﻿528 
  PROF. 
  F. 
  SCHMIDT 
  ON 
  THE 
  SILURIAN 
  STRATA 
  

  

  This 
  stage 
  is 
  doubtless 
  a 
  representative 
  of 
  the 
  typical 
  Wenlock 
  

   Limestone 
  of 
  England. 
  A 
  long 
  list 
  of 
  identical 
  fossils 
  might 
  be 
  ad- 
  

   duced 
  ; 
  for 
  instance, 
  Ortlioceras 
  annulatum, 
  Sow., 
  0. 
  canaliculatum, 
  

   Sow., 
  Euomplialus 
  funatus, 
  Sow., 
  sculptus, 
  Sow., 
  cliscors, 
  Sow., 
  

   Turbo 
  striatus, 
  Sow., 
  Spirifer 
  cyrtcena, 
  Dalm. 
  (radiatus, 
  Sow.), 
  S. 
  

   crispus, 
  Dalm., 
  Orthis 
  rustica, 
  Sow., 
  0. 
  elegantida, 
  Sow., 
  Leptcena 
  

   transversalis, 
  Sow., 
  Cornulites 
  serpidarius, 
  Schl., 
  and 
  the 
  common 
  

   Trilobites 
  and 
  corals. 
  In 
  the 
  Swedish 
  island 
  of 
  Gothland 
  the 
  cor- 
  

   responding 
  stage 
  is 
  the 
  upper 
  part 
  of 
  the 
  Middle 
  Gothland 
  zone, 
  and 
  

   in 
  Norway 
  the 
  stage 
  7 
  of 
  Kjeralf. 
  In 
  America, 
  as 
  is 
  well 
  known, 
  

   the 
  Niagara 
  Limestone 
  is 
  the 
  equivalent. 
  In 
  our 
  stage 
  I, 
  dolomites 
  

   prevail, 
  and 
  so 
  we 
  do 
  not 
  possess 
  so 
  many 
  good 
  localities 
  for 
  collecting 
  

   fossils 
  as 
  in 
  Gothland. 
  The 
  best 
  locality 
  with 
  us 
  is 
  St. 
  Johannis, 
  on 
  

   the 
  north 
  shore 
  of 
  Oesel. 
  The 
  thickness 
  of 
  the 
  stage 
  may 
  attain 
  

   60 
  feet. 
  

  

  Stage 
  K, 
  or 
  Upper 
  Oesel 
  Zone. 
  

  

  The 
  stage 
  K 
  can 
  as 
  easily 
  be 
  correlated 
  with 
  the 
  Ludlow 
  group 
  of 
  

   England 
  as 
  the 
  stage 
  I 
  with 
  the 
  Wenlock. 
  It 
  occupies 
  the 
  southern 
  

   and 
  western 
  part 
  of 
  the 
  island 
  of 
  Oesel, 
  and 
  may 
  attain 
  a 
  thickness 
  

   of 
  perhaps 
  50-60 
  feet. 
  Within 
  its 
  limits 
  can 
  be 
  distinguished 
  two 
  

   different 
  contemporaneous 
  facies 
  passing 
  over 
  into 
  each 
  other. 
  On 
  

   the 
  south 
  coast, 
  and 
  on 
  the 
  peninsula 
  of 
  Sworbe 
  (the 
  Kangatoma 
  and 
  

   Ohhesaare 
  Pank), 
  grey 
  limestones 
  and 
  marls 
  predominate, 
  with 
  

   Spirifer 
  elevatus, 
  His., 
  Atrypa 
  prunum, 
  His., 
  Retzia 
  Salteri, 
  Dav., 
  

   Rhynchonella 
  nucula, 
  Sow., 
  Chonetes 
  striatella, 
  Dalm., 
  Beyrichiatu- 
  

   berculata, 
  Klod., 
  B. 
  Wfflcinsiana, 
  Jones, 
  and 
  quantities 
  of 
  a 
  large 
  form 
  

   of 
  Ptilodictya 
  lanceolata, 
  Lonsd., 
  and 
  several 
  Tentacidites 
  (inceqnalis, 
  

   Eichw., 
  and 
  curvatus, 
  Boll). 
  The 
  large 
  Pterinea 
  retrofleoca 
  and 
  reticu- 
  

   lata 
  and 
  Grammysia 
  cingulata, 
  His., 
  are 
  also 
  common 
  in 
  some 
  places. 
  

   In 
  Sworbe 
  there 
  are 
  also 
  found 
  numerous 
  specimens 
  of 
  Onchus, 
  and 
  

   small 
  scales 
  of 
  Pachylepis, 
  Pand. 
  (nearly 
  the 
  same 
  as 
  Thelodus 
  

   parvidens, 
  Sil. 
  Syst.). 
  All 
  the 
  fish-remains 
  were 
  described 
  in 
  1856 
  

   by 
  the 
  late 
  M. 
  Chr. 
  Pander. 
  

  

  To 
  the 
  north-west 
  of 
  Arensburg, 
  in 
  the 
  interior, 
  and 
  on 
  the 
  western 
  

   shore 
  of 
  the 
  island, 
  the 
  other 
  facies 
  is 
  developed, 
  yellow 
  limestones 
  

   with 
  Leperditia 
  phaseol 
  us, 
  His., 
  Ortlioceras 
  imbricatum, 
  Wahl., 
  Spi- 
  

   nigera 
  didyma, 
  Dalm., 
  Chonetes 
  striatella, 
  Dalm., 
  Murchisonia 
  cin- 
  

   gidata, 
  His., 
  Lucina 
  prisca, 
  His., 
  Goniophora 
  cymbceformis, 
  His., 
  

   Syringopora 
  reticulata, 
  His., 
  and 
  others. 
  These 
  yellow 
  beds 
  repose 
  

   on 
  dolomitic 
  flagstones, 
  in 
  most 
  places 
  entirely 
  devoid 
  of 
  fossils, 
  but 
  

   furnishing 
  near 
  the 
  west 
  coast 
  of 
  Oesel, 
  at 
  Rotzikiill, 
  a 
  highly 
  inter- 
  

   esting 
  Eurypterid 
  fauna, 
  exactly 
  corresponding 
  to 
  that 
  of 
  the 
  famous 
  

   British 
  locality 
  of 
  Lesmahago 
  and 
  the 
  American 
  Waterlime 
  

   group. 
  I 
  am 
  now 
  preparing 
  a 
  detailed 
  description 
  of 
  the 
  fossil 
  

   crustaceans 
  of 
  this 
  locality, 
  and 
  may 
  mention 
  here 
  the 
  results 
  of 
  

   my 
  latest 
  inquiries. 
  The 
  most 
  frequent 
  fossil 
  is 
  Eurypterus 
  

   Fischeri, 
  Eichw. 
  (formerly 
  called 
  E. 
  remipes, 
  Dek., 
  by 
  Dr. 
  Nieszkow- 
  

   ski). 
  I 
  believe 
  that 
  nowhere 
  can 
  be 
  found 
  such 
  abundant 
  and 
  such 
  

   completely 
  preserved 
  specimens 
  of 
  this 
  interesting 
  genus. 
  I 
  have 
  

  

  