﻿I02 
  NEW 
  YORK 
  STATE 
  MUSEUM 
  

  

  Spirifer 
  crispus 
  is 
  commonly 
  deficient 
  in 
  plications 
  

   approaching 
  in 
  this 
  respect 
  and 
  in 
  the 
  character 
  of 
  the 
  sinus, 
  

   S. 
  e 
  r 
  i 
  e 
  n 
  s 
  i 
  s 
  from 
  the 
  Manlius 
  limestone. 
  A 
  t 
  r 
  y 
  p 
  a 
  

   nodostriata 
  is 
  robust, 
  convex, 
  with 
  coarse 
  rounded 
  

   plications 
  and 
  rather 
  faint 
  concentric 
  striations, 
  characters 
  

   intermediate 
  between 
  A. 
  reticularis 
  of 
  the 
  Clinton 
  

   and 
  A. 
  nodostriata 
  of 
  the 
  Rochester 
  shale. 
  Besides 
  

   these 
  species 
  and 
  some 
  not 
  yet 
  identified, 
  the 
  following 
  

   occur. 
  

  

  Cephalopoda 
  

  

  26 
  Orthoceras 
  annu 
  latum 
  

  

  27 
  O. 
  m 
  e 
  d 
  u 
  1 
  1 
  a 
  r 
  e 
  (?) 
  rare 
  

  

  28 
  O. 
  sp. 
  

  

  Pelecypoda 
  

  

  29Modiolopsis 
  cf. 
  subalatus? 
  

  

  The 
  origin 
  of 
  these 
  lenses 
  is 
  still 
  obscure. 
  Many 
  of 
  the 
  fossils 
  

   found 
  in 
  them 
  are 
  characteristic 
  of 
  the 
  Niagara 
  group 
  of 
  the 
  west, 
  

   but 
  are 
  rare 
  or 
  wanting 
  in 
  the 
  Niagaran 
  of 
  New 
  York. 
  This 
  is 
  

   specially 
  the 
  case 
  with 
  the 
  trilobites 
  (Illaenus 
  ioxus) 
  and 
  

   the 
  cephalopoda. 
  Dr 
  E. 
  N. 
  S. 
  Ringueberg 
  many 
  years 
  ago 
  studied 
  

   these 
  limestone 
  masses 
  as 
  exposed 
  at 
  Lockport 
  and 
  other 
  more 
  

   eastern 
  localities, 
  and 
  he 
  termed 
  them 
  the 
  " 
  Niagara 
  transition 
  

   group 
  ".^ 
  He 
  found 
  in 
  this 
  rock 
  32 
  Niagara 
  species, 
  11 
  species 
  

   common 
  to 
  the 
  Clinton 
  and 
  Niagara, 
  two 
  species 
  found 
  otherwise 
  

   only 
  in 
  the 
  Clinton, 
  and 
  two 
  species 
  not 
  found 
  outside 
  of 
  this 
  rock. 
  

   The 
  origin 
  and 
  significance 
  of 
  these 
  unique 
  deposits 
  are 
  being 
  care- 
  

   fully 
  studied 
  by 
  the 
  state 
  paleontologist. 
  

  

  Rochester 
  shale 
  

  

  The 
  Rochester 
  (Niagara) 
  shale 
  has 
  a 
  total 
  thickness 
  of 
  about 
  68 
  

   feet 
  in 
  the 
  gorge 
  of 
  the 
  Niagara. 
  It 
  is 
  here 
  divisible 
  into 
  a 
  lower 
  

   and 
  an 
  upper 
  half. 
  The 
  lower 
  portion 
  is 
  a 
  highly 
  fossiliferous 
  shale 
  

   with 
  numerous 
  limestone 
  bands, 
  and 
  terminates 
  in 
  a 
  series 
  of 
  thin 
  

   calcareous 
  beds 
  with 
  shaly 
  partings 
  in 
  all 
  about 
  4 
  feet 
  thick, 
  and 
  

   extremely 
  rich 
  in 
  bryozoa. 
  The 
  upper 
  34 
  feet 
  are 
  quite 
  barren 
  and 
  

   have 
  few 
  limestone 
  layers. 
  

  

  'Am. 
  nat. 
  1882. 
  6:711-15. 
  

  

  