﻿Mr. 
  R. 
  Lydekker 
  on 
  Nototherium 
  and 
  Zygomatums. 
  149 
  

  

  paradise 
  as 
  compared 
  with 
  Ascension, 
  which 
  consists 
  of 
  a 
  

   scorched 
  mass 
  of 
  volcanic 
  matter 
  in 
  part 
  resembling 
  bottle- 
  

   glass 
  and 
  in 
  part 
  coke 
  and 
  cinders." 
  In 
  his 
  ' 
  Lecture 
  on 
  

   Insular 
  Floras 
  ' 
  Sir 
  Joseph 
  Hooker 
  expresses 
  himself 
  in 
  the 
  

   following 
  manner 
  on 
  the 
  island 
  and 
  the 
  vegetation 
  which 
  

   covers 
  it 
  : 
  — 
  " 
  A 
  small 
  green 
  peak, 
  2800 
  feet 
  above 
  the 
  sea, 
  

   monopolizes 
  nearly 
  all 
  the 
  vegetation, 
  which 
  consists 
  of 
  

   Purslane, 
  a 
  grass, 
  and 
  a 
  Euphorbia 
  in 
  the 
  lower 
  parts 
  of 
  the 
  

   island, 
  whilst 
  the 
  green 
  peak 
  is 
  clothed 
  with 
  a 
  carpet 
  of 
  ferns, 
  

   and 
  here 
  and 
  there 
  a 
  shrub." 
  

  

  I 
  have 
  been 
  led 
  to 
  add 
  these 
  data 
  on 
  Juan 
  Fernandez 
  and 
  

   Ascension 
  to 
  show 
  that 
  the 
  facts 
  established 
  for 
  Krakatao 
  do 
  

   not 
  constitute 
  an 
  exception. 
  

  

  I 
  think, 
  finally, 
  that 
  I 
  am 
  therefore 
  justified 
  in 
  stating 
  

   that 
  : 
  

  

  During 
  the 
  advent 
  of 
  a 
  new 
  flora 
  on 
  a 
  volcanic 
  island 
  which 
  

   is 
  under 
  the 
  same 
  conditions 
  as 
  Krakatao, 
  the 
  Phanerogams 
  

   will 
  always 
  he 
  preceded 
  hy 
  Ferns, 
  and 
  this 
  doubtless 
  owing 
  to 
  

   the 
  less 
  physiological 
  differentiation 
  of 
  the 
  latter. 
  

  

  After 
  an 
  island 
  — 
  or 
  a 
  portion 
  of 
  a 
  continent 
  — 
  has 
  been 
  

   devastated 
  by 
  an 
  eruption 
  and 
  covered 
  with 
  volcanic 
  matter, 
  

   the 
  vascular 
  Cryptogams 
  — 
  and 
  especially 
  the 
  Ferns 
  — 
  still 
  per- 
  

   form 
  at 
  the 
  present 
  day 
  the 
  same 
  part 
  which 
  they 
  very 
  fre- 
  

   quently 
  did 
  in 
  the 
  remote 
  periods 
  when 
  they 
  predominated 
  on 
  

   the 
  eartli's 
  surface. 
  

  

  Voorschoten, 
  

   March 
  3, 
  1888. 
  

  

  XVII. 
  — 
  Nototherium 
  and 
  Zygomaturus. 
  

   By 
  R. 
  Lydekkee, 
  B.A., 
  F.G.S. 
  

  

  In 
  a 
  short 
  paper 
  recently 
  published 
  in 
  the 
  Proc. 
  R. 
  Soc. 
  

   Queensland, 
  vol. 
  v. 
  pp. 
  111-116, 
  and 
  plate, 
  Mr. 
  C. 
  W. 
  De 
  

   Vis 
  again 
  raises 
  the 
  question 
  whether 
  the 
  humerus 
  referred 
  

   by 
  Sir 
  R. 
  Owen 
  to 
  Nototherium 
  is 
  rightly 
  determined 
  *. 
  

  

  This 
  time, 
  however, 
  a 
  new 
  point 
  of 
  departure 
  is 
  taken. 
  It 
  

   may 
  be 
  observed 
  in 
  passing 
  that 
  Mr. 
  l)e 
  Vis 
  starts 
  the 
  un- 
  

   tenable 
  proposition 
  that 
  the 
  type 
  of 
  Nototherium 
  being- 
  

   imperfect 
  cannot 
  be 
  taken 
  as 
  the 
  real 
  type 
  of 
  the 
  genus 
  : 
  but 
  

   since 
  this 
  does 
  not 
  affect 
  the 
  question 
  he 
  has 
  raised 
  it 
  need 
  not 
  

   be 
  further 
  mentioned. 
  The 
  gist 
  of 
  his 
  contention 
  is 
  that 
  the 
  

  

  * 
  De 
  Vis, 
  Proc. 
  Linn. 
  Soc. 
  N. 
  S. 
  Wales, 
  vol. 
  viii. 
  p. 
  404. 
  See 
  also 
  

   Lydekker, 
  Cat. 
  Foss. 
  Manim. 
  Brit. 
  Mus. 
  pt. 
  v. 
  p. 
  161. 
  

  

  