﻿FIFTH 
  REPORT 
  OF 
  THE 
  DIRECTOR 
  I908 
  209 
  

  

  Stones 
  in 
  tlie 
  Mohawkian 
  stages 
  (not 
  only 
  in 
  the 
  Trenton 
  and 
  

   Black 
  River 
  limestone, 
  but 
  also 
  in 
  the 
  Lowville 
  limestone) 
  which 
  

   may 
  be 
  strongly 
  suspected 
  to 
  be 
  of 
  vegetable 
  origin. 
  In 
  Europe 
  

   similar 
  rocks 
  of 
  the 
  Lower 
  Siluric 
  have 
  been 
  recognized 
  by 
  Stolley 
  

   to 
  owe 
  their 
  origin 
  to 
  verticillate 
  Siphoneae. 
  There 
  is 
  neither 
  any 
  

   doubt 
  that 
  forms 
  corresponding 
  to 
  the 
  important 
  rock-forming 
  

   nullipores 
  of 
  later 
  eras 
  have 
  been 
  very 
  active 
  then 
  and 
  productive 
  

   of 
  much 
  of 
  our 
  Lower 
  Siluric 
  limestones, 
  at 
  least 
  in 
  Chazy 
  to 
  

   Trenton 
  times. 
  This 
  is 
  i) 
  indicated 
  by 
  the 
  common 
  occurrence 
  in 
  

   some 
  of 
  our 
  Mohawkian 
  rocks 
  of 
  Solenopora 
  compacta, 
  

   a 
  form 
  that 
  is 
  placed 
  among 
  the 
  calcareous 
  algae 
  by 
  Rothpletz 
  

   and 
  considered 
  as 
  either 
  an 
  ancestor 
  of 
  the 
  Coralline 
  algae 
  or 
  as 
  

   representing 
  an 
  earlier 
  development 
  of 
  a 
  corresponding 
  or 
  parallel 
  

   branch 
  of 
  the 
  algae, 
  and 
  2) 
  it 
  is 
  demonstrated 
  by 
  the 
  composition 
  

   of 
  whole 
  beds 
  of 
  all 
  three 
  divisions 
  of 
  our 
  Chazy 
  by 
  the 
  small 
  

   nodular 
  bodies 
  described 
  by 
  Seely^ 
  as 
  a 
  new 
  type 
  of 
  sponge 
  under 
  

   the 
  name 
  of 
  Strephochetus 
  with 
  a 
  small 
  number 
  of 
  species. 
  

   Professor 
  Seely's 
  careful 
  figures 
  of 
  microscopic 
  sections, 
  especially 
  

   of 
  his 
  S 
  . 
  o 
  c 
  e 
  1 
  1 
  a 
  t 
  u 
  s 
  , 
  leave, 
  however, 
  no 
  doubt 
  that 
  Strepho- 
  

   chetus 
  is 
  identical 
  with 
  Girvanella 
  N. 
  & 
  E. 
  The 
  latter 
  had 
  already 
  

   been 
  suspected 
  by 
  Nicholson 
  and 
  Etheridge, 
  and 
  later 
  has 
  been 
  

   proved 
  by 
  Rothpletz 
  to 
  be 
  a 
  calcareous 
  alga, 
  that 
  invites 
  compari- 
  

   son 
  with 
  the 
  Siphonean 
  family 
  Codiaceae. 
  If 
  Girvanella 
  is 
  an 
  alga, 
  

   much 
  of 
  our 
  Qiazy 
  limestone 
  is 
  of 
  vegetable 
  origin. 
  

  

  xA.lso 
  our 
  Beekmantown 
  beds 
  contain 
  strata 
  filled 
  with 
  similar 
  

   small 
  fiat 
  pebbles 
  that 
  are 
  highly 
  suggestive 
  of 
  the 
  water 
  biscuits 
  

   of 
  our 
  lakes.2 
  For 
  these, 
  occurring 
  frequently 
  in 
  upper 
  D. 
  in 
  the 
  

   so 
  called 
  " 
  Wing 
  coiiglomerate 
  of 
  Vermont,'' 
  Seeley 
  has 
  erected 
  

   the 
  genus 
  Wingia,^ 
  considering 
  them 
  again 
  as 
  sponges. 
  It 
  is 
  an 
  

   invituig 
  task 
  to 
  investigate 
  these 
  and 
  other 
  forms 
  of 
  pebbles 
  of 
  the 
  

   Beelmiantown 
  and 
  late 
  Paleozoic 
  stages 
  as 
  to 
  their 
  possible 
  vege- 
  

   table 
  origin. 
  

  

  ^ 
  Seely, 
  H. 
  M. 
  Some 
  Sponges 
  of 
  the 
  Chazy 
  Formation. 
  Vt. 
  State 
  Geol. 
  

   Rep't 
  1902. 
  p. 
  151. 
  

  

  ^ 
  Calcareous 
  water 
  biscuit 
  have 
  been 
  described 
  from 
  Canandaigua 
  lake 
  

   where 
  they 
  largely 
  contribute 
  to 
  the 
  composition 
  of 
  the 
  beach, 
  by 
  Clarke 
  

   [N. 
  Y. 
  State 
  ^lus. 
  Bui. 
  39. 
  19CX). 
  p. 
  195]. 
  They 
  are 
  glomerated 
  masses 
  of 
  

   algae 
  such 
  as 
  are 
  known 
  from 
  many 
  European 
  lakes 
  (''algoid 
  lake 
  balls") 
  

   that 
  by 
  their 
  own 
  metabolic 
  processes 
  have 
  caused 
  a 
  deposition 
  of 
  carbonate 
  

   of 
  lime 
  on 
  them. 
  The 
  similarity 
  of 
  the 
  structure 
  of 
  these 
  water 
  balls 
  to 
  that 
  

   of 
  Girvanella 
  has 
  induced 
  Seward 
  [Fossil 
  Plants. 
  1895- 
  i 
  : 
  125] 
  to 
  place 
  

   the 
  latter 
  genus 
  among 
  the 
  Schizophyate, 
  a 
  view 
  opposed 
  by 
  Rothpletz 
  

   [loc. 
  cit. 
  p. 
  5]. 
  

  

  ^ 
  Seely, 
  H. 
  M. 
  Contribution 
  to 
  the 
  Geology 
  and 
  Paleontolog>- 
  of 
  Vermont. 
  

   Vt. 
  State 
  Geol. 
  5th 
  Rep't 
  1906. 
  p. 
  25. 
  

  

  