﻿Vol. 
  53-] 
  

  

  OF 
  THE 
  CHALK 
  ROCK. 
  

  

  395 
  

  

  or 
  12 
  in 
  Bohemia. 
  So 
  far 
  as 
  I 
  know, 
  no 
  species 
  of 
  cephalopod, 
  with 
  

   the 
  exception 
  of 
  Nautilus 
  sublcevigatus, 
  d'Orb., 
  is 
  common 
  to 
  the 
  

   Chalk 
  Eock 
  and 
  the 
  Belgian 
  Cretaceous 
  beds. 
  

  

  The 
  palaeontological 
  characters 
  of 
  the 
  Reussianum-zone 
  as 
  seen 
  in 
  

   England 
  are 
  well 
  maintained 
  in 
  the 
  ' 
  Zone 
  of 
  Heteroceras 
  Reussia- 
  

   num 
  and 
  Sjpondylus 
  spinosus 
  ' 
  (Schliiter) 
  of 
  North-western 
  Germany. 
  

   This 
  is 
  especially 
  true 
  as 
  regards 
  the 
  cephalopoda, 
  which 
  have 
  been 
  

   so 
  carefully 
  described 
  by 
  Prof. 
  Schliiter 
  ; 
  the 
  gasteropoda 
  and 
  

   lamellibranchia, 
  however, 
  are 
  not 
  so 
  abundant 
  nor 
  so 
  well 
  preserved, 
  

   and 
  have 
  not 
  yet 
  been 
  studied 
  in 
  detail. 
  

  

  In 
  Saxony, 
  the 
  Planer- 
  Kalk 
  of 
  Strehlen 
  (near 
  Dresden) 
  contains 
  

   the 
  fauna 
  we 
  are 
  now 
  considering, 
  with, 
  perhaps, 
  that 
  of 
  part 
  of 
  a 
  

   lower 
  zone 
  also. 
  That 
  rock 
  can 
  no 
  longer 
  be 
  studied 
  at 
  Strehlen, 
  

   the 
  site 
  of 
  the 
  old 
  exposure 
  having 
  been 
  built 
  over. 
  The 
  fossils, 
  

   however, 
  have 
  been 
  fully 
  described 
  and 
  figured 
  in 
  Geinitz's 
  great 
  

   work, 
  ' 
  Das 
  Elbthalgebirge 
  in 
  Sachsen,' 
  and 
  the 
  originals 
  are 
  pre- 
  

   served 
  in 
  the 
  Dresden 
  Museum. 
  Even 
  allowing 
  for 
  the 
  possibility 
  

   that 
  the 
  Planer-Kalk 
  includes 
  a 
  little 
  more 
  than 
  the 
  Reussianum- 
  

   zone, 
  the 
  number 
  of 
  species 
  in 
  that 
  part 
  of 
  it 
  is 
  still 
  considerably 
  

   greater 
  than 
  in 
  the 
  same 
  zone 
  in 
  England. 
  This 
  is 
  indeed 
  what 
  

   we 
  should 
  expect 
  from 
  the 
  fact 
  that 
  the 
  Upper 
  Cretaceous 
  rocks 
  of 
  

   Saxony 
  were 
  deposited 
  in 
  shallower 
  water 
  and 
  much 
  nearer 
  the 
  

   shore-line 
  than 
  were 
  those 
  of 
  the 
  same 
  age 
  in 
  England. 
  The 
  greater 
  

   richness 
  of 
  the 
  fauna 
  is 
  seen 
  particularly 
  in 
  the 
  Lamellibranchia, 
  

   Gasteropoda, 
  and 
  Eishes 
  ; 
  of 
  these 
  three 
  groups 
  Geinitz 
  describes 
  

   about 
  50, 
  30, 
  and 
  28 
  species 
  respectively. 
  There 
  is 
  no 
  important 
  

   difference 
  in 
  the 
  number 
  of 
  forms 
  of 
  Cephalopoda, 
  Brachiopoda, 
  

   Echinoidea, 
  and 
  Actinozoa 
  in 
  the 
  two 
  countries 
  ; 
  but 
  in 
  the 
  Planer- 
  

   Kalk 
  the 
  Asteroidea, 
  Crinoidea, 
  and 
  Eeptilia, 
  which, 
  so 
  far 
  as 
  I 
  

   know 
  (with 
  the 
  exception 
  of 
  a 
  single 
  specimen 
  of 
  Pentacrinus), 
  are 
  

   not 
  found 
  in 
  the 
  Chalk 
  Eock 
  at 
  all, 
  are 
  each 
  represented 
  by 
  one 
  or 
  

   two 
  species. 
  

  

  The 
  genera 
  of 
  gasteropods 
  and 
  lamellibranchs 
  which 
  are 
  present 
  

   in 
  the 
  Planer-Kalk, 
  but 
  unknown 
  in 
  the 
  Chalk 
  Eock, 
  are 
  : 
  — 
  

  

  Patella. 
  

  

  Anomia. 
  

  

  Crassatella 
  

  

  JRissoa. 
  

  

  Glycimeris. 
  

  

  Venus. 
  

  

  Turritella. 
  

  

  Pinna. 
  

  

  Isocardia. 
  

  

  Actcpon. 
  

  

  Gervillia. 
  

  

  Eriphyla. 
  

  

  The 
  species 
  which 
  are 
  found 
  in 
  the 
  Chalk 
  Eock, 
  but 
  n 
  1 
  in 
  the 
  

  

  Planer-Kalk 
  of 
  Strehlen, 
  are 
  : 
  — 
  

  

  Ptychoceras 
  Smithi, 
  Woods. 
  

  

  Heteroceras 
  sp. 
  

  

  Emarginula 
  Sanctce- 
  Catharines, 
  Passy. 
  

  

  „ 
  aff. 
  divisiensis, 
  Gard. 
  

  

  Trochus 
  Schluteri, 
  Woods. 
  

  

  ,, 
  berocscirensis, 
  Woods. 
  

   Turbo 
  gemmatus. 
  Sow. 
  

  

  „ 
  Geinltzi, 
  Woods. 
  

   Cer 
  itlnum 
  cuckhamsliense, 
  Woods. 
  

  

  ,, 
  Saundersi, 
  Woods. 
  

   Aporrhais 
  (Lispodesthes) 
  Mantelli, 
  Gard. 
  

   Larnpusia 
  ? 
  sp. 
  

   Avellana 
  cf. 
  Humboldti, 
  Mull. 
  

  

  Bentalium 
  turoniense, 
  Woods. 
  

   Area 
  cf. 
  Galliennei, 
  d'Orb. 
  

   Limopsis, 
  sp. 
  

   Lima 
  granosa, 
  Sow. 
  

  

  ,, 
  {Acesta?) 
  subabrupta, 
  d'Orb. 
  

   Cardium 
  turoniense, 
  Woods. 
  

   „ 
  cf. 
  cenomanense, 
  d'Orb. 
  

   „ 
  cf. 
  Mailleanum, 
  d'Orb. 
  

   Cardita 
  cancellata, 
  Woods. 
  

   Arctica 
  ? 
  equisulcata, 
  Woods. 
  

   Trapezium 
  redangulare. 
  Woods. 
  

   Corbis'i 
  Morisoni, 
  Woods. 
  

   Martesia 
  ? 
  rotunda 
  (Sow.). 
  

  

  