﻿72 
  NEW 
  YORK 
  STATE 
  MUSEUM 
  

  

  tlie 
  Ithaca 
  and 
  Oneonta 
  formations 
  are 
  no 
  more 
  reliable 
  than 
  the 
  

   massive 
  greenish 
  gray 
  sandstones, 
  for 
  they 
  also 
  appear 
  at 
  lower 
  

   and 
  lower 
  horizons 
  as 
  the 
  Chemung 
  series 
  is 
  followed 
  eastward. 
  

   It 
  is 
  evident, 
  however, 
  that 
  in 
  the 
  vicinity 
  of 
  Oneonta, 
  Vahuxem, 
  

   who 
  named 
  the 
  formation, 
  referred 
  these 
  lowest 
  massive 
  greenish 
  

   gray 
  sandstones 
  to 
  it, 
  for 
  he 
  mentions 
  their 
  crossbedded 
  structure 
  

   and 
  gives 
  as 
  an 
  example 
  the 
  ledges 
  near 
  the 
  top 
  of 
  the 
  hill 
  below 
  

   Oneonta,^ 
  which 
  is 
  the 
  continuation, 
  down 
  the 
  river, 
  of 
  the 
  zone 
  

   just 
  described. 
  

  

  XXIII 
  C 
  1 
  . 
  Along 
  the 
  highway 
  that 
  turns 
  up 
  the 
  valley 
  of 
  the 
  

   brook 
  to 
  the 
  north 
  of 
  the 
  river 
  road 
  about 
  one 
  and 
  a 
  half 
  miles 
  

   northeast 
  of 
  Oneonta 
  are 
  exposures 
  of 
  argillaceous 
  and 
  very 
  thin 
  

   sandstones. 
  Some 
  of 
  the 
  shales 
  are 
  greatly 
  iron-stained. 
  Toward 
  

   the 
  top 
  of 
  the 
  hill 
  which 
  is 
  covered 
  by 
  the 
  Oneonta 
  formation 
  the 
  

   rocks 
  are 
  largely 
  hidden 
  by 
  the 
  drift. 
  The 
  shales 
  of 
  C 
  1 
  along 
  the 
  

   highway 
  are 
  quite 
  fossiliferous 
  and 
  belong 
  in 
  the 
  Ithaca 
  forma- 
  

   tion. 
  The 
  list 
  is 
  : 
  

  

  1 
  Spirifer 
  mesastrialis 
  Hall 
  (c) 
  

  

  2 
  S. 
  mesacostalis 
  Hall 
  (a) 
  

  

  3 
  S. 
  mucronatus 
  (Con.) 
  Bill. 
  (r) 
  

  

  4 
  Tropidoleptus 
  carinatus 
  (Con.) 
  Hall 
  (rr) 
  

  

  5 
  Chonetes 
  scitula 
  Hall 
  (r) 
  

  

  6 
  Camarotoechia 
  ewimia 
  (Hall) 
  H. 
  & 
  C. 
  (c) 
  

  

  7 
  Gyrtina 
  hamiltonensis 
  Hall 
  ' 
  (rr) 
  

  

  8 
  Leda 
  diversa 
  Hall 
  (r) 
  

  

  9 
  Paracyclas 
  Mr 
  at 
  a 
  (Con.) 
  Hall 
  (rr) 
  

  

  10 
  Niicula 
  cf. 
  bellistriata 
  (Con.) 
  Hall 
  (c) 
  

  

  Small 
  and 
  poorly 
  preserved. 
  

  

  1 
  1 
  Palaeoneilo 
  cf 
  . 
  muta 
  Hall 
  (rr) 
  

  

  12 
  Nuculites 
  cuneiformis 
  Con. 
  (rr) 
  

  

  13 
  Modiomorpha 
  cf. 
  subalata 
  (Con.) 
  Hall 
  (rr) 
  

  

  var. 
  chemungerms 
  Hall 
  

  

  This 
  is 
  a 
  more 
  elongated 
  specimen 
  than 
  any 
  figured 
  and 
  in 
  

   this 
  respect 
  agrees 
  with 
  other 
  specimens 
  seen 
  in 
  the 
  

   Ithaca 
  formation 
  in 
  the 
  eastern 
  counties. 
  

  

  14 
  Gonioplwra 
  carinata 
  (Con.) 
  Hall 
  (rr) 
  

  

  15 
  Pleumtomaria 
  sulcomarginata 
  Con. 
  (rr) 
  

  

  a 
  Geology 
  of 
  New 
  York. 
  1842, 
  pt 
  3, 
  p. 
  1S7. 
  

  

  