﻿Derby 
  — 
  Constituents 
  of 
  the 
  Canon 
  Diablo 
  Meteorite. 
  101 
  

  

  continental 
  lands 
  sufficient 
  to 
  disturb 
  the 
  reign 
  of 
  the 
  marine 
  

   faunas 
  till 
  near 
  the 
  close 
  of 
  the 
  Carboniferous 
  age. 
  Thus 
  in 
  

   the 
  Appalachian 
  province 
  diversity 
  and 
  alternation 
  of 
  deposits 
  

   is 
  marked 
  by 
  numerous 
  successive 
  and 
  distinct 
  faunas; 
  in 
  the 
  

   western 
  continental 
  border 
  province 
  uniformity 
  of 
  prevailing 
  

   calcareous 
  sedimentation 
  for 
  long 
  periods 
  is 
  marked 
  by 
  the 
  

   abnormally 
  long 
  continuance 
  of 
  many 
  of 
  the 
  Devonian 
  species; 
  

   while 
  the 
  central 
  continental 
  province 
  midway 
  between 
  the 
  

   two 
  is 
  marked 
  by 
  the 
  unmistakable 
  recurrence 
  of 
  Devonian 
  

   species 
  far 
  up 
  in 
  the 
  midst 
  of 
  Carboniferous 
  sediments. 
  

  

  While 
  theoretically 
  such 
  a 
  fact 
  might 
  be 
  expected, 
  this 
  

   unique 
  case 
  of 
  recurrence 
  furnishes 
  us 
  with 
  the 
  evidence 
  

   connecting 
  the 
  three 
  distinct 
  geological 
  provinces, 
  and 
  makes 
  

   it 
  possible 
  to 
  correlate, 
  with 
  more 
  than 
  ordinary 
  precision, 
  the 
  

   chronological 
  horizon 
  of 
  the 
  several 
  widely 
  separated 
  faunas. 
  

   This 
  series 
  of 
  observations 
  furnishes 
  a 
  demonstration 
  of 
  the 
  

   hypotheses 
  that 
  the 
  persistence 
  of 
  species 
  without 
  modification 
  

   is 
  associated 
  with 
  continuance 
  of 
  uniformity 
  of 
  conditions 
  of 
  

   environment, 
  and 
  that 
  change 
  in 
  the 
  successive 
  faunas 
  of 
  

   geological 
  time 
  is 
  associated 
  with 
  the 
  change 
  and 
  rearrangment 
  

   of 
  the 
  conditions 
  of 
  environment 
  to 
  which 
  the 
  fauna 
  is 
  sub- 
  

   jected. 
  

  

  Art. 
  IX. 
  — 
  Constituents 
  of 
  the 
  Canon 
  Diablo 
  Meteorite 
  • 
  

   by 
  Orville 
  A. 
  Derby. 
  

  

  A 
  specimen" 
  of 
  the 
  Canon 
  Diablo 
  meteorite 
  obtained 
  from 
  

   Mr. 
  E. 
  E. 
  Howell 
  of 
  Washington 
  and 
  stated 
  to 
  be 
  one 
  of 
  the 
  

   original 
  lot 
  brought 
  from 
  Arizona 
  by 
  Dr. 
  A. 
  E. 
  Foote, 
  has 
  

   been 
  treated 
  in 
  the 
  laboratory 
  of 
  the 
  Commissao 
  Geographica 
  

   e 
  Geologica 
  de 
  Sao 
  Paulo 
  by 
  the 
  fractional 
  method 
  of 
  Prof. 
  E. 
  

   Cohen 
  with 
  the 
  following 
  results. 
  The 
  chemical 
  analyses 
  

   accompanying 
  this 
  paper 
  have 
  been 
  kindly 
  made 
  for 
  me 
  by 
  

   Dr. 
  Guilherme 
  Florence, 
  assistant 
  to 
  the 
  Commission. 
  

  

  The 
  specimen, 
  weighing 
  nearly 
  200 
  grams, 
  was 
  a 
  perfect 
  

   meteoric 
  individual 
  ; 
  that 
  is 
  to 
  say, 
  it 
  presented 
  no 
  fractural 
  

   surfaces, 
  but 
  everywhere 
  the 
  rough 
  pitted 
  surface 
  of 
  meteoric 
  

   masses. 
  In 
  appearance 
  it 
  suggested 
  a 
  metallic 
  bleb 
  broken 
  or 
  

   weathered 
  out 
  of 
  friable, 
  or 
  more 
  easily 
  decomposable, 
  material. 
  

   An 
  examination 
  of 
  a 
  considerable 
  number 
  of 
  specimens 
  of 
  all 
  

   sizes 
  in 
  Mr. 
  Howell's 
  collection 
  shows 
  this 
  to 
  be 
  a 
  general 
  

   characteristic 
  of 
  the 
  Canon 
  Diablo 
  group. 
  Nothing 
  in 
  the 
  

   shape 
  and 
  aspect 
  of 
  the 
  masses 
  suggests 
  the 
  occurrence 
  of 
  planes 
  

   of 
  slight 
  cohesion 
  (presumed 
  to 
  be 
  the 
  limits 
  of 
  crystalline 
  

  

  