﻿HUDSON 
  RIVER 
  BEDS 
  NEAR 
  ALBANY 
  539 
  

  

  while 
  an 
  investigation 
  of 
  the 
  rocks 
  to 
  the 
  east 
  of 
  the 
  Trenton 
  

   zone 
  has 
  furnished 
  ample 
  evidence 
  of 
  the 
  presence 
  of 
  the 
  

   Dicellograptus 
  zone. 
  

   The 
  following 
  stations 
  with 
  these 
  fossils 
  were 
  found: 
  

  

  Station 
  27. 
  Cahill's 
  hill, 
  south 
  Troy 
  

  

  Behind 
  the 
  Brothers's 
  quarry 
  outcrops 
  of 
  mostly 
  dark 
  shales 
  

   may 
  be 
  followed 
  up 
  almost 
  to 
  the 
  top 
  of 
  Cahill's 
  hill, 
  whence 
  a 
  

   small 
  gully 
  runs 
  north 
  into 
  the 
  Poesten 
  kill 
  in 
  upper 
  Spring 
  ave- 
  

   nue, 
  south 
  Troy 
  (station 
  27). 
  This 
  gully 
  furnishes 
  a 
  good 
  section. 
  

   In 
  its 
  upper 
  part 
  greenish 
  gray 
  argillaceous 
  shales, 
  farther 
  down 
  

   gray, 
  somewhat 
  sandy 
  shales, 
  and 
  at 
  the 
  bottom 
  softer, 
  black 
  

   argillaceous 
  shales 
  are 
  exposed. 
  The 
  last 
  contain 
  graptolites 
  in 
  

   a 
  fine 
  state 
  of 
  preservation; 
  besides 
  Corynoides 
  calicu- 
  

   1 
  a 
  r 
  i 
  s 
  and 
  a 
  narrow 
  Diplograptus 
  which 
  closely 
  ap- 
  

   proaches 
  D. 
  amplexicaulis; 
  well 
  developed 
  specimens 
  of 
  

   Diplograptus 
  folia 
  ceus 
  occur 
  in 
  fair 
  number. 
  The 
  

   combined 
  presence 
  of 
  these 
  indicates 
  the 
  transition 
  of 
  the 
  middle 
  

   Trenton 
  shale 
  of 
  station 
  24 
  into 
  another 
  zone. 
  

  

  Station 
  28. 
  Poesten 
  kill, 
  South 
  Troy 
  

  

  The 
  Trenton 
  shales 
  of 
  the 
  Brothers's 
  quarry 
  appear 
  again 
  across 
  

   the 
  Poesten 
  kill 
  in 
  Spring 
  avenue 
  in 
  a 
  small 
  road 
  metal 
  pit 
  be- 
  

   hind 
  the 
  northern 
  row 
  of 
  houses. 
  Going 
  from 
  here 
  200 
  yards 
  

   east, 
  along 
  the 
  north 
  bank 
  of 
  the 
  Poesten 
  kill, 
  just 
  above 
  Ruff's 
  

   canal 
  mills, 
  a 
  four 
  foot 
  sandstone 
  bed 
  is 
  met 
  with 
  to 
  the 
  left 
  

   of 
  the 
  road, 
  which 
  is 
  overlain 
  by 
  black, 
  strongly 
  carbonaceous, 
  

   argillaceous, 
  rather 
  thick 
  bedded 
  shales. 
  These 
  were 
  found 
  to 
  

   contain 
  graptolites 
  in 
  considerable 
  number 
  and 
  in 
  a 
  fair 
  state 
  

   of 
  preservation 
  (station 
  19). 
  There 
  were 
  observed: 
  

  

  Leptograptus 
  subtenuis, 
  Hall 
  sp. 
  

  

  Dicellograptus 
  intortus, 
  Gurlcij 
  

  

  D. 
  sextans, 
  Hall 
  sp. 
  

  

  Climacograptus 
  bicornis, 
  Hall 
  

  

  C. 
  parvus, 
  Hall 
  

  

  Diplograptus 
  foliaceus, 
  Mwchison 
  sp. 
  

  

  