﻿CONTENTS. VII 



Chapter VIII. — Young Fructifications 169-186 



Cycadcoidca sp. (sections 410 and 411) 169 



Cycadcoidea sp. (section 389) 170 



Cycadcoidca pulcherrima (?) (section 409) 171 



Cycadcoidca superba (type) 171-174 



Cycadcoidea Paynei (?) 174 



Cycadcoidca Colei (?) 174 



Cycadclla Wyomingcnsis I 75~i76 



The young ovulate axes of Cycadcoidea dacotensis 176-183 



Fruits ix, vi and viii 177-180 



Fruits 1 and in 180 



Fruit vn 180 



Fruit x 180 



Fruit xiv 181-182 



Fruit n 182 



Fruit v 183 



Bisexuality of Cycadcoidea dacotensis 184 



Fruiting habit of Cycadcoidea dacotensis 184-185 



The pulcherrima stage of trunk growth 186 



RELATIONSHIPS (pages 187-246). 



Chapter IX. — Existing and Fossil Cycads Compared 189-238 



The Cycadaceae 189-226 



Distribution 189-191 



Zatnia 191 



Zamia Horidana 192-195 



Trunk structure 195-206 



The medulla or pith 195-196 



The vascular zone 196-200 



The cortex 201-204 



The armor 205 



The periderm 205-206 



The root 207-208 



The leaves 209-213 



Resume of vegetative characters of the Cycadaceje 213 



Fructification 213-226 



Microsporophylls 215 



Fertilization 216 



Megasporophylls 217 



Ovules 217-219 



Bundle system of seed 219-222 



Structure of megaspore bundle supply 222-224 



Structure and significance of the axis of the cones 224-226 



Fruits 226 



Summary of relationships of the cycadeoidean to existing Cycads. . 226-238 



Comparison of vegetative characters 227-228 



Comparison of reproductive characters 228-234 



Tabular comparison of ovulate and staminate cones 235 



Systematic position of the Cycadeoidea; 236-238 



