﻿Hatcher 
  — 
  Sedimentary 
  Rocks 
  of 
  Southern 
  Patagonia. 
  87 
  

  

  adjoining 
  islands 
  as 
  far 
  south 
  as 
  Cape 
  Horn, 
  has 
  been 
  prepared 
  

   to 
  accompany 
  the 
  present 
  paper. 
  

  

  While 
  most 
  of 
  the 
  more 
  important 
  geographic 
  features 
  at 
  

   present 
  known 
  are 
  located 
  on 
  the 
  map, 
  especial 
  attention 
  has 
  

   been 
  given 
  in 
  its 
  construction 
  to 
  indicate 
  all 
  those 
  features 
  

   which, 
  though 
  of 
  little 
  purely 
  geographic 
  interest, 
  might 
  prove 
  

   of 
  considerable 
  value 
  to 
  any 
  field 
  geologist 
  who 
  in 
  the 
  future 
  

   may 
  wish 
  to 
  examine 
  the 
  same 
  localities 
  visited 
  by 
  myself 
  for 
  

   the 
  purpose 
  of 
  verifying 
  my 
  observations. 
  It 
  is 
  believed 
  that 
  

   with 
  the 
  text 
  and 
  accompanying 
  map 
  in 
  hand 
  it 
  will 
  not 
  be 
  a 
  

   difficult 
  matter 
  for 
  any 
  fairly 
  competent 
  person 
  to 
  identify 
  the 
  

   different 
  localities 
  mentioned 
  in 
  the 
  text 
  or 
  to 
  verify 
  the 
  

   stratigraphic 
  sections 
  herein 
  described. 
  

  

  The 
  great 
  value 
  of 
  explicit 
  descriptions 
  concerning 
  the 
  loca- 
  

   tion 
  of 
  important 
  geologic 
  sections 
  and 
  of 
  the 
  surface 
  expos- 
  

   ures 
  of 
  new 
  or 
  little 
  known 
  geologic 
  horizons, 
  especially, 
  as 
  

   frequently 
  happens, 
  when 
  such 
  exposures 
  are 
  of 
  limited 
  area, 
  

   must 
  already 
  have 
  become 
  apparent 
  to 
  working 
  geologists 
  

   everywhere. 
  This 
  is 
  especially 
  true 
  in 
  a 
  little 
  known 
  and 
  

   sparsely 
  settled 
  or 
  entirely 
  unsettled 
  country 
  like 
  the 
  interior 
  

   of 
  Patagonia. 
  In 
  the 
  progress 
  of 
  my 
  work 
  in 
  Patagonia 
  I 
  

   have 
  been 
  materially 
  handicapped 
  by 
  the 
  want 
  of 
  just 
  such 
  

   explicit 
  and 
  accurate 
  descriptions 
  of 
  localities 
  as 
  I 
  have 
  myself 
  

   always 
  endeavored 
  to 
  give 
  in 
  all 
  my 
  published 
  papers 
  relating 
  

   to 
  the 
  geology 
  of 
  the 
  fossil 
  fields 
  of 
  either 
  North 
  or 
  South 
  

   America. 
  

  

  In 
  naming 
  and 
  defining 
  a 
  new 
  geologic 
  horizon 
  it 
  appears 
  to 
  

   me 
  that 
  the 
  discoverer, 
  if 
  endowed 
  with 
  a 
  true 
  scientific 
  spirit 
  

   and 
  considering 
  the 
  best 
  interests 
  of 
  his 
  chosen 
  science, 
  will 
  be 
  

   impelled 
  to 
  give 
  at 
  least 
  one 
  definite 
  locality 
  where 
  the 
  horizon 
  

   may 
  be 
  found 
  well 
  represented 
  and 
  containing 
  the 
  fossils 
  

   characteristic 
  of 
  it, 
  when 
  such 
  fossils 
  are 
  known 
  to 
  exist 
  any- 
  

   where 
  in 
  the 
  newly-discovered 
  beds. 
  It 
  should 
  not 
  be 
  consid- 
  

   ered 
  sufficient 
  to 
  say 
  that 
  certain 
  beds 
  are 
  found 
  represented 
  

   "in 
  the 
  region 
  of 
  Lakes 
  Yiedma 
  and 
  San 
  Martin" 
  when 
  the 
  

   limits 
  of 
  these 
  lakes 
  are 
  separated 
  by 
  a 
  distance 
  of 
  more 
  than 
  

   100 
  miles. 
  Nor 
  after 
  describing 
  an 
  exceedingly 
  important 
  

   geological 
  section 
  is 
  it 
  enough 
  to 
  add 
  that 
  " 
  this 
  section 
  is 
  

   shown 
  in 
  a 
  bluff 
  in 
  the 
  region 
  of 
  Lakes 
  Colhue 
  and 
  Musters," 
  

   since 
  the 
  limits 
  of 
  these 
  lakes, 
  both 
  of 
  large 
  size, 
  are 
  separated 
  

   by 
  long 
  distances. 
  

  

  The 
  want 
  of 
  more 
  explicit 
  information 
  regarding 
  localities, 
  

   due 
  perhaps 
  to 
  thoughtlessness 
  on 
  the 
  part 
  of 
  Dr. 
  Ameghino, 
  

   has 
  rendered 
  much 
  of 
  my 
  work 
  in 
  Patagonia 
  necessarily 
  a 
  work 
  

   of 
  exploration 
  and 
  not 
  so 
  productive 
  of 
  paleontologic 
  and 
  geo- 
  

   logic 
  results 
  as 
  it 
  would 
  have 
  been, 
  had 
  I 
  been 
  possessed 
  of 
  

   data 
  enabling 
  me 
  to 
  go 
  directly 
  to 
  localities 
  previously 
  discov- 
  

   ered 
  by 
  Sen 
  or 
  Carlos 
  Ameghino. 
  

  

  