﻿2g: 



AMERICAN FOSSIL CYCADS. 



Cycadeoidea superba — Continued. 



Young fructifications of, 171-174. *I75 

 Cycadeoidea turrila: 



Bisexuality of, 130, 131 

 Ovulate cone of, 129, 130 

 Leaf bases of, *53, *54, *63 

 Cycadeoidea Uhleri (type), 6, 12, 22 



Columnar form of, 35, 33 

 Cycadeoidea Wielandi, 29, 107, 108, *m, *H2, 129. 

 130, 149 

 Bracts, 115 



Cone-bearing habitus of, 126, 127 

 Cortex of, 68-74 

 Cotyledons of, 124 

 General features of cones, 109, *iii 

 Hypogynous disks of, 114, 115 

 Integumentary structures of, 123, 124 

 Interseminal scales, n6-*H9 

 Leaf bases of, *S4 

 Longitudinal sections of cones, 112 

 Megaspore membrane, 122, 123 

 Nucellus, 122 

 Ovulate cone of, 108-126 

 Peduncle and its bundle supply, *H3, 114 

 Seed pedicels, 118, *H9, 120 

 Seeds, 120-126, *i2i, *I22 

 Transverse section of cones of, no, *II2 

 Trunk structure illustrated, *6g-*77 

 Cycadeoidea, 102, 123, 194, 210, 216 

 Adventitious leaves in, 94, 100, 104 



Bisexuality in certain species of, 130, 131 

 Bisporangiate axes of, 138-167 



Branches, late development of, 39 



Branching forms of, 36, 37 



Colloquial names of silicified trunks of, 6 



Columnar forms, 33 



Cone-bearing habitus in species of, 126-130 



Cortex of, 66-74, 227 



Culminant fructification in, 126-128, 185, 186 



Embryos and pre-embryonal structures in, 

 124-126, 234 



Extent of foliage preservation in, 99 



Fern-like characters of, 239-240 



HyP gyn ous disks of, 114 



Hypothetical forms of, 244 



Leaf bases, 55-66, 227 



Limits of stature in, 30, 34, 35 



List of bisporangiate forms of, 167 



Prefoliation of, 227 



Probable root type of, 35 



Proposed by Robert Brown, 14 



Ramental growth, 51, 54, 227 



Relationships of, 187-246 



Reproductive structures, 105-186 



Resume of bisporangiate characters, 165-167 



Resume of chief outer trunk characters, 44 



Resume of ovulate cone features, 137 



Scale leaves in, 227 



Short columnar forms, 33 



Size limited by stem structure, 35 



Staminate disk a sporophyll emplacement, 230 



Staminate fronds of, 209 



Stature of trunks from Maryland, 31 



Cycadeoidea — Continued. 



Stature of trunks from Black Hills, 31 

 Strobilar homologies of, 235 

 Strobili equivalent to lateral branches, 30 

 Summary of relationships with Cycadacece, 

 226-235 

 (a) Vegetative characters, 227-228 

 (6) Reproductive characters, 228-235 

 (c) Strobilar homologies, 235 

 Synangia of, 216 

 Systematic position of, 236-238 

 Young fructifications of, 169-186 

 Vegetative features, 49-104 

 Cycadites, 15, 28 



pecten, 17 

 Saxbyanus, 15 

 Cycadocephalus Sezvardi, bisporangiate strobilus 



of, 167 

 CycadoHlices, 66, 76, 123, 236, 239, 242, 244 

 "Cycadophytes," 213, 243 



Cycadospadix Hennoquei, carpellary leaf of, *232 

 Cycads, hypothetical ancestry of, 237 

 Cycas, 14, 26, 30, 76, 79, 189, 197, 199, 201, 210, 212, 

 223, 224, 225, 226, 227, 234 

 Armor retention in, 50, 206 

 Antiquity of, 191 

 Branching of, 27, 3§ 



Carpellary leaves of, 14, 66, *I90, 213, 214, 

 *2i7, 232, 236, 238, 239, 241, 244, 245, 246 

 Cone axis of, 224 

 Excrescent growth on roots of, 207 

 Fertilization in, 216 

 Microsporophylls of, 215, 245 

 Nervation of, 213 



Scale-leaf buds of, 56, 103, 228, 229 

 Sori of, 215. 240 

 Spermatozoids of, 216, 239 

 Cycas celebica, 65 



Leaf-base bundle pattern of, *62 

 Cycas circinalis: 

 Trunk of, 195 

 Microsporophylls of, *2I4 

 Ovules of, *2i7, *2i8 

 Seed-bundle system of, *2IQ, 220 

 Cycas Jenkinsoniana, 209, 

 Young leaves of, *2io 

 Cycas media, *igo, 206 



Concentric cortical traces in, 202 

 Cycas neo-calcdonica, 204 

 Cycas Normanbyana, *i9o, 204 

 Height of, 34, 36 

 Megasporophyll of, *2I7 

 Cycas revoluta, *39, *44, 127, 190, *20o 

 Carpel bundle of, *223 

 Cortical bundles of, 202 

 Fronds of, *2il 

 Great trunks of, in garden of Ryugeji temple, 



* fronts page 20, 34 

 "Hoso" form of Japanese gardeners, 38, *39 

 Megaspore bundle supply, *22l, 222, 232, 233 

 Megasporophyll of, *2I7, 232 

 Seed-bundle system of, *2I9, 220 

 "Shishi" type of Japanese gardeners, *36-38, 43 



