﻿AND 
  OTHER 
  FAMILIES. 
  97 
  

  

  Remarks. 
  — 
  This 
  species 
  has, 
  perhaps, 
  most 
  resemblance 
  in 
  its 
  exte- 
  

   rior 
  to 
  the 
  marginalis 
  (Lamarck), 
  which 
  comes 
  from 
  the 
  great 
  rivers 
  

   of 
  India. 
  In 
  the 
  interior, 
  however, 
  it 
  diners 
  much. 
  Our 
  shell 
  is 
  of 
  a 
  

   very 
  dark 
  salmon 
  colour. 
  It 
  is 
  also 
  a 
  thicker 
  shell, 
  and 
  the 
  teeth 
  are 
  

   much 
  thicker. 
  In 
  the 
  colour 
  of 
  the 
  epidermis 
  it 
  somewhat 
  resembles 
  

   the 
  lanceolatus 
  (nobis). 
  

  

  Unio 
  modioliformis. 
  Plate 
  XIII. 
  fig. 
  40. 
  

  

  Testa 
  ovatd, 
  transversa, 
  insequilaterali, 
  injiatd, 
  antice 
  angustd, 
  postice 
  lata; 
  

   valvulis 
  tenuissimis 
  ; 
  natibus 
  minutis 
  et 
  fere 
  terminalibus 
  ; 
  dentibus 
  cardinalibus 
  

   parvis, 
  compressis, 
  lateralibus 
  longis 
  curvisque; 
  margaritd 
  subpurpured, 
  valde 
  

   iridescenti. 
  

  

  Shell 
  ovate, 
  transverse, 
  very 
  inequilateral, 
  inflated, 
  narrow 
  before 
  and 
  broad 
  behind 
  ; 
  

   valves 
  very 
  thin 
  ; 
  beaks 
  small, 
  nearly 
  terminal 
  ; 
  cardinal 
  teeth 
  small, 
  compressed 
  ; 
  

   lateral 
  teeth 
  long 
  and 
  curved 
  ; 
  nacre 
  slightly 
  purple, 
  very 
  iridescent. 
  

  

  Hab. 
  Santee 
  Canal, 
  South 
  Carolina. 
  Professor 
  Ravenel. 
  

  

  My 
  Cabinet. 
  

  

  Cabinet 
  of 
  Professor 
  Ravenel. 
  

  

  Cabinet 
  of 
  P. 
  H. 
  Nicklin. 
  

  

  Diam. 
  1*1, 
  Length 
  1-5, 
  Breadth 
  2*7 
  inches. 
  

  

  Shell 
  reversely 
  ovate, 
  transverse, 
  very 
  inequilateral, 
  inflated, 
  narrow 
  

   before 
  and 
  broad 
  behind, 
  emarginate 
  at 
  basal 
  margin 
  ; 
  substance 
  of 
  the 
  

   shell 
  very 
  thin, 
  diaphanous 
  ; 
  beaks 
  small, 
  nearly 
  terminal, 
  slightly 
  un- 
  

   dulated; 
  ligament 
  rather 
  long 
  and 
  thin 
  ; 
  epidermis 
  brown, 
  shining 
  ; 
  rays 
  

   indistinct 
  ; 
  cardinal 
  teeth 
  small, 
  compressed, 
  disposed 
  to 
  be 
  double 
  in 
  

   the 
  left 
  and 
  single 
  in 
  the 
  right 
  valve 
  ; 
  lateral 
  teeth 
  long, 
  curved 
  and 
  ele- 
  

   vated 
  in 
  their 
  direction 
  ; 
  anterior 
  cicatrices 
  distinct 
  ; 
  posterior 
  cicatrices 
  

   confluent 
  ; 
  dorsal 
  cicatrices 
  small, 
  situated 
  in 
  the 
  cavity 
  of 
  the 
  beaks 
  ; 
  

   cavity 
  of 
  the 
  shell 
  deep 
  ; 
  cavity 
  of 
  the 
  beaks 
  shallow 
  ; 
  nacre 
  slightly 
  

   purple, 
  very 
  iridescent. 
  

  

  Remarks. 
  — 
  The 
  spreading 
  out 
  of 
  the 
  posterior 
  portion 
  of 
  the 
  shell, 
  

   and 
  the 
  narrowness 
  of 
  the 
  anterior 
  portion, 
  is 
  very 
  striking 
  in 
  this 
  spe- 
  

   VOL. 
  v. 
  — 
  z 
  

  

  