《American fossil cycades vol 2 taxonomy》

CHAPTER Ⅰ.—STATUS AND SCOPE OF FOSSIL CYCAD STUDY3

CHAPTER Ⅱ.—CRITERIA OF CYCADEOIDEAN SPECIES9

CHAPTER Ⅲ.—SYSTEMATIC POSITION OF THE CYCADEOIDE?17

CHAPTER Ⅳ.—THE MARYLAND GROUP OF CYCADEOIDEAS27

(1) Cycadeoidea marylandica30

(2) Cycadeoidea Tysoniana30

(3) Cycadeoidea Mc Geeana30

(4) Cycadeoidea Fontaineana30

(5) Cycadeoidea Goucheriana31

(6) Cycadeoidea Uhleri31

(7) Cycadeoidea Bibbinsi31

(8) Cycadeoidea Fisher?31

(9) Cycadeoidea Clarkiana31

Synonymy of the Cycadeoidea species from the Potomac Group of Maryland30

CHAPTER Ⅴ.—PIEDMONT-BLACK HAWK SERIES33

Cycadeoidea Jenneyana (with note on fructification)36

Cycadeoidea ingens42

Cycadeoidea formosa47

Cycadeoidea Stilwelli48

Cycadeoidea (rhombica) cicatricula48

CHAPTER Ⅵ.—THE MINNEKAHTA CYCADEOIDEAS51

Cycadeoidea dacotensis52

Cycadeoidea Marshiana56

Floral features59

Flowers of Yale Museum trunk No.359

Flower-buds of Yale Museum trunk No.16464

Cycadeoidea McBridei65

Cycadeoidea colossalis67

Isolated flower-buds68

Specific position of specimens70

Description of structure70

Comparison with other Cycadeoidean flower-buds72

Leaf-base bundles73

Note on the United States National Museum type75

Cycadeoidea nana76

Cycadeoidea Wielandi77

Description of additional sections from Yale trunks77,393, and13180

Cycadeoidea Paynei85

Cycadeoidea protea87

Cycadeoidea excelsa88

General status of Minnekahta species90

Species of uncertain status: C. Colei, C. furcata, C. insolita, C. minima, C. occidentalis,C. pulcherrima, C. turrita, C. Wellsii, C. superba, C. heliochorea93

CHAPTER Ⅶ.—THE HERMOSA CYCADEOID95

Cycadeoidea Dartoni, sp. nov95

The ovulate cone series99

Young fronds102

CHAPTER ⅤⅢ.—THE FREEZE OUT HILLS GROUP OF TRUNKS105

(1) Cycadeoidea (Cycadella) Reedii106

(2) Cycadeoidea (Cycadella) Beecheriana106

(3) Cycade- oidea utopiensis106

(4) Cycadeoidea (Cycadella) wyomingensis, etc106

CHAPTER Ⅸ.—ISOLATED TYPES FROM COLORADO, CALIFORNIA, AND TEXAS109

Cycadeoidea mirabilis. (Colorado)109

Cycadeoidea Stanton. (California)111

Cycadeoidea nigra. (Colorado)111

Cycadeoidea Uddeni n. sp. (Texas)113

CHAPTER Ⅹ.—NOTABLE EUROPEAN SILICIFIED CYCADEOIDS115

Bennettites Gibsonianus118

Fittonia squamata121

Cycadeoidea Reichenbachiana123

Cycadeoidea etrusca128

CHAPTER Ⅺ.—THE SEEDS OF CYCADEOIDEA131

American and European Cycadeoid seed material132

Previous descriptions of testal features136

Comparison of testal structure in American and European Cycadeoidean seeds138

Lateral testal components140

Middle stone140

Inner flesh142

Seed tips and micropylar tube143

Homologies of the Cycadeoid seed-coat146

Dual integuments153

Polyphyly154

Hypothetic relation of seed to flower156

The synangial hypothesis of testal origin157

The disk hypothesis of testal origin163

Expansion of the cornuted disk164

Cornuted disks and tentacled seeds165

Modifications of the lagenostome region168

Is there an analogy between seed and flower?169

References to literature on the structure of fossil seeds172

CHAPTER Ⅻ .—THE CYCADEOID ALLIANCE175

Cycadophytan foliage of the Mesozoic178

Dominance of Cycadeoid foliage types181

Occurrence of frond genera in time184

Older Cycadophytan leaf types186

Trunks of Williamsoni?186

Cycadolepis189

Structure of node-bearing stems189

Early described ovulate cones and buds191

Williamsonia (Podocarya) Bucklandi Saporta191

Williamsonia scotica Seward192

Yorkshire coast strobili195

Seed-cone structure195

Oaxacan strobili198

Staminate fructification202

Disk structure202

Floral types204

CHAPTER ⅩⅢ.—CYCADOPHYTAN DISTRIBUTION207

Scarcity of fossil Cycadace?207

The Cycadeoid element in Mesozoic floras214

CHAPTER ⅩⅣ.—CYCAD DERIVATIVES219

Cycadeoidea an unusual stem type219

Palms a fixed columnar type221

Ultimate branching in dicotyls223

Persistence of specialized forest types224

Isolated specialized types225

Primitive Magnolias228

Conifer-Angiosperm relationships230

Is Araucaria old?230

Bisporangiate conifers233

The Ginkgoales a primitive race234

Position of the Gnetaleans235

Persistence of the Cordaiteans in the Lias237

Certain general inferences237

BIBLIOGRAPHY239

LIST OF TEXT-FIGURES249

DESCRIPTION OF PLATES250

INDEX269