﻿246 
  PUOCKKDINGS 
  OF 
  THK 
  JI 
  ALACOLOGICA 
  L 
  SOCIKiT, 
  

  

  genus 
  Venus, 
  this 
  cau 
  be 
  described 
  as 
  having 
  normally 
  a 
  cancellate 
  

   structure, 
  the 
  radial 
  element 
  sometimes 
  becoming 
  obsolete 
  except 
  

   along 
  the 
  valve-margins, 
  which 
  are 
  always 
  crenulated. 
  

  

  Cytheuea 
  (Bolten). 
  

  

  The 
  revival 
  of 
  a 
  name 
  which 
  has 
  been 
  associated 
  for 
  a 
  long 
  time 
  

   with 
  one 
  group 
  of 
  shells 
  but 
  displaced 
  by 
  an 
  older 
  one, 
  and 
  its 
  

   subsequent 
  application 
  to 
  another 
  group, 
  is 
  a 
  very 
  irritating 
  con- 
  

   sequence 
  of 
  the 
  modern 
  rules 
  of 
  nomenclature. 
  If, 
  however, 
  we 
  are 
  

   to 
  adhere 
  strictly 
  to 
  the 
  rule 
  of 
  priority 
  and 
  to 
  definition 
  by 
  genotype, 
  

   such 
  transferences 
  of 
  names 
  must 
  sometimes 
  be 
  the 
  result 
  ; 
  and 
  it 
  is 
  

   so 
  in 
  the 
  case 
  of 
  the 
  name 
  Cytherea. 
  

  

  Every 
  conchologist 
  knows 
  that 
  this 
  name 
  was 
  used 
  by 
  Lamarck 
  in 
  

   1806 
  because 
  he 
  repented 
  of 
  having 
  adopted 
  the 
  name 
  Meretrix 
  for 
  

   a 
  certain 
  genus 
  in 
  1799, 
  but 
  under 
  the 
  law 
  of 
  priority 
  even 
  the 
  author 
  

   of 
  a 
  genus 
  cannot 
  abandon 
  his 
  earlier 
  name, 
  and 
  consequently 
  Meretrix 
  

   has 
  displaced 
  Cytherea 
  for 
  the 
  group 
  of 
  which 
  Venus 
  meretrix 
  (Linn.) 
  

   is 
  the 
  type. 
  

  

  Lamarck, 
  however, 
  was 
  not 
  the 
  first 
  to 
  employ 
  the 
  name 
  Cytherea, 
  

   for, 
  as 
  we 
  have 
  seen, 
  Bolten 
  had 
  given 
  it 
  to 
  one 
  of 
  his 
  divisions 
  of 
  

   Venus. 
  His 
  Cytherea 
  was 
  a 
  very 
  heterogeneous 
  assemblage, 
  for 
  the 
  

   species 
  which 
  he 
  included 
  therein 
  belong 
  to 
  several 
  different 
  genera, 
  

   and 
  seem 
  to 
  have 
  little 
  in 
  common. 
  His 
  first 
  species 
  is 
  V. 
  granulata, 
  

   Gmel. 
  (a 
  Chione), 
  the 
  second 
  is 
  V. 
  tigrina 
  (a 
  Codahia), 
  two 
  belong 
  to 
  

   Circe, 
  five 
  to 
  Dosinia, 
  and 
  the 
  remaining 
  three 
  are 
  V. 
  puerpura, 
  

   V. 
  ruyosa, 
  and 
  V. 
  rerrucosa. 
  

  

  In 
  dealing 
  with 
  this 
  assemblage 
  for 
  the 
  purpose 
  of 
  selecting 
  a 
  type. 
  

   Dr. 
  Dall 
  rightly 
  eliminated 
  the 
  species 
  belonging 
  to 
  genera 
  established 
  

   by 
  Scopoli, 
  Megerle, 
  and 
  Schumacher, 
  and 
  then 
  remarked 
  that 
  

   "Schumacher's 
  names 
  reduce 
  Cytherea 
  (Bolten) 
  to 
  Veneridae 
  of 
  the 
  

   type 
  of 
  V. 
  puerpura, 
  for 
  which 
  it 
  must 
  be 
  retained 
  ". 
  

  

  This 
  selection 
  bj' 
  Dr. 
  Dall 
  is 
  unalterable, 
  unless 
  it 
  can 
  be 
  shown 
  

   that 
  there 
  was 
  an 
  earlier 
  selection 
  o£ 
  type, 
  as 
  in 
  the 
  ease 
  of 
  

   Gafrarium. 
  So 
  far 
  as 
  I 
  can 
  ascertain, 
  no 
  one 
  else 
  has 
  noticed 
  or 
  

   commented 
  on 
  Bolten's 
  use 
  of 
  Cytherea 
  except 
  the 
  Messrs. 
  H. 
  & 
  A. 
  

   Adams, 
  and 
  they 
  seem 
  to 
  have 
  overlooked 
  it 
  when 
  compiling 
  their 
  

   arrangement 
  of 
  Veneridse, 
  for 
  it 
  is 
  only 
  in 
  their 
  Corrigenda 
  at 
  the 
  

   end 
  of 
  vol. 
  ii, 
  Genera 
  of 
  Rectnt 
  MoUusca, 
  that 
  we 
  find 
  "for 
  Timocha, 
  

   Leach, 
  read 
  Cytherea, 
  Bolten". 
  Clearlj^ 
  they 
  would 
  have 
  taken 
  

   Bolten's 
  first 
  species 
  as 
  the 
  tj^pe 
  of 
  his 
  group, 
  but 
  such 
  a 
  note 
  in 
  the 
  

   corrigenda 
  of 
  a 
  book 
  is 
  certainly 
  not 
  a 
  proper 
  designation 
  of 
  a 
  type 
  ; 
  

   consequently 
  it 
  counts 
  for 
  nothing. 
  

  

  We 
  have 
  seen 
  that 
  Gray 
  in 
  1847 
  chose 
  to 
  regard 
  Venus 
  verrucosa 
  as 
  

   the 
  type 
  of 
  Venus, 
  because 
  Lamarck 
  had 
  given 
  that 
  species 
  as 
  an 
  

   example 
  in 
  1801 
  ; 
  but 
  that 
  Lamarck's 
  examples 
  were 
  not 
  intended 
  to 
  

   be 
  taken 
  as 
  types, 
  and 
  that 
  Gray 
  cannot 
  be 
  said 
  to 
  have 
  made 
  

   a 
  selection 
  from 
  the 
  whole 
  group 
  Venus 
  of 
  Lamarck. 
  Hence 
  I 
  regard 
  

   Dr. 
  Dall's 
  selection 
  of 
  V. 
  puerpura 
  as 
  the 
  type 
  of 
  Bolten's 
  Cytherea 
  as 
  

   a 
  valid 
  designation. 
  

  

  