﻿2 86 



TEXT FIGURES. 



Fig. 79- 



80. 



81. 

 82. 

 83. 



84. 



85. 



86. 



87. 

 88. 



89. 

 90. 

 91. 

 92. 



93- 

 94- 

 95- 

 96. 

 »7- 

 98. 

 99- 



101. 

 102. 



103. 

 104. 

 105. 

 106. 



107. 

 108. 



Page 

 Cycadeoidea, bisporangiate strobilus. 155 

 Cycadeoidea daco tends, structural de- 

 tails of bisporangiate strobilus 156 



Cycadeoidea dacotensis, synangia .... 157 

 Cycadeoidea dacotensis. synangium... 158 

 Pollen grains of existing and fossil 

 cycads ( including Stephanosper- 



mum) 159 



Cycadeoidea dacotensis, markings on 



pollen grains 160 



Cycadeoidea dacotensis, transverse sec- 

 tion of bisporangiate strobilus 161 



Cycadeoidea dacotensis, synangia.... 162 



Cycadeoidea dacotensis, flower 164 



Cycadeoidea. flower bud in longitudi- 

 nal section 165 



Cycadeoidea dacotensis, Trunk 214. . 168 

 Young fructifications of Cycadeoidea 170 

 Cycadeoidea pulcherrima, strobilus... 171 

 Young fructifications of Cycadeoidea 173 

 Transverse sections of young bispor- 

 angiate strobili of Cycadeoidea;.... 175 

 Cycadeoidea dacotensis (Trunk 214 1 



[facing] 176 



Cycadeoidea dacotensis(T. 214"). radial 



and transverse sections of axis iv.178, 179 

 Cycadeoidea dacotensis (T. 214), axis 



viii 180 



Cycadeoidea dacotensis (T. 214), axis 



x in radial and transverse section.. 181 

 Cycadeoidea dacotensis (T. 214), 



transverse sections of axis xiv 182 



Cycadeoidea dacotensis (T. 214), long- 

 itudinal section of axis n 183 



Cycadeoidea dacotensis (T. 214). 



serial sections of axis v 183. 184. 185 



Dion edule, staminate plant 188 



Cycas Normanbyana and Cycas media. 



habitus of 190 



Zamia van Houtteii, habitus of 190 



Zatnia Roczlii, habitus of 191 



Zamia glabra 192 



Zamia tloridana. plant habitus 193 



Zamia' tloridana. staminate cones 194 



Extremes of variation in size and form 

 of trunks of existing cycads 195 



Page 



Fig. 109. Ceratosamia Mexicana ( ?) 196 



no. Encephalartos Altenstcini'i 197 



in. Macrozamia Fraseri, trunk 199 



112. Cycas revoluta, young trunks 200 



113. Zamia floiidana. conical transverse 



section of stem 201 



114. Cycas Rumphii, plant bearing partially 



emergent fronds 203 



115. Cyril.? neo-caledonica, staminate plant 204 



1 16. Cycas siamensis (?) 205 



1 17. Cycas media, a small plant 206 



118. Encephalartos Ghcllinckii 207 



119. Dion edule, entire plant 208 



120. Stangeria paradoxa and oak seedlings 209 



121. Very young cycad fronds 210 



122. Margin, nervation, and other charac 



ters of cycad fronds 211 



123. Pinnule forms in Encephalartos and 



Zamia 212 



124. Microsporophylls of Cycadaceae .... 214 



125. Sori and synangia of existing Maratti- 



aceae 215 



126. Megasporophylls of the Cycadaceae... 217 



127. Cycas circinalis, developing and ma- 



ture ovules 218 



128. Bilateral and radiosymmetric mega- 



spore bundle traces of various Cy- 

 cadaceae 219 



129. Concentric megaspore supply and 



other bundles of existing cycads... 221 



130. Stangeria paradoxa, transverse section 



of a staminate peduncular bundle.. 222 



131. Cycas revoluta, transverse section of 



bundle from stalk of a carpel 223 



132. Poroxylon Edwardsii, transverse sec- 



tion of stem 224 



133- Welioitschia mirabilis or Tumboa. 



staminate disk of 220 



134. Zamia tloridana. monstrous ovulate 



cone 231 



135. Encephalartos villosus, monstrous ovu- 



late cone 231 



136. Zamiostrobus stenorhachis and Cy- 



eadospadix Hennoquei 232 



137- -Irchu-opteris 233 



138. Dictyosamites indicus 234 



