﻿CLASSIFICATION, 
  ETC. 
  OP 
  HAMILTON 
  AND 
  CHEMUNG 
  SERIES 
  253 
  

  

  stonville 
  where 
  lower 
  rocks 
  occur. 
  Again 
  below 
  Cooksburg 
  in 
  

   the 
  northern 
  part 
  of 
  Durham 
  township, 
  Greene 
  co. 
  for 
  a 
  few 
  

   miles 
  the 
  creek 
  has 
  cut 
  through 
  the 
  Oneonta 
  formation 
  and 
  shows 
  

   along 
  its 
  valley 
  the 
  rocks 
  of 
  the 
  underlying 
  Sherburne 
  formation. 
  

  

  XXX 
  C. 
  The 
  ridge 
  to 
  the 
  east 
  of 
  Rensselaerville 
  ends 
  in 
  an 
  ab- 
  

   rupt 
  slope 
  facing 
  the 
  valley 
  of 
  the 
  Switzkill 
  about 
  one 
  and 
  one 
  

   third 
  miles 
  directly 
  northeast 
  of 
  the 
  village. 
  At 
  the 
  base 
  of 
  the 
  

   hill 
  is 
  a 
  small 
  quarry 
  showing 
  some 
  six 
  to 
  eight 
  feet 
  of 
  blue 
  flag- 
  

   ging 
  stone 
  covered 
  by 
  blue 
  argillaceous 
  shales 
  in 
  which 
  Hamilton 
  

   fossils 
  are 
  common. 
  These 
  shales 
  in 
  lithologic 
  characters 
  are 
  

   very 
  similar 
  to 
  the 
  typical 
  Hamilton 
  and 
  the 
  exposure 
  is 
  in 
  this 
  

   formation 
  though 
  near 
  its 
  top. 
  The 
  following 
  species 
  were 
  

   collected 
  and 
  it 
  will 
  be 
  seen 
  that 
  the 
  fauna 
  is 
  very 
  similar 
  to 
  

   that 
  of 
  the 
  shales 
  in 
  the 
  Agrippa 
  quarry 
  (55C 
  5 
  ) 
  near 
  the 
  top 
  of 
  

   Agrippa 
  hill. 
  It 
  is 
  probable 
  that 
  both 
  exposures 
  are 
  in 
  the 
  same 
  

   general 
  zone 
  of 
  the 
  Hamilton 
  formation 
  : 
  

  

  1 
  Prodiwtella 
  dumosa 
  Hall 
  (a) 
  

  

  2 
  Spirifer 
  mucronatus 
  (Con.) 
  Bill. 
  (c) 
  

  

  3 
  S. 
  granulosus 
  (Con.) 
  H. 
  & 
  C. 
  (c) 
  

  

  4 
  S. 
  audaculus 
  (Con.) 
  Whitfield 
  (rr) 
  

  

  5 
  Tropidoleptus 
  carinatus 
  (Con.) 
  Hall 
  (c) 
  

  

  6 
  Camarotoechia 
  prolifica 
  (Hall) 
  H. 
  & 
  C. 
  . 
  (r) 
  

  

  7 
  CJionetes 
  mucronata 
  Hall 
  (rr) 
  

  

  8 
  OrtJiothetes 
  chemungensis 
  (Con.) 
  H. 
  & 
  C. 
  

  

  var. 
  arctostriata 
  Hall 
  • 
  (rr) 
  

  

  9 
  Nyassa 
  arguta 
  Hall 
  (r) 
  

  

  10 
  Nucula 
  corbuliformis 
  Hall 
  (a) 
  

  

  11 
  Tellinopsis 
  subemarginata 
  (Con.) 
  Hall 
  (r) 
  

  

  12 
  Palaeoneilo 
  perplana 
  Hall 
  (rr) 
  

  

  13 
  Sphenotus 
  solenoides 
  Hall 
  (rr) 
  

  

  14 
  Grammy 
  sia 
  alveata 
  (Con.) 
  Hall 
  (rr) 
  

  

  15 
  G. 
  circularis 
  Hall 
  , 
  (r) 
  

  

  16 
  Paracyclas 
  tenuis 
  Hall 
  (?) 
  (rr) 
  

  

  17 
  Glyptodesma 
  erectum 
  (Con.) 
  Hall 
  (c) 
  

  

  18 
  Aviculopecten 
  fasciculatus 
  Hall 
  (?) 
  (a) 
  

  

  19 
  Pterinea 
  flabella 
  (Con.) 
  Hall 
  (r) 
  

  

  