﻿294 



AMERICAN FOSSIL CYC ADS. 



Macrozamia Fraseri — Continued. 



Megasporopliyll of, *2\j 

 Macrozamia heteromera, fronds of, *2ii 

 Macrozamia Miqueli, young leaves of, *2io 

 Macrozamia spiralis, *86 



Occurrence, 189 

 Pinnule growth in, 86, 209 

 Marattia, 141. 142, 158, 159, 166, 216, 236, 240. 246 



Locular septation in synangia of, 159 

 Marattia fraxinca, synangium of. *2I5 

 Marattiacca, 142, 237, 239 



Sori of, *2i5 

 Maryland Academy of Natural Sciences, types 



originally in collections of, 6 

 Maryland, cycads from Potomac Group of, 5-6, 



22 ^2 

 Medulla of: 



Cycadacca, 195-196 



Cycadeoidea, 77-78 



Cordaitalcs, 195 



Cyathea medullaris, 195, 239 

 Medullosa, 246 



Megaspore membrane, 122, 123 

 Microcycas, 189. 197 

 Mineralization of plant tissues, 21-22 



In Black Hills. 23 



In Potomac of Maryland, 23 



Control of, by local conditions, 23 



Rare occurrence of requisite conditions for, 26 

 Minnekahta, South Dakota. 9, 24. 133 



Cycad discoveries at. 7, 8, 41 



Pollen-bearing cycad fruits from, 143 



Series of branching cycads from, 38, 39 

 Morosaurus, 100 

 Morrison Formation. 100 

 Neuropteris, discovery of seeds of, 230, 246 

 Ncuropteris heterophylla , 232 

 Nilssonia, occurrence in Black Hills, 100 

 Xostoc, in cycad roots, 207 

 Old World cycadean types, list of, 18-20 

 Onoclea, 237 



Oolite quarries of Isle of Portland, 14 

 Oospore of gymnosperms, 125 

 Ophioglossacca, 218 

 Osmunda, 158 



Wilting of fertile fronds, 129 

 Otozamites, 63, 64 



Nervation of, 213 

 Ovulate cones of Cycadaceai 



Composed of frond derivatives, 229-233 



Homologies of, 235 



Reversion forms of, 214. *230, *23l 

 Ovulate cones of Cycadeoidea, 213-215 



Cycadeoidea dacotensis, 133-134, 147-149 



Tenneyana, 131-132 



Marshiana, 135-136 



Wielandi, 108-126 

 Paleozamia, ]6 

 Pandamts, 245 

 Pccopteris, seeds of, 246 



Periderm, formation and action of. in Cycada- 

 cca-, 205-206 

 Petrotome. for section cutting, 74 



Piedmont, South Dakota, 94 

 Piedmont-Black Hawk cycad area, 94 

 Podocarya, 81 

 Podozamitcs, 91 

 Pollen grains of — 



Cycadacca:, 216 



Cycadeoidea, *i59-i62 

 Polystichutn acrostichoides, 241 

 Poroxylece, 225 



Poroxylon Edwardsii, stem section of, *224 

 Pre-embryonal stages of Cycadeoidea, 124-126 

 Prefoliation of : 



Cycadacca, *84, *85. *86, 209-210 



Cycadella ramentosa, 99, 100 



Cycadeoidea ingens, 86, *93 



Cycadeoidea colossalis, 99 

 Pritchardia Martii, *205 

 Proangiosperms, 243. 245 

 Prothalli : 



Dicecism of, 242 



Elimination of, 241-243 

 Pterophyllum [should be Ptilophyllum], 25 

 Ptilophyllum acutifolium, 16, *iy, [63] 

 Ptilophyllum cutchense, 17. 63, 79 



Persistent ( ?) cambial cylinder of, 79 

 Quasi-ferns, 237, 239. 240 



Evolution of. 241 

 Rajmahal series, silicified stems from. 16 

 Ramentum, 51-54, 239 



Profuse growth of, 102 

 Red Valley. 94 

 Rhabdocarpon, 230, 232 

 Ricinus, 245 

 Roots of — 



Cycadacca, 207-20S 

 Cycadeoidea [not silicified], 208 

 Ryiigeji temple garden. 34 

 Scale-leaf buds of — 



Cycadeoidea, 103 



Cycas, 103 

 Sciadopitys, 229 

 Section cutting, 45-4H, 74 



Carborundum used in securing cores for, 46 



Chiseling out cores for, 45 



Cylindrical cores for. 45, 46, 47 



Double sectioning, 46, 47, 74, 181 



Mcycrischc Stcinkitte used in, 46 



Petrotome used in, 74 



Use of plate-glass mounting, 48 



Use of bort-charged drills for core cutting, 48 



Tubular drills devised to secure cores for, 45 

 Section numbers, system of, 53 

 Seeds, 234 



Of Cycadacca, 217-222, 226 



Of Cycadeoidea, 120-126 

 Seed pedicels, 1 18-120 



Homology of, 230-233 

 Silicification of plant tissues (see Mineralization 



of) 

 South Dakota (see Black Hawk; Black Hills; 



Black Hills Rim; Minnekahta) 

 Spermatozoids, 216 

 Sporophytes, foliar homology of, 30, 242, 245 



