﻿214 
  PEOCEEDINGS 
  OF 
  THE 
  MALACOLOGICAL 
  SOCIETY. 
  

  

  ON 
  FETRICOLA, 
  LUCINOPSIS, 
  AND 
  THE 
  FAMILY 
  PETRICOLID^. 
  

  

  By 
  A. 
  J. 
  Jukes-Beowne, 
  F.B.S., 
  F.G.S. 
  

  

  Bead 
  10th 
  June, 
  1910. 
  

  

  Contents. 
  

  

  1. 
  Nomenclature 
  and 
  generic 
  types. 
  

  

  2. 
  Description 
  of 
  the 
  shells. 
  

  

  3. 
  Description 
  of 
  the 
  animals. 
  

  

  4. 
  Conclusions. 
  

  

  1. 
  Nomenclatuee 
  and 
  Geneeic 
  Types. 
  

  

  Before 
  1853 
  the 
  genus 
  Petricola 
  was 
  included 
  in 
  a 
  family 
  which 
  

   was 
  generally 
  known 
  as 
  Lithophaga, 
  though 
  the 
  group 
  was 
  called 
  

   Petricolidse 
  by 
  d'Orbigny 
  in 
  1837.^ 
  This 
  family 
  comprised 
  Saxicava 
  

   and 
  Venerupis 
  as 
  well 
  as 
  Petricola. 
  Gray 
  was 
  the 
  first 
  to 
  restrict 
  

   the 
  Petricolidse 
  ^ 
  and 
  to 
  separate 
  Saxicava 
  and 
  Venerupis 
  from 
  it, 
  

   and 
  he 
  recognized 
  two 
  genera, 
  Petricola 
  (Lam.) 
  and 
  Naranio 
  (Gray). 
  

   In 
  the 
  same 
  year 
  the 
  family 
  was 
  adopted 
  by 
  Deshayes,^ 
  but 
  in 
  the 
  

   second 
  part 
  of 
  his 
  Catalogue 
  (1854) 
  he 
  added 
  a 
  third 
  genus 
  

   [Lajoiihairea 
  ^), 
  then 
  first 
  proposed 
  for 
  the 
  shells 
  previously 
  known 
  as 
  

   Venerupis 
  clecussata, 
  Phil., 
  and 
  V. 
  suhstriata, 
  Mont. 
  

  

  S. 
  P. 
  Woodward 
  in 
  his 
  Manual 
  of 
  the 
  Mollusca 
  (1855) 
  regarded 
  

   Petricola 
  as 
  a 
  member 
  of 
  the 
  Veneridse 
  and 
  not 
  as 
  the 
  type 
  of 
  a 
  new 
  

   family, 
  but 
  the 
  Messrs. 
  Adams 
  (1857) 
  adopted 
  Gray's 
  arrangement, 
  

   except 
  that 
  they 
  substituted 
  Choristodon 
  (Jonas) 
  for 
  his 
  Naranio^ 
  and 
  

   did 
  not 
  recognize 
  Lajonliairia. 
  

  

  From 
  that 
  date 
  to 
  the 
  present 
  the 
  Petricolidse 
  have 
  been 
  generally 
  

   recognized 
  as 
  a 
  distinct 
  family, 
  the 
  only 
  further 
  separation 
  being 
  that 
  

   of 
  a 
  sub-genus 
  Petricolaria 
  for 
  certain 
  elongate 
  species. 
  Dr. 
  Dall, 
  

   however, 
  regards 
  a 
  group 
  of 
  shells, 
  separated 
  from 
  Venerupis 
  by 
  

   P. 
  Pischer 
  in 
  1887^ 
  under 
  the 
  name 
  of 
  Claudiconcha, 
  as 
  a 
  section 
  or 
  

   sub-genus 
  of 
  Petricola.^ 
  

  

  In 
  the 
  following 
  pages 
  I 
  shall 
  endeavour 
  to 
  show 
  that 
  Lucinopsis 
  

   (Forb. 
  & 
  Hani.) 
  ought 
  also 
  to 
  be 
  included 
  in 
  this 
  family 
  Petricolidae, 
  

   notwithstanding 
  the 
  different 
  shape 
  of 
  the 
  shell 
  and 
  the 
  habits 
  of 
  the 
  

   animal. 
  

  

  With 
  regard 
  to 
  Lajonhairea 
  the 
  views 
  which 
  different 
  authors 
  have 
  

   taken 
  are 
  both 
  curious 
  and 
  interesting. 
  Searles 
  Wood 
  regarded 
  the 
  

   fossil 
  form 
  from 
  the 
  Coralline 
  Crag 
  as 
  a 
  species 
  of 
  Limnopsis, 
  assuming 
  

   its 
  inclusion 
  in 
  that 
  genus 
  without 
  any 
  discussion 
  of 
  its 
  special 
  

   characteristics.'' 
  Gray 
  & 
  Deshayes 
  made 
  it 
  a 
  genus 
  of 
  Petricolidae, 
  

  

  ^ 
  Moll. 
  rec. 
  mix 
  lien 
  Canaries 
  (1837), 
  p. 
  109. 
  

  

  2 
  Ann. 
  Mag. 
  Nat. 
  Hist., 
  vol. 
  xi, 
  p. 
  38, 
  1853. 
  

  

  3 
  Cat. 
  Bivalve 
  Shells 
  Erit. 
  Mus., 
  pt. 
  i, 
  p. 
  205, 
  1853. 
  

  

  * 
  Deshayes 
  spelt 
  it 
  Lajonkairia, 
  but, 
  being 
  derived 
  from 
  M. 
  de 
  la 
  Jonkaire, 
  under 
  

  

  international 
  rules 
  it 
  should 
  be 
  written 
  as 
  Lajonkairea. 
  

   ^ 
  Manuel 
  de 
  Conchyliologie, 
  p. 
  1087. 
  

  

  ■ 
  Trans. 
  "Wagner 
  Free 
  Inst. 
  Sc, 
  vol. 
  iii, 
  pt. 
  v, 
  p. 
  1057, 
  1900. 
  

   ' 
  The 
  Crag 
  Mollusca, 
  vol. 
  ii, 
  p. 
  148 
  : 
  Pal. 
  Soc., 
  1853. 
  

  

  