﻿OSTREA. 
  Panama 
  Shells. 
  469 
  

  

  SYS. 
  Amomia 
  tenuis. 
  Nov. 
  sp. 
  

  

  Shell 
  orbicular 
  : 
  flat, 
  extremely 
  thin 
  : 
  white, 
  subtransparent, 
  

   pearly 
  : 
  externally 
  somewhat 
  uneven 
  : 
  upper 
  scar 
  large, 
  

   rounded, 
  with 
  the 
  lower 
  side 
  arcuated 
  : 
  two 
  lower 
  scars 
  small, 
  

   circular, 
  equal: 
  anterior 
  one 
  nearly 
  entering 
  the 
  arcuation 
  of 
  

   the 
  upper 
  scar 
  ; 
  posterior 
  one 
  near 
  the 
  other, 
  with 
  the 
  upper 
  

   margin 
  as 
  high 
  as 
  the 
  centre 
  of 
  the 
  other. 
  

  

  Diameter 
  about 
  .85 
  inch. 
  

  

  Station. 
  — 
  Near 
  low 
  water 
  mark. 
  

  

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

   3 
  specimens 
  were 
  obtained. 
  

  

  379. 
  Anoillia. 
  . 
  Sp. 
  indet. 
  a. 
  

  

  A 
  very 
  small 
  yellow 
  shell 
  with 
  the 
  convex 
  valve 
  excessively 
  

   convex, 
  and 
  the 
  margin 
  lobate. 
  Although 
  only 
  1 
  valve 
  was 
  

   found, 
  it 
  is 
  obvious 
  that 
  it 
  belongs 
  to 
  a 
  very 
  distinct 
  species. 
  

  

  380. 
  Ostrea 
  • 
  Sp. 
  indet. 
  a. 
  

  

  Eather 
  large 
  and 
  ovate 
  ; 
  with 
  the 
  upper 
  valve 
  radiately 
  cor- 
  

   rugated, 
  with 
  many 
  notches 
  on 
  both 
  sides 
  of 
  the 
  hinge 
  : 
  lower 
  

   valve 
  attached 
  to 
  a 
  ledge 
  of 
  rock 
  by 
  the 
  whole 
  of 
  its 
  surface 
  : 
  

   on 
  this 
  account 
  it 
  is 
  rarely 
  possible 
  to 
  detach 
  a 
  specimen 
  entire. 
  

   It 
  occurs 
  more 
  commonly 
  near 
  half 
  tide 
  level. 
  It 
  is 
  rather 
  com- 
  

   mon, 
  but 
  not 
  abundant 
  on 
  the 
  reef 
  at 
  Panama. 
  We 
  collected 
  

   only 
  6 
  specimens. 
  It 
  is 
  an 
  edible 
  species 
  of 
  excellent 
  flavor. 
  

   During 
  the 
  recess 
  of 
  the 
  tide 
  the 
  natives 
  open 
  the 
  shells 
  on 
  the 
  

   rocks, 
  Avithout 
  detaching 
  the 
  lower 
  valves, 
  and 
  collect 
  the 
  soft 
  

   parts 
  in 
  a 
  calabash. 
  

  

  381. 
  Ostrea 
  . 
  Sp. 
  indet. 
  h. 
  

  

  Rather 
  large 
  and 
  solid, 
  with 
  both 
  valves 
  strongly 
  notched 
  on 
  

   both 
  sides 
  of 
  the 
  hinge 
  : 
  surface 
  without 
  sculpture 
  other 
  than 
  

  

  