﻿CLASSIFICATION, 
  ETC. 
  OP 
  HAMILTON 
  AND 
  CHEMUNG 
  SERIES 
  313 
  

  

  Tully 
  limestone 
  and 
  Genesee 
  slate, 
  fossils 
  are 
  comparatively 
  rare 
  

   in 
  it, 
  but 
  to 
  the 
  east 
  of 
  the 
  Chenango 
  valley 
  in 
  Otsego 
  and 
  Scho- 
  

   harie 
  counties 
  they 
  are 
  more 
  common 
  and 
  constitute 
  a 
  modified 
  

   Hamilton 
  fauna. 
  In 
  eastern 
  New 
  York 
  across 
  Greene 
  and 
  Ulster 
  

   counties 
  the 
  upper 
  part 
  of 
  the 
  flagstones 
  or 
  " 
  North 
  river 
  blue 
  

   stone 
  " 
  is 
  apparently 
  in 
  the 
  Sherburne 
  formation, 
  but 
  contains 
  

   scarcely 
  any 
  fossils 
  except 
  occasionally 
  a 
  few 
  species 
  of 
  plants. 
  

  

  5 
  Above 
  the 
  Sherburne 
  is 
  the 
  Ithaca 
  formation 
  which 
  has 
  a 
  

   thickness 
  of 
  500 
  feet 
  in 
  the 
  Chenango 
  valley 
  and 
  extends 
  from 
  the 
  

   vicinity 
  of 
  Keuka 
  lake 
  where 
  it 
  has 
  been 
  shown 
  by 
  Prof. 
  

   Clarke 
  that 
  the 
  " 
  Portage 
  or 
  Naples 
  fauna 
  prevails 
  largely 
  to 
  the 
  

   exclusion 
  of 
  representatives 
  of 
  the 
  Ithaca 
  fauna 
  " 
  a 
  eastward 
  

   across 
  Schuyler, 
  Tompkins, 
  Cortland, 
  Chenango, 
  Otsego 
  and 
  Scho- 
  

   harie 
  counties. 
  In 
  eastern 
  New 
  York 
  across 
  Albany, 
  Greene, 
  

   Ulster 
  and 
  Sullivan 
  counties 
  the 
  physical 
  conditions 
  which 
  ex- 
  

   isted 
  during 
  the 
  deposition 
  of 
  the 
  Oneonta 
  and 
  Catskill 
  forma- 
  

   tions 
  appear 
  to 
  have 
  also 
  prevailed 
  during 
  Ithaca 
  time 
  and 
  per- 
  

   haps 
  they 
  began 
  in 
  the 
  Sherburne, 
  so 
  that 
  there 
  is 
  very 
  little 
  

   evidence 
  of 
  the 
  Ithaca 
  fauna, 
  the 
  fossiliferous, 
  bluish 
  and 
  grayish 
  

   shales 
  of 
  the 
  more 
  western 
  counties 
  being 
  replaced 
  by 
  the 
  unfos- 
  

   siliferous 
  red 
  and 
  greenish 
  shales 
  and 
  sandstones. 
  In 
  Orange 
  

   county 
  and 
  northeastern 
  Pennsylvania 
  there 
  is 
  some 
  representa- 
  

   tion 
  of 
  the 
  Ithaca 
  fauna, 
  the 
  reds 
  appearing 
  later 
  as 
  one 
  follows 
  

   this 
  series 
  to 
  the 
  southwest. 
  Prof. 
  Clarke 
  has 
  clearly 
  shown 
  

   that 
  the 
  Ithaca 
  fauna 
  in 
  the 
  Chenango 
  valley 
  is 
  composed 
  of 
  " 
  a 
  

   more 
  abundant 
  representation 
  of 
  unmodified 
  Hamilton 
  species 
  " 
  

   than 
  in 
  the 
  Ithaca 
  region, 
  h 
  which 
  is 
  also 
  true 
  to 
  the 
  east 
  of 
  the 
  

   Chenango 
  valley 
  as 
  demonstrated 
  by 
  the 
  numerous 
  lists 
  of 
  fossils 
  

   given 
  in 
  this 
  report. 
  

  

  6 
  From 
  the 
  Chenango 
  valley 
  eastward 
  the 
  Ithaca 
  is 
  capped 
  

   by 
  the 
  Oneonta 
  formation 
  which 
  is 
  composed 
  of 
  red 
  and 
  green 
  

   shales, 
  reddish 
  sandstones 
  and 
  coarse 
  grained 
  grayish 
  to 
  greenish 
  

   gray 
  sandstones. 
  These 
  rocks 
  are 
  nearly 
  unfossiliferous, 
  con- 
  

   taining 
  only 
  an 
  occasional 
  specimen 
  of 
  Archaeopteris 
  and 
  Amni- 
  

  

  a 
  15th 
  an. 
  rep't 
  N. 
  Y. 
  state 
  geol.p. 
  SI 
  and 
  " 
  Geological 
  map 
  showing 
  the 
  distribution 
  of 
  the 
  Port- 
  

   age 
  group." 
  

   b 
  Ibid. 
  p. 
  46-63. 
  

  

  