A study of history
- Oxford University Press 1956
- P 633 VI 21 CM
General World HistoryEQUISETALES, VEGETATIVE STRUCTURE, EQUISETALES, FRUCTIFICATIONS AND CLASSIFICATION, SPHENOPHYLLEAC, CHUROSTROBEAC, PSEUDOBORIALES, IEPIDODENDRON AND LEPIDOPHLOIOS, ULOD ENDRON AND HALONIA, SIGILARIA AND STIGMARIA, BOTRYOPTERIDACCAC, EARLY DEVONIAN PTERIDOPHYTES,