﻿66 
  ON 
  THE 
  NAIADES, 
  

  

  Remarks. 
  — 
  I 
  am 
  indebted 
  to 
  an 
  amiable 
  and 
  intelligent 
  friend, 
  Mrs 
  

   Corrie 
  of 
  Birmingham, 
  England, 
  for 
  this 
  new 
  species, 
  which 
  comes 
  

   from 
  Calcutta 
  ; 
  and 
  to 
  her 
  I 
  dedicate 
  it, 
  as 
  a 
  mark 
  of 
  sincere 
  friendship. 
  

   It 
  closely 
  resembles 
  the 
  U. 
  marginalis 
  of 
  Lamarck, 
  but 
  diners 
  from 
  

   that 
  species 
  in 
  being 
  more 
  transverse, 
  in 
  the 
  beaks 
  being 
  more 
  retuse, 
  

   in 
  the 
  dorsal 
  line 
  being 
  nearly 
  straight, 
  and 
  in 
  its 
  not 
  being 
  possessed 
  

   of 
  a 
  light 
  border 
  along 
  the 
  margin. 
  The 
  cardinal 
  teeth 
  are 
  remark- 
  

   ably 
  thin, 
  and 
  form 
  nearly 
  a 
  line 
  with 
  the 
  lateral 
  teeth. 
  

  

  Unio 
  Grayanus. 
  Plate 
  IX. 
  fig. 
  26. 
  

  

  Testa 
  lanceolatd, 
  tra?isve?*sissimd, 
  antice 
  rotundata 
  et 
  postice 
  acutissime 
  angu- 
  

   latd, 
  prope 
  nates 
  et 
  partem 
  posticam 
  plicatd 
  ; 
  lateribus 
  planulatis 
  ; 
  clivo 
  umboniali 
  

   subcarinato 
  ; 
  valvulis 
  tenuibus 
  ; 
  natibus 
  prope 
  raarginem 
  anticam 
  locatis, 
  de- 
  

   pressis 
  ; 
  epidermide 
  luteold, 
  obsolete 
  radiatd 
  ; 
  dentibus 
  cardinalibus 
  in 
  valvuld 
  

   utrdque 
  duplicibus 
  et 
  erectis 
  ; 
  lateralibus 
  longissimis, 
  tenuibus, 
  sub-erectisque 
  ; 
  

   margarita 
  pulchrd 
  et 
  iridescente. 
  

  

  Shell 
  lanceolate, 
  very 
  transverse, 
  rounded 
  before 
  and 
  very 
  acutely 
  angular 
  behind, 
  

   plicate 
  about 
  the 
  beaks 
  and 
  posterior 
  part 
  of 
  the 
  shell, 
  flattened 
  on 
  the 
  sides 
  ; 
  umbonial 
  

   slope 
  ridged 
  ; 
  valves 
  thin 
  ; 
  beaks 
  depressed, 
  placed 
  near 
  the 
  anterior 
  margin 
  ; 
  epidermis 
  

   yellowish 
  with 
  obsolete 
  rays; 
  cardinal 
  teeth 
  double 
  in 
  both 
  valves 
  and 
  erect; 
  lateral 
  

   teeth 
  very 
  long, 
  thin 
  and 
  nearly 
  straight 
  ; 
  nacre 
  beautifully 
  pearly 
  and 
  iridescent. 
  

  

  Hab. 
  China. 
  

  

  My 
  Cabinet. 
  

   Cabinet 
  of 
  Mr 
  Hyde. 
  

   Cabinet 
  of 
  Mr 
  Gray, 
  London. 
  

   Diam. 
  *6, 
  Length 
  -8, 
  Breadth 
  8-3 
  inches. 
  

  

  Shell 
  lanceolate, 
  very 
  transverse, 
  very 
  inequilateral, 
  rounded 
  before 
  

   and 
  very 
  acutely 
  angular 
  behind, 
  irregularly 
  folded 
  in 
  the 
  region 
  of 
  

   the 
  beaks, 
  several 
  larger 
  folds 
  on 
  the 
  anterior 
  slope, 
  on 
  the 
  poste- 
  

   rior 
  portion 
  the 
  folds 
  are 
  parallel 
  being 
  nearly 
  perpendicular 
  to 
  the 
  

   basal 
  margin, 
  flattened 
  on 
  the 
  sides; 
  umbonial 
  slope 
  elevated 
  into 
  a 
  

   ridge, 
  green 
  ; 
  substance 
  of 
  the 
  shell 
  thin 
  ; 
  beaks 
  depressed, 
  placed 
  very 
  

   near 
  to 
  the 
  anterior 
  margin 
  ; 
  ligament 
  thin, 
  not 
  very 
  long 
  ; 
  epidermis 
  

   finely 
  wrinkled, 
  yellowish 
  with 
  obsolete 
  rays, 
  disposed 
  to 
  be 
  greenish 
  

  

  