed 
  suture; 
  aperture 
  large, 
  more 
  than 
  one 
  

   half 
  the 
  length 
  of 
  the 
  shell;- 
  Hp 
  simple, 
  and 
  surface 
  

   Fig. 
  m 
  Lim-^^^S^^'^^^^^^^y 
  wrinkled 
  by 
  growth 
  Unes. 
  

  

  naea 
  columella 
  t 
  i*^ 
  /^ 
  ^ 
  • 
  i 
  j 
  i 
  'j. 
  

  

  Locality. 
  Goat 
  island 
  gravel 
  pits. 
  

  

  Only 
  one 
  specimen 
  of 
  this 
  species 
  was 
  found, 
  leading 
  me 
  to 
  be- 
  

   lieve 
  that 
  it 
  was 
  an 
  uncommon 
  shell 
  in 
  early 
  post-PHocene 
  times, 
  as 
  

   it 
  is 
  at 
  the 
  present 
  time. 
  Lime 
  lake 
  being 
  the 
  only 
  locality 
  

   in 
  this 
  vicinity 
  where 
  the 
  recent 
  shell 
  occurs. 
  

  

  Limnaea 
  desidiosa 
  Say 
  1821 
  (Fig. 
  172). 
  L. 
  d 
  e 
  - 
  

   s 
  i 
  d 
  i 
  o 
  s 
  a 
  Say 
  (1821. 
  Acad. 
  nat. 
  sci. 
  Phil. 
  Jour. 
  2:169) 
  

  

  Shell 
  oblong 
  and 
  subconic, 
  with 
  five 
  very 
  convex 
  

   whorls; 
  suture 
  deeply 
  impressed; 
  last 
  whorl 
  slightly 
  

   swollen; 
  slight 
  growth 
  lines 
  visible 
  with 
  a 
  lens. 
  nael" 
  desidiosa" 
  

  

  Localities. 
  Goat 
  island. 
  Whirlpool 
  and 
  Foster's 
  fiats. 
  

  

  This 
  is 
  the 
  most 
  common 
  Limnaea 
  found 
  in 
  these 
  deposits. 
  

  

  Limnaea 
  catascopium 
  Say 
  1817 
  (Fig. 
  173). 
  L. 
  catascop- 
  

   i 
  u 
  m 
  Say 
  (1817-19. 
  Nich. 
  enc. 
  Am. 
  ed. 
  p. 
  11, 
  fig. 
  3. 
  1834. 
  

   Am. 
  conch, 
  v 
  6. 
  pi. 
  v, 
  fig. 
  2; 
  1841. 
  Haldeman. 
  Monograph 
  

  

  ^^ 
  Shell 
  thin, 
  sculptured 
  spirally 
  by 
  deHcate 
  lines, 
  giving 
  it 
  

   ^naeaS-'a 
  vcry 
  bcautiful 
  appearance 
  under 
  the 
  lens; 
  growth 
  lines' 
  

   scopmm 
  j^g^yy 
  ^|- 
  |-j^g 
  suture, 
  making 
  slight 
  plications; 
  whorls 
  four 
  

   or 
  five, 
  decreasing 
  to 
  an 
  acute 
  apex; 
  aperture 
  about 
  three 
  quarters 
  

   the 
  length 
  of 
  the 
  shell; 
  lip 
  simple, 
  folding 
  back 
  on 
  the 
  columellar 
  

   side 
  and 
  leaving 
  a 
  narrow 
  umbilicus. 
  

  

  Localities. 
  Goat 
  island. 
  Whirlpool 
  and 
  Foster's 
  flats. 
  

  

  Genus 
  physa 
  Draparnaud 
  

  

  The 
  animal 
  of 
  Physa 
  is 
  triangular 
  in 
  general 
  shape; 
  tentacles 
  

   slender 
  and 
  setaceous; 
  mantle 
  covers 
  part 
  of 
  the 
  shell, 
  the 
  margin 
  

   folding 
  over 
  the 
  body 
  whorl 
  in 
  a 
  fringe. 
  The 
  shell 
  is 
  sinistral, 
  thin, 
  

   with 
  an 
  acute 
  spire; 
  body 
  whorl 
  large, 
  inflated 
  and 
  the 
  aperture 
  

   large 
  and 
  oval; 
  lip 
  simple. 
  

  

  