﻿62 
  PKOCKEDINGS 
  OF 
  THE 
  MALACOLOGICAL 
  SOCIETT. 
  

  

  Pholas 
  coshdata 
  differs 
  from 
  P. 
  Candida 
  in 
  the 
  more 
  convex 
  ventral 
  

   margin 
  ; 
  in 
  the 
  less 
  evenly 
  rounded 
  anterior 
  end, 
  which 
  is 
  more 
  

   inclined 
  to 
  become 
  angular; 
  in 
  the 
  more 
  attenuated 
  and 
  more 
  widely 
  

   gaping 
  posterior 
  end 
  ; 
  and 
  in 
  the 
  greater 
  thickening 
  of 
  the 
  shell 
  on 
  

   the 
  dorsal 
  margin 
  hj 
  the 
  base 
  of 
  the 
  internal 
  tooth 
  or 
  myophore 
  ; 
  as 
  

   well 
  as 
  in 
  the 
  external 
  ribbing, 
  as 
  pointed 
  out 
  by 
  Dr. 
  Goodall. 
  

  

  I 
  am 
  not 
  greatly 
  concerned 
  with 
  the 
  question 
  whether 
  conchologists 
  

   will 
  accept 
  the 
  name 
  costulata, 
  Goodall, 
  as 
  representing 
  a 
  species 
  

   truly 
  distinct 
  from 
  Candida, 
  but 
  I 
  have 
  seen 
  no 
  intermediate 
  forms, 
  

   and 
  should 
  at 
  once 
  recognize 
  any 
  similar 
  specimens. 
  My 
  personal 
  

   interest 
  in 
  the 
  subject 
  is 
  specially 
  due 
  to 
  the 
  unexpected 
  coincidence 
  

   that 
  again 
  connects 
  it 
  with 
  my 
  family. 
  It 
  is 
  somewhat 
  remarkable 
  

   that 
  a 
  grandson, 
  at 
  the 
  age 
  of 
  72, 
  should 
  practically 
  rediscover 
  

   a 
  IJritish 
  shell 
  known 
  to 
  liis 
  grandmother 
  as 
  a 
  new 
  species 
  in 
  1820, 
  

   wliich 
  has 
  escaped 
  recognition 
  and 
  publication 
  from 
  that 
  time 
  to 
  this, 
  

   except 
  in 
  the 
  paper 
  above 
  mentioned. 
  

  

  P.S. 
  — 
  On 
  the 
  6th 
  of 
  October, 
  1916, 
  I 
  spent 
  several 
  hours 
  in 
  

   searching 
  for 
  more 
  specimens 
  of 
  Pholas 
  costulata. 
  Failing 
  to 
  find 
  it 
  

   on 
  the 
  beach 
  where 
  1 
  had 
  first 
  met 
  with 
  it, 
  I 
  visited 
  the 
  coast 
  

   between 
  Hlack 
  Rock 
  and 
  llottingdeari 
  to 
  the 
  east 
  of 
  Brighton. 
  

   Beneath 
  the 
  cliffs, 
  at 
  low 
  tide, 
  many 
  acres 
  of 
  broken 
  chalk-beds 
  are 
  

   exposed, 
  and 
  these 
  are 
  plentifully 
  bored 
  by 
  Pholas. 
  P. 
  parva 
  was 
  in 
  

   great 
  abundance, 
  solid 
  and 
  detached 
  blocks 
  of 
  chalk 
  containing 
  many 
  

   examples; 
  in 
  the 
  latter 
  case 
  no 
  living 
  specimens 
  were 
  found. 
  

   P. 
  Candida 
  also 
  occurred, 
  but 
  quite 
  sparingly. 
  I 
  was 
  unable 
  to 
  

   discover 
  a 
  single 
  specimen 
  of 
  P. 
  costulata, 
  and 
  am 
  inclined 
  to 
  think 
  

   that 
  those 
  found 
  at 
  Hove 
  must 
  have 
  come 
  from 
  some 
  other, 
  submarine 
  

   bed 
  of 
  chalk, 
  rather 
  than 
  from 
  that 
  underlying 
  the 
  cliffs 
  toward 
  

   llottingdean. 
  

  

  