﻿596 
  Mr. 
  H. 
  L. 
  Clark 
  on 
  the 
  

  

  divides 
  it 
  into 
  four 
  varieties 
  or 
  forms. 
  Fortunately 
  the 
  

   references 
  to 
  figures 
  under 
  these 
  forms 
  are 
  sufficiently 
  con- 
  

   sistent, 
  so 
  that 
  it 
  is 
  easy 
  to 
  determine 
  to 
  what 
  species 
  each 
  

   form 
  is 
  to 
  be 
  referred. 
  Leske 
  recognized 
  this 
  fact, 
  and 
  gave 
  

   each 
  form 
  a 
  new 
  name. 
  He 
  first 
  selected 
  the 
  third 
  one, 
  and 
  

   called 
  it 
  Echinodiscus 
  quinquiesperforatus 
  ; 
  next 
  he 
  removed 
  

   the 
  fourth 
  form 
  as 
  Echinodiscus 
  orbicularis 
  ; 
  next 
  comes 
  the 
  

   second, 
  which 
  he 
  called 
  Echinodiscus 
  deciesdigitatus. 
  The 
  

   name 
  orbiculus 
  is 
  thus 
  left 
  for 
  the 
  first 
  form 
  alone, 
  and 
  

   Leske's 
  name 
  dentatus, 
  which 
  he 
  gave 
  last 
  of 
  the 
  four, 
  must 
  

   be 
  regarded 
  as 
  a 
  synonym. 
  As 
  Agassiz 
  in 
  1841 
  placed 
  this 
  

   species 
  (under 
  a 
  pre-Liunean 
  name) 
  in 
  his 
  genus 
  Rotula, 
  

   where 
  it 
  has 
  since 
  remained, 
  it 
  becomes 
  the 
  type 
  of 
  that 
  

   genus 
  by 
  virtual 
  tautonomy, 
  if 
  for 
  no 
  other 
  reason. 
  

  

  The 
  first 
  post-Linnean 
  writer 
  whose 
  work 
  affects 
  clype- 
  

   astroid 
  nomenclature 
  is 
  Leske, 
  1778. 
  The 
  idea 
  of 
  dating 
  

   Echinocyamus 
  and 
  Echinoneus 
  from 
  Van 
  Phelsum, 
  1774, 
  

   seems 
  to 
  me 
  absurd. 
  It 
  is 
  true 
  that 
  he 
  uses 
  both 
  names, 
  

   but 
  he 
  is 
  not 
  a 
  binomial 
  writer, 
  his 
  diagnoses 
  are 
  inadequate, 
  

   and 
  he 
  gives 
  no 
  species 
  under 
  either 
  " 
  genus." 
  Even 
  if 
  we 
  

   wished 
  to, 
  we 
  could 
  not 
  use 
  generic 
  names 
  which 
  are 
  neither 
  

   adequately 
  diagnosed 
  nor 
  assigned 
  any 
  constituent 
  species. 
  

   The 
  question 
  whether 
  we 
  accept 
  these 
  names 
  of 
  Van 
  Phelsum 
  

   or 
  not 
  is 
  unimportant, 
  however, 
  for 
  our 
  nomenclature 
  will 
  

   not 
  be 
  affected, 
  but 
  only 
  the 
  date 
  and 
  author 
  of 
  the 
  two 
  

   names 
  *. 
  It 
  may 
  be 
  added 
  that 
  if 
  we 
  are 
  to 
  date 
  these 
  

   names 
  from 
  Van 
  Phelsum, 
  then 
  Agassiz's 
  name 
  Heliophora, 
  

   proposed 
  in 
  1840, 
  has 
  precedence 
  over 
  the 
  universally 
  used 
  

   name 
  Rotula, 
  Agassiz, 
  1841. 
  Heliophora 
  has 
  been 
  rejected, 
  

   and 
  rightfully 
  it 
  seems 
  to 
  me, 
  because 
  it 
  has 
  no 
  constituent 
  

   species, 
  and 
  therefore 
  cannot 
  be 
  assigned 
  a 
  type 
  ; 
  and 
  this 
  is 
  

   the 
  status 
  of 
  Echinocyamus 
  and 
  Echinoneus 
  of 
  Van 
  Phelsum. 
  

   For 
  my 
  part 
  I 
  do 
  not 
  see 
  how, 
  under 
  the 
  Code, 
  such 
  genera 
  

   can 
  be 
  maintained. 
  Under 
  Article 
  30 
  we 
  read 
  — 
  " 
  In 
  no 
  case 
  

   . 
  . 
  . 
  can 
  a 
  species 
  he 
  selected 
  as 
  type 
  which 
  was 
  not 
  originally 
  

   included 
  in 
  the 
  genus 
  " 
  ; 
  and 
  I 
  do 
  not 
  see 
  how 
  one 
  can 
  

   determine 
  what 
  species 
  are 
  included 
  in 
  a 
  genus, 
  where 
  no 
  

   species 
  at 
  all 
  are 
  mentioned, 
  unless, 
  indeed, 
  the 
  diagnosis 
  is 
  

   exceptionally 
  exact. 
  

  

  Leske 
  (1778, 
  Add. 
  ad 
  Klein) 
  groups 
  his 
  clypeastroid 
  

  

  * 
  Mortensen's 
  argument 
  (1907, 
  ' 
  Ingolf 
  ' 
  Ech. 
  pt. 
  2, 
  p. 
  38) 
  seems 
  to 
  me 
  

   sufficient 
  to 
  dispose 
  of 
  Lambert's 
  most 
  unwelcome 
  attempt 
  to 
  upset 
  the 
  

   hitherto 
  universally 
  accepted 
  usage 
  of 
  the 
  names 
  Echinocyamus 
  and 
  

   Fibularia. 
  But 
  personally 
  I 
  cannot 
  consider 
  Van 
  Phelsum 
  entitled 
  to 
  

   consideration 
  in 
  this 
  matter. 
  

  

  