﻿50 
  ON 
  THE 
  NAIADES, 
  

  

  genus. 
  It 
  is 
  remarkable 
  for 
  its 
  size 
  and 
  weight, 
  and 
  the 
  strong 
  and 
  

   wide 
  callus 
  on 
  the 
  columella. 
  Under 
  the 
  epidermis 
  it 
  varies 
  from 
  a 
  

   dark 
  orange 
  to 
  lemon 
  yellow. 
  A 
  depauperated 
  specimen 
  in 
  my 
  pos- 
  

   session 
  would 
  scarcely 
  he 
  recognized 
  as 
  the 
  same 
  species, 
  owing 
  to 
  the 
  

   density 
  of 
  the 
  orange 
  colour. 
  The 
  apex 
  of 
  the 
  perfect 
  shell, 
  having 
  

   but 
  a 
  thin 
  epidermis, 
  presents 
  an 
  orange 
  appearance, 
  — 
  this 
  colour 
  may 
  

   also 
  be 
  observed 
  on 
  the 
  inside 
  of 
  the 
  shell. 
  At 
  the 
  base 
  of 
  the 
  colum- 
  

   ella 
  there 
  is 
  an 
  obsolete 
  tubercle. 
  The 
  band 
  sometimes 
  consists 
  of 
  a 
  

   single 
  white 
  line 
  only. 
  It 
  is 
  believed 
  these 
  specimens 
  formed 
  part 
  of 
  

   the 
  collection 
  brought 
  from 
  Java 
  bv 
  Mr 
  Shillaber. 
  

  

  Helicina 
  virginea. 
  Plate 
  XIX. 
  fig. 
  58. 
  

  

  Testa 
  subconicd, 
  apice 
  acuta, 
  subtus 
  inflatd, 
  c?'assd, 
  transversim 
  multisulcatd; 
  

   anfractibus 
  senis 
  ; 
  spira 
  elevatd; 
  aperturd 
  valde 
  dilatatd 
  ; 
  labro 
  effuso 
  ; 
  colu- 
  

   mella 
  subcallosd. 
  

  

  Shell 
  subcorneal, 
  acutely 
  pointed, 
  inflated 
  below, 
  thick, 
  with 
  many 
  transverse 
  fur- 
  

   rows 
  ; 
  whorls 
  six 
  ; 
  spire 
  elevated 
  ; 
  aperture 
  much 
  dilated 
  ; 
  outer 
  lip 
  effuse 
  ; 
  columella 
  

   thinly 
  coated. 
  

  

  Hab. 
  Java? 
  

  

  Helicina 
  striata 
  ? 
  Lam. 
  

  

  My 
  Cabinet. 
  

  

  Diam. 
  '8, 
  Length 
  -8 
  of 
  an 
  inch. 
  

  

  Remarks. 
  — 
  This 
  species 
  came 
  in 
  the 
  same 
  collection 
  as 
  that 
  de- 
  

   scribed 
  last. 
  It 
  is 
  nearly 
  of 
  the 
  same 
  diameter. 
  It 
  differs 
  from 
  it 
  

   altogether 
  in 
  form 
  and 
  colour. 
  It 
  is 
  remarkable 
  for 
  its 
  acutely 
  pointed 
  

   apex, 
  its 
  milk-white 
  appearance, 
  and 
  its 
  numerous 
  furrows. 
  The 
  

   outer 
  lip 
  may, 
  with 
  propriety, 
  be 
  said 
  to 
  be 
  effuse 
  rather 
  than 
  re- 
  

   flected. 
  

  

  