﻿392 
  Panama 
  Shells. 
  littorinid^. 
  

  

  eleven 
  or 
  twelve 
  very 
  prominent 
  strong 
  compressed 
  ribs 
  : 
  in 
  the 
  

   interspaces 
  with 
  fine 
  spiral 
  striae, 
  of 
  which 
  five 
  or 
  six 
  are 
  seen 
  

   on 
  the 
  penult 
  whorl 
  : 
  apex 
  with 
  the 
  axis 
  oblique 
  : 
  spire 
  with 
  

   the 
  outlines 
  curvilinear 
  : 
  whorls 
  seven, 
  margined 
  above 
  with 
  a 
  

   spiral 
  compressed 
  ridge, 
  moderately 
  convex, 
  with 
  a 
  well 
  

   impressed 
  suture: 
  last 
  whorl 
  with 
  the 
  periphery 
  rounded: 
  

   aperture 
  small, 
  oblique, 
  ovate 
  : 
  labrum 
  thin 
  : 
  labium 
  with 
  a 
  

   distinct 
  deposit 
  : 
  umbilicus 
  wanting. 
  

  

  Mean 
  divergence 
  about 
  28° 
  ; 
  length 
  .115 
  inch 
  ; 
  breadth 
  .042 
  

   inch 
  ; 
  length 
  of 
  spire 
  .08 
  inch. 
  

  

  /Station. 
  — 
  Unknown. 
  

  

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

   2 
  specimens 
  were 
  found. 
  

  

  227. 
  Chemnitzia 
  Panamensis. 
  Nov. 
  sp. 
  

  

  Shell 
  long, 
  conic 
  : 
  white 
  : 
  with, 
  on 
  each 
  whorl, 
  about 
  twenty- 
  

   seven 
  oblique 
  ribs, 
  which 
  become 
  obsolete 
  on 
  the 
  middle 
  of 
  the 
  

   last 
  whorl, 
  the 
  anterior 
  part 
  of 
  which 
  is 
  very 
  smooth 
  : 
  spire 
  

   with 
  the 
  outlines 
  nearly 
  rectilinear 
  : 
  whorls 
  twelve, 
  moderately 
  

   convex, 
  with 
  a 
  well 
  impressed 
  suture 
  : 
  last 
  whorl 
  sub-angular 
  at 
  

   the 
  periphery: 
  aperture 
  obhquely 
  ovate: 
  labrum 
  thin: 
  colu- 
  

   mella 
  nearly 
  straight 
  : 
  umbilicus 
  wanting. 
  

  

  Mean 
  divergence 
  about 
  17° 
  ; 
  length 
  .22 
  inch 
  ; 
  breadth 
  .055 
  

   inch 
  ; 
  length 
  of 
  spire 
  .17 
  inch. 
  

  

  Station. 
  — 
  In 
  the 
  sand 
  between 
  high 
  water 
  and 
  half 
  tide 
  

   levels. 
  

  

  Habitat 
  — 
  Panama 
  ; 
  C. 
  B. 
  A. 
  ! 
  

  

  11 
  specimens 
  were 
  found 
  on 
  the 
  reef. 
  , 
  

  

  228. 
  Chemnitzia 
  similis. 
  Nov. 
  sp. 
  

  

  Shell 
  long, 
  conic 
  : 
  white 
  : 
  with, 
  on 
  each 
  whorl, 
  about 
  twenty- 
  

   six 
  rather 
  obtuse 
  ribs, 
  which 
  terminate 
  abruptly 
  on 
  the 
  peri- 
  

   phery 
  of 
  the 
  last 
  whorl 
  : 
  spire 
  with 
  the 
  outlines 
  nearly 
  rectili- 
  

  

  