﻿56 
  ON 
  THE 
  NAIADES, 
  

  

  its 
  translucency, 
  and 
  its 
  colours 
  are 
  very 
  characteristic. 
  On 
  the 
  infe- 
  

   rior 
  part 
  of 
  the 
  carina, 
  which 
  is 
  obtuse, 
  the 
  brown 
  colour 
  is 
  more 
  in- 
  

   tense 
  — 
  on 
  the 
  superior 
  part 
  the 
  yellow 
  is 
  brightest. 
  

  

  Helix 
  vesica. 
  Plate 
  XIX. 
  fig. 
  67. 
  

  

  &• 
  

  

  Testa 
  tenni, 
  pellucidd, 
  svperne 
  elevatd 
  et 
  fusco-hded, 
  in 
  feme 
  inflatd 
  albdque, 
  

   transversim 
  minute 
  striata, 
  umbilical 
  a, 
  anfractibus 
  quinis 
  ; 
  spird 
  obtuso-conicd 
  ; 
  

   aperturd 
  subrotundd 
  ; 
  labro 
  tenui 
  et 
  reflexo, 
  infeme 
  crassescenti 
  ; 
  columella 
  Isevi. 
  

  

  Shell 
  thin, 
  transparent, 
  elevated 
  and 
  hrownish 
  yellow 
  above, 
  inflated 
  and 
  white 
  be- 
  

   low, 
  longitudinally 
  and 
  minutely 
  striate, 
  umbilicated; 
  whorls 
  five; 
  spire 
  obtusely 
  

   conical 
  ; 
  aperture 
  nearly 
  round 
  ; 
  outer 
  lip 
  thin 
  and 
  reflected, 
  on 
  the 
  lower 
  part 
  slightly 
  

   thickened 
  ; 
  columella 
  smooth. 
  

  

  Hab 
  

  

  My 
  Cabinet. 
  

   Diam. 
  -7, 
  Length 
  -5 
  of 
  an 
  inch. 
  

  

  Remarks. 
  — 
  This 
  species 
  is 
  peculiarly 
  transparent, 
  and 
  very 
  strongly 
  

   resembles 
  the 
  cuticle 
  of 
  a 
  blister 
  or 
  the 
  bladder 
  of 
  a 
  fish. 
  This 
  char- 
  

   acter, 
  and 
  its 
  pale 
  brownish-yellow 
  superior 
  portion, 
  and 
  white 
  inferior 
  

   portion, 
  together 
  with 
  its 
  longitudinal 
  striae, 
  eminently 
  distinguish 
  it. 
  

   The 
  lower 
  part 
  of 
  the 
  reflected 
  lip 
  is 
  so 
  much 
  thickened 
  as 
  almost 
  to 
  

   form 
  a 
  tooth. 
  

  

  Helix 
  cincta. 
  Plate 
  XIX. 
  fier. 
  68. 
  

  

  &■ 
  

  

  Testd 
  supeme 
  deprcssd, 
  infeme 
  inflatd, 
  longitudinaliter 
  striata, 
  umbilicatd, 
  

   rufo-fuscd, 
  fasciam 
  fuscam 
  aut 
  nigram 
  super 
  medios 
  anfractus 
  habenle 
  ; 
  anfrac- 
  

   tibus 
  qualemis 
  ; 
  spird 
  planulald, 
  aperturd 
  subrotundatd 
  ; 
  labro 
  simplici; 
  colum- 
  

   ella 
  Isevi. 
  

  

  Shell 
  depressed 
  above, 
  inflated 
  below, 
  longitudinally 
  striate, 
  umbilicated, 
  reddish 
  

   brown, 
  with 
  a 
  dark 
  brown 
  or 
  black 
  band 
  above 
  the 
  middle 
  of 
  the 
  whorls 
  ; 
  whorls 
  four 
  ; 
  

   spire 
  flattened 
  ; 
  aperture 
  nearly 
  round 
  ; 
  outer 
  lip 
  simple 
  ; 
  columella 
  smooth. 
  

  

  