﻿694 
  NEW 
  YORK 
  STATE 
  MUSEUM 
  

  

  penetrate 
  the 
  clay, 
  absorbing 
  water 
  from 
  it 
  and 
  rejecting 
  the 
  

   contained 
  lime, 
  which 
  deposits 
  itself 
  around 
  the 
  root 
  forming 
  the 
  

   hard 
  rhizomorph. 
  Their 
  interior 
  structure 
  is 
  crystalline. 
  

  

  Another 
  form 
  of 
  concretion 
  is 
  found 
  in 
  the 
  delta 
  sands 
  at 
  Croton 
  

   point. 
  It 
  consists 
  of 
  botryoidal 
  masses 
  of 
  sand, 
  cemented 
  by 
  oxid 
  

   of 
  iron. 
  Some 
  of 
  them 
  show 
  the 
  layers 
  of 
  deposition 
  of 
  the 
  sand. 
  

   The 
  concretions 
  are 
  usually 
  small, 
  but 
  one 
  mass 
  was 
  noticed 
  fully 
  

   6 
  feet 
  long 
  and 
  4 
  feet 
  wide. 
  

  

  Concerning 
  the 
  origin 
  of 
  these 
  concretions 
  various 
  opinions 
  are 
  

   expressed 
  by 
  different 
  geologists. 
  

  

  Organic 
  remains 
  are 
  extremely 
  rare 
  in 
  these 
  clays. 
  The 
  

   writer 
  has 
  discovered 
  sponge 
  spicules, 
  probably 
  referable 
  to 
  

   H 
  y 
  a 
  1 
  o 
  n 
  e 
  m 
  a 
  or 
  an 
  allied 
  genus, 
  and 
  which 
  are 
  figured. 
  The 
  

   following 
  diatoms 
  were 
  also 
  found 
  : 
  [NTavicula 
  Gruendleri 
  

   A. 
  S. 
  ; 
  Navicula 
  permagna, 
  Edw. 
  (fragments) 
  ; 
  M 
  e 
  1 
  o 
  - 
  

   sira 
  granulata 
  (Ehr.) 
  Ralfs; 
  I^itzshia 
  granulata 
  

   Grun., 
  all 
  fresh 
  water 
  species. 
  At 
  01*0 
  ton 
  landing 
  a 
  number 
  of 
  

   impressions 
  were 
  found 
  in 
  the 
  blue 
  clay 
  and 
  on 
  being 
  submitted 
  

   to 
  Prof. 
  Hall 
  were 
  pronounced 
  to 
  be 
  worm 
  tracks. 
  Mather 
  in 
  his 
  

   report"^ 
  mentions 
  the 
  finding 
  of 
  leaves 
  in 
  the 
  clay 
  beds 
  back 
  of 
  the 
  

   medical 
  college 
  at 
  Albany, 
  and 
  states 
  that 
  they 
  resemble 
  those 
  of 
  

   an 
  aquatic 
  plant. 
  

  

  Clays 
  of 
  the 
  Champlain 
  valley^ 
  

  

  The 
  clays 
  of 
  the 
  Champlain 
  valley 
  are 
  estuary 
  formations 
  of 
  

   the 
  same 
  age 
  as 
  the 
  Hudson 
  river 
  clays. 
  They 
  underlie 
  terraces 
  

   along 
  the 
  lake 
  which 
  have 
  been 
  elevated 
  to 
  a 
  hight 
  of 
  393 
  feet 
  

   above 
  sea 
  level. 
  These 
  terraces 
  may 
  be 
  traced 
  almost 
  continu- 
  

   ously 
  from 
  Whitehall, 
  at 
  the 
  head 
  of 
  Lake 
  Champlain, 
  to 
  the 
  

   northern 
  end 
  of 
  the 
  lake 
  and 
  beyond 
  it, 
  but 
  on 
  account 
  of 
  the 
  

   extensive 
  erosion 
  which 
  has 
  taken 
  place 
  they 
  are 
  usually 
  narrow, 
  

   and 
  it 
  is 
  only 
  at 
  sheltered 
  points 
  like 
  Port 
  Kent 
  and 
  Beauport 
  

   that 
  they 
  become 
  specially 
  prominent. 
  The 
  section 
  involved 
  is 
  

  

  1 
  Mather. 
  Geol. 
  New 
  York, 
  1st 
  dist. 
  1842. 
  p. 
  123. 
  

  

  2 
  Compiled 
  largely 
  from 
  Emmons's 
  Report 
  geol. 
  N. 
  T., 
  2 
  d 
  dist. 
  

  

  