THE FLORA OF THE IPSWICH AND WALLOON 



SERIES — concluded. 

 By A. B. Walkom, B.Sc. 



DESCRIPTION OF SPECIMENS. 



GINKGOALES. 



Fossil leaves belonging to this class are abundant in the Lower 

 Mesozoic Rocks of Queensland. Associated with these leaves at 

 Denmark Hill, Ipswich, there are numerous seed-like bodies which 

 in all probability belonged to the same plants. 



Some of these seeds resemble in a general way specimens to 

 which the name Beania gracilis has been applied. Others bear a 

 resemblance to the female seeds of Ginkgo. The examination of 

 these seeds is not at present completed, but a preliminary account 

 is given of them, and a few of them figured (see p. 26). 



There is no distinct line of demarcation between the genera 

 Ginkgo and Baiera ; the latter name is usually applied to those 

 forms having the leaves deeply divided into nari-ow, linear segments. 

 This distinction is, of course, artificial, but it distinguishes between 

 leaves of two distinct types, and since there is only small chance 

 of finding the leaves of these plants in actual connection with the 

 reproductive organs, a useful purpose is served in keeping the two 

 types distinct. 



GINKGO. 



The great amount of variation in leaves from a single ]ilant 

 of the recent species G. biloba points to the probability of similar 

 variation in fossil leaves of this genus. In dealing with the fossils, 

 therefore, allowance must be made for this variation, and there will 

 always be difficulty in defining the limits of species. The tendency 

 will be towards the establishment of more species than necessary. 



Ginkgo Antarctica, Saporta. 

 (Plate 1, figs. 1,2.) 



1885. Salisburia antarctica, Renault, Cours de botaniquc fossile, 



vol. 4, p. 57, t. 2, fig. 19. 

 1898. Ginkgo antarctica, Shirley, Q'land Greol. Survey, Bull. 1, 



p. 11, t. 1, fig. 1. 



