﻿New 
  Species 
  of 
  Stoastoma. 
  67 
  

  

  This 
  species 
  resembles 
  S. 
  Redfieldianum 
  ; 
  but 
  the 
  shell 
  

   is 
  larger, 
  the 
  spiral 
  lines 
  arc 
  smaller, 
  and 
  the 
  spire 
  is 
  larger 
  

   in 
  proportion 
  at 
  the 
  last 
  whorl. 
  

  

  Stoastoma 
  Petitianum. 
  Shell 
  between 
  globose 
  and 
  dis- 
  

   coidal 
  : 
  dingy 
  white 
  : 
  with 
  eight 
  or 
  ten 
  raised 
  slender 
  spiral 
  

   lines, 
  of 
  which 
  three 
  or 
  four 
  are 
  visible 
  on 
  the 
  spire, 
  and 
  as 
  

   many 
  others 
  which 
  are 
  more 
  minute 
  : 
  spire 
  moderately 
  eleva- 
  

   ted, 
  convex 
  : 
  whorls 
  three 
  and 
  one-half, 
  moderately 
  convex, 
  

   with 
  a 
  lightly 
  impressed 
  suture 
  ; 
  last 
  whorl 
  well 
  rounded 
  : 
  

   aperture 
  much 
  contracted 
  behind 
  the 
  labrum, 
  which 
  is 
  but 
  

   moderately 
  produced, 
  and 
  is 
  double, 
  with 
  the 
  outer 
  margin 
  

   scarcely 
  modified 
  by 
  the 
  larger 
  spiral 
  lines 
  ; 
  labium 
  moder- 
  

   ately 
  detached 
  from 
  the 
  penult 
  whorl 
  : 
  umbilicus 
  rather 
  small, 
  

   with 
  the 
  spiral 
  lamella 
  but 
  moderately 
  developed. 
  

  

  Mean 
  divergence 
  about 
  125° 
  ; 
  height 
  .04 
  inch 
  ; 
  greatest 
  

   breadth 
  .06 
  inch 
  ; 
  least 
  breadth 
  .05 
  inch. 
  

  

  Stoastoma 
  Anthonianum. 
  This 
  shell 
  is 
  like 
  the 
  preceding 
  ; 
  

   but 
  the 
  'spire 
  is 
  much 
  depressed 
  ; 
  the 
  spiral 
  lines 
  are 
  rather 
  

   stronger 
  ; 
  and 
  the 
  aperture 
  is 
  very 
  campanulate, 
  the 
  labrum 
  

   being 
  very 
  much 
  produced 
  before 
  the 
  deep 
  constriction. 
  

  

  Mean 
  divergence 
  about 
  145° 
  ; 
  height 
  .035 
  inch 
  ; 
  greatest 
  

   breadth 
  .07 
  inch 
  ; 
  least 
  breadth 
  .055 
  inch. 
  

  

  