﻿460 
  Panama 
  Shells. 
  FISSURELLIDJS. 
  

  

  355. 
  Fissiirella 
  alta. 
  Nov. 
  sp. 
  

  

  Shell 
  subconic, 
  high 
  : 
  dingy 
  white, 
  often 
  more 
  or 
  less 
  covered 
  

   with 
  broad 
  ashy 
  black 
  rays, 
  which 
  may 
  be 
  seen 
  through 
  the 
  

   shell 
  : 
  with 
  prominent 
  radiating 
  ribs, 
  of 
  which 
  the 
  alternate 
  

   ones 
  are 
  excessively 
  developed, 
  and 
  intermediate 
  small 
  raised 
  

   lines 
  ; 
  with 
  many 
  concentric 
  ridges, 
  which 
  are 
  less 
  prominent 
  

   than 
  the 
  larger 
  radiating 
  ribs, 
  and 
  more 
  so 
  than 
  the 
  others: 
  

   summit 
  nearer 
  to 
  and 
  somewhat 
  inclined 
  towards 
  the 
  anterior 
  

   extremity 
  : 
  fissure 
  small, 
  ovate-elliptic 
  : 
  margin 
  pectinated 
  by 
  

   the 
  radiating 
  ribs. 
  

  

  The 
  following 
  are 
  the 
  dimensions 
  of 
  a 
  very 
  large 
  and 
  high 
  

   shell 
  and 
  of 
  another 
  of 
  average 
  size 
  : 
  

  

  Height 
  .42 
  inch 
  ; 
  length 
  .55 
  inch 
  ; 
  breadth 
  .41 
  inch. 
  

   u 
  22 
  " 
  " 
  .42 
  " 
  " 
  .29 
  " 
  

  

  Station. 
  — 
  Unknown. 
  

  

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

   26 
  specimens 
  were 
  obtained. 
  

  

  356. 
  Fis§urella 
  macrotrenia. 
  

  

  Synonymy. 
  

  

  Fissurella 
  macrofrema 
  Sowb. 
  in 
  Proc. 
  Zool. 
  SocLond. 
  p. 
  1.25. 
  Nov. 
  1834. 
  

  

  Miill. 
  Synop. 
  Nov. 
  Test. 
  Viv. 
  p. 
  155. 
  May 
  1836. 
  

  

  Sowb. 
  Conch. 
  111. 
  No. 
  33. 
  pi. 
  74. 
  f. 
  41. 
  1841. 
  

  

  Chenu. 
  111. 
  Conch, 
  pi. 
  1. 
  f. 
  14. 
  1843. 
  

  

  Reeve 
  Conch, 
  Icon. 
  pi. 
  5. 
  f. 
  31. 
  Aug. 
  1849. 
  

  

  Station. 
  — 
  Under 
  stones 
  on 
  the 
  shore 
  ; 
  Cuming 
  ! 
  Sowerby. 
  

  

  Habitat. 
  — 
  Gallapago 
  Is. 
  and 
  Eeal 
  Llejos 
  ; 
  var's 
  at 
  Lobos 
  I. 
  

   and 
  Lambeyeque, 
  Peru; 
  Cuming! 
  Sowerby: 
  also 
  

   Miiller. 
  

   Gallapago 
  Is. 
  ; 
  Cuming 
  ! 
  Eeeve. 
  

   Taboga; 
  C. 
  B. 
  A.! 
  

   We 
  collected 
  5 
  specimens, 
  which 
  are 
  somewhat 
  narrower 
  

   than 
  the 
  figures 
  in 
  Sowerby 
  and 
  in 
  Reeve. 
  

  

  