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  Forty-seventh 
  Report 
  on 
  the 
  State 
  Museum. 
  

  

  The 
  Pentamerus 
  beds, 
  " 
  heavy 
  knotted, 
  grayish-blue 
  beds 
  with 
  

   irregular 
  Dodules 
  of 
  chert" 
  and 
  a 
  thickness 
  of 
  forty 
  to 
  fifty 
  

   feet, 
  Shaly 
  beds, 
  "deep 
  blue, 
  weathering 
  brown 
  and 
  shaly," 
  

   thickness 
  fifty 
  to 
  sixty 
  feet, 
  Scutella 
  beds, 
  " 
  hard-gray 
  crystalline 
  

   limestone, 
  largely 
  made 
  of 
  fragments 
  of 
  shells 
  in 
  somewhat 
  even 
  

   layers," 
  thickness 
  forty 
  to 
  fifty 
  feet. 
  

  

  Two 
  miles 
  northeast 
  of 
  Becraft's 
  mountain 
  there 
  is 
  another 
  

   outlier 
  constituting 
  a 
  knob 
  known 
  as 
  Mount 
  Ida 
  or 
  Mount 
  Bob. 
  

   It 
  has 
  recently 
  been 
  described 
  in 
  detail 
  by 
  T. 
  W. 
  Harris,* 
  who 
  

   finds 
  that 
  it 
  is 
  a 
  synclinal 
  area 
  containing 
  Tentaculite, 
  Pentamerus 
  

   and 
  Shaly 
  limestone 
  beds 
  presenting 
  the 
  usual 
  characteristics. 
  

  

  In 
  Orange 
  county, 
  N. 
  Y., 
  in 
  the 
  great 
  synclinal 
  of 
  Skunemunk 
  

   mountain 
  there 
  are 
  several 
  outlying 
  areas 
  of 
  Helderberg 
  lime- 
  

   stones 
  of 
  which 
  the 
  most 
  notable 
  is 
  at 
  Cornwall 
  Station. 
  The 
  

   relations 
  at 
  this 
  locality 
  were 
  described 
  by 
  N. 
  H. 
  Darton 
  in 
  

   1886.f 
  Although 
  miles 
  from 
  the 
  edge 
  of 
  the 
  main 
  Helderberg 
  

   belt 
  to 
  the 
  westward, 
  the 
  Tentaculite, 
  Pentamerus 
  and 
  Shaly 
  

   limestone 
  beds 
  are 
  well 
  characterized 
  at 
  this 
  point, 
  the 
  latter 
  

   containing 
  nodules 
  of 
  hematites 
  and 
  a 
  great 
  profusion 
  of 
  

   beautiful 
  casts 
  of 
  fossils. 
  

  

  Salma 
  waterlime. 
  — 
  The 
  attenuated 
  eastern 
  extension 
  of 
  the 
  

   great 
  Salina 
  formation 
  is 
  of 
  variable 
  character 
  and 
  thickness 
  and 
  

   may 
  not 
  be 
  continuous 
  throughout. 
  Locally 
  it 
  consists 
  of 
  heavy 
  

   beds 
  of 
  cement 
  rock 
  but 
  generally 
  it 
  is 
  composed 
  of 
  thin 
  beds 
  of 
  

   more 
  or 
  less 
  impure 
  cement 
  intercalated 
  with 
  thin-bedded 
  lime- 
  

   stones 
  of 
  various 
  character. 
  The 
  cement 
  beds 
  attain 
  their 
  

   greatest 
  development 
  about 
  Kosendale 
  and 
  Kondout 
  where 
  they 
  

   are 
  extensively 
  worked. 
  The 
  cement 
  rock 
  is 
  a 
  blue 
  black, 
  very 
  

   fine 
  grained, 
  massively 
  bedded 
  deposit 
  consisting 
  of 
  calcareous, 
  

   magnesian 
  and 
  argillaceous 
  materials, 
  and 
  is 
  of 
  somewhat 
  vari- 
  

   able 
  composition. 
  The 
  rock 
  produces 
  a 
  cement 
  of 
  good 
  quality 
  

   only 
  when 
  these 
  components 
  bear 
  certain 
  relative 
  proportions 
  

   to 
  each 
  other. 
  A 
  characteristic 
  feature 
  of 
  the 
  rock 
  is 
  the 
  

   light 
  buff 
  hue 
  to 
  which 
  its 
  surface 
  weathers. 
  At 
  Eosendale 
  there 
  

   is 
  a 
  twenty-one 
  foot 
  bed 
  of 
  cement 
  at 
  the 
  base 
  of 
  the 
  formation, 
  

   then 
  from 
  twelve 
  to 
  fifteen 
  feet 
  of 
  mixed 
  impure 
  cement 
  and 
  

  

  *Am. 
  Jour. 
  Sci., 
  3d 
  series, 
  vol. 
  43, 
  pp. 
  236-238. 
  1892. 
  

  

  t 
  On 
  an 
  area 
  of 
  Upper 
  Silurian 
  rocks 
  near 
  Cornwall 
  Station, 
  Orange 
  county, 
  N. 
  Y., 
  Am. 
  Jour. 
  

   Sci., 
  3d 
  series 
  vol. 
  31, 
  pp. 
  209-216. 
  

  

  