﻿CLASSIFICATION, 
  ETC. 
  OK 
  HAMILTON 
  AND 
  CHEMUNG 
  SERIES 
  213 
  

  

  the 
  same 
  as 
  that 
  described 
  in 
  Mr 
  Vanuxeni's 
  report, 
  in 
  which' 
  he 
  

   first 
  discovered 
  the 
  fossils 
  at 
  Mt 
  Upton 
  on 
  the 
  Unadilla. 
  The 
  

   discovery 
  of 
  this 
  stratum 
  (or 
  strata, 
  for 
  there 
  are 
  several) 
  at 
  

   Gilboa, 
  at 
  the 
  base 
  of 
  adjacent 
  mountains, 
  identifies 
  two 
  distant 
  

   series, 
  and 
  proves 
  their 
  equivalency 
  and 
  age. 
  . 
  . 
  It 
  has 
  been 
  

   said 
  that 
  the 
  rocks 
  of 
  Gilboa 
  belong 
  to 
  the 
  Hamilton 
  group, 
  

   and 
  as 
  fossils 
  closely 
  resembling 
  those 
  of 
  this 
  formation 
  were 
  dis- 
  

   covered 
  six 
  or 
  seven 
  hundred 
  feet 
  at 
  least 
  above 
  the 
  locality 
  on 
  

   the 
  Manorkill, 
  where 
  Devonian 
  fossils 
  had 
  been 
  found, 
  it 
  became 
  

   important 
  to 
  accumulate 
  as 
  many 
  facts 
  as 
  possible 
  which 
  would 
  

   bear 
  upon 
  the 
  question; 
  and 
  we 
  were 
  fortunate 
  enough 
  to 
  dis- 
  

   cover 
  the 
  remains 
  of 
  fish 
  in 
  the 
  strata 
  between 
  Prattsville 
  and 
  

   Gilboa, 
  and, 
  what 
  was 
  still 
  more 
  satisfactory 
  was 
  their 
  associa- 
  

   tion 
  with 
  the 
  Cypricardia 
  catskillensis 
  [Amnigenia 
  catshillemis 
  

   (Van.) 
  Hall] 
  discovered 
  by 
  Mr 
  Vanuxem, 
  on 
  the 
  Unadilla. 
  These 
  

   fossils 
  will 
  undoubtedly 
  be 
  found 
  quite 
  numerous 
  in 
  this 
  neigh- 
  

   borhood, 
  as* 
  we 
  observed 
  several 
  specimens 
  in 
  the 
  rock 
  two 
  miles 
  

   above 
  Prattsville, 
  on 
  the 
  banks 
  of 
  the 
  creek. 
  It 
  appears, 
  there- 
  

   fore, 
  that 
  it 
  has 
  a 
  wide 
  range 
  in 
  this 
  series, 
  and 
  may 
  be 
  regarded 
  

   as 
  characteristic 
  of 
  the 
  formation 
  in 
  which 
  it 
  is 
  found." 
  a 
  

  

  Darton 
  states 
  that 
  the 
  Oneonta 
  formation 
  " 
  begins 
  at 
  the 
  

   Manorkill 
  falls 
  and 
  extends 
  about 
  12 
  miles 
  southward 
  " 
  & 
  ; 
  while 
  

   on 
  the 
  Geologic 
  map 
  of 
  New 
  York 
  the 
  red 
  shales 
  in 
  the 
  gorge 
  above 
  

   the 
  highway 
  are 
  apparently 
  considered 
  as 
  marking 
  the 
  bottom 
  of 
  

   the 
  formation. 
  

  

  On 
  the 
  geological 
  map 
  accompanying 
  this 
  report 
  the 
  writer 
  has 
  

   accepted 
  for 
  the 
  base 
  of 
  the 
  Oneonta 
  formation 
  from 
  the 
  Schoharie 
  

   valley 
  eastward, 
  the 
  lowest 
  thick 
  beds 
  of 
  red 
  shales 
  and 
  sand- 
  

   stones 
  accompanied 
  by 
  coarse 
  greenish 
  gray 
  sandstones. 
  These 
  

   red 
  rocks 
  are 
  not 
  considered 
  as 
  marking 
  the 
  same 
  horizon 
  from 
  

   this 
  valley 
  eastward, 
  for 
  the 
  evidence 
  seems 
  to 
  the 
  writer 
  to 
  clearly 
  

   show 
  that 
  the 
  reds 
  appear 
  at 
  a 
  lower 
  horizon 
  as 
  they 
  are 
  followed 
  

   into 
  Albany 
  and 
  Greene 
  counties. 
  The 
  lowest 
  reds, 
  however, 
  seem 
  

   to 
  be 
  about 
  the 
  only 
  zone 
  that 
  can 
  be 
  followed 
  for 
  the 
  purpose 
  

  

  a 
  Agriculture 
  of 
  New 
  York, 
  1846, 
  1:195-96. 
  

   b 
  Ame-. 
  jour, 
  science, 
  3d 
  ser. 
  45:JJ06. 
  

  

  