﻿514 
  Panama 
  Shells. 
  mactridje, 
  

  

  radiating 
  striae 
  over 
  the 
  whole 
  surface: 
  beak 
  small, 
  approxi- 
  

   mate 
  : 
  left 
  umbo 
  more 
  convex 
  than 
  the 
  right 
  one 
  : 
  corselet 
  and 
  

   lunule 
  long 
  and 
  narrow, 
  concave. 
  It 
  is 
  closely 
  allied 
  by 
  varieties 
  

   to 
  A. 
  ellipttcum 
  Sowb. 
  : 
  it 
  corresponds 
  mostly 
  to 
  the 
  descriptions 
  

   of 
  A. 
  lenticulare 
  Sowb., 
  but 
  the 
  figures 
  of 
  that 
  species 
  in 
  Sowb. 
  

   Conch. 
  111. 
  and 
  Hanley 
  App, 
  Wood 
  Ind. 
  appear 
  to 
  represent 
  a 
  

   distinct 
  species. 
  

  

  Sometimes 
  the 
  shell 
  is 
  tinged 
  with 
  brownish 
  orange 
  near 
  

   the 
  beaks 
  and 
  middle 
  portion, 
  especially 
  in 
  the 
  interior. 
  In 
  

   some 
  specimens 
  the 
  inner 
  surface 
  within 
  the 
  pallial 
  line 
  is 
  finely 
  

   and 
  deeply 
  punctated, 
  and 
  the 
  deep 
  pallial 
  sinus 
  is 
  marked 
  

   with 
  striae 
  radiating 
  from 
  the 
  opening 
  of 
  the 
  sinus. 
  

  

  Length 
  1.8 
  inch; 
  height 
  1.58 
  inch 
  ; 
  breadth 
  .82 
  inch. 
  

  

  Station. 
  — 
  Unknown. 
  

  

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

  

  18 
  specimens 
  were 
  taken 
  on 
  the 
  reef 
  at 
  low 
  water 
  mark. 
  

  

  488. 
  Amphiclesma 
  pulchrum. 
  

  

  Synonymy. 
  

  

  Amphidesma 
  pulchrum 
  Sowb. 
  in 
  Proc. 
  Zool. 
  Soc. 
  Lond, 
  p. 
  57. 
  Mar. 
  1832. 
  

  

  Mull. 
  Syn. 
  Test. 
  Viv. 
  p. 
  221. 
  May 
  1836. 
  

  

  Sowb. 
  Conch. 
  111. 
  No, 
  2. 
  pi. 
  17. 
  I 
  2. 
  1841. 
  

  

  Reeve 
  Conch. 
  Syst. 
  pi. 
  47. 
  f. 
  2. 
  Sept. 
  1841. 
  

  

  Hanley 
  Supp. 
  Wood 
  Ind. 
  Test. 
  pi. 
  12. 
  f. 
  6. 
  1845 
  ? 
  

  

  Hanley 
  Descr. 
  Catal. 
  p. 
  45. 
  1845 
  ? 
  

  

  Orb. 
  Voy. 
  Amer. 
  Merid. 
  Moll. 
  p. 
  534. 
  1846. 
  

  

  Station. 
  — 
  Unknown. 
  

  

  Habitat. 
  — 
  Bay 
  of 
  Caraccas 
  ; 
  Cuming 
  I 
  Sowerby 
  in 
  Proc. 
  Zool. 
  

  

  Soc. 
  : 
  also 
  Miiller. 
  

   Bay 
  of 
  Caraccas 
  ; 
  Orbigny. 
  

   St. 
  Elena 
  and 
  Panama; 
  Cuming! 
  Sowerby 
  in 
  

  

  Conch. 
  111. 
  

   S. 
  America; 
  Hanley. 
  

  

  