﻿12 
  

  

  ON 
  THE 
  TAXONOMIC 
  POSITION 
  OF 
  ZEMIRA, 
  H. 
  & 
  A. 
  ADAMS. 
  

   By 
  the 
  llev. 
  A. 
  H. 
  Cooke, 
  Sc.D., 
  F.Z.S. 
  

  

  Read 
  8th 
  March, 
  1918. 
  

  

  The 
  subgenus 
  Zemira, 
  founded 
  by 
  H. 
  & 
  A. 
  Adams 
  in 
  1853 
  (Genera, 
  

   vol. 
  i, 
  p. 
  1 
  10), 
  for 
  the 
  reception 
  of 
  the 
  single 
  species 
  Zemira 
  australisy 
  

   Sowb., 
  has 
  long 
  been 
  a 
  waif 
  and 
  a 
  stray 
  in 
  the 
  waters 
  of 
  classification. 
  

   Its 
  career 
  was 
  stormy 
  from 
  the 
  first. 
  Kiener 
  (" 
  Iconographie," 
  

   Shurna, 
  1835, 
  p. 
  3), 
  taking 
  up 
  a 
  hint 
  of 
  Gray's 
  (" 
  Cancellaria 
  spirata, 
  

   secund. 
  D. 
  Gray," 
  Sowerby, 
  Concli. 
  lUust., 
  pt. 
  xx, 
  1833, 
  No. 
  8, 
  fig, 
  5)» 
  

   wildly 
  remarked 
  that 
  Sowerby's 
  Eburna 
  australis 
  as 
  figured 
  in 
  Conch. 
  

   Illust. 
  ought 
  to 
  remain 
  in 
  Cancellaria 
  where 
  Lamarck 
  had 
  placed 
  it, 
  

   as 
  it 
  united 
  all 
  the 
  characteristics 
  of 
  tliat 
  genus. 
  

  

  Kobelt 
  (Jahrb. 
  Malak. 
  Gesell., 
  vol. 
  vii, 
  1880. 
  p. 
  335, 
  pi. 
  vii, 
  figs. 
  5-8) 
  

   redescribed 
  the 
  species, 
  the 
  figures 
  of 
  Keeve 
  (Conch. 
  Icon., 
  vol. 
  v, 
  

   Ebiirna, 
  p. 
  4, 
  fig. 
  4) 
  and 
  Sowerby 
  (loc. 
  cit.) 
  being 
  from 
  worn 
  

   specimens. 
  He 
  first 
  figured 
  the 
  operculum, 
  and 
  concluded 
  that 
  the 
  

   species 
  was 
  a 
  genuine 
  Ehuriui., 
  but 
  that 
  the 
  subgenus 
  Zemira, 
  as 
  

   constituted 
  by 
  the 
  brothers 
  Adams 
  for 
  its 
  reception, 
  was 
  fully 
  

   justified. 
  

  

  Mr. 
  C. 
  Hedley 
  (Rec. 
  Austr. 
  Museum, 
  vol. 
  iii, 
  1897, 
  pp. 
  118-20, 
  

   "A 
  review 
  of 
  the 
  systematic 
  position 
  of 
  Zemira, 
  Adams") 
  gives 
  an 
  

   excellent 
  account 
  of 
  the 
  literary 
  and 
  scientific 
  wanderings 
  of 
  the 
  

   subgenus. 
  He 
  concludes 
  with 
  a 
  suggestion 
  of 
  his 
  own, 
  based 
  on 
  

   purely 
  conchological 
  grounds, 
  that 
  it 
  should 
  no 
  longer 
  be 
  placed 
  

   among 
  the 
  Rachiglossa, 
  but 
  rank 
  in 
  the 
  Struthiolariidas, 
  i.e. 
  among 
  

   the 
  Taenioglossa. 
  He 
  admits, 
  however, 
  that 
  " 
  though 
  the 
  operculum 
  

   of 
  Zemira, 
  as 
  figured 
  by 
  Kobelt, 
  does 
  not 
  well 
  agree 
  with 
  that 
  of 
  

   Eburna, 
  figured 
  by 
  Adams, 
  yet 
  it 
  does 
  not 
  answer 
  to 
  those 
  of 
  

   Struthiolaria, 
  figured 
  by 
  Graj' 
  or 
  Smith 
  ". 
  

  

  The 
  shell 
  of 
  Zemira, 
  in 
  spite 
  of 
  its 
  curious 
  spine, 
  and 
  the 
  groove 
  

   on 
  which 
  it 
  rests, 
  looks 
  certainly 
  very 
  like 
  an 
  Eburna, 
  or, 
  as 
  we 
  now 
  

   call 
  it, 
  Latrunculus. 
  In 
  Latruncuhis 
  there 
  are 
  at 
  least 
  two 
  types 
  

   of 
  operculum. 
  In 
  L. 
  spiratus. 
  Lam., 
  and 
  bornemsis, 
  Sowb., 
  it 
  is 
  

   thick, 
  massive, 
  and 
  the 
  nucleus 
  is 
  terminal 
  at 
  the 
  forward 
  end 
  ; 
  in 
  

   L. 
  valentinianus, 
  Swains., 
  it 
  is 
  thin, 
  while 
  the 
  nucleus 
  is 
  subcentral 
  

   on 
  the 
  columella 
  side. 
  In 
  Zemira 
  the 
  nucleus 
  is 
  subterminal, 
  but 
  the 
  

   special 
  feature 
  of 
  the 
  operculum 
  is 
  the 
  series 
  of 
  radiating 
  stria), 
  which 
  

   cross 
  the 
  lines 
  of 
  growth 
  and 
  give 
  the 
  surface 
  a 
  finely 
  tessellated 
  

   appearance. 
  

  

  The 
  radula 
  of 
  Latrunculus 
  shows 
  a 
  five-cusped 
  rhachidian 
  tooth, 
  the 
  

   three 
  central 
  cusps 
  being 
  long, 
  sharp, 
  and 
  very 
  thick, 
  while 
  the 
  two 
  

   outer 
  cusps 
  are 
  removed 
  from 
  the 
  others 
  and 
  are 
  much 
  thinner 
  and 
  

   shorter; 
  the 
  base-line 
  is 
  waved 
  and 
  produced 
  into 
  a 
  blunt 
  angle 
  at 
  

   the 
  ends; 
  the 
  laterals 
  are 
  bicuspid, 
  cusps 
  as 
  in 
  Alectrion, 
  hut 
  \erj 
  

   thick 
  and 
  solid 
  (japonicus. 
  Reeve). 
  

  

  In 
  Zemira 
  the 
  average 
  length 
  of 
  the 
  radula 
  is 
  74-5 
  rows. 
  The 
  

   rhachidian 
  tooth 
  shows 
  three 
  long 
  triangular 
  cusps 
  of 
  equal 
  size, 
  

  

  