Reviews — The Maidenhair Tree in Spitsbergen. 423 



Queensland (see Geol. Mag., Dec. VI, Vol. V, p. 516, 1918). The 

 author's analysis of the different floras, showing the percentages in 

 which the chief plant groups are represented, are particularly- 

 suggestive. 



Large collections of marine fossils have been obtained from the 

 Maryborough Series (Lower Cretaceous), the predominant forms 

 being Pelecypods and Cephalopods. In association with these animal 

 remains, there are a number of fragmentary plants ; about 34 

 specimens have been obtained, representing 14 species. Of these 

 34 specimens, 11 are of Pagiophyllum, 8 of Tamiopteris, 4 of 

 Araucarites, 2 of Ginkgo, 2 of ? Taxites, 2 of indeterminate roots, and 

 1 each of Equisetites, Sphenopteris, Ptilophylhim, ? Pterophyllum, and 

 siiicified wood. This list indicates a flora in which Gymnosperms 

 largely preponderated. 



The flora of the Burrum Series, which was formerly described as 

 Lower Trias-Jura in age, is found by Walkom to be typically Lower 

 Cretaceous and undoubtedly homotaxial with such floras as the 

 Wealden of Europe and the Lower Cretaceous (Neocomian) of North 

 America. Thirty-six species have been obtained, 22 of which are 

 Gymnosperms, while 13 belong to the Filicales. "Walkom draws 

 attention to the fact that one leaf-type, which he describes as 

 " ? Dictyophyllum sp.", may possibly be Dicotyledonous. 



The Styx Series proves to be somewhat younger than the Burrum 

 Series, and it is suggested that it may be the equivalent of the Albian 

 stage. The association of Dicotyledonous leaves with a number of 

 typical Mesozoic plants makes it clear that the age of the strata is 

 Cretaceous, probably Lower Cretaceous. The flora shows considerable 

 resemblance to the Patapsco Flora of Maryland and Waikato Heads 

 Flora of NewZealand. The species represented includeEquisetales(l), 

 Filicales (4), Cycadophyta (3), Coniferales (3), and Dicotyledons (3). 



2. In the general paper cited above, Walkom discusses the 

 conditions prevailing in Queensland in Lower Mesozoic times, and 

 the geography of the Australasian region during that period — basing 

 his conclusions in part upon his detailed study of the palseobotanical 

 evidence. 



A. A. 



III. — The Maidenhair Tree in Spitsbergen. 



Ginkgo adiantoides (Unger) Heer iji Tertiar Spitzbergens 



nebst einer kurzen TJbersicht der iibrigen fossilen Ginkgophyten 



desselben Landes. By A. G. Nathorst. Geol. Foren. i 



Stockholm Forhandl., Bd. xli, H. iii, pp. 234-48, 4 text-figures, 



1919. 



rpHIS paper records the occurrence of Ginkgo adiantoides in 



1 Spitsbergen, associated with Popnlns arctica and other leaves 



characteristic of the Tertiaries of this region. This species, which is 



probably identical with the living G. biloba, has been obtained from 



many localities in Europe, from horizons ranging from the Eocene to 



the tipper Pliocene. The present discovery earries its known range 



further to the north, since Braganza Bay and Green Harbour 



(lat. 78° N.), where it has now been found, lie considerably nearer 



