NO. 3.] GEOLOGICAL AGE OF THE DEPOSIT. 25 



Land, of Elatides curvifolia Dkr. sp., which both at Cape Staratschin and Advent 

 Bay predominates to such a degree. Baiera spetsbergensis is also not found at 

 Franz Josef Land, while at Advent Bay no Ginkgo polaris, Phoenicopsis, etc., 

 appear to have been discovered. Under these circumstances it is not probable 

 that the plant-bearing deposit of Franz Josef Land is quite contemporaneous with 

 the plant-bearing strata of Cape Staratschin and Advent Bay, but it is diffi- 

 cult to decide whether it is to be considered older or younger. In favour of 

 the former supposition there is the fact of the similarity or affinity of species 

 in the fossil floras of Siberia and Cape Boheman (Sphenopteris, Ginkgo 

 polaris, Czekanotvskia, Phoenicopsis, Pityospermum Maakianum) ; and 

 the most natural conclusion, in consequence, would be to consider the flora 

 of Franz Josef Land as belonging to a period between the fossil floras of 

 Cape Boheman and Advent Bay. The material at hand is, however, so in- 

 complete, that a precise determination of the age of the deposit can only be 

 made to an approximate degree. As regards its downward limits, as pre- 

 viously stated, it may be adduced with certainty that it must be younger 

 than the Jurassic flora of Siberia and Cape Boheman. As these, as before 

 stated, owing to the stratigraphical conditions must be younger than the 

 Oxfordian, or belong to the uppermost part of it, the fossil flora of Franz 

 Josef Land must in consequence, be still younger. How much younger, how- 

 ever, it is very difficult to decide. As regards its upward limits there is 

 the difficulty that in the Polar regions no real Wealden flora is, as yet, 

 described. There appears to be no agreement with the Urgonian flora of 

 Greenland, and it must therefore be supposed that the fossil flora of Franz 

 Josef Land is older than the Urgonian. The result of the age-problem can 

 therefore only be thus defined: that the plant-bearing deposit was formed 

 towards the close of the Jurassic or commencement of the Cretaceous Period, 

 without our being able at present to settle which. 



In order to avoid misapprehension, it is perhaps best, for me to mention 

 that, together with many other authors, I reckon the Wealden as belonging 

 to the Jurassic Period and not to the Cretaceous; a question in itself, of 

 very slight importance. 



It seems, however, as if the conditions at King Charles Land, as examined 

 by myself in 1898, might possibly define with somewhat more precision the age 

 of the deposit. Above the fossil-bearing marine strata which, according to 



