﻿INDEX. 



Alsophila excelsa, height of, compared with cy- 



cads, 36 

 Amentacece, 245 

 American Museum of Natural History, cycad 



collection secured for, 8 

 Aneimites, discovery of seeds of, 246 

 Angiopteris, 216, 237, 240, 246 

 Angiopteris crassipes, sorus of, *2is 

 Angiopteris evecta, 241 



Size of stem, 35 



Sporangium of, 159 

 Angiopteris Teysmanniana, *30 

 Angiosperms, possible ancestry of, 38, 143, 245 

 Anomosamites, 44, 228 

 Anomosamites minor, 38, *4i, 244 

 Araucaria brasiliana, pitted tracheids of, 75 

 Araucarioxylon, occurrence in form of logs in 



talus of Black Hills rim, 33, 34. 1°° 

 Archangiopteris Hcnryi, sorus of, *2IS 

 Armor of — 



Cycadacca, 193, 205, 206 



Cycadeoidea, 51-66 

 Artificial staining of silicified plant tissues, 91, 132 

 Atlantosaurus Beds of Marsh, 23, 24, 94, 95, 100 

 Balantium antarcticum, stature comparison, 36 

 Barosaurus, occurrence in lower cycad horizon of 



the Black Hills, 100 

 Bcnnettitales, 236, 237 

 Bennettiteee, 139, 236 



Bennettites Gibsonianus, 15, 16, 33, 67, 108, 127, 

 137. 139, 140, 141, 143, [233] 



Described by William Carruthers, 15 



Discovery of ovulate strobili of, 107, 139 



Embryos of, 16, 107, 124 



Hypogynous disk of, 114 



Leaf-base bundle structure, 64 



Of bisporangiate character, 163 



Ramentum, 52 



Stomata of bracts, 115 

 Bennettites Morierei, 13, 107, 108, 109, 137 



Embryo, 121, 124 



Integumentary structures of, 123, 124 



Interseminal scales, 118, 120 



Of bisporangiate character, 163 



Sections of type in Yale Museum, 123 



Seeds, *i22, 234 

 Big Horn Mountains, "Rim" of, 8, 10 

 Bisexuality, evolution of, in cycad ancestry, 241 

 Bisporangiate strobili : 



Homologies of, 235 



Of Cycadeoidea, 139-167 



Of Tumboa, *229 



Significance of, 236, 244 



Note. — An asterisk preceding the page 



Black Hawk, South Dakota, 8, 9, 25 



Pollen-bearing cycad trunks from, 143 

 Black Hills, 141, 142, 143, 246 



Branching cycads of, 31, 38 



Discovery of cycads in, 7 



Exploration in cycad-bearing horizons of, 39 



Occurrence of cycad types from "Rim" of, 9 



Profusion of young fruits borne by cycad 

 trunks from, 169 



Silicified crowns of cycad leaves from, 82, 102 

 Black Hills Rim, 94, 102 



Lower and upper cycad-bearing horizons of, 

 23, 24 

 Blechnum, 239 

 Blepharoplasts, 216 

 Borassus Habeliifcr, branching -of, 36 

 Botrychium, 158, 210 

 Botryopteris, 239 



Bozvenia, 31, 102, 157, 189, 199, 201, 223, 225, 

 227, 233 



Leaf-base bundle pattern, 62, 63 

 Bozvenia spectabilis, *3i, 92, 101 



Fronds of, *2ii 



Leaf-base bundle pattern, *62 



Megasporophyll bundle of, 221, 233 



Pinnule bundle structure, *93 



Seed bundle system of, *2i9, 220 

 Branching of cycads. 36-44, 191, 194. 244, 245 

 British Museum, Black Hills cycad trunk in, 10 

 Brontosaurus, 100 

 Bucklandia, 14, 16 

 Calcium oxalate crystals in cycad stem tissues, 



198, 204 

 California, cycad from Colusa County, 10 

 Carpels, evolution from asexual sporophytes, 241 



(See Cycas, carpellary leaves of.) 

 Carpellary disk of Williamsonia, 154, 156 

 Ceratozamia, 189, 197, 203, 207, 210, 225, 226 



Microsporophylls of, 215 



Old peduncle bundles in pith of, 196 



Petiolar thorns of, 209 

 Ceratozamia longifolia, pollen of, *IS9 

 Ceratozamia mexicana, *ig6 



Fronds of, *2ii 



Megasporophyll of, *2i7 



Phyllotaxy of cone, 215 

 Chorionoptcris, synangia of, 237 

 Cocos nucifcra, branching of, 36 

 Codonotheca, 230 

 Cordaitales, 76, 126, 195, 212 

 Cordaites, 90, 92, 166, 230, 240 



Pollen of, 160, 161, 162 



Woody cylinder of, 79 



number denotes a figure in the text. 



289 



