BY R. M. JOHNSTON, F.L.S. 189 



derived from the associated or underlying sandstones, clays, 

 shales, and carbonaceous formations of Mesozoic age. 



In each case, notwithstanding the similarity or identity 

 of fossil plants common to them all, the nature of the 

 later rocks shows that the mineral characteristics of each 

 basin vary in correspondence with the rocks with which 

 they are now immediately associated, and from the waste 

 of which, in the main, they originally derived theii" sands, 

 clays, grits, and gravels. 



The clays and ferruginous sandstones are in most places 

 replete with the remains of a luxuriant vegetation, among 

 which the leaf impressions of forms more alhed to the 

 existing European flora are especially noticeable— such as 

 those belonging to certain extinct species of the oak, elm, 

 beech, laurel, willow, and elder. With these occur ancestral 

 forms of banksia, lomatia, eucalyptus, pittosporum, cinna- 

 mon, fig, araucaria, and other conifers. The mixture in 

 our Tertiary formations of types which characterise widely 

 separated provinces of the globe at the present day is very 

 interesting, and has already been commented upon in a 

 previous chapter. It would seem that the Phylones or 

 ancestral-types of the existing flora had already attained a 

 very high state of development and specialization into well- 

 known generic types in the early Tertiary period, and 

 that the existing vegetation, restricted more or less to 

 particular provinces, now only partially preserves the 

 descendants of genera once more widely distributed. The 

 tendency of influences operating in later times apparently 

 is marked in the isolation into widely separated provinces 

 of generic groups, once intimately associated together, 

 rather than in the direction of newer generic creations ; 

 and, therefore, it is absolutely true, as indicated by Dr. 

 von Ettingshausen, " the materials for comparison of the 

 flora of any one province, or even hemisphere, are not at 

 all sufficient for the investigation of the Tertiary one, and 

 must be completed from other floras of the globe." 



During the last seventeen years the author has also 

 devoted much time to the investigation of the Tertiary 

 Flora of Tasmania, the results of which have been com- 

 municated in a series of papers to the Royal Society of 

 Tasmania. Nine of these papers* (with numerous figures 



» 1. Johnston (R. M.) Regarding the composition and extent of certain 

 Tertiary Beds in and around Launceston. Proc. K. Soc. of Tas- 

 mania for 1873, pp. 34-48 (sections and figures). 



