﻿Geology 
  and 
  Mineralogy. 
  487 
  

  

  diverse 
  regions 
  offer, 
  into 
  the 
  framework 
  of 
  the 
  actual 
  systems. 
  

   After 
  the 
  examination 
  of 
  these 
  first 
  points, 
  it 
  is 
  greatly 
  to 
  be 
  

   desired 
  that 
  a 
  decision 
  be 
  reached 
  on 
  a 
  second 
  question 
  of 
  prin- 
  

   ciple, 
  viz: 
  that 
  of 
  the 
  rules 
  to 
  be 
  followed 
  in 
  the 
  introduction 
  of 
  

   new 
  terms 
  in 
  stratigraphic 
  nomenclature. 
  Every 
  one 
  knows 
  how 
  

   new 
  denominations 
  for 
  indicating 
  the 
  different 
  geological 
  divisions 
  

   have 
  been 
  appearing 
  in 
  literature. 
  Often 
  the 
  authors 
  of 
  the 
  new 
  

   terms 
  introduce 
  them 
  without 
  any 
  argument, 
  either 
  petrographic 
  

   or 
  faunistic, 
  which 
  may 
  serve 
  to 
  distinguish, 
  in 
  a 
  clear 
  manner, 
  

   the 
  sediments 
  to 
  which 
  the 
  denominations 
  are 
  applied 
  from 
  the 
  

   neighboring 
  deposits; 
  it 
  often 
  happens 
  that 
  the 
  authors 
  them- 
  

   selves 
  have 
  a 
  very 
  vague 
  notion 
  of 
  the 
  criteria 
  by 
  which 
  they 
  

   apply 
  the 
  name. 
  Such 
  new 
  terms 
  evidently 
  being 
  only 
  useless 
  

   incumbrances 
  to 
  the 
  science, 
  it 
  is 
  greatly 
  to 
  be 
  desired 
  that 
  the 
  

   congress, 
  which 
  has 
  already 
  established 
  rules 
  to 
  be 
  followed 
  in 
  

   paleontological 
  nomenclature, 
  pronounce 
  also 
  on 
  the 
  question 
  of 
  

   stratigraphic 
  nomenclature 
  and 
  that 
  it 
  establish 
  the 
  data 
  upon 
  

   which 
  the 
  application 
  of 
  new 
  denominations 
  to 
  particular 
  deposits 
  

   be 
  authorized. 
  

  

  Another 
  question, 
  considered 
  to 
  be 
  of 
  no 
  less 
  importance 
  by 
  

   the 
  committee, 
  is 
  the 
  determination 
  of 
  the 
  principles 
  to 
  be 
  applied 
  

   in 
  the 
  application 
  of 
  petrographic 
  nomenclature. 
  The 
  flood 
  of 
  

   new 
  terms 
  in 
  this 
  science 
  has 
  attained 
  such 
  dimensions, 
  that 
  soon 
  

   no 
  one's 
  memory 
  will 
  be 
  able 
  to 
  retain 
  all 
  and 
  the 
  reader 
  of 
  each 
  

   memoir 
  will 
  be 
  obliged 
  to 
  employ 
  a 
  special 
  glossary. 
  The 
  works 
  

   undertaken 
  in 
  this 
  direction 
  should 
  be 
  accomplished 
  simultane- 
  

   ously 
  with 
  the 
  deliberations 
  regarding 
  the 
  principles 
  of 
  petro- 
  

   graphic 
  classification, 
  the 
  elaboration 
  of 
  which 
  was 
  entrusted 
  by 
  

   the 
  congress 
  of 
  Zurich 
  to 
  a 
  special 
  commission 
  under 
  the 
  presi- 
  

   dency 
  of 
  M. 
  A. 
  Michel-Levy. 
  

  

  Regarding 
  excursions, 
  the 
  committee 
  announces 
  an 
  additional 
  

   excursion 
  to 
  the 
  Tselsky 
  glacier. 
  The 
  number 
  of 
  participants 
  is 
  

   restricted 
  to 
  25 
  persons. 
  

  

  Excursion 
  C 
  to 
  Finland 
  will 
  cost 
  130 
  francs, 
  instead 
  of 
  50 
  frcs. 
  

   as 
  previously 
  announced. 
  

  

  In 
  response 
  to 
  several 
  letters 
  recently 
  received, 
  the 
  committee 
  

   of 
  organization 
  finds 
  it 
  necessary 
  to 
  state 
  that 
  the 
  passes 
  {billets 
  

   gratuits) 
  over 
  the 
  Russian 
  railroads 
  will 
  be 
  good 
  from 
  July 
  22d 
  

   to 
  October 
  17th. 
  The 
  tickets 
  will 
  give 
  to 
  the 
  geologists 
  the 
  right 
  

   to 
  pass 
  from 
  the 
  frontier 
  to 
  the 
  points 
  of 
  departure 
  of 
  the 
  excur- 
  

   sions 
  (St. 
  Petersburg, 
  Moscow, 
  etc.) 
  and 
  to 
  take 
  part 
  in 
  all 
  the 
  

   parts 
  of 
  the 
  itineraries 
  of 
  the 
  proposed 
  excursions. 
  They 
  will 
  

   also 
  be 
  valid 
  for 
  the 
  return 
  of 
  the 
  excursionists 
  to 
  the 
  frontier 
  

   from 
  whatever 
  point 
  they 
  may 
  choose 
  to 
  leave 
  the 
  excursions. 
  

  

  The 
  committee 
  receives 
  daily 
  requests 
  for 
  admission 
  to 
  the 
  

   excursions 
  on 
  the 
  part 
  of 
  students 
  of 
  special 
  high 
  schools 
  and 
  of 
  

   foreign 
  universities. 
  While 
  appreciating 
  the 
  benefit 
  the 
  excur- 
  

   sions 
  would 
  be 
  to 
  these 
  young 
  men, 
  the 
  committee 
  finds 
  itself, 
  to 
  

   its 
  deep 
  regret, 
  unable 
  to 
  admit 
  students, 
  either 
  foreign 
  or 
  Rus- 
  

   sian, 
  to 
  the 
  excursions, 
  on 
  account 
  of 
  the 
  great 
  number 
  of 
  geolo- 
  

  

  