﻿242 
  NEW 
  YORK 
  STATE 
  MUSEUM 
  

  

  Genus 
  bythinella 
  Moquin-Tandon. 
  1855 
  

   Shell 
  elongated 
  and 
  pyriform; 
  imperforate; 
  apex 
  obtuse; 
  aper- 
  

   ture 
  oval; 
  lip 
  simple; 
  operculum 
  corneous. 
  

  

  Bythinella 
  obtusa 
  (Lea) 
  Binney 
  1865 
  (Fig. 
  166). 
  P 
  a 
  1 
  u 
  d 
  i 
  n 
  a 
  

   obtusa 
  Lea 
  (1844. 
  Philos. 
  soc. 
  Phil. 
  Trans. 
  9:13). 
  Bythin- 
  

   ella 
  obtusa 
  Binney 
  (1865. 
  Smith. 
  Misc. 
  coll. 
  no. 
  

   ^?^ 
  144, 
  p. 
  70) 
  

  

  Shell 
  small, 
  subcylindric, 
  comparatively 
  thin; 
  five 
  

  

  whorls; 
  spire 
  very 
  short, 
  giving 
  the 
  shell 
  a 
  truncated 
  ap- 
  

  

  twne'iia^ 
  Ob." 
  pcaraucc 
  ; 
  apex 
  obtuse; 
  sutures 
  well 
  defined; 
  delicate 
  

  

  tusa. 
  x3 
  growth 
  lines 
  may 
  be 
  seen 
  with 
  a 
  lens; 
  the 
  aperture 
  is 
  

  

  small 
  and 
  round; 
  the 
  umbilicus 
  narrow 
  and 
  deep. 
  

  

  Found 
  in 
  the 
  Goat 
  island 
  gravel 
  pits. 
  

  

  Genus 
  pomatiopsis 
  Tryon. 
  1862 
  

  

  Animal 
  with 
  a 
  broad, 
  short 
  foot, 
  and 
  short 
  pointed 
  tentacles. 
  

   Shell 
  thin 
  and 
  smooth, 
  having 
  a 
  produced 
  spire; 
  aperture 
  oval, 
  and 
  

   provided 
  with 
  an 
  operculum. 
  

  

  Pomatiopsis 
  lapidaria 
  (Say) 
  Tryon 
  1862 
  (Fig. 
  167). 
  C 
  y 
  c 
  1 
  o 
  s 
  - 
  

   toma 
  lapidaria 
  Say 
  (1817. 
  Acad. 
  nat. 
  sci. 
  Phil. 
  Jour. 
  1:13). 
  

   Pomatiopsis 
  lapidaria 
  Tryon 
  (1862. 
  Acad. 
  nat. 
  sci. 
  

   Phil. 
  Proc. 
  p. 
  452) 
  

  

  Shell 
  conic; 
  spire 
  high, 
  seven 
  whorls, 
  well 
  rounded 
  and 
  trans- 
  

   versely 
  wrinkled; 
  sutures 
  impressed; 
  aperture 
  rounded 
  

   and 
  about 
  one 
  third 
  the 
  length 
  of 
  the 
  shell 
  ; 
  subumbilicate. 
  

  

  Found 
  at 
  Foster's 
  flats. 
  This 
  species 
  is 
  not 
  found 
  in 
  

   any 
  of 
  the 
  other 
  deposits. 
  

  

  The 
  locality 
  at 
  Foster's 
  flats, 
  where 
  this 
  little 
  shell 
  is 
  

   iound, 
  is 
  just 
  below 
  the 
  old 
  fall. 
  At 
  the 
  present 
  time, 
  the 
  pjg 
  ^^^ 
  p^. 
  

   only 
  locality 
  for 
  P. 
  lapidaria 
  thus 
  far 
  discovered 
  daria. 
  x3 
  

   along 
  the 
  river 
  is 
  on 
  the 
  rocks 
  in 
  the 
  constant 
  rain 
  of 
  spray, 
  bel'ow 
  

   the 
  present 
  fah. 
  

  

  Genus 
  valvata 
  Miiller. 
  1842 
  

  

  Animal 
  with 
  a 
  bilobed 
  foot, 
  simple 
  mantle 
  and 
  feather-like 
  gills, 
  

   protected 
  by 
  a 
  long, 
  slender 
  respiratory 
  lobe. 
  The 
  shell 
  is 
  discoidal, 
  

   has 
  a 
  deep 
  umbilicus 
  and 
  is 
  provided 
  -with 
  an 
  operculum. 
  

  

  