﻿890 
  Panama 
  Shells. 
  LiTTORiNiDiB. 
  

  

  and 
  of 
  wHicti 
  the 
  remainder 
  cover 
  the 
  anterior 
  part 
  of 
  the 
  last 
  

   whorl 
  : 
  apex 
  very 
  minute 
  : 
  spire 
  with 
  the 
  outlines 
  nearly 
  rec- 
  

   tilinear 
  : 
  whorls 
  eight, 
  more 
  or 
  less 
  angular 
  in 
  the 
  upper 
  part, 
  

   with 
  a 
  well 
  impressed 
  suture 
  ; 
  last 
  whorl 
  rather 
  long, 
  with 
  a 
  

   well 
  rounded 
  periphery 
  : 
  aperture 
  subovate 
  : 
  labrum 
  thin 
  : 
  

   columella 
  rather 
  stout 
  : 
  umbilicus 
  wanting. 
  

  

  Mean 
  divergence 
  about 
  16° 
  ; 
  length 
  .13 
  inch 
  ; 
  breadth 
  .04 
  

   inch 
  ; 
  length 
  of 
  spire 
  .1 
  inch. 
  

  

  Station. 
  — 
  Unknown. 
  

  

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

  

  10 
  specimens, 
  in 
  various 
  stages 
  of 
  growth, 
  were 
  collected 
  from 
  

   the 
  sand. 
  

  

  223. 
  Cheninitzia 
  commuiiis. 
  Nov. 
  sp. 
  

  

  Shell 
  long, 
  fusiform 
  conic 
  : 
  dingy 
  white 
  : 
  with, 
  on 
  the 
  penult 
  

   whorl, 
  about 
  twenty-two 
  transverse 
  ridges, 
  and 
  on 
  the 
  last 
  whorl 
  

   a 
  greater 
  number, 
  which 
  are 
  less 
  prominent, 
  and 
  which 
  become 
  

   obsolete 
  anteriorly 
  : 
  with 
  spiral 
  ridges, 
  of 
  which 
  four 
  or 
  five 
  are 
  

   seen 
  on 
  the 
  spire, 
  and 
  which 
  on 
  the 
  last 
  two 
  whorls 
  are 
  as 
  pro- 
  

   minent 
  as 
  the 
  transverse 
  ridges, 
  but 
  above 
  are 
  less 
  developed 
  : 
  

   apex 
  with 
  the 
  axis 
  oblique 
  : 
  spire 
  with 
  the 
  outlines 
  curvilinear 
  : 
  

   whorls 
  eight, 
  moderately 
  convex, 
  with 
  a 
  well 
  impressed 
  suture: 
  

   last 
  whorl 
  rather 
  long: 
  aperture 
  ovate, 
  acute 
  above, 
  very 
  

   broadly 
  effuse 
  below 
  : 
  labrum 
  rather 
  thin, 
  but 
  not 
  sharp 
  : 
  colu- 
  

   mellar 
  lip 
  well 
  thickened, 
  below 
  reflected 
  over 
  a 
  minute 
  umbili- 
  

   cal 
  indentation 
  : 
  columella 
  with 
  one 
  small 
  plait. 
  A 
  large 
  speci- 
  

   men 
  has 
  the 
  following 
  dimensions 
  : 
  — 
  

  

  Mean 
  divergence 
  about 
  23° 
  ; 
  length 
  .165 
  inch 
  ; 
  breadth 
  .05 
  

   inch 
  ; 
  length 
  of 
  spire 
  .11 
  inch. 
  

  

  Station. 
  — 
  Under 
  stones 
  near 
  low 
  water 
  mark. 
  

  

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

   90 
  specimens 
  were 
  collected. 
  

  

  