TWO NEW SPECIES OF PTEEOPHYLLUM 



(FXjA-TE •VII.) 



By JOHN SHIRLEY, B.Sc, 



(District Inspector of Schools.) 



[Read before the Royal Society of Queensland, August 8, 1896.] 



In examining the various formations for plant remains, it is 

 universally observed that the more recent the formation, the 

 more the flora resembles that of the present day ; and the more 

 ancient the formation the more numerous become the points of 

 divergence between the ancient flora thus revealed and that now 

 in existence. But however far back we go, the flora of any 

 given region has a stamp and quality of its own that links it to 

 living forms, however it may have changed through the course of 

 ages. Unfortunately all plant remains are not equally endowed 

 with the qualities which favour preservation in the difterent 

 strata ; some, as the conifers, cycads, and ferns, have tough 

 membranous leaves which resist pressure and decay until 

 their forms have been impressed upon the sedimentary layers ; and 

 are thus preserved against injury until revealed by the miner, 

 engineer, or geologist. A considerable number of these have 

 been unearthed in Australia ; and, as is elsewhere the case, they 

 bear ample testimony to the now almost universally accepted 

 theory, that, through these ancient forms, the existing plants of 

 the same orders have descended. This evolutionary descent has 

 been likened to a tree ; the numerous species of to-day, like the 

 branches of a tree, being traceable to one archaic form represent- 

 ed by the parent trunk. But the typical tree may not always 

 be a vigorous and healthy one ; but may be withering and decay- 

 ing with only a few live twigs, the present species, to represent 

 what in the past was a number of strong, well represented branches. 



