﻿438 
  Panama 
  Shells. 
  bullidje. 
  

  

  impressed 
  suture 
  ; 
  last 
  whorl 
  rather 
  short 
  and 
  subangular, 
  but 
  

   ventricose 
  : 
  aperture 
  broadly 
  ovate 
  : 
  labrum 
  thin 
  : 
  labium 
  a 
  

   little 
  reflected 
  below, 
  above 
  interrupted 
  by 
  the 
  penult 
  whorl. 
  

  

  Mean 
  divergence 
  about 
  45° 
  ; 
  length 
  .083 
  inch 
  ; 
  breadth 
  .055 
  

   inch 
  ; 
  length 
  of 
  spire 
  .045 
  inch. 
  

  

  Operculum 
  corneous. 
  

  

  Station. 
  — 
  With 
  Truncatella 
  Bairdiana. 
  

  

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

  

  550 
  specimens 
  were 
  collected. 
  

  

  This 
  species 
  cannot 
  properly 
  be 
  referred 
  to 
  Truncatella. 
  The 
  

   apex 
  is 
  not 
  truncated 
  ; 
  the 
  operculum 
  is 
  horny 
  ; 
  and 
  the 
  general 
  

   form 
  and 
  texture 
  indicate 
  a 
  different 
  genus. 
  In 
  form 
  it 
  approxi- 
  

   mates 
  to 
  T. 
  fusca, 
  T. 
  littorea, 
  &c., 
  which 
  are 
  not 
  Truncatellae, 
  but 
  

   which 
  probably 
  belong 
  to 
  Bemhicium. 
  From 
  the 
  habits 
  of 
  our 
  

   species, 
  it 
  may 
  be 
  inferred 
  to 
  be 
  an 
  air-breathing 
  mollusc, 
  while 
  

   the 
  characters 
  of 
  the 
  shell 
  are 
  very 
  different 
  from 
  those 
  of 
  

   Bembicium. 
  The 
  shell 
  appears 
  too 
  deficient 
  in 
  characters 
  suit- 
  

   able 
  for 
  generic 
  distinction, 
  and 
  we 
  refrain 
  from 
  proposing 
  a 
  

   new 
  genus 
  until 
  the 
  soft 
  parts 
  shall 
  be 
  known. 
  

  

  Family— 
  BULLION. 
  

   319. 
  Bulla 
  (Tornatina) 
  infrequent. 
  Nov. 
  sp. 
  

  

  Shell 
  cylindric, 
  not 
  compressed 
  about 
  the 
  middle 
  : 
  white 
  : 
  

   smooth 
  : 
  apex 
  papillary, 
  very 
  minute 
  and 
  prominent 
  : 
  spire 
  

   moderately 
  elevated, 
  convex 
  : 
  whorls 
  four 
  and 
  one-half, 
  acutely 
  

   shouldered, 
  with 
  a 
  deeply 
  channeled 
  suture 
  : 
  aperture 
  long 
  and 
  

   narrow, 
  anteriorly 
  rounded 
  : 
  labrum 
  very 
  thin, 
  much 
  advanced 
  

   along 
  the 
  middle 
  : 
  columella 
  terminating 
  in 
  a 
  very 
  robust 
  

   spiral 
  plait. 
  

  

  Mean 
  divergence 
  about 
  130° 
  ; 
  length 
  .28 
  inch 
  ; 
  breadth 
  .11 
  

   inch 
  ; 
  length 
  of 
  spire 
  .03 
  inch. 
  

  

  Station. 
  — 
  Unknown. 
  

  

  