﻿78 
  PROCEEDINGS 
  OF 
  THE 
  GEOLOGICAL 
  SOCIETY. 
  

  

  This 
  species 
  is 
  well 
  distinguished 
  by 
  its 
  straight 
  and 
  sharply- 
  

   pointed 
  leaflets, 
  and 
  was 
  named, 
  in 
  MS., 
  by 
  Mr. 
  Bean 
  many 
  years 
  

   ago. 
  Like 
  P. 
  medianum 
  it 
  is 
  found 
  only 
  at 
  Gristhorpe, 
  where 
  also 
  

   it 
  is 
  rare. 
  

  

  6. 
  Pterophyllttm 
  minus, 
  Lindley. 
  PI. 
  IX. 
  fig. 
  2. 
  

  

  This 
  species 
  I 
  suspect 
  to 
  be 
  a 
  mere 
  variety 
  or 
  condition 
  of 
  Tcenio- 
  

   pteris 
  vittata, 
  in 
  which 
  the 
  leaf 
  is 
  split 
  more 
  or 
  less 
  frequently, 
  and 
  

   with 
  great 
  irregularity, 
  so 
  as 
  to 
  resemble 
  leaflets. 
  The 
  figures 
  will 
  

   illustrate 
  my 
  meaning. 
  

  

  7. 
  Ctenis 
  Leckenbyi, 
  Bean, 
  MS. 
  PI. 
  X. 
  figs, 
  la, 
  lb. 
  

  

  Frond 
  bipinnate, 
  spreading 
  ; 
  principal 
  stem 
  very 
  thick 
  and 
  deeply 
  

   grooved 
  ; 
  secondary 
  stems 
  slender 
  ; 
  leaflets 
  attached 
  by 
  their 
  entire 
  

   base 
  ; 
  veins 
  much 
  forked, 
  parallel, 
  or 
  nearly 
  so, 
  to 
  the 
  upper 
  mar- 
  

   gin, 
  running 
  out 
  at 
  the 
  under 
  margin. 
  

  

  Mr. 
  Bean 
  has 
  kindly 
  given 
  my 
  name 
  to 
  a 
  Plant 
  which, 
  rather 
  than 
  

   create 
  a 
  new 
  genus, 
  I 
  have 
  referred 
  to 
  the 
  convenient 
  one 
  Ctenis, 
  

   provided 
  by 
  the 
  authors 
  of 
  the 
  ' 
  Fossil 
  Flora 
  ' 
  for 
  " 
  the 
  reception 
  of 
  

   leaves 
  having 
  the 
  general 
  character 
  of 
  Cycadea?, 
  but 
  with 
  the 
  veins 
  

   connected 
  by 
  forks 
  or 
  transverse 
  bars." 
  But 
  the 
  species 
  now 
  

   described 
  is 
  bipinnate, 
  which 
  perhaps 
  invalidates 
  its 
  claim 
  to 
  be 
  

   classed 
  with 
  the 
  Cycadeae. 
  

  

  8. 
  Otopteris 
  mediana, 
  nobis. 
  PI. 
  X. 
  fig. 
  2. 
  

   Pachypteris 
  maxima, 
  Bean, 
  MS. 
  

  

  Frond 
  elongated; 
  leaflets 
  oblong-ovate, 
  crowded 
  towards 
  the 
  base, 
  more 
  

   distant 
  towards 
  the 
  apex. 
  

  

  Some 
  fronds 
  of 
  this 
  very 
  distinct 
  Otopteris, 
  in 
  a 
  coarse 
  dark-brown 
  

   sandstone 
  in 
  which 
  the 
  bases 
  of 
  the 
  leaflets 
  and 
  their 
  mode 
  of 
  attach- 
  

   ment 
  were 
  obscure, 
  have 
  been 
  referred 
  by 
  Mr. 
  Bean 
  to 
  Brongniart's 
  

   genus 
  Pachypteris. 
  It 
  is, 
  however, 
  a 
  true 
  Otopteris, 
  and 
  the 
  specific 
  

   name 
  of 
  " 
  maxima 
  " 
  being 
  inappropriate, 
  I 
  have 
  named 
  it 
  0. 
  me- 
  

   diana. 
  

  

  9. 
  Otopteris 
  lanceolata, 
  Bean, 
  MS. 
  PL 
  VIII. 
  fig. 
  4. 
  

  

  Frond 
  tapering, 
  contracting 
  abruptly 
  at 
  the 
  apex 
  ; 
  leaflets 
  long 
  and 
  

   slender, 
  patent, 
  slightly 
  deflected, 
  their 
  apices 
  acute. 
  

  

  The 
  long 
  and 
  slender 
  leaflets 
  of 
  this 
  species 
  are 
  not 
  unlike 
  those 
  of 
  

   the 
  upper 
  portion 
  of 
  the 
  fronds 
  of 
  Zamia 
  gigas. 
  They 
  are 
  patent, 
  

   and 
  slightly 
  curving 
  downwards. 
  It 
  is 
  probably 
  the 
  species 
  figured 
  

   (pi. 
  2. 
  fig. 
  4) 
  in 
  Young 
  and 
  Bird's 
  ' 
  Geology 
  of 
  Yorkshire.' 
  

  

  10. 
  Otopteris 
  graphica, 
  Bean, 
  MS. 
  PI. 
  VIII. 
  fig. 
  5. 
  

  

  Frond 
  very 
  long 
  ; 
  leaflets 
  cuneiform, 
  oblique, 
  their 
  bases 
  expanded 
  ; 
  

   apices 
  subacute. 
  

  

  A 
  very 
  fine 
  example 
  of 
  this 
  species, 
  two 
  feet 
  in 
  length, 
  was 
  ob- 
  

   tained 
  by 
  me 
  some 
  years 
  ago, 
  and 
  placed 
  in 
  Mr. 
  Bean's 
  museum. 
  

   It 
  is 
  now 
  in 
  the 
  British 
  Museum. 
  

  

  