﻿^°1' 
  53*] 
  THE 
  M( 
  5 
  LL1[JSCA 
  or 
  THE 
  chalk 
  K0CK. 
  377 
  

  

  :2S.^The 
  Mollusca 
  of 
  the 
  Chalk 
  Rock 
  : 
  Part 
  II. 
  By 
  Henry 
  Woods, 
  

   M.A., 
  F.G.S. 
  (Read 
  May 
  12th, 
  1897.) 
  

  

  [Plates 
  XXVII. 
  & 
  XXVIII.] 
  

  

  Contents. 
  

  

  Page 
  

  

  I. 
  Introduction 
  377 
  

  

  II. 
  Lamellibranchia 
  377 
  

  

  Nuculana. 
  Ostrea, 
  Cardita. 
  

  

  Nucula. 
  Chlamys. 
  Arctica. 
  

  

  Area. 
  Lima. 
  Trapezium. 
  

  

  Limo'psis. 
  Spondylus. 
  Corbis 
  ? 
  

  

  Modiola. 
  Plicatula. 
  Martesia 
  ? 
  

  

  Inoceramus. 
  Cardium. 
  Cuspidaria. 
  

  

  III. 
  Table 
  of 
  Distribution 
  of 
  the 
  Lamellibranchia 
  facing 
  394 
  

  

  IV. 
  Distribution 
  and 
  Relations 
  of 
  the 
  Fauna 
  394 
  

  

  V. 
  Conditions 
  under 
  which 
  the 
  Chalk 
  Eock 
  was 
  Deposited 
  398 
  

  

  I. 
  Introduction. 
  

  

  The 
  first 
  part 
  of 
  this 
  paper, 
  dealing 
  with 
  the 
  Cephalopoda, 
  Gastero- 
  

   poda, 
  and 
  Scaphopoda, 
  appeared 
  in 
  the 
  preceding 
  volume 
  of 
  this 
  

   Journal. 
  1 
  In 
  the 
  present 
  communication 
  I 
  propose 
  to 
  consider 
  the 
  

   Lamellibranchia, 
  and 
  to 
  discuss 
  the 
  relations 
  and 
  distribution 
  of 
  the 
  

   fauna 
  of 
  the 
  Chalk 
  Rock 
  and 
  the 
  conditions 
  under 
  which 
  that 
  fauna 
  

   lived. 
  

  

  The 
  Lamellibranchs 
  are 
  represented 
  by 
  a 
  larger 
  number 
  of 
  species 
  

   than 
  either 
  the 
  Cephalopoda 
  or 
  the 
  Gasteropoda, 
  but, 
  on 
  account 
  of 
  

   the 
  imperfect 
  manner 
  in 
  which 
  their 
  remains 
  are 
  preserved, 
  greater 
  

   difficulty 
  has 
  been 
  found 
  in 
  studying 
  them 
  than 
  was 
  the 
  case 
  with 
  

   the 
  groups 
  considered 
  in 
  Part 
  I. 
  Again, 
  there 
  is 
  evidence 
  of 
  the 
  

   existence 
  of 
  forms 
  other 
  than 
  those 
  herein 
  described, 
  but 
  the 
  speci- 
  

   mens 
  now 
  at 
  my 
  disposal 
  are 
  not 
  sufficiently 
  good 
  for 
  determination. 
  

   I 
  shall 
  hope, 
  after 
  more 
  collecting 
  has 
  been 
  done, 
  to 
  be 
  able 
  to 
  

   supplement 
  this 
  work, 
  and 
  shall 
  be 
  grateful 
  for 
  any 
  opportunity 
  of 
  

   examining 
  specimens 
  from 
  this 
  zone. 
  

  

  For 
  further 
  assistance 
  I 
  must 
  again 
  thank 
  the 
  gentlemen 
  men- 
  

   tioned 
  in 
  Part 
  I., 
  particularly 
  Mr. 
  Jukes-Browne, 
  Mr. 
  E. 
  T. 
  Newton, 
  

   Mr. 
  G. 
  C. 
  Crick, 
  and 
  Mr. 
  R. 
  M. 
  Brydone. 
  

  

  II. 
  Class 
  LAMELLIBRANCHIA. 
  

   Family 
  Nuculanidae, 
  Stoliczka. 
  

  

  Genus 
  Nuculana, 
  Link, 
  1807 
  

   \_ 
  = 
  Leda, 
  Schumacher, 
  1817]. 
  

   Nuculana 
  cf. 
  siliqua 
  (Goldfuss). 
  

  

  1837. 
  Nucula 
  siliqua, 
  A. 
  Goldfuss, 
  ' 
  Petref. 
  Germ.' 
  vol. 
  ii. 
  p. 
  156, 
  pi. 
  exxv. 
  f 
  . 
  13 
  ; 
  

   1846. 
  A. 
  E. 
  Reuss, 
  'Die 
  Verstein. 
  der 
  bohm. 
  Kreideformat.' 
  pt. 
  ii. 
  p. 
  7, 
  pi. 
  xxxiv. 
  

  

  1 
  Vol. 
  lii. 
  (1896) 
  pp. 
  68-98 
  & 
  pis. 
  ii-iv. 
  Correction 
  to 
  be 
  noted 
  there: 
  — 
  

   (pp. 
  88 
  et 
  seqq., 
  for 
  Trochus 
  berocscirense 
  read 
  Trochus 
  berocseirensts. 
  

  

  