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  Scientific 
  Intelligence. 
  

  

  with 
  comparisons 
  of 
  the 
  special 
  fauna. 
  It 
  is 
  followed 
  by 
  another 
  

   on 
  the 
  relations 
  of 
  the 
  Lower 
  Cambrian 
  fauna 
  to 
  those 
  of 
  the 
  

   overlying 
  Cambrian. 
  

  

  This 
  latest 
  review 
  of 
  the 
  species 
  makes 
  the 
  tribes 
  represented 
  

   in 
  the 
  American 
  Lower 
  Cambrian 
  include 
  : 
  Sponges 
  of 
  four 
  

   genera 
  ; 
  Hydrozoa 
  of 
  the 
  group 
  of 
  Graptolites, 
  and 
  perhaps 
  

   Medusa? 
  ; 
  Actinozoa 
  or 
  true 
  Coral 
  polyps 
  ; 
  Echinoderms, 
  of 
  the 
  

   group 
  of 
  Cystids 
  ; 
  Annelids 
  ; 
  Brachiopods 
  of 
  10 
  genera 
  and 
  29 
  

   species 
  ; 
  Lamellibranchs, 
  probably 
  of 
  two 
  species 
  ; 
  Gasteropods, 
  

   of 
  the 
  genera 
  Stenotheca, 
  Platyceras 
  and 
  Pleurotomaria 
  ; 
  Ptero- 
  

   pods, 
  of 
  4 
  genera 
  and 
  15 
  species 
  ; 
  Crustaceans 
  of 
  Ostracoid 
  type, 
  

   of 
  the 
  genera 
  Leperditia, 
  Aristozoe 
  and 
  Isoxys 
  ; 
  and 
  of 
  the 
  

   Phyllopod 
  type, 
  in 
  his 
  Protocaris; 
  and 
  Trilobites 
  of 
  16 
  genera 
  

   and 
  53 
  species. 
  

  

  Notes 
  of 
  new 
  facts 
  and 
  views 
  relating 
  to 
  the 
  genera 
  and 
  

   species 
  follow, 
  his 
  former 
  papers 
  being 
  referred 
  to 
  for 
  full 
  

   descriptions. 
  Fifty 
  plates 
  of 
  figures 
  of 
  the 
  various 
  species 
  close 
  

   the 
  memoir. 
  Mr. 
  Walcott 
  observes 
  that 
  nothing 
  is 
  learned 
  from 
  

   the 
  rocks 
  with 
  regard 
  to 
  the 
  genesis 
  of 
  these 
  Lower 
  Cambrian 
  

   types. 
  

  

  5. 
  Relation 
  of 
  secular 
  Rock-disintegration 
  to 
  certain 
  transi- 
  

   tional 
  crystalline 
  schists; 
  by 
  R. 
  Pumpelly 
  (Bull. 
  G-eol. 
  Soc. 
  

   Amer., 
  ii, 
  209). 
  — 
  This 
  paper 
  is 
  a 
  very 
  valuable 
  contribution 
  to 
  

   geological 
  science. 
  Some 
  of 
  its 
  facts 
  and 
  conclusions 
  are 
  here 
  

   cited. 
  A 
  dike 
  of 
  basic 
  rocks 
  intersecting 
  the 
  pre-Cambrian 
  

   Clarksburg 
  mountain 
  gneiss, 
  near 
  Williamstown, 
  Mass., 
  does 
  not 
  

   pass 
  up 
  into 
  the 
  overlying 
  Cambrian 
  quartzyte. 
  The 
  dike 
  

   bears 
  evidence 
  of 
  having 
  been 
  decayed 
  before 
  covered 
  by 
  the 
  

   quartzyte 
  ; 
  and 
  thus 
  leads 
  to 
  the 
  conclusion 
  that 
  the 
  region 
  was 
  

   dry 
  land 
  before 
  the 
  deposition 
  of 
  the 
  Cambrian. 
  In 
  Hoosic 
  

   Mountain, 
  which 
  has 
  a 
  core 
  of 
  pre-Cambrian 
  granitoid 
  gneiss, 
  

   this 
  gneiss 
  has 
  over 
  it 
  a 
  formation, 
  in 
  an 
  anticlinal, 
  consisting 
  of 
  

   well 
  defined 
  conglomerate 
  at 
  the 
  north 
  end, 
  a 
  gneiss 
  with 
  parallel 
  

   foliation 
  on 
  the 
  east, 
  a 
  fine-grained, 
  white 
  gneiss, 
  with 
  little 
  mica 
  

   and 
  rather 
  obscure 
  foliation 
  on 
  the 
  west. 
  The 
  lateral 
  transition 
  

   of 
  the 
  Lower 
  Cambrian 
  quartzyte 
  of 
  the 
  valley 
  was 
  traced 
  into 
  

   these 
  white 
  gneisses, 
  " 
  definitely 
  settling 
  the 
  Cambrian 
  age 
  of 
  

   this 
  conglomerate-gneiss 
  formation." 
  At 
  many 
  points 
  there 
  is 
  

   complete 
  structural 
  conformity 
  between 
  the 
  pre-Cambrian 
  and 
  

   the 
  overlying 
  Cambrian 
  gneiss. 
  But 
  on 
  the 
  Clarksburg 
  mountain, 
  

   where 
  similar 
  facts 
  occur, 
  the 
  quartzyte 
  mantling 
  the 
  granitoid 
  

   gneiss 
  is 
  crinkled 
  into 
  minute 
  fan-like 
  plications, 
  and 
  the 
  gran- 
  

   itoid 
  gneiss 
  has 
  similar 
  plications 
  in 
  perfect 
  parallelism. 
  This 
  

   fine 
  lamination 
  disappears 
  a 
  short 
  distance 
  from 
  the 
  line 
  of 
  con- 
  

   tact. 
  It 
  is 
  evident, 
  says 
  Mr. 
  Pumpelly, 
  that 
  this 
  structure 
  in 
  

   the 
  older 
  rock 
  was 
  formed 
  at 
  the 
  same 
  time 
  and 
  by 
  the 
  same 
  

   pressure 
  as 
  that 
  in 
  the 
  younger. 
  The 
  hypothesis 
  of 
  a 
  pre- 
  

   Cambrian 
  decajr 
  of 
  the 
  granitoid 
  gneiss 
  affords 
  a 
  key 
  to 
  the 
  

   problem 
  in 
  the 
  Green 
  mountains 
  here 
  exemplified. 
  The 
  trans- 
  

   itional 
  beds 
  between 
  the 
  two 
  rocks 
  arc 
  made 
  of 
  the 
  results 
  of 
  

  

  