CONTENTS 



PAGE 



I. Introduction i 



Petrifaction 3 



Incrustation 5 



Coal-seams, a peculiar mode of incrustation 9 



Peat 14 



Brown coal . . . . 16 



Mode of formation of coals 1 8 



Mode of formation of petrifactions 24 



II. Thallophytes, Bryinae 34 



Fungi 34 



Diatomaceae 35 



Chlorosporeae 36 



Florideae .............. 44 



Doubtful Alga-forms, and forms wrongly placed with Algae .... 45 



Mosses 51 



III. Coniferae 53 



Abietineae "... 54 



Araucaria 57 



Sequoieae 58 



Cupressineae ............. 60 



Taxineae 61 



Salisburieae 62 



Forms, whose place is not certainly ascertained 67 



Leafless branches of Coniferae 79 



Coniferous woods 80 



Prototaxites 84 



IV. Cycadeae, Medulloseae 85 



Cycas 86 



Leaves of Cycadeae 87 



Flowers of Cycadeae 89 



Stems of Cycadeae 91 



Bennettites 94 



Medullosa 100 



V. Cordaiteae 104 



Leaves 105 



Branches 108 



Artisiae 109 



Forms from newer formations resembling Cordaitae no 



Flowers . . . in 



Seeds 117 



