﻿408 
  Panama 
  Shells. 
  trochid^. 
  

  

  Station. 
  — 
  Unknown. 
  

  

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

  

  40 
  specimens 
  were 
  found 
  in 
  th.e 
  sand. 
  

  

  VITRinTEIiliA. 
  — 
  The 
  number 
  of 
  species 
  and 
  the 
  scarcity 
  

   of 
  individuals 
  in 
  this 
  genus 
  of 
  minute 
  shells 
  is 
  remarkable. 
  To 
  

   the 
  5 
  species 
  from 
  Jamaica, 
  of 
  which 
  the 
  genus 
  was 
  originally 
  

   constituted, 
  we 
  now 
  add 
  12 
  from 
  Panama. 
  It 
  will 
  be 
  seen, 
  

   however, 
  that 
  we 
  have 
  only 
  60 
  specimens, 
  of 
  which 
  24 
  belong 
  

   to 
  one 
  species, 
  and 
  13 
  to 
  another. 
  

  

  258. 
  Vitrinella 
  conciniia. 
  Nov. 
  sp. 
  

  

  Shell 
  discoidal 
  : 
  white 
  : 
  with 
  five 
  prominent 
  acute 
  spiral 
  

   keels, 
  of 
  which 
  one 
  is 
  next 
  below 
  the 
  suture 
  : 
  the 
  second 
  is 
  

   about 
  equidistant 
  between 
  the 
  suture 
  and 
  the 
  periphery 
  of 
  the 
  

   last 
  whorl 
  ; 
  the 
  third 
  is 
  a 
  little 
  below 
  the 
  periphery 
  ; 
  the 
  fourth 
  

   is 
  on 
  the 
  middle 
  of 
  the 
  lower 
  side 
  of 
  the 
  last 
  whorl 
  ; 
  and 
  the 
  

   fifth 
  is 
  within 
  the 
  umbilicus 
  ; 
  with 
  a 
  more 
  or 
  less 
  distinct 
  ridge 
  

   between 
  the 
  first 
  two 
  keels 
  ; 
  with 
  curved 
  transverse 
  elevated 
  

   lines, 
  which 
  become 
  obsolete 
  on 
  the 
  last 
  half 
  of 
  the 
  last 
  whorl 
  : 
  

   apex 
  minute, 
  papillary 
  : 
  spire 
  nearly 
  flat 
  : 
  whorls 
  three 
  and 
  

   one-half: 
  planulate 
  above, 
  with 
  the 
  suture 
  subcanaliculate 
  ; 
  last 
  

   whorl 
  declining 
  near 
  the 
  aperture 
  below 
  the 
  plane 
  of 
  the 
  spire 
  : 
  

   aperture 
  orbicular, 
  very 
  oblique 
  : 
  lip 
  moderately 
  thickened, 
  

   slightly 
  angulated 
  by 
  the 
  keels 
  : 
  umbilicus 
  broad 
  and 
  deep. 
  

  

  Divergence 
  about 
  175° 
  ; 
  greatest 
  breadth 
  .062 
  inch 
  ; 
  least 
  

   breadth 
  .05 
  inch 
  ; 
  height 
  .03 
  inch. 
  

  

  Station. 
  — 
  Unknown. 
  

  

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

   Only 
  1 
  specimen 
  was 
  found. 
  

  

  259. 
  Titrinella 
  exi^iia, 
  Nov. 
  sp. 
  

  

  Shell 
  subdiscoidal 
  : 
  white 
  : 
  on 
  the 
  periphery 
  of 
  the 
  last 
  whorl 
  

  

  