﻿244 
  PROCEEDINGS 
  OF 
  THE 
  MALACOLOGICAL 
  SOCIETY. 
  

  

  and 
  he 
  candidly 
  admits 
  the 
  difficulty 
  of 
  designating 
  the 
  type-species 
  

   in 
  the 
  case 
  of 
  authors 
  " 
  who 
  only 
  give 
  the 
  genera 
  and 
  simply 
  mention 
  

   one 
  or 
  two 
  examples 
  as 
  the 
  types 
  of 
  their 
  genus 
  ". 
  

  

  In 
  this 
  puhlication 
  he 
  abandons 
  his 
  name 
  Bosina, 
  and 
  under 
  the 
  

   head 
  of 
  Venus 
  he 
  cites 
  the 
  example 
  ( 
  V. 
  verrucosa) 
  given 
  by 
  Lamarck 
  

   in 
  1801, 
  instead 
  of 
  that 
  given 
  in 
  1799, 
  and 
  does 
  not 
  adduce 
  any 
  reason 
  

   for 
  selecting 
  the 
  one 
  rather 
  than 
  the 
  other. 
  It 
  is 
  clear, 
  however, 
  that 
  

   he 
  is 
  not 
  himself 
  designating 
  a 
  type, 
  but 
  supposes 
  that 
  he 
  is 
  indicating 
  

   what 
  Lamarck 
  m.eant 
  to 
  be 
  his 
  type. 
  At 
  tlie 
  same 
  time 
  there 
  is 
  no 
  

   doubt 
  that 
  he 
  thought 
  he 
  had 
  fixed 
  what 
  ought 
  to 
  be 
  known 
  as 
  the 
  

   genus 
  Venus. 
  Hence 
  a 
  few 
  years 
  later 
  we 
  find 
  Deshayes, 
  in 
  a 
  British 
  

   Museum 
  Catalogue 
  published 
  under 
  Gray's 
  supervision, 
  referring 
  to 
  

   Grav's 
  group 
  of 
  1847 
  as 
  "genus 
  eraendatum, 
  rectius 
  circumscriptum 
  ".' 
  

   At 
  the 
  present 
  day 
  there 
  is 
  no 
  unanimity 
  about 
  the 
  application 
  of 
  the 
  

   Linnean 
  name 
  ; 
  some 
  following 
  Gray 
  in 
  applying 
  it 
  to 
  the 
  puerpura 
  

   and 
  verrucosa 
  group; 
  some, 
  like 
  Fischer 
  (1887) 
  and 
  Dall 
  (1903), 
  

   preferring 
  Lamarck's 
  earlier 
  example 
  {V. 
  mercenaria) 
  as 
  the 
  type. 
  

  

  Thus 
  we 
  arrive 
  at 
  the 
  conclusion 
  that 
  no 
  one 
  has 
  yet 
  pi'operly 
  

   selected 
  a 
  type 
  for 
  Venus 
  ; 
  the 
  original 
  Linnean 
  genus 
  has 
  simply 
  been 
  

   broken 
  up 
  into 
  a 
  number 
  of 
  genera 
  and 
  subgenera, 
  each 
  individual 
  

   author 
  reserving 
  a 
  genus 
  Venus 
  and 
  mentioning 
  one 
  or 
  more 
  species 
  as 
  

   examples 
  to 
  indicate 
  his 
  conception 
  of 
  it, 
  but 
  without 
  making 
  any 
  

   definite 
  selection 
  of 
  a 
  type-species. 
  

  

  Consequently 
  it 
  is 
  necessary 
  to 
  review 
  the 
  whole 
  question 
  in 
  order 
  

   to 
  ascertain 
  what 
  species 
  ought 
  to 
  be 
  regarded 
  as 
  the 
  type 
  of 
  the 
  

   genus. 
  In 
  doing 
  tliis 
  I 
  shall 
  try 
  to 
  follow 
  the 
  rules 
  and 
  recom- 
  

   mendations 
  of 
  the 
  International 
  Commission 
  as 
  far 
  as 
  possible. 
  In 
  

   the 
  first 
  place 
  the 
  species 
  chosen 
  must 
  be 
  among 
  those 
  mentioned 
  

   by 
  Linnaeus. 
  Secondly, 
  Ilecommendation 
  Jc 
  says: 
  "If 
  some 
  of 
  the 
  

   original 
  species 
  have 
  later 
  been 
  classified 
  in 
  other 
  genera, 
  preference 
  

   should 
  be 
  shown 
  to 
  the 
  species 
  still 
  remaining 
  in 
  the 
  oiiginal 
  genus." 
  

   In 
  this 
  case 
  the 
  original 
  genus 
  is 
  what 
  would 
  now 
  be 
  called 
  a 
  family, 
  

   and 
  all 
  the 
  species 
  have 
  been 
  assigned 
  by 
  different 
  authors 
  to 
  sub- 
  

   sequently 
  created 
  genera. 
  It 
  is 
  impossible 
  to 
  proceed 
  b}^ 
  the 
  simple 
  

   elimination 
  of 
  genera 
  ; 
  moreover, 
  Bolten's 
  subdivisions 
  were 
  mei'e 
  

   arbitrary 
  assemblages, 
  not 
  distinguishable 
  from 
  one 
  another 
  by 
  any 
  

   common 
  generic 
  characters 
  ; 
  so 
  that 
  Lamarck 
  was 
  really 
  the 
  first 
  to 
  

   make 
  a 
  reasonable 
  and 
  truly 
  scientific 
  division 
  of 
  the 
  Linnean 
  Venus. 
  

   I 
  think, 
  therefore, 
  everyone 
  will 
  admit 
  that 
  the 
  type 
  of 
  Venus 
  should 
  

   be 
  selected 
  from 
  among 
  the 
  species 
  classed 
  by 
  Lamarck 
  under 
  that 
  

   name, 
  after 
  the 
  separation 
  of 
  those 
  which 
  possess 
  conspicuous 
  lateral 
  

   teeth, 
  and 
  after 
  the 
  separation 
  of 
  some 
  Linnean 
  species 
  which 
  belonged 
  

   to 
  very 
  different 
  genera. 
  At 
  the 
  same 
  time 
  it 
  will 
  be 
  desirable 
  to 
  

   avoid 
  choosing 
  any 
  species 
  actually 
  mentioned 
  by 
  Bolten 
  under 
  his 
  

   divisional 
  names 
  of 
  Paphia, 
  Gafrarium, 
  and 
  Cytherea. 
  

  

  Coming, 
  then, 
  to 
  the 
  consideration 
  of 
  the 
  Lamarckian 
  species 
  of 
  

   Venus, 
  we 
  must 
  remember 
  that 
  many 
  more 
  species 
  were 
  known 
  to 
  

   Lamarck 
  than 
  to 
  Linnseus, 
  and 
  that 
  none 
  of 
  these 
  are 
  eligible. 
  All 
  

  

  •^ 
  Catalogue 
  of 
  the 
  Bivalve 
  Shells 
  in 
  the 
  British 
  Museum, 
  1853, 
  p. 
  98. 
  

  

  