﻿106 
  ON 
  THE 
  NAIADES, 
  

  

  Diam. 
  '8, 
  Length 
  1-3, 
  Breadth 
  2-1 
  inches. 
  

  

  Shell 
  reversely 
  ovate, 
  very 
  inequilateral, 
  slightly 
  inflated, 
  rather 
  

   straight 
  on 
  the 
  basal 
  margin 
  and 
  elevated 
  on 
  the 
  posterior 
  dorsal 
  mar- 
  

   gin 
  ; 
  substance 
  of 
  the 
  shell 
  thin 
  ; 
  beaks 
  slightly 
  elevated 
  ; 
  ligament 
  long 
  

   and 
  narrow 
  ; 
  epidermis 
  dark 
  brown 
  and 
  rather 
  smooth 
  ; 
  anterior 
  and 
  

   posterior 
  cicatrices 
  confluent; 
  dorsal 
  cicatrices 
  situated 
  in 
  the 
  cavity 
  of 
  

   the 
  beaks 
  ; 
  cavity 
  of 
  the 
  shell 
  wide 
  and 
  rather 
  deep 
  ; 
  cavity 
  of 
  the 
  

   beaks 
  very 
  shallow 
  ; 
  nacre 
  purple. 
  

  

  Remarks. 
  — 
  To 
  the 
  kindness 
  of 
  Dr 
  Burrough 
  I 
  am 
  indebted 
  for 
  the 
  

   privilege 
  of 
  describing 
  this 
  species. 
  It 
  is 
  with 
  pleasure 
  I 
  take 
  the 
  op- 
  

   portunity 
  of 
  placing 
  his 
  name 
  upon 
  it. 
  It 
  was 
  procured 
  by 
  him 
  near 
  

   the 
  city 
  of 
  Manilla. 
  It 
  resembles, 
  in 
  outline 
  and 
  colour, 
  the 
  Unio 
  

   cuprinus 
  (nobis), 
  but 
  has 
  no 
  trace 
  of 
  teeth. 
  It 
  is 
  most 
  remarkable 
  

   perhaps 
  for 
  its 
  deep 
  colour. 
  

  

  Margaritana* 
  Raveneliana. 
  Plate 
  XVII. 
  fig. 
  50. 
  

  

  Testa 
  subcylindracea, 
  valde 
  transversa 
  et 
  inseqiiilaterali,injlata 
  ; 
  valvulis 
  tenui- 
  

   bus; 
  natibus 
  exiguis 
  ; 
  dentibus 
  cardinalibus 
  parvis. 
  subcompressis 
  ; 
  margaritd 
  

   coeruleo-albd. 
  

  

  Shell 
  subcylindrical, 
  very 
  transverse, 
  inequilateral, 
  inflated 
  ; 
  valves 
  thin 
  ; 
  beaks 
  

   small 
  ; 
  cardinal 
  teeth 
  small, 
  rather 
  compressed 
  ; 
  nacre 
  bluish 
  white. 
  

  

  Hab. 
  French 
  Broad 
  and 
  Swananoe 
  rivers, 
  North 
  Carolina. 
  

  

  My 
  Cabinet. 
  

   Cabinet 
  of 
  Dr 
  Ravenel. 
  

   Diam. 
  '9, 
  Length 
  1-1, 
  Breadth 
  2-2 
  inches. 
  

  

  Shell 
  subcylindrical, 
  very 
  transverse, 
  inequilateral, 
  inflated, 
  disposed 
  

   to 
  be 
  compressed 
  near 
  the 
  basal 
  margin, 
  where 
  it 
  is 
  often 
  emarginate 
  ; 
  

   substance 
  of 
  the 
  shell 
  thin; 
  beaks 
  small; 
  ligament 
  rather 
  short; 
  epi- 
  

   dermis 
  brown, 
  with 
  rays 
  on 
  the 
  posterior 
  part; 
  umbonial 
  slope 
  large, 
  

   rounded 
  ; 
  cardinal 
  teeth 
  consisting 
  in 
  each 
  valve 
  of 
  a 
  small 
  compressed 
  

  

  * 
  See 
  note 
  at 
  page 
  429, 
  Vol. 
  III. 
  

  

  