﻿412 
  Panama 
  Shells. 
  trochid^. 
  

  

  ■wrinkles, 
  which 
  are 
  obsolete 
  on 
  tlie 
  upper 
  part 
  of 
  tlie 
  whorls 
  ; 
  

   apex 
  obtuse 
  : 
  spire 
  flat 
  : 
  whorls 
  nearly 
  three, 
  moderately 
  con- 
  

   yex, 
  with 
  a 
  distinct 
  suture 
  ; 
  last 
  whorl 
  very 
  large 
  : 
  aperture 
  

   orbicular, 
  very 
  oblique 
  : 
  lip 
  slightly 
  thickened 
  : 
  umbilicus 
  

  

  deep. 
  

  

  Mean 
  divergence 
  180°; 
  greatest 
  breadth 
  .037 
  inch; 
  least 
  

   breadth 
  .031 
  inch 
  ; 
  height 
  .015 
  inch. 
  

  

  Station. 
  — 
  Unknown. 
  

  

  Habitat. 
  — 
  Panama 
  ; 
  C. 
  B. 
  A. 
  ! 
  

  

  3 
  specimens 
  were 
  found 
  in 
  the 
  calcareous 
  sand. 
  

  

  266. 
  Vitrinella 
  re^ularis. 
  Nov. 
  sp. 
  

  

  Shell 
  subdiscoidal 
  : 
  pearl 
  white 
  : 
  smooth 
  and 
  shining, 
  with 
  

   an 
  impressed 
  spiral 
  line 
  just 
  below 
  the 
  suture 
  : 
  apex 
  subacute; 
  

   spire 
  convex, 
  moderately 
  elevated 
  : 
  whorls 
  four 
  and 
  one-half^ 
  

   convex, 
  with 
  a 
  distinct 
  suture; 
  last 
  whorl 
  somewhat 
  ventri- 
  

   cose 
  : 
  aperture 
  nearly 
  orbicular 
  : 
  lip 
  thin 
  : 
  umbilical 
  region 
  

   deeply 
  indented. 
  

  

  Mean 
  divergence 
  about 
  120°; 
  greatest 
  breadth 
  .07 
  inch; 
  

   least 
  breadth 
  .06 
  inch 
  ; 
  height 
  .05 
  inch. 
  

  

  Station. 
  — 
  Unknown. 
  

  

  Habitat. 
  — 
  Panama 
  ; 
  0. 
  B. 
  A. 
  ! 
  

  

  1 
  specimen 
  was 
  found 
  in 
  the 
  calcareous 
  sand. 
  

  

  267. 
  Vitrinella 
  seminuda. 
  Nov. 
  sp. 
  

  

  Shell 
  discoidal 
  : 
  white 
  : 
  above 
  with 
  excessively 
  minute 
  striee 
  

   of 
  growth 
  ; 
  beneath 
  covered 
  with 
  spiral 
  striae 
  : 
  apex 
  obtuse 
  : 
  

   spire 
  scarcely 
  elevated, 
  convex 
  : 
  whorls 
  three, 
  moderately 
  con- 
  

   vex, 
  with 
  a 
  distinct 
  suture; 
  last 
  whorl 
  with 
  the 
  periphery 
  sub- 
  

   angular 
  : 
  aperture 
  orbicular, 
  very 
  oblique 
  : 
  lip 
  thin 
  : 
  umbilicus 
  

   narrow, 
  deep. 
  

  

  