﻿44 
  ON 
  THE 
  NAIADES, 
  

  

  inflatis, 
  prope 
  apices 
  undulatis 
  ; 
  cicatricibus 
  vix 
  cernendis 
  ; 
  margaritd 
  pulchrd 
  et 
  

   iridescente. 
  

  

  Shell 
  subrotund, 
  much 
  inflated 
  near 
  the 
  beaks, 
  inequilateral, 
  obtusely 
  angular 
  behind; 
  

   valves 
  thin; 
  epidermis 
  yellow, 
  with 
  numerous 
  green 
  rays 
  ; 
  beaks 
  inflated, 
  near 
  the 
  tip 
  

   undulated; 
  cicatrices 
  scarcely 
  perceptible; 
  nacre 
  beautifully 
  pearly 
  and 
  iridescent. 
  

  

  Hab. 
  China. 
  W. 
  W. 
  Wood. 
  

  

  My 
  Cabinet. 
  

   Cabinet 
  of 
  the 
  Academy 
  of 
  Natural 
  Sciences 
  of 
  Philadelphia. 
  

   Cabinet 
  of 
  Mr 
  Hyde. 
  

   Diam. 
  1-6, 
  Length 
  2-3, 
  Breadth 
  3-4 
  inches. 
  

  

  Shell 
  subrotund, 
  much 
  inflated 
  in 
  the 
  region 
  of 
  the 
  beaks, 
  inequi- 
  

   lateral, 
  connate 
  before 
  and 
  behind 
  the 
  beaks, 
  obtusely 
  angular 
  behind, 
  

   rounded 
  before, 
  posterior 
  slope 
  carinate 
  ; 
  substance 
  of 
  the 
  shell 
  thin 
  ; 
  

   epidermis 
  smooth, 
  yellow 
  with 
  numerous 
  beautiful 
  green 
  rays 
  over 
  the 
  

   whole 
  disk, 
  which 
  are 
  darker 
  on 
  the 
  posterior 
  part 
  and 
  obsolete 
  on 
  the 
  

   umbones 
  ; 
  ligament 
  long 
  and 
  thin 
  ; 
  beaks 
  inflated 
  and 
  terminated 
  with 
  

   about 
  six 
  nearly 
  parallel 
  undulations 
  ; 
  teeth, 
  none 
  ; 
  cicatrices 
  scarcely 
  

   perceptible 
  ; 
  cavity 
  of 
  the 
  beaks 
  shallow 
  and 
  rounded 
  ; 
  nacre 
  beautifully 
  

   pearly 
  and 
  highly 
  iridescent, 
  sometimes 
  tinged 
  with 
  salmon 
  and 
  pink. 
  

  

  Remarks. 
  — 
  Several 
  specimens 
  of 
  this 
  species 
  have 
  been 
  within 
  a 
  few 
  

   years 
  received 
  from 
  Canton, 
  and 
  Mr 
  Wood, 
  to 
  whom 
  I 
  owe 
  one 
  of 
  

   mine, 
  informed 
  me 
  that 
  he 
  believes 
  it 
  to 
  be 
  a 
  native 
  of 
  that 
  country, 
  and 
  

   most 
  probably 
  dwelling 
  in 
  the 
  waters 
  of 
  the 
  neighbourhood 
  of 
  Canton. 
  

   It 
  is 
  certainly 
  among 
  the 
  most 
  beautiful 
  of 
  the 
  genus 
  which 
  has 
  come 
  

   under 
  my 
  notice, 
  and 
  is 
  remarkable 
  for 
  its 
  great 
  area, 
  its 
  inflation 
  of 
  

   the 
  region 
  of 
  the 
  beaks, 
  its 
  smooth 
  epidermis, 
  its 
  splendid 
  rays 
  and 
  ex- 
  

   quisitely 
  beautiful 
  nacre, 
  which 
  no 
  pencil 
  can 
  imitate. 
  I 
  have 
  it 
  of 
  

   several 
  different 
  ages 
  — 
  when 
  very 
  young 
  it 
  is 
  less 
  rotund, 
  being 
  some- 
  

   what 
  trapezoidal, 
  the 
  dorsal 
  margin 
  nearly 
  straight 
  and 
  the 
  rays 
  obso- 
  

   lete. 
  The 
  specimen 
  figured 
  is 
  not 
  half 
  the 
  size 
  of 
  the 
  largest 
  specimen 
  

   in 
  my 
  cabinet, 
  but 
  I 
  have 
  chosen 
  it 
  for 
  its 
  great 
  perfection 
  in 
  having 
  

   the 
  valves 
  completely 
  connate 
  before 
  and 
  behind 
  the 
  beaks. 
  

  

  