﻿24 
  ME. 
  A. 
  C. 
  SEWAKD 
  ON 
  CTCADEOIDEA 
  GXGANTEA. 
  [Feb. 
  1.897,- 
  

  

  Passing 
  to 
  the 
  apex 
  of 
  the 
  trunk, 
  we 
  find 
  that 
  the 
  leaf-bases 
  become 
  

   smaller 
  in 
  size 
  (PI. 
  II. 
  fig. 
  1), 
  and 
  finally 
  at 
  the 
  extreme 
  tip 
  there 
  is 
  a 
  

   conical 
  bud 
  surrounded 
  by 
  several 
  long 
  and 
  narrow 
  bud-scales 
  (fig. 
  3). 
  

   Covering 
  the 
  apex 
  of 
  the 
  bud 
  there 
  is 
  an 
  irregularly-shaped 
  cap 
  of 
  

   whitish 
  colour, 
  of 
  which 
  the 
  surface 
  is 
  marked 
  by 
  numerous 
  wavy 
  

   lines 
  suggestive 
  of 
  fine 
  scaly 
  or 
  hair-like 
  structures. 
  The 
  bud 
  has 
  

   a 
  height 
  of 
  about 
  3 
  or 
  4 
  cm., 
  and 
  the 
  scale-leaves 
  which 
  are 
  best 
  seen 
  

   are 
  about 
  1*5 
  cm. 
  long 
  and 
  6 
  mm. 
  broad. 
  The 
  appearance 
  of 
  this 
  

   terminal 
  bud 
  is 
  shown 
  in 
  PI. 
  I., 
  and 
  more 
  clearly 
  in 
  PI. 
  II. 
  fig. 
  1, 
  

   and 
  in 
  fig. 
  3. 
  The 
  lighter-coloured 
  cap 
  gives 
  a 
  flat-topped 
  appear- 
  

   ing. 
  3. 
  — 
  Apical 
  bud 
  of 
  Cycadeoidea 
  gigantea, 
  sp. 
  nov. 
  

  

  V\ 
  

  

  ance 
  to 
  the 
  bud, 
  and 
  hides 
  the 
  tips 
  of 
  the 
  uppermost 
  scale-leaves 
  ; 
  

   the 
  form 
  of 
  the 
  scales 
  is, 
  however, 
  clearly 
  seen 
  in 
  the 
  lower 
  portion 
  

   of 
  the 
  bud. 
  It 
  is 
  important 
  to 
  note 
  that 
  the 
  stem 
  at 
  the 
  base 
  of 
  

   the 
  bud 
  is 
  almost 
  circular 
  in 
  outline, 
  thus 
  confirming 
  the 
  opinion 
  

   that 
  the 
  flattened 
  appearance 
  shown 
  in 
  fig. 
  2 
  (p. 
  23) 
  is 
  in 
  great 
  

   measure 
  due 
  to 
  crushing. 
  In 
  the 
  neighbourhood 
  of 
  the 
  stem-apex 
  

   the 
  surface-features 
  are 
  imperfectly 
  preserved, 
  but 
  the 
  leaf-bases 
  are 
  

   distinctly 
  visible 
  in 
  many 
  places, 
  and 
  their 
  gradual 
  increase 
  in 
  size 
  

   as 
  we 
  pass 
  down 
  the 
  stem 
  is 
  easily 
  recognized. 
  

  

  The 
  material 
  of 
  which 
  the 
  specimen 
  consists 
  is 
  highly 
  siliceous 
  ; 
  

   as 
  shown 
  in 
  fig. 
  2, 
  the 
  central 
  portion 
  exhibits 
  no 
  trace 
  of 
  plant- 
  

   structure, 
  and 
  is 
  composed 
  of 
  cherty 
  rock, 
  while 
  at 
  the 
  periphery 
  

   the 
  basal 
  portion 
  of 
  the 
  petioles 
  and 
  the 
  interpetiolar 
  substance 
  are 
  

   more 
  or 
  less 
  clearly 
  seen, 
  and 
  are 
  represented 
  in 
  the 
  sketch 
  by 
  

   radial 
  lines 
  extending 
  inward 
  a 
  short 
  distance 
  (4 
  to 
  5 
  cm.) 
  from 
  the 
  

   surface. 
  There 
  are 
  no 
  traces 
  on 
  the 
  stem 
  of 
  any 
  large 
  lateral 
  buds 
  

   such 
  as 
  form 
  so 
  striking 
  a 
  feature 
  in 
  some 
  fossil 
  Cycadean 
  plants, 
  

   as, 
  for 
  example, 
  in 
  Bennettites 
  Gibsonianns, 
  Carr., 
  and 
  in 
  some 
  of 
  

   the 
  large 
  specimens 
  from 
  North 
  America 
  and 
  Italy. 
  1 
  An 
  example 
  

   figured 
  by 
  McBride, 
  2 
  from 
  Dakota, 
  shows 
  a 
  number 
  of 
  lateral 
  shoots 
  

  

  1 
  Capellini 
  & 
  Solras-Laubach, 
  ' 
  Tronchi 
  di 
  Bennettitee,' 
  Mem. 
  Eeal. 
  Accad. 
  

   Sci. 
  Istit. 
  Bologna, 
  [5], 
  vol. 
  ii. 
  1892, 
  p. 
  3. 
  

  

  2 
  ' 
  The 
  American 
  Geologist,' 
  vol. 
  xii. 
  (1893) 
  p. 
  248, 
  pi. 
  xi. 
  

  

  