﻿254 
  G. 
  R. 
  Wieland 
  — 
  On 
  Liassic 
  Floras. 
  

  

  A. 
  — 
  Localities 
  and 
  Geologic 
  Sections. 
  

  

  The 
  material 
  on 
  which 
  is 
  based 
  the 
  longer 
  memoir 
  on 
  the 
  

   Liassic 
  Flora 
  of 
  the 
  Mixteca 
  Alta 
  mentioned 
  above 
  was 
  all 
  

   personally 
  collected 
  by 
  the 
  writer 
  during 
  the 
  spring 
  and 
  early 
  

   summer 
  of 
  1909. 
  The 
  chief 
  localities 
  yielding 
  fossil 
  plants 
  in 
  

   abundance 
  and 
  at 
  which 
  collections 
  were 
  made 
  are 
  : 
  — 
  

  

  1. 
  On 
  the 
  Tlaxiaoo 
  river 
  to 
  the 
  westward 
  of 
  the 
  town 
  of 
  

   Tlaxiaco 
  at 
  prospects 
  of 
  the 
  Oaxaca 
  Iron 
  and 
  Coal 
  Com- 
  

   pany. 
  Cf. 
  fig. 
  1. 
  

  

  2. 
  In 
  the 
  hills 
  three 
  to 
  five 
  kilometers 
  northwesterly 
  from 
  

  

  Tlaxiaco. 
  

  

  3. 
  At 
  Mixtepec 
  on 
  the 
  Rio 
  Mixtepec, 
  where 
  considerable 
  pro- 
  

  

  specting 
  for 
  coal 
  has 
  been 
  carried 
  on. 
  

  

  4. 
  About 
  and 
  to 
  the 
  east 
  of 
  the 
  Cerro 
  del 
  Lucero 
  in 
  the 
  

  

  Tezoatlan 
  and 
  Rosario 
  region. 
  

  

  5. 
  On 
  the 
  Barranca 
  Consuelo 
  between 
  the 
  Cerro 
  del 
  Lucero 
  

  

  and 
  Cerro 
  de 
  Venado. 
  Here 
  a 
  magnificently 
  exposed 
  sec- 
  

   tion 
  permitted 
  the 
  location 
  of 
  various 
  quarries 
  and 
  the 
  

   accurate 
  measurement 
  of 
  plant 
  beds 
  reaching 
  nearly 
  six 
  

   hundred 
  meters 
  in 
  thickness. 
  In 
  addition 
  the 
  prospects 
  of 
  

   the 
  Oaxaca 
  Iron 
  and 
  Coal 
  Company, 
  where 
  some 
  coal 
  is 
  

   actually 
  mined, 
  made 
  possible 
  collections 
  from 
  the 
  lower 
  

   third 
  of 
  the 
  section 
  which 
  could 
  hardly 
  have 
  been 
  had 
  

   from 
  the 
  surface 
  quarries 
  alone. 
  

  

  The 
  plant 
  occurrences 
  in 
  the 
  Barranca 
  Consuelo 
  are 
  so 
  many 
  

   and 
  striking 
  that 
  in 
  this 
  preliminary 
  notice 
  the 
  material 
  from 
  

   the 
  other 
  localities 
  only 
  needs 
  to 
  be 
  considered 
  in 
  a 
  minor 
  or 
  

   supplementary 
  way. 
  

  

  But 
  it 
  should 
  be 
  recorded 
  that 
  in 
  a 
  hasty 
  visit 
  to 
  the 
  valley 
  

   of 
  the 
  Kochixtlan 
  river 
  at 
  a 
  point 
  to 
  the 
  southeast 
  of 
  Chalco- 
  

   tongo, 
  Sr. 
  Bonillas 
  of 
  the 
  Instituto 
  Geologico 
  observed 
  in 
  the 
  

   spring 
  of 
  1909 
  a 
  heavy 
  development 
  of 
  plant-bearing 
  beds 
  

   fully 
  four 
  hundred 
  meters 
  in 
  thickness. 
  And 
  from 
  his 
  account 
  

   and 
  my 
  own 
  observations 
  made 
  later 
  along 
  the 
  Yaqui 
  River 
  

   valley 
  in 
  Sonora 
  I 
  suspect 
  that 
  here 
  is 
  a 
  true 
  Triassic 
  extension 
  

   of 
  the 
  Barranca 
  Consuelo 
  section. 
  Moreover 
  in 
  the 
  following 
  

   year 
  Sr. 
  Bonillas 
  had 
  the 
  fortune 
  to 
  find 
  Williamsonia 
  flowers 
  

   near 
  Tlapa 
  in 
  the 
  State 
  of 
  Guerrero 
  in 
  sandstones 
  of 
  a 
  some- 
  

   what 
  light-colored 
  to 
  vitreous 
  appearance 
  recalling 
  very 
  sharply 
  

   the 
  characters 
  of 
  some 
  of 
  the 
  cycad-bearing 
  rock 
  of 
  the 
  Rajma- 
  

   hal 
  series 
  as 
  first 
  reported 
  by 
  Oldham 
  and 
  Morris. 
  

  

  The 
  first 
  observation 
  of 
  fossil 
  cycads 
  in 
  southern 
  Mexico 
  was 
  

   doubtless 
  made 
  by 
  Senor 
  Aguilera, 
  formerly 
  director 
  of 
  the 
  

   Instituto 
  Geologico, 
  who 
  not 
  only 
  visited 
  the 
  Barranca 
  Con- 
  

   suelo 
  some 
  thirty-five 
  years 
  ago, 
  but 
  also 
  noted 
  what 
  must 
  

   have 
  been 
  Williamsonia 
  disks 
  near 
  the 
  prominence 
  called 
  the 
  

   "Pina 
  de 
  Ayuquila" 
  near 
  the 
  village 
  of 
  Ayuquililla 
  in 
  the 
  

  

  