﻿HUDSON 
  RIVER 
  BEDS 
  NEAR 
  ALBANY 
  547 
  

  

  One 
  fossil 
  of 
  the 
  Rysedorph 
  hill 
  fauna 
  deserves 
  special 
  notice 
  

   in 
  this 
  place. 
  It 
  is 
  a 
  small 
  graptolite, 
  several 
  specimens 
  of 
  which 
  

   were 
  found 
  in 
  an 
  exquisite, 
  uncompressed 
  state 
  of 
  preservation 
  

   in 
  a 
  small, 
  dark 
  gray 
  limestone 
  pebble 
  which 
  within 
  a 
  cubic 
  inch 
  

   contained, 
  besides 
  the 
  graptolites, 
  a 
  cranidium 
  of 
  A 
  m 
  p 
  y 
  x 
  h 
  a 
  s 
  - 
  

   t 
  a 
  t 
  u 
  s 
  , 
  a 
  cephalon 
  of 
  Pterygometopus 
  calli- 
  

   cephalus, 
  Plectambonites 
  aff 
  . 
  g 
  i 
  b 
  b 
  o 
  s 
  a 
  and 
  a 
  

   Callopora 
  {see 
  pi. 
  1, 
  fig. 
  1). 
  The 
  graptolite 
  is 
  a 
  C 
  li 
  ma- 
  

   cog 
  r 
  a 
  p 
  t 
  u 
  s 
  . 
  A 
  careful 
  comparison 
  of 
  it 
  with 
  all 
  the 
  spe- 
  

   cies 
  of 
  CHmacograptus 
  obtained 
  so 
  far 
  from 
  the 
  Nor- 
  

   mans 
  kill 
  and 
  Utica 
  shales 
  of 
  New 
  York 
  shows 
  its 
  absolute 
  iden- 
  

   tity 
  with 
  a 
  form 
  which 
  is 
  quite 
  common 
  in 
  the 
  Normans 
  kill 
  

   shale 
  of 
  Mt 
  Moreno 
  near 
  Hudson. 
  It 
  differs 
  from 
  all 
  other 
  spe- 
  

   cies 
  of 
  Climacograptus 
  by 
  its 
  strong 
  sculpture 
  and 
  

   specially 
  by 
  the 
  characteristic 
  deep, 
  strongly 
  zigzag 
  groove 
  

   along 
  the 
  median 
  line 
  of 
  the 
  rhabdosome. 
  This 
  is 
  a 
  character- 
  

   istic 
  feature 
  of 
  Climacogr 
  a 
  p 
  t 
  u 
  is 
  s 
  c 
  h 
  a 
  r 
  e 
  n 
  b 
  e 
  r 
  g 
  i 
  Lap- 
  

   worth, 
  with 
  which 
  it 
  also 
  agrees 
  in 
  the 
  rectangular 
  outline 
  of 
  

   the 
  thecae 
  and 
  apparent 
  absence 
  of 
  appendages. 
  01. 
  scha 
  r 
  en- 
  

   be 
  r 
  g 
  i 
  has 
  been 
  reported 
  before 
  by 
  Lapworth 
  and 
  Gurley 
  from 
  

   the 
  lower 
  and 
  upper 
  Dicellograptus 
  zones 
  (the 
  former=Normans 
  

   kill 
  zone) 
  of 
  Canada. 
  It 
  does 
  not 
  rise 
  into 
  the 
  Utica 
  and 
  Lor- 
  

   raine 
  beds. 
  Its 
  association 
  at 
  Rysedorph 
  hill 
  with 
  a 
  peculiar 
  

   lower 
  Trenton 
  fauna, 
  is, 
  hence, 
  a 
  strong 
  argument 
  in 
  favor 
  of 
  

   the 
  lower 
  Trenton 
  age 
  of 
  the 
  Normans 
  kill 
  shale. 
  

  

  In 
  Europe 
  this 
  graptolite 
  occurs 
  at 
  even 
  deeper 
  horizons; 
  for 
  

   Roemer 
  (54:612) 
  collected 
  it 
  in 
  the 
  Phyllograptus 
  shales 
  near 
  

   Christiania, 
  and 
  Tullberg 
  reports 
  it 
  from 
  the 
  horizons 
  with 
  

   Didymograptus 
  geminus 
  and 
  Diplograptus 
  

   putillus, 
  which, 
  in 
  Scania, 
  lie 
  below 
  the 
  Coenograptus 
  

   gracilis 
  zone 
  (=lower 
  Dicellograptus 
  zone). 
  In 
  Scotland 
  it 
  oc- 
  

   curs 
  in 
  the 
  corresponding 
  Glenkiln 
  shales, 
  which 
  also 
  lie 
  deeper 
  

   than 
  the 
  zone 
  with 
  Coenograptus 
  gracilis 
  which 
  forms 
  

   the 
  base 
  of 
  the 
  Moffat 
  beds. 
  

  

  The 
  beds 
  on 
  Rysedorph 
  hill 
  which 
  outcrop 
  at 
  the 
  fault 
  be- 
  

   tween 
  the 
  Normans 
  kill 
  shales 
  and 
  the 
  Cambrian 
  slates 
  repre- 
  

  

  